ORCID Profile
0000-0003-1591-5871
Current Organisations
Curtin University
,
Edith Cowan University
,
Radboud University Nijmegen
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Publisher: Frontiers Media SA
Date: 26-06-2019
Publisher: Wiley
Date: 24-04-2020
DOI: 10.1111/LIV.14453
Publisher: Elsevier BV
Date: 06-2021
Publisher: Cambridge University Press (CUP)
Date: 24-01-2011
DOI: 10.1017/S0007114510005349
Abstract: Epidemiological studies have suggested that dietary fibre lowers the risk of colorectal cancer, which may be due to increased butyrate production from colonic fermentation of a type of fibre, resistant starch (RS). The present study investigated the effects of dietary RS and butyrylated RS on the faecal microbiota of rats treated with azoxymethane. A total of four groups of nine rats were fed diets containing either standard maize starch (low-amylose maize starch (LAMS), low RS), LAMS with 3 % tributyrin (LAMST), cooked 10 % high-amylose maize starch (HAMS, high RS) or cooked 10 % butyrylated HAMS (HAMSB). Faecal s les were examined by denaturing gradient gel electrophoresis (DGGE) of PCR- lified 16S rRNA gene fragments. Multivariate analysis demonstrated no differences between faecal microbiota before treatment but revealed differences in DGGE patterns between diet groups, with the exception of the two low-RS groups (LAMS and LAMST). Subsequent analysis identified eleven DGGE bands contributing significantly to the differentiation between diets. These phylotypes belonged to Clostridiales (five), Lactobacillus (one) and Bacteroidetes (five) lineages. Rats fed HAMS had increased concentration of propionate in their distal colonic digesta and developed faecal populations containing Ruminococcus bromii- like bacteria. HAMSB increased propionate and butyrate concentrations in distal colonic digesta and was associated with the appearance of two non-butyrate-producing bacteria, Lactobacillus gasseri and Parabacteroides distasonis. In conclusion, supplementation with specific dietary RS leads to changes in faecal microbiota profiles that may be associated with improved bowel health.
Publisher: Research Square Platform LLC
Date: 16-02-2021
DOI: 10.21203/RS.3.RS-199162/V1
Abstract: Associations between the human gut microbiome and health outcomes continues to be of great interest, although fecal s le collection methods which impact microbiome studies are sometimes neglected. Here, we expand on previous work in s le optimization, to promote high quality microbiome data. To compare fecal s le collection methods, licons from the bacterial 16S rRNA gene (V4) and fungal (ITS2) region, as well as short chain fatty acid (SCFA) concentrations were determined in fecal material over three timepoints. We demonstrated that spot s ling of stool results in variable detection of some microbial members, and inconsistent levels of SCFA therefore, s le homogenization prior to subsequent analysis or subs ling is recommended. We also identify a trend in microbial and metabolite composition that shifts over two consecutive stool collections less than 25h apart. Lastly, we show significant differences in bacterial composition that result from collecting stool s les in OMNIgeneGUT tube (DNA Genotec) or Stool Nucleic Acid Collection and Preservation Tube (NORGEN) compared to immediate freezing. To assist microbiome investigators plan their fecal s le collection and storage procedures for multiple analyses, we recommend participants to collect the first full bowel movement of the day and freeze the s le immediately after collection.
Publisher: Elsevier BV
Date: 09-2009
Abstract: Diet is an important factor in colorectal carcinogenesis thus, dietary supplements may have a role in colorectal cancer prevention. The objective was to establish the relative luminal, epithelial, and epigenetic consequences of prebiotic, probiotic, and synbiotic dietary supplementation in humans. This was a randomized, double-blind, placebo-controlled, 4-wk crossover trial of resistant starch and Bifidobacterium lactis, either alone or as a combined synbiotic preparation, in 20 human volunteers. Rectal biopsy, feces, and serum s les were collected. The rectal mucosal endpoints were DNA methylation at 16 CpG island loci and LINE-1, epithelial proliferation (Ki67 immunohistochemistry), and crypt cellularity. The fecal endpoints were short-chain fatty acid concentrations, pH, ammonia, and microbiological profiles (by denaturing gradient gel electrophoresis and sequencing). Serum endpoints were a panel of cytokines and high-sensitivity C-reactive protein. Seventeen subjects completed the entire study. The synbiotic intervention fostered a significantly different fecal stream bacterial community than did either the prebiotic (P = 0.032) or the probiotic (P = 0.001) intervention alone, in part because of a greater proportion of patients harboring fecal Lachnospiraceae spp. These changes developed in the absence of any significant differences in fecal chemistry. There were no differences in epithelial kinetics. This synbiotic supplementation with B. lactis and resistant starch, in the doses used, induced unique changes in fecal microflora but did not significantly alter any other fecal, serum, or epithelial variables. This trial was registered in the Australian New Zealand Clinical Trials Registry at www.anzctr.org.au as ACTRN012606000115538.
Publisher: MDPI AG
Date: 30-09-2021
DOI: 10.3390/MICROORGANISMS9102066
Abstract: Dysbiosis refers to a reduction in microbial ersity, combined with a loss of beneficial taxa, and an increase in pathogenic microorganisms. Dysbiosis of the intestinal microbiota can have a substantial effect on the nervous and immune systems, contributing to the onset of several inflammatory diseases. Epidemiological studies provided insight in how changes in the living environment have contributed to an overall loss of ersity and key taxa in the gut microbiome, coinciding with increased reports of atopy and allergic diseases. The gut microbiome begins development at birth, with major transition periods occurring around the commencement of breastfeeding, and the introduction of solid foods. As such, the development of the gut microbiome remains highly plastic and easily influenced by environmental factors until around three years of age. Developing a erse and rich gut microbiome during this sensitive period is crucial to setting up a stable gut microbiome into adulthood and to prevent gut dysbiosis. Currently, the delivery route, antibiotic exposure, and diet are the best studied drivers of gut microbiome development, as well as risk factors of gut dysbiosis during infancy. This review focuses on recent evidence regarding key environmental factors that contribute to promoting gut dysbiosis.
Publisher: BMJ
Date: 18-07-2015
DOI: 10.1136/GUTJNL-2014-307198
Abstract: Colonic fermentation in patients with UC in remission was compared with that in matched healthy subjects on habitual diets and when dietary fibre was increased. Fibre intake, faecal output of fibre (measured as non-starch polysaccharide (NSP)), starch, microbiota and fermentation products, and whole gut transit time (WGTT) were assessed in association with habitual diet and when dietary intake of wheat bran (WB)-associated fibre and high amylose-associated resistant starch (RS) was increased in an 8-week, randomised, single-blind, cross-over study. Despite a tendency to lower habitual fibre intake in UC patients, faecal NSP and starch concentrations were threefold higher than in controls, whereas concentrations of phenols and short-chain fatty acids, pH and WGTT were similar. Increasing RS/WB intake was well tolerated. In controls (n=10), it more than doubled faecal NSP and starch excretion (p=0.002 for both), had no effect on NSP usage and reduced WGTT (p=0.024). In UC patients (n=19), high intake of RS/WB tended to normalise gut transit, but did not increase the proportion of NSP fermented. Increasing intake of RS/WB had little effect on faecal fermentation patterns or the structure of the microbiota. However, faeces from the UC cohort had lower proportions of Akkermansia muciniphila and increased ersity within Clostridium cluster XIVa compared to controls. Gut fermentation of NSP and starch is diminished in patients with UC. This cannot be explained by abnormal gut transit and was not corrected by increasing RS/WB intake, and may be due to abnormal functioning of the gut microbiota. Australian New Zealand Clinical Trials Registry: ACTRN12614000271606.
Publisher: Springer Science and Business Media LLC
Date: 05-07-2019
DOI: 10.1007/S00394-019-02036-Y
Abstract: The Paleolithic diet is promoted worldwide for improved gut health. However, there is little evidence available to support these claims, with existing literature examining anthropometric and cardiometabolic outcomes. To determine the association between dietary intake, markers of colonic health, microbiota, and serum trimethylamine- N -oxide (TMAO), a gut-derived metabolite associated with cardiovascular disease. In a cross-sectional design, long-term ( n = 44, 1 year) self-reported followers of a Paleolithic diet (PD) and controls ( n = 47) consuming a diet typical of national recommendations were recruited. Diets were assessed via 3-day weighed diet records 48-h stool for short chain fatty acids using GC/MS, microbial composition via 16S rRNA sequencing of the V4 region using Illumina MiSeq. TMAO was quantified using LC–MS/MS. Participants were grouped according to PD adherence namely excluding grains and dairy products. Strict Paleolithic (SP) ( n = 22) and Pseudo-Paleolithic (PP) ( n = 22) groups were formed. General linear modelling with age, gender, energy intake and body fat percentage as covariates assessed differences between groups. Intake of resistant starch was lower in both Paleolithic groups, compared to controls [2.62, 1.26 vs 4.48 g/day ( P 0.05)] PERMANOVA analysis showed differences in microbiota composition ( P 0.05), with higher abundance of TMA-producer Hungatella in both Paleolithic groups ( P 0.001). TMAO was higher in SP compared to PP and control ( P 0.01), and inversely associated with whole grain intake ( r = − 0.34, P 0.01). Although the PD is promoted for improved gut health, results indicate long-term adherence is associated with different gut microbiota and increased TMAO. A variety of fiber components, including whole grain sources may be required to maintain gut and cardiovascular health. Australian and New Zealand Clinical Trial Registry (ANZCTRN12616001703493).
Publisher: BMJ
Date: 08-2020
DOI: 10.1136/BMJGAST-2020-000448
Abstract: A diet low in fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAP) is an effective way to reduce gut symptoms in people with irritable bowel syndrome (IBS). This diet reduces the intake of fermentable fibres, leading to changes of the gut microbiota and insufficient fermentation in the large bowel, resulting in reduced production of short-chain fatty acids (SCFAs), such as butyrate, which has unfavourable implications for gut health, sleep and mental health. This study will examine the effect of Fibre-fix, a supplement containing a mix of dietary fibres, on the human gut microbiome composition, fermentative capacity, sleep, quality of life (QOL) and mental health of people with IBS who consume a low FODMAP diet (LFD). A randomised, double-blind, placebo-controlled, study design is proposed to examine whether Fibre-fix added to an existing LFD may help modulate gastrointestinal function, improve markers of sleep, mental health and promote QOL in patients with IBS. Participants will provide stool and blood s les, daily bowel symptoms diaries and 3-day diet records. Additionally, they will complete validated questionnaires relating to FODMAP intake, sleep, mental health and QOL before and after a 3-week intervention. Gut health will be assessed via faecal microbiome composition, faecal pH and SCFA levels. Alteration of sleep will be recorded using an actigraphy device worn by all participants over the whole study. Multivariate analysis will be used to examine the gut microbiome and repeated measures Analysis of variance (ANOVA) will be used for dependent variables from questionnaires related to bowel symptoms, stool type, sleep, mental health and QOL to assess the differences between intervention and control groups after adjustment for confounding variables. Ethics approval was obtained from the Human Research Ethics Committee of Edith Cowan University (2019-00619-YAN). Results will be disseminated in peer-review journal publications, and conference presentations. Participants will be provided with a summary of findings once the study is completed. If Fibre-fix is shown to result in favourable changes in gut microbial composition, SCFA production, sleep and mental well-being without exacerbating symptoms, this will provide additional dietary management options for those with IBS following an LFD. ACTRN12620000032954.
Publisher: MDPI AG
Date: 28-10-2022
DOI: 10.3390/NU14214547
Abstract: Diabetes is the leading cause of kidney disease, and as the number of in iduals with diabetes increases there is a concomitant increase in the prevalence of diabetic kidney disease (DKD). Diabetes contributes to the development of DKD through a number of pathways, including inflammation, oxidative stress, and the gut-kidney axis, which may be amenable to dietary therapy. Resistant starch (RS) is a dietary fibre that alters the gut microbial consortium, leading to an increase in the microbial production of short chain fatty acids. Evidence from animal and human studies indicate that short chain fatty acids are able to attenuate inflammatory and oxidative stress pathways, which may mitigate the progression of DKD. In this review, we evaluate and summarise the evidence from both preclinical models of DKD and clinical trials that have utilised RS as a dietary therapy to limit the progression of DKD.
Publisher: Frontiers Media SA
Date: 03-09-2020
Publisher: American Society for Microbiology
Date: 15-09-2011
DOI: 10.1128/AEM.05212-11
Abstract: Gastrointestinal disturbance is frequently reported for in iduals with autism. We used quantitative real-time PCR analysis to quantify fecal bacteria that could influence gastrointestinal health in children with and without autism. Lower relative abundances of Bifidobacteria species and the mucolytic bacterium Akkermansia muciniphila were found in children with autism, the latter suggesting mucus barrier changes.
Publisher: MDPI AG
Date: 19-12-2019
DOI: 10.3390/NU12010016
Abstract: The consortium of trillions of microorganisms that live inside the human gut are integral to health. Little has been done to collate and characterize the microbiome of children. A systematic review was undertaken to address this gap (PROSPERO ID: CRD42018109599). MEDLINE and EMBASE were searched using the keywords: “healthy preadolescent children” and “gut microbiome” to 31 August 2018. Of the 815 journal articles, 42 met the inclusion criteria. The primary outcome was the relative abundance of bacteria at the phylum, family, and genus taxonomic ranks. α- ersity, short chain fatty acid concentrations, diet, 16S rRNA sequencing region, and geographical location were documented. The preadolescent gut microbiome is dominated at the phylum level by Firmicutes (weighted overall average relative abundance = 51.1%) and Bacteroidetes (36.0%) genus level by Bacteroides (16.0%), Prevotella (8.69%), Faecalibacterium (7.51%), and Bifidobacterium (5.47%). Geographic location and 16S rRNA sequencing region were independently associated with microbial proportions. There was limited consensus between studies that reported α- ersity and short chain fatty acids. Broadly speaking, participants from non-Western locations, who were less likely to follow a Westernized dietary pattern, had higher α- ersity and SCFA concentrations. Confirmatory studies will increase the understanding of the composition and functional capacity of the preadolescent gut microbiome.
Publisher: MDPI AG
Date: 23-09-2013
DOI: 10.3390/NU5093740
Publisher: Wageningen Academic Publishers
Date: 11-2010
DOI: 10.3920/BM2010.0041
Abstract: The metabolic end products of the large bowel microbiota contribute significantly to human health. After weaning to solid foods, some of the most important of these are the short chain fatty acids (SCFA) produced by the fermentation of undigested dietary components and endogenous secretions. The main SCFA are acetate, propionate and butyrate which have numerous documented effects promoting large bowel function. Of the major acids, butyrate seems especially important. It is a major metabolic fuel for colonocytes and promotes a normal phenotype in these cells, potentially lowering the risk of diseases such as colo-rectal cancer. Imbalances in the microbiota are thought to predispose to large bowel dysfunction and probiotics are being developed to correct this. However, most commercial products contain bacteria (lactobacilli and bifidobacteria) which are dominant species in milk-fed infants but have limited roles in adults. Prebiosis is defined usually by the specific stimulation of these bacteria. However, the end products of most probiotics do not include butyrate or propionate which raises questions about their effectiveness in promoting bowel health in adults. Resistant starch (RS) is a dietary fibre component and its fermentation generally favours butyrate production. Dietary RS intakes and faecal butyrate levels are high in populations at low risk of diet-related large bowel diseases. Conversely, RS intakes and faecal butyrate levels are very low in high risk groups. This raises the possibility that greater RS consumption could be of health benefit. RS is not regarded widely as a prebiotic but (according to the accepted definition) most forms show the requisite features in stimulating specific bacteria, giving raised total SCFA and butyrate levels and a consequent benefit to the host. Current efforts to improve public health through increasing RS consumption could be facilitated by greater recognition of its prebiotic role.
Publisher: Oxford University Press (OUP)
Date: 19-02-2016
Abstract: This study evaluated whether dietary resistant starch (RS) and green tea extract (GTE), which have anti-inflammatory and anticancer properties, protect against colitis-associated colorectal cancer (CAC) using a rat model, also investigated potential mechanisms of action of these agents including their effects on the gut microbiota. Rats were fed a control diet or diets containing 10% RS, 0.5% GTE or a combination of the two (RS + GTE). CAC was initiated with 2 weekly azoxymethane (AOM) injections (10mg/kg) followed by 2% dextran sodium sulphate in drinking water for 7 days after 2 weeks on diets. Rats were killed 20 weeks after the first AOM. Colon tissues and tumours were examined for histopathology by H&E, gene rotein expression by PCR and immunohistochemistry and digesta for analyses of fermentation products and microbiota populations. RS and RS + GTE (but not GTE) diets significantly (P< 0.05) decreased tumour multiplicity and adenocarcinoma formation, relative to the control diet. Effects of RS + GTE were not different from RS alone. RS diet caused significant shifts in microbial composition/ ersity, with increases in Parabacteroides, Barnesiella, Ruminococcus, Marvinbryantia and Bifidobacterium as primary contributors to the shift. RS-containing diets increased short chain fatty acids (SCFA) and expression of the SCFA receptor GPR43 mRNA, and reduced inflammation (COX-2, NF-kB, TNF-α and IL-1β mRNA) and cell proliferation P< 0.05. GTE had no effect. This is the first study that demonstrates chemopreventive effects of RS (but not GTE) in a rodent CAC model, suggesting RS might have benefit to patients with ulcerative colitis who are at an increased risk of developing CRC.
Publisher: Cambridge University Press (CUP)
Date: 17-06-2015
DOI: 10.1017/S0007114515001750
Abstract: Epidemiological studies have identified increased colorectal cancer (CRC) risk with high red meat (HRM) intakes, whereas dietary fibre intake appears to be protective. In the present study, we examined whether a HRM diet increased rectal O 6 -methyl-2-deoxyguanosine (O 6 MeG) adduct levels in healthy human subjects, and whether butyrylated high-amylose maize starch (HAMSB) was protective. A group of twenty-three in iduals consumed 300 g/d of cooked red meat without (HRM diet) or with 40 g/d of HAMSB (HRM+HAMSB diet) over 4-week periods separated by a 4-week washout in a randomised cross-over design. Stool and rectal biopsy s les were collected for biochemical, microbial and immunohistochemical analyses at baseline and at the end of each 4-week intervention period. The HRM diet increased rectal O 6 MeG adducts relative to its baseline by 21 % ( P 0·01), whereas the addition of HAMSB to the HRM diet prevented this increase. Epithelial proliferation increased with both the HRM ( P 0·001) and HRM+HAMSB ( P 0·05) diets when compared with their respective baseline levels, but was lower following the HRM+HAMSB diet compared with the HRM diet ( P 0·05). Relative to its baseline, the HRM+HAMSB diet increased the excretion of SCFA by over 20 % ( P 0·05) and increased the absolute abundances of the Clostridium coccoides group ( P 0·05), the Clostridium leptum group ( P 0·05), Lactobacillus spp. ( P 0·01), Parabacteroides distasonis ( P 0·001) and Ruminococcus bromii ( P 0·05), but lowered Ruminococcus torques ( P 0·05) and the proportions of Ruminococcus gnavus , Ruminococcus torques and Escherichia coli ( P 0·01). HRM consumption could increase the risk of CRC through increased formation of colorectal epithelial O 6 MeG adducts. HAMSB consumption prevented red meat-induced adduct formation, which may be associated with increased stool SCFA levels and/or changes in the microbiota composition.
Publisher: MDPI AG
Date: 23-06-2021
DOI: 10.3390/NU13072159
Abstract: Irritable bowel syndrome (IBS) is a common functional gastrointestinal disorder affecting 4–5% of the global population. This disorder is associated with gut microbiota, diet, sleep, and mental health. This scoping review therefore aims to map existing research that has administrated fibre-related dietary intervention to IBS in iduals and reported outcomes on at least two of the three following themes: gut microbiota, sleep, and mental health. Five digital databases were searched to identify and select papers as per the inclusion and exclusion criteria. Five articles were included in the assessment, where none reported on all three themes or the combination of gut microbiota and sleep. Two studies identified alterations in gut microbiota and mental health with fibre supplementation. The other three studies reported on mental health and sleep outcomes using subjective questionnaires. IBS-related research lacks system biology-type studies targeting gut microbiota, sleep, and mental health in patients undergoing diet intervention. Further IBS research is required to explore how human gut microbiota functions (such as short-chain fatty acids) in sleep and mental health, following the implementation of dietary pattern alteration or component supplementation. Additionally, the application of objective sleep assessments is required in order to detect sleep change with more accuracy and less bias.
Publisher: Springer Science and Business Media LLC
Date: 30-06-2020
DOI: 10.1186/S12889-020-09124-3
Abstract: Australia, like other nations, has experienced a shift in dietary patterns away from home cooking of nutritious foods, towards a reliance on pre-prepared convenience meals. These are typically energy-dense, nutrient-poor and contribute to the rising prevalence of obesity and chronic disease burden. The aims of this study were to evaluate whether a community-based cooking program instigated a change to participants’ skills, attitudes, knowledge, enjoyment and satisfaction of cooking and cooking confidence (self-efficacy). The pseudo-random, pre-post study design consisted of an intervention and a control group. Participant recruitment and group allocation was based on their program start dates. Intervention participants were surveyed three times (baseline, 7 weeks and 6 months) and the control group were surveyed at baseline and 5 weeks. All participants were registered via an online website and were 18 years or over. Upon consent, participants were offered four levels of commitment, defined by different assessments. The minimum participation level included an online survey and levels 2, 3 and 4 involved attendance at a clinic with increasing functional, anthropometric and biomarker measurements. Primary endpoints were participants’ cooking confidence as a proxy for self-efficacy. Secondary endpoints were dietary intake, physical activity levels, body composition, anthropometry, blood, urine and faecal biomarkers of systemic, physical and mental health. The community cooking program provided participants with information and advice on food sourcing, preparation and nutrition to improve home cooking skills. The study was designed to explore whether food literacy programs are efficacious in improving participant physical health and well-being in order to combat the rise in obesity and diet-related disease . It will support future use of public health cooking program initiatives aimed at improving food literacy, self-efficacy and physical and mental health. The extensive data collected will inform future research into the relationship between diet, the gut-microbiota and human health. Retrospectively registered on 16.08.2019 with the Australian New Zealand Clinical Trials Registry (ANZCTR). ACTRN12619001144101 . Protocol version 4.
Publisher: Informa UK Limited
Date: 05-2012
DOI: 10.4161/GMIC.19579
Publisher: Frontiers Media SA
Date: 22-07-2021
DOI: 10.3389/FIMMU.2021.699633
Abstract: High risk for virus-induced asthma exacerbations in children is associated with an IRF7lo immunophenotype, but the underlying mechanisms are unclear. Here, we applied a Systems Biology approach to an animal model comprising rat strains manifesting high (BN) versus low susceptibility (PVG) to experimental asthma, induced by virus/allergen coexposure, to elucidate the mechanism(s)-of-action of the high-risk asthma immunophenotype. We also investigated potential risk mitigation via pretreatment with the immune training agent OM-85. Virus/allergen coexposure in low-risk PVG rats resulted in rapid and transient airways inflammation alongside IRF7 gene network formation. In contrast, responses in high-risk BN rats were characterized by severe airways eosinophilia and exaggerated proinflammatory responses that failed to resolve, and complete absence of IRF7 gene networks. OM-85 had more profound effects in high-risk BN rats, inducing immune-related gene expression changes in lung at baseline and reducing exaggerated airway inflammatory responses to virus/allergen coexposure. In low-risk PVG rats, OM-85 boosted IRF7 gene networks in the lung but did not alter baseline gene expression or cellular influx. Distinct IRF7-associated asthma risk immunophenotypes have dichotomous responses to virus/allergen coexposure and respond differentially to OM-85 pretreatment. Extrapolating to humans, our findings suggest that the beneficial effects OM-85 pretreatment may preferentially target those in high-risk subgroups.
Publisher: Cambridge University Press (CUP)
Date: 05-2002
DOI: 10.1017/S0022029902005526
Abstract: The amount of protein synthesis translational elongation factor 2 (eEF-2) was estimated employing diphtheria toxin-dependent ADP-ribosylation in s les prepared from small amounts of tissue from mammary gland, skeletal muscle and liver from lactating dairy cows. A very high level of ADP-ribosylatable eEF-2 was found in mammary gland, amounting to 20-times the level found in liver and 50-times the level found in skeletal muscle. This obviously reflects the high protein synthesis activity in mammary tissue. To our knowledge, similar high activities have previously been reported only for cancer cells. A close linear relationship was found between the amount of diphtheria-toxin catalysed ADP-ribosylated eEF-2 and protein and casein output in milk from cows in late lactation. This strongly suggests that eEF-2 may be a limiting factor in milk protein synthesis.
Publisher: Springer Science and Business Media LLC
Date: 07-07-2021
DOI: 10.1038/S41598-021-93031-Z
Abstract: Associations between the human gut microbiome and health outcomes continues to be of great interest, although fecal s le collection methods which impact microbiome studies are sometimes neglected. Here, we expand on previous work in s le optimization, to promote high quality microbiome data. To compare fecal s le collection methods, licons from the bacterial 16S rRNA gene (V4) and fungal (ITS2) region, as well as short chain fatty acid (SCFA) concentrations were determined in fecal material over three timepoints. We demonstrated that spot s ling of stool results in variable detection of some microbial members, and inconsistent levels of SCFA therefore, s le homogenization prior to subsequent analysis or subs ling is recommended. We also identify a trend in microbial and metabolite composition that shifts over two consecutive stool collections less than 25 h apart. Lastly, we show significant differences in bacterial composition that result from collecting stool s les in OMNIgene·Gut tube (DNA Genotec) or Stool Nucleic Acid Collection and Preservation Tube (NORGEN) compared to immediate freezing. To assist with planning fecal s le collection and storage procedures for microbiome investigations with multiple analyses, we recommend participants to collect the first full bowel movement of the day and freeze the s le immediately after collection.
Publisher: Cambridge University Press (CUP)
Date: 17-12-2018
DOI: 10.1017/S000711451800329X
Abstract: The Paleolithic diet excludes two major sources of fibre, grains and legumes. However, it is not known whether this results in changes to resistant starch (RS) consumption. Serum trimethylamine- N -oxide (TMAO) is produced mainly from colonic fermentation and hepatic conversion of animal protein and is implicated in CVD, but changes in RS intake may alter concentrations. We aimed to determine whether intake of RS and serum concentrations of TMAO varied in response to either the Paleolithic or the Australian Guide to Healthy Eating (AGHE) diets and whether this was related to changes in food group consumption. A total of thirty-nine women (mean age 47 ( sd 13) years, BMI 27 ( sd 4) kg/m 2 ) were randomised to AGHE ( n 17) or Paleolithic diets ( n 22) for 4 weeks. Serum TMAO concentrations were measured using liquid chromatography–MS food groups, fibre and RS intake were estimated from weighed food records. The change in TMAO concentrations between groups (Paleolithic 3·39 μ m v . AGHE 1·19 μ m , P = 0·654) did not reach significance despite greater red meat and egg consumption in the Paleolithic group (0·65 serves/d 95 % CI 0·2, 1·1 P ·01, and 0·22 serves/d 95 % CI 0·1, 0·4, P ·05, respectively). RS intake was significantly lower on the Paleolithic diet ( P ·01) and was not associated with TMAO concentrations. However, the limited data for RS and the small s le size may have influenced these findings. While there were no significant changes in TMAO concentrations, increased meat consumption and reduced RS intake warrant further research to examine the markers of gastrointestinal health of Paleolithic diet followers and to update Australian food databases to include additional fibre components.
Publisher: Wiley
Date: 20-06-2017
Abstract: Reducing sodium intakes remains a global challenge for the food industry. KCl is a potential salt substitute but imparts bitterness when used at high concentrations. Little is known about how oil concentrations (OC) affect consumers' perception of saltiness and bitterness in emulsion products such as mayonnaise containing KCl. We evaluated consumers' perception and physical properties of mayonnaise-type spreads at various oil and tastant (NaCl or KCl) concentrations. Consumers (N = 306) evaluated saltiness, bitterness, overall taste liking (OTL) and purchase intent (PI). Viscosity, pH, water activity, and consistency/texture were also measured. Oil and tastant (NaCl or KCl) concentrations had significant effects on saltiness, viscosity, and pH. As OC increased, saltiness intensity slightly decreased for spreads. Increasing oil concentration increased viscosity. Generally, spreads containing KCl had higher bitterness and pH than spreads containing NaCl. All spreads containing KCl were penalized for being "too bitter." PI was affected by OTL for all spreads but OC was also a significant factor in the purchase decision of spreads containing NaCl. This study demonstrated that increasing OC affected consumers' taste perception (saltiness and bitterness) and spreads' physical properties including pH and viscosity.
Publisher: Elsevier BV
Date: 03-2021
Publisher: American Society for Microbiology
Date: 15-05-2011
DOI: 10.1128/AEM.02851-10
Abstract: The dominant genus of sulfate-reducing bacteria (SRB) in humans is Desulfovibrio , and quantitative PCR (QPCR) targeting the 16S rRNA gene is often used in assays. We show that the 16S rRNA gene assay overestimated SRB abundance in feces from 24 adults compared to QPCR assays using primers targeting two genes involved in SRB energy metabolism.
Publisher: Future Medicine Ltd
Date: 03-2014
DOI: 10.2217/BMM.14.12
Abstract: Autism spectrum disorder (ASD) is a neurodevelopmental disorder. Many affected in iduals also display symptoms of gastrointestinal (GI) disturbance, suggesting GI factors may play an important role in the pathogenesis of ASD and/or related complications. The current review will focus on evidence supporting a role for the GI microbiota and their fermentation products in the etiology and/or symptoms of ASD, and their potential use as biomarkers. GI-related biomarkers could potentially enable early identification of ASD at risk of GI disturbance, and thereby guide targeted interventions, potentially improving the health and quality of life of affected in iduals.
Publisher: Springer Science and Business Media LLC
Date: 26-04-2012
DOI: 10.1007/S10620-012-2167-7
Abstract: Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder where a high frequency of gastrointestinal disturbance (e.g., constipation and diarrhea) is reported. As large bowel fermentation products can have beneficial or detrimental effects on health, these were measured in feces of children with and without ASD to examine whether there is an underlying disturbance in fermentation processes in the disorder. Fecal s les (48 h) were collected from children with ASD (n = 23), and without ASD (n = 31) of similar age. Concentrations of short chain fatty acids, phenols and ammonia were measured. Fecal total short chain fatty acid concentrations were significantly higher in children with ASD compared to controls (136.6 ± 8.7 vs. 111.1 ± 6.6 mmol/kg). Moreover, when concentrations of fecal acetic, butyric, isobutyric, valeric, isovaleric and caproic acids were measured, all were significantly higher in children with ASD compared with controls except for caproic acid. The concentration of fecal ammonia was also significantly greater in ASD participants than controls (42.7 ± 3.3 vs. 32.3 ± 1.9 mmol/kg). Fecal phenol levels and pH did not differ between groups. Macronutrient intake, as determined from dietary records kept by caregivers, also did not differ significantly between study groups. Our results suggest fermentation processes or utilization of fermentation products may be altered in children with ASD compared to children without ASD.
Publisher: BMJ
Date: 04-2019
DOI: 10.1136/BMJOPEN-2018-024872
Abstract: A potential link exists between prostate cancer (PCa) disease and treatment and increased inflammatory levels from gut dysbiosis. This study aims to examine if exercise favourably alters gut microbiota in men receiving androgen deprivation therapy (ADT) for PCa. Specifically, this study will explore whether: (1) exercise improves the composition of gut microbiota and increases the abundance of bacteria associated with health promotion and (2) whether gut health correlates with favourable inflammatory status, bowel function, continence and nausea among patients participating in the exercise intervention. A single-blinded, two-armed, randomised controlled trial will explore the influence of a 3-month exercise programme (3 days/week) for men with high-risk localised PCa receiving ADT. Sixty patients will be randomly assigned to either exercise intervention or usual care. The primary endpoint (gut health and function assessed via feacal s les) and secondary endpoints (self-reported quality of life via standardised questionnaires, blood biomarkers, body composition and physical fitness) will be measured at baseline and following the intervention. A variety of statistical methods will be used to understand the covariance between microbial ersity and metabolomics profile across time and intervention. An intention-to-treat approach will be utilised for the analyses with multiple imputations followed by a secondary sensitivity analysis to ensure data robustness using a complete cases approach. Ethics approval was obtained from the Human Research Ethics Committee of Edith Cowan University (ID: 19827 NEWTON). Findings will be reported in peer-reviewed publications and scientific conferences in addition to working with national support groups to translate findings for the broader community. If exercise is shown to result in favourable changes in gut microbial ersity, composition and metabolic profile, and reduce gastrointestinal complications in PCa patients receiving ADT, this study will form the basis of a future phase III trial. ANZCTR12618000280202.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 04-2016
DOI: 10.1038/CTG.2016.22
Publisher: Springer Science and Business Media LLC
Date: 15-12-2019
DOI: 10.1007/S00216-018-1522-8
Abstract: Serum branched chain amino acids and trimethylamine-N-oxide are monitored as potential indicators of diabetes and cardiovascular health respectively. A rapid method for their simultaneous determination using liquid chromatography and tandem mass spectrometry is described here. Branched chain amino acids and trimethylamine-N-oxide were quantified based on their specific MS/MS fragments using a selected reaction monitoring approach. A number of columns were tested for their ability to separate the analytes. A C18-PFP column separated the analytes in just 4 minutes, and resulted in excellent peak shape and retention time repeatability, and was therefore chosen as the optimal column. A second column, the Intrada Amino Acid column, was chosen for comparison and validation experiments as it provided an orthogonal separation mechanism. The intra-day and inter-day precision and accuracy were less than 12% for trimethylamine-N-oxide and less than 6% for the branched chain amino acids. Recoveries, where serum was spiked with three different concentrations of the analytes, ranged from 97 to 113%. The LODs and LOQs for trimethylamine-N-oxide were 1 and 6 ng/mL, for leucine and isoleucine were 4 and 8 ng/mL, and for valine were 5 and 15 ng/mL, respectively. The C18-PFP column method was validated using the Intrada Amino Acid column method and percentage agreement for all four analytes was within 10%. S le preparation was minimal, and use of labelled internal standards accounted for matrix effects. The method was successfully applied to human plasma s les. Graphical abstract ᅟ.
Publisher: American Society for Microbiology
Date: 03-2004
DOI: 10.1128/AEM.70.3.1263-1270.2004
Abstract: The molecular ersity of rumen methanogens in sheep in Australia was investigated by using in idual 16S rRNA gene libraries prepared from the rumen contents obtained from six merino sheep grazing pasture (326 clones), six sheep fed an oaten hay-based diet (275 clones), and five sheep fed a lucerne hay-based diet (132 clones). A total of 733 clones were examined, and the analysis revealed 65 phylotypes whose sequences (1,260 bp) were similar to those of cultivated methanogens belonging to the order Methanobacteriales . Pasture-grazed sheep had more methanogen ersity than sheep fed either the oaten hay or lucerne hay diet. Methanobrevibacter strains SM9, M6, and NT7 accounted for over 90% of the total number of clones identified. M6 was more prevalent in grazing sheep, and SM9, despite being found in 16 of the 17 sheep, was more prevalent in sheep fed the lucerne-based diet. Five new species were identified. Two of these species exhibited very little sequence similarity to any cultivated methanogens and were found eight times in two of the six sheep that were grazing pasture. These unique sequences appear to represent a novel group of rumen archaea that are atypical for the rumen environment.
Publisher: Frontiers Media SA
Date: 17-03-2022
Abstract: Obesity and mental health disorders are rising simultaneously with shifting dietary behavior away from home cooking, toward typically nutrition-poor and energy-dense convenience meals. Food literacy strongly influences nutrition choices. Community-based cooking interventions target barriers to healthy eating and facilitate development of food literacy skills, thereby potentially increasing preparation of home-cooked meals and positively influencing health. This study of 657 healthy Australian adults explored the efficacy of a 7-week cooking program in improving cooking confidence, whether this transferred to behavior surrounding food, and/or affected mental health. Significant post-program improvements in cooking confidence and satisfaction (all p & 0.001, η p 2 1.12 large), ability to change eating habits ( p & 0.001) and overcome lifestyle barriers ( p = 0.005) were observed for the intervention group but not control. Participation also improved mental and general health (all p & 0.05, η p 2 0.02 small). No changes were observed for acquisition and consumption of food, or nutrition knowledge in either group. This 7-week cooking program built cooking confidence and improved general and mental health but did not change dietary behavior. To further improve nutrition related behaviors associated with better mental health, more effort is needed to recruit those with below-average nutrition knowledge and interest in cooking.
Publisher: Springer Science and Business Media LLC
Date: 04-11-2013
Abstract: A recent report indicated that numbers of Sutterella spp. are elevated in gastrointestinal biopsies taken from children with autism spectrum disorder (ASD). We have recently reported changes in the numbers of some bacteria within the stool of ASD children, and now examine whether numbers of Sutterella spp. and some other mucosa-associated bacteria linked with gastrointestinal disease ( Ruminococcus gnavus and Ruminococcus torques ) are also altered in the stool of these children. We show that numbers of Sutterella spp. are elevated in feces of ASD children relative to controls, and that numbers of R. torques are higher in the children with ASD with a reported functional gastrointestinal disorder than those without such a disorder. We show further evidence of changes in the gut microbiota of children with ASD and confirm that the abundance of Sutterella spp. is altered in stool.
Publisher: MDPI AG
Date: 24-04-2021
DOI: 10.3390/NU13051447
Abstract: Increasing prevalence of mental health disorders within the Australian population is a serious public health issue. Adequate intake of fruits and vegetables (FV), dietary fibre (DF) and resistant starch (RS) is associated with better mental and physical health. Few longitudinal studies exist exploring the temporal relationship. Using a validated food frequency questionnaire, we examined baseline FV intakes of 5845 Australian adults from the AusDiab study and estimated food group-derived DF and RS using data from the literature. Perceived mental health was assessed at baseline and 5 year follow up using SF-36 mental component summary scores (MCS). We conducted baseline cross-sectional analysis and prospective analysis of baseline dietary intake with perceived mental health at 5 years. Higher baseline FV and FV-derived DF and RS intakes were associated with better 5 year MCS (p 0.001). A higher FV intake (754 g/d vs. 251 g/d, Q4 vs. Q1) at baseline had 41% lower odds (OR = 0.59: 95% CI 0.46–0.75) of MCS below population average ( ) at 5 year follow up. Findings were similar for FV-derived DF and RS. An inverse association was observed with discretionary food-derived DF and RS. This demonstrates the association between higher intakes of FV and FV-derived DF and RS with better 5 year mental health outcomes. Further RCTs are necessary to understand mechanisms that underlie this association including elucidation of causal effects.
Publisher: Springer Science and Business Media LLC
Date: 11-04-2011
Abstract: Probiotics purportedly reduce symptoms of gastrointestinal and upper respiratory-tract illness by modulating commensal microflora. Preventing and reducing symptoms of respiratory and gastrointestinal illness are the primary reason that dietary supplementation with probiotics are becoming increasingly popular with healthy active in iduals. There is a paucity of data regarding the effectiveness of probiotics in this cohort. The aim of this study was to evaluate the effectiveness of a probiotic on faecal microbiology, self-reported illness symptoms and immunity in healthy well trained in iduals. Competitive cyclists (64 males and 35 females age 35 ± 9 and 36 ± 9 y, VO 2 max 56 ± 6 and 52 ± 6 ml.kg -1 .min -1 , mean ± SD) were randomised to either probiotic (minimum 1 × 10 9 Lactobacillus fermentum (PCC ® ) per day) or placebo treatment for 11 weeks in a double-blind, randomised, controlled trial. The outcome measures were faecal L. fermentum counts, self-reported symptoms of illness and serum cytokines. Lactobacillus numbers increased 7.7-fold (90% confidence limits 2.1- to 28-fold) more in males on the probiotic, while there was an unclear 2.2-fold (0.2- to 18-fold) increase in females taking the probiotic. The number and duration of mild gastrointestinal symptoms were ~2-fold greater in the probiotic group. However, there was a substantial 0.7 (0.2 to 1.2) of a scale step reduction in the severity of gastrointestinal illness at the mean training load in males, which became more pronounced as training load increased. The load (duration×severity) of lower respiratory illness symptoms was less by a factor of 0.31 (99%CI 0.07 to 0.96) in males taking the probiotic compared with placebo but increased by a factor of 2.2 (0.41 to 27) in females. Differences in use of cold and flu medication mirrored these symptoms. The observed effects on URTI had too much uncertainty for a decisive outcome. There were clear reductions in the magnitude of acute exercise-induced changes in some cytokines. L. fermentum may be a useful nutritional adjunct for healthy exercising males. However, uncertainty in the effects of supplementation on URTI and on symptoms in females needs to be resolved. The trial was registered in the Australia and New Zealand Clinical Trials Registry ( ACTRN12611000006943 ).
Publisher: Oxford University Press (OUP)
Date: 21-12-2020
Abstract: ESO 149-G003 is a close-by, isolated dwarf irregular galaxy. Previous observations with the ATCA indicated the presence of anomalous neutral hydrogen ($\\rm{H{\\small I}}$) deviating from the kinematics of a regularly rotating disc. We conducted follow-up observations with the MeerKAT radio telescope during the 16-dish Early Science programme as well as with the MeerLICHT optical telescope. Our more sensitive radio observations confirm the presence of anomalous gas in ESO 149-G003, and further confirm the formerly tentative detection of an extraplanar $\\rm{H{\\small I}}$ component in the galaxy. Employing a simple tilted-ring model, in which the kinematics is determined with only four parameters but including morphological asymmetries, we reproduce the galaxy’s morphology, which shows a high degree of asymmetry. By comparing our model with the observed $\\rm{H{\\small I}}$, we find that in our model, we cannot account for a significant (but not dominant) fraction of the gas. From the differences between our model and the observed data cube, we estimate that at least 7–8 per cent of the $\\rm{H{\\small I}}$ in the galaxy exhibits anomalous kinematics, while we estimate a minimum mass fraction of less than 1 per cent for the morphologically confirmed extraplanar component. We investigate a number of global scaling relations and find that, besides being gas-dominated with a neutral gas-to-stellar mass ratio of 1.7, the galaxy does not show any obvious global peculiarities. Given its isolation, as confirmed by optical observations, we conclude that the galaxy is likely currently acquiring neutral gas. It is either re-accreting gas expelled from the galaxy or accreting pristine intergalactic material.
Publisher: MDPI AG
Date: 14-06-2019
DOI: 10.3390/NU11061345
Abstract: In adults, fermentation of high amylose maize starch (HAMS), a resistant starch (RS), has a prebiotic effect. Were such a capacity to exist in infants, intake of RS might programme the gut microbiota during a critical developmental period. This study aimed to determine if infant faecal inocula possess the capacity to ferment HAMS or acetylated-HAMS (HAMSA) and characterise associated changes to microbial composition. Faecal s les were collected from 17 healthy infants at two timepoints: Preweaning and within 10 weeks of first solids. Fermentation was assessed using in vitro batch fermentation. Following 24 h incubation, pH, short-chain fatty acid (SCFA) production and microbial composition were compared to parallel control incubations. In preweaning infants, there was a significant decrease at 24 h in pH between control and HAMS incubations and a significant increase in the production of total SCFAs, indicating fermentation. Fermentation of HAMS increased further following commencement of solids. Fermentation of RS with weaning faecal inocula increased Shannon’s ersity index (H) and was associated with increased abundance of Bifidobacterium and Bacteroides. In conclusion, the faecal inocula from infants is capable of RS fermentation, independent of stage of weaning, but introduction of solids increases this fermentation capacity. RS may thus function as a novel infant prebiotic.
Publisher: Wiley
Date: 09-03-2021
Abstract: Metabarcoding of environmental DNA (eDNA) when coupled with high throughput sequencing is revolutionising the way bio ersity can be monitored across a wide range of applications. However, the large number of tools deployed in downstream bioinformatic analyses often places a challenge in configuration and maintenance of a workflow, and consequently limits the research reproducibility. Furthermore, scalability needs to be considered to handle the growing amount of data due to increase in sequence output and the scale of project. Here, we describe eDNAFlow, a fully automated workflow that employs a number of state‐of‐the‐art applications to process eDNA data from raw sequences (single‐end or paired‐end) to generation of curated and noncurated zero‐radius operational taxonomic units (ZOTUs) and their abundance tables. This pipeline is based on Nextflow and Singularity which enable a scalable, portable and reproducible workflow using software containers on a local computer, clouds and high‐performance computing (HPC) clusters. Finally, we present an in‐house Python script to assign taxonomy to ZOTUs based on user specified thresholds for assigning lowest common ancestor (LCA). We demonstrate the utility and efficiency of the pipeline using an ex le of a published coral ersity biomonitoring study. Our results were congruent with the aforementioned study. The scalability of the pipeline is also demonstrated through analysis of a large data set containing 154 s les. To our knowledge, this is the first automated bioinformatic pipeline for eDNA analysis using two powerful tools: Nextflow and Singularity. This pipeline addresses two major challenges in the analysis of eDNA data scalability and reproducibility.
Publisher: Oxford University Press (OUP)
Date: 17-03-2021
Abstract: Magnetars are a promising candidate for the origin of fast radio bursts (FRBs). The detection of an extremely luminous radio burst from the Galactic magnetar SGR J1935+2154 on 2020 April 28 added credence to this hypothesis. We report on simultaneous and non-simultaneous observing c aigns using the Arecibo, Effelsberg, LOFAR, MeerKAT, MK2, and Northern Cross radio telescopes and the MeerLICHT optical telescope in the days and months after the April 28 event. We did not detect any significant single radio pulses down to fluence limits between 25 mJy ms and 18 Jy ms. Some observing epochs overlapped with times when X-ray bursts were detected. Radio images made on 4 d using the MeerKAT telescope revealed no point-like persistent or transient emission at the location of the magnetar. No transient or persistent optical emission was detected over seven days. Using the multicolour MeerLICHT images combined with relations between DM, NH, and reddening, we constrain the distance to SGR J1935+2154, to be between 1.5 and 6.5 kpc. The upper limit is consistent with some other distance indicators and suggests that the April 28 burst is closer to two orders of magnitude less energetic than the least energetic FRBs. The lack of single-pulse radio detections shows that the single pulses detected over a range of fluences are either rare, or highly clustered, or both. It may also indicate that the magnetar lies somewhere between being radio-quiet and radio-loud in terms of its ability to produce radio emission efficiently.
Publisher: Informa UK Limited
Date: 26-02-2020
Publisher: Springer International Publishing
Date: 2016
Publisher: Oxford University Press (OUP)
Date: 02-2008
Abstract: The interaction of retention time in the rumen and concentrate diet on methane production in vitro and acetate:propionate ratio was examined. Twenty-four fistulated sheep were used in a complete factorial design with the sheep randomly ided into 4 groups. The sheep had a 5-wk acclimatization period on an oaten chaff diet, followed by two 3-wk diet phases. Two of the 4 groups were maintained on the oaten chaff diet for the duration of the experiment, with pot scrubbers added to the rumen of 1 of the 2 groups. The remaining 2 groups were offered a low-grain diet (35% grain) in the first diet phase followed by a high-grain diet (70% grain) in the second diet phase. Pot scrubbers were also added to the rumen of 1 of these 2 groups of grain-fed sheep. Pot scrubbers in combination with a low-grain diet decreased the amount of methane produced in vitro from 4.25 to 3.71 mmol/mL of digesta when compared with oaten chaff-fed sheep without pot scrubbers (P < 0.05). The acetate:propionate ratio was 1.6 in sheep fed a high-grain diet with pot scrubbers compared with 2.4 in sheep fed a high-grain diet without pot scrubbers in their rumen (P < 0.05). At high levels of grain, when employing a multivariate statistical analysis including all data, sheep given the combined treatment of grain and pot scrubbers were different from all other sheep groups in this experiment (P < 0.05). Furthermore, sheep fed a high-grain diet were different from sheep receiving the oaten chaff diets with and without pot scrubbers (P < 0.01 and P < 0.05, respectively). In conclusion, pot scrubbers combined with grain alter the rumen fermentation, and introducing pot scrubbers into the rumens of livestock consuming low levels of grain may be a way to lower methane emissions.
Publisher: Wiley
Date: 11-01-2023
DOI: 10.1002/DEV.22360
Abstract: The aim of this review was to map the literature assessing associations between maternal or infant immune or gut microbiome biomarkers and child neurodevelopmental outcomes within the first 5 years of life. We conducted a PRISMA‐ScR compliant review of peer‐reviewed, English‐language journal articles. Studies reporting gut microbiome or immune system biomarkers and child neurodevelopmental outcomes prior to 5 years were eligible. Sixty‐nine of 23,495 retrieved studies were included. Of these, 18 reported on the maternal immune system, 40 on the infant immune system, and 13 on the infant gut microbiome. No studies examined the maternal microbiome, and only one study examined biomarkers from both the immune system and the gut microbiome. Additionally, only one study included both maternal and infant biomarkers. Neurodevelopmental outcomes were assessed from 6 days to 5 years. Associations between biomarkers and neurodevelopmental outcomes were largely nonsignificant and small in effect size. While the immune system and gut microbiome are thought to have interactive impacts on the developing brain, there remains a paucity of published studies that report biomarkers from both systems and associations with child development outcomes. Heterogeneity of research designs and methodologies may also contribute to inconsistent findings. Future studies should integrate data across biological systems to generate novel insights into the biological underpinnings of early development.
Publisher: Springer Science and Business Media LLC
Date: 18-01-2022
DOI: 10.1186/S12884-021-04366-4
Abstract: Gestational Diabetes Mellitus (GDM) is prevalent with lasting health implications for the mother and offspring. Medical nutrition therapy is the foundation of GDM management yet achieving optimal glycaemic control often requires treatment with medications, like insulin. New dietary strategies to improve GDM management and outcomes are required. Gut dysbiosis is a feature of GDM pregnancies, therefore, dietary manipulation of the gut microbiota may offer a new avenue for management. Resistant starch is a fermentable dietary fibre known to alter the gut microbiota and enhance production of short-chain fatty acids. Evidence suggests that short-chain fatty acids improve glycaemia via multiple mechanisms, however, this has not been evaluated in GDM. An open-label, parallel-group design study will investigate whether a high dietary resistant starch intake or resistant starch supplement improves glycaemic control and changes the gut microbiome compared with standard dietary advice in women with newly diagnosed GDM. Ninety women will be randomised to one of three groups - standard dietary treatment for GDM (Control), a high resistant starch diet or a high resistant starch diet plus a 16 g resistant starch supplement. Measurements taken at Baseline (24 to 30-weeks’ gestation), Day 10 and Day 56 (approximately 36 weeks’ gestation) will include fasting plasma glucose levels, microbial composition and short-chain fatty acid concentrations in stool, 3-day dietary intake records and bowel symptoms questionnaires. One-week post-natal data collection will include microbial composition and short-chain fatty acid concentrations of maternal and neonatal stools, microbial composition of breastmilk, birthweight, maternal and neonatal outcomes. Mixed model analysis of variance will assess change in glycaemia and permutation-based multivariate analysis of variance will assess changes in microbial composition within and between intervention groups. Distance-based linear modelling will identify correlation between change in stool microbiota, short-chain fatty acids and measures of glycaemia. To improve outcomes for GDM dyads, evaluation of a high dietary intake of resistant starch to improve glycaemia through the gut microbiome needs to be established. This will expand the dietary interventions available to manage GDM without medication. Australian New Zealand Clinical Trial Registry, ACTRN12620000968976p . Registered 28 September 2020
Publisher: MDPI AG
Date: 03-04-2017
DOI: 10.3390/NU9040355
Publisher: Elsevier BV
Date: 04-2015
Publisher: CSIRO Publishing
Date: 15-06-2021
DOI: 10.1071/MA21023
Abstract: Preterm birth (PTB) is a significant health problem globally, with an estimate of 15 million cases annually. Approximately 10% of neonates born early will die prematurely, while a subset will develop severe life-long morbidities. Unfortunately, preterm birth’s syndromic nature has evaded prevention strategies, and it continues to impose a high burden on healthcare systems and families. The role of vaginal bacteria in triggering biomolecular causes of PTB has been recognised for years. However, translating this knowledge to practical diagnostic and therapeutic strategies has remained elusive. New techniques in high-throughput sequencing have improved our understanding of the nature and role of the vaginal microbiome during pregnancy. Several multi-ethnic and multi-geographical studies into the vaginal microbiome have identified five distinct bacterial profiles termed community state types (CSTs), one of which is positively associated with dysbiosis and increased risk of PTB. In a small pilot study of first-trimester vaginal microbial DNA obtained from pregnant women at high-risk of PTB, we compared the CST profiles generated using standard 16S licon sequencing with shallow shotgun metagenomics (SSM). Both methods identified the presence of the five CSTs as has been reported previously, although the metagenomic data showed greater taxonomic resolution and more accurate CST assignation. These findings suggest that SSM is a cost-effective and potentially superior alternative to 16S sequencing for vaginal microbiome analysis.
Publisher: Cold Spring Harbor Laboratory
Date: 10-03-2023
DOI: 10.1101/2023.03.09.23287071
Abstract: Phenyl- γ- valerolactones (PVLs) have been proposed as potential biomarkers of dietary flavan-3-ol exposure. We investigate the performance of a range of PVLs as biomarkers indicative of flavan-3-ol intake. We report results of two companion studies: a 5-way randomised cross-over trial (RCT) and an observational cross-sectional study. In the RCT, 16 healthy participants were randomly assigned to 1-day flavan-3-ol rich interventions (of either apple, cocoa, black tea, green tea, or water [control]). Participants collected 24-hour urine and first morning urine s les, with diet standardised throughout. For each participant, one of the five intervention periods was randomly extended to two days, to monitor PVL kinetics following repeated days of flavan-3-ol exposure. In the cross-sectional study, 86 healthy participants collected 24-hour urines and concurrent weighed food diaries from which flavan-3-ol consumption was estimated using Phenol-Explorer. A panel of 10 urinary PVLs was quantified using liquid chromatography tandem mass spectrometry. In both studies, two urinary PVLs [5-(3’ s-hydroxyphenyl)-γ-valerolactone-4’-sulfate and tentatively identified 5-(4’-hydroxyphenyl)-γ-valerolactone-3’-glucuronide] were the principal compounds excreted ( %). In the RCT, the sum of these PVLs was significantly higher than the water (control) following each intervention in idually, there was a shift from sulfation towards glucuronidation as the total excretion of PVLs increased across the different interventions. In the extended RCT intervention period, after two days of treatment, there was no evidence of accumulation of these compounds in the urine, and following withdrawal of treatment on the third day, there was a return towards negligible PVL excretion. All results were consistent, whether compounds were measured in 24-hour urine or first morning voids. In the observational study, the sum of the principal PVLs correlated dose-dependently ( R s = 0.37, P = 0.0006) with dietary flavan-3-ol intake, with similar associations for each in idually. Urinary 5-(3’-hydroxyphenyl)-γ-valerolactone-4’-sulfate and tentatively identified 5-(4’-hydroxyphenyl)-γ-valerolactone-3’-glucuronide are recommended biomarkers for dietary flavan-3-ol exposure.
Publisher: EDP Sciences
Date: 11-2020
DOI: 10.1051/0004-6361/202038894
Abstract: Aims. We present the results of three commissioning H I observations obtained with the MeerKAT radio telescope. These observations make up part of the preparation for the forthcoming MHONGOOSE nearby galaxy survey, which is a MeerKAT large survey project that will study the accretion of gas in galaxies and the link between gas and star formation. Methods. We used the available H I data sets, along with ancillary data at other wavelengths, to study the morphology of the MHONGOOSE s le galaxy, ESO 302-G014, which is a nearby gas-rich dwarf galaxy. Results. We find that ESO 302-G014 has a lopsided, asymmetric outer disc with a low column density. In addition, we find a tail or filament of H I clouds extending away from the galaxy, as well as an isolated H I cloud some 20 kpc to the south of the galaxy. We suggest that these features indicate a minor interaction with a low-mass galaxy. Optical imaging shows a possible dwarf galaxy near the tail, but based on the current data, we cannot confirm any association with ESO 302-G014. Nonetheless, an interaction scenario with some kind of low-mass companion is still supported by the presence of a significant amount of molecular gas, which is almost equal to the stellar mass, and a number of prominent stellar clusters, which suggest recently triggered star formation. Conclusions. These data show that MeerKAT produces exquisite imaging data. The forthcoming full-depth survey observations of ESO 302-G014 and other s le galaxies will, therefore, offer insights into the fate of neutral gas as it moves from the intergalactic medium onto galaxies.
Publisher: Elsevier BV
Date: 05-2013
Publisher: Springer Science and Business Media LLC
Date: 03-10-2019
DOI: 10.1007/S00394-018-1830-Y
Abstract: Intestinal fermentation of inulin-type fructans, including oligofructose, can modulate adiposity, improve energy regulation, and increase mineral absorption. We aimed to determine whether cereal fructans had greater effects on reducing adiposity and improving mineral absorption compared with oligofructose. Thirty-two male Sprague-Dawley rats were randomly assigned to one of four dietary treatments that contained 0% fructan (control), or 5% fructan provided by oligofructose (OF), a barley grain fraction (BGF), or a wheat stem fraction (WSF). After 1 week on the diets, mineral absorption and retention was assessed. At 4 weeks, blood s les were collected for gut hormone analysis, adipose depots were removed and weighed, and caecal digesta was analyzed for pH and short-chain fatty acids (SCFA). The BGF and WSF, but not OF, had lower total visceral fat weights than the Control (p < 0.05). The fructan diets all lowered caecal pH and raised caecal digesta weight and total SCFA content, in comparison to the Control. Caecal propionate levels for OF were similar to the Control and higher for WSF (p < 0.05). Plasma peptide YY and glucagon-like peptide-1 levels were elevated for all fructan groups when compared to Control (p < 0.001) and gastric inhibitory peptide was lower for the WSF compared to the other groups (p < 0.05). The fructan diets improved calcium and magnesium retention, which was highest for WSF (p < 0.05). BGF and WSF in comparison to OF showed differential effects on fermentation, gut hormone levels, and adiposity. Cereal fructan sources have favorable metabolic effects that suggest greater improvements in energy regulation and mineral status to those reported for oligofructose.
Publisher: BMJ
Date: 12-07-2014
DOI: 10.1136/GUTJNL-2014-307264
Abstract: A low FODMAP (Fermentable Oligosaccharides, Disaccharides, Monosaccharides And Polyols) diet reduces symptoms of IBS, but reduction of potential prebiotic and fermentative effects might adversely affect the colonic microenvironment. The effects of a low FODMAP diet with a typical Australian diet on biomarkers of colonic health were compared in a single-blinded, randomised, cross-over trial. Twenty-seven IBS and six healthy subjects were randomly allocated one of two 21-day provided diets, differing only in FODMAP content (mean (95% CI) low 3.05 (1.86 to 4.25) g/day vs Australian 23.7 (16.9 to 30.6) g/day), and then crossed over to the other diet with ≥21-day washout period. Faeces passed over a 5-day run-in on their habitual diet and from day 17 to day 21 of the interventional diets were pooled, and pH, short-chain fatty acid concentrations and bacterial abundance and ersity were assessed. Faecal indices were similar in IBS and healthy subjects during habitual diets. The low FODMAP diet was associated with higher faecal pH (7.37 (7.23 to 7.51) vs. 7.16 (7.02 to 7.30) p=0.001), similar short-chain fatty acid concentrations, greater microbial ersity and reduced total bacterial abundance (9.63 (9.53 to 9.73) vs. 9.83 (9.72 to 9.93) log10 copies/g p<0.001) compared with the Australian diet. To indicate direction of change, in comparison with the habitual diet the low FODMAP diet reduced total bacterial abundance and the typical Australian diet increased relative abundance for butyrate-producing Clostridium cluster XIVa (median ratio 6.62 p<0.001) and mucus-associated Akkermansia muciniphila (19.3 p<0.001), and reduced Ruminococcus torques. Diets differing in FODMAP content have marked effects on gut microbiota composition. The implications of long-term reduction of intake of FODMAPs require elucidation. ACTRN12612001185853.
Publisher: Springer Science and Business Media LLC
Date: 2012
Publisher: Elsevier BV
Date: 10-2011
Abstract: Short-chain fatty acids (SCFAs) maintain human colonic function and may help prevent colonic disease. A study with ileostomists showed that starches acylated with specific SCFAs largely survive passage through the small intestine, but the percentage released in the colon has not been established. The objective was to determine the percentage of ingested esterified butyrate released in the human gastrointestinal tract. The study was a randomized, crossover, controlled trial consisting of baseline and four 2-wk periods during which 16 volunteers consumed diets low in resistant starch plus 20 and 40 g cooked high-amylose maize starch (HAMS: HAMS20 or HAMS40) or butyrylated HAMS (HAMSB20 or HAMSB40) daily. HAMSB20 contained 31.8 mmol esterified butyrate. Complete 48-h fecal collections were made on days 2-3 and 12-13 of each period. Free fecal butyrate concentrations were higher after HAMSB40 than after HAMSB20 (P < 0.005) and HAMS (P < 0.0001) and higher than baseline data (P < 0.0001). Fecal esterified butyrate concentrations were highest in the HAMSB40 (days 12-13 P < 0.0001) group, and concentrations in the HAMSB40 (days 2-3) and HAMSB20 groups were higher than those in the HAMS groups and those at baseline (P < 0.0001). Ingestion of HAMSB20 and HAMSB40 resulted in the release of 26.8 ± 1.0 and 50.2 ± 2.4 mmol butyrate/d (days 12-13) (84.2 ± 3.0% and 79.0 ± 3.1% of total ingested esterified butyrate), respectively, in the gastrointestinal tract. By calculation, ∼57.2% of ingested esterified butyrate was released in the colon. Microbial analysis showed that this release was probably facilitated mainly by Parabacteroides distasonis, which increased in abundance with HAMSB40 (days 12-13) (P < 0.001). This study shows that cooked butyrylated starch delivers esterified butyrate to the human colon effectively and has the potential to improve human bowel health. This trial is registered in the Australian Clinical Trials Registry as ACTRN012606000398505.
Publisher: Frontiers Media SA
Date: 28-07-2022
DOI: 10.3389/FMICB.2022.905901
Abstract: The human gut microbiome has increasingly been associated with autism spectrum disorder (ASD), which is a neurological developmental disorder, characterized by impairments to social interaction. The ability of the gut microbiota to signal across the gut-brain-microbiota axis with metabolites, including short-chain fatty acids, impacts brain health and has been identified to play a role in the gastrointestinal and developmental symptoms affecting autistic children. The fecal microbiome of older children with ASD has repeatedly shown particular shifts in the bacterial and fungal microbial community, which are significantly different from age-matched neurotypical controls, but it is still unclear whether these characteristic shifts are detectable before diagnosis. Early microbial colonization patterns can have long-lasting effects on human health, and pre-emptive intervention may be an important mediator to more severe autism. In this study, we characterized both the microbiome and short-chain fatty acid concentrations of fecal s les from young children between 21 and 40 months who were showing early behavioral signs of ASD. The fungal richness and acetic acid concentrations were observed to be higher with increasing autism severity, and the abundance of several bacterial taxa also changed due to the severity of ASD. Bacterial ersity and SCFA concentrations were also associated with stool form, and some bacterial families were found with differential abundance according to stool firmness. An exploratory analysis of the microbiome associated with pre-emptive treatment also showed significant differences at multiple taxonomic levels. These differences may impact the microbial signaling across the gut-brain-microbiota axis and the neurological development of the children.
No related grants have been discovered for Claus T Christophersen.