ORCID Profile
0000-0003-0338-3441
Current Organisations
CSIRO Health and Biosecurity
,
Flinders University
,
University of Adelaide
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Publisher: Elsevier BV
Date: 10-2017
Publisher: Cambridge University Press (CUP)
Date: 12-09-2009
DOI: 10.1017/S0007114508056031
Abstract: Dietary non-digestible carbohydrates (NDC) play an important role in large-bowel health and one form of NDC, resistant starch (RS), can promote low levels of DNA damage and other markers of colonic health. The objective of the present study was to determine whether the ability of dietary RS or other NDC to influence colonic health, particularly DNA damage, is dependent on the type of dietary oil. We compared the effects of diets containing 10 % of NDC from cellulose, wheat bran, high-amylose maize starch (HAS, a rich source of RS type 2) or a retrograded HAS (RHAS, a rich source of RS type 3) on DNA damage, SCFA production and bacterial changes in the large bowel of rats. Each carbohydrate source was combined with 10 % fish oil (FO) or Sunola™ oil (SO rich in oleic acid). There was a significant interaction between NDC and oil treatments on single-strand DNA breaks in colonocytes isolated from the colon. The damage in rats consuming RHAS was greater for FO consumption than for SO consumption. There was a significant interaction between NDC and oils on caecum weights and treatment effects of NDC and oils were observed for the weights and lengths of other gut tissues. Significant differences were found in colonic SCFA pools and caecal numbers of lactobacilli, bifidobacteria, Escherichia coli and Bacteroides fragilis with the various NDC and oil treatments. The present results demonstrate that the effects of NDC and oils, particularly on colonic DNA damage, can depend on how they are combined within the diet.
Publisher: Informa UK Limited
Date: 03-2006
DOI: 10.4161/CBT.5.3.2382
Abstract: In a previous study we have shown that high levels of dietary protein (as casein) result in increased levels of colonic DNA damage, measured by the comet assay, and thinning of the colonic mucus layer in rats when dietary resistant starch (RS) is negligible. Feeding RS abolishes these effects. This study aimed to establish whether a diet high in protein as cooked red meat would have similar effects and whether RS was protective. Rats were fed a diet containing 15% or 25% casein or 25% cooked lean red beef, each with or without the addition of 48% high amylose maize starch (a rich source of RS) for four weeks. As expected, high dietary casein caused a 2-fold increase in colonic DNA damage compared with a low casein diet and reduced the thickness of the colonic mucus layer by 41%. High levels of cooked meat caused 26% greater DNA damage than the high casein diet but reduced mucus thickness to a similar degree to casein. Addition of RS to the diet abolished the increase in DNA damage and the loss of colonic mucus thickness induced by either high protein diet. Cecal and fecal short chain fatty acid pools were also increased by inclusion of RS in the diet. Because DNA damage is an early step in the initiation of cancer, these findings suggest that increased DNA damage due to high dietary protein as cooked red meat or casein could increase colorectal cancer risk but inclusion of resistant starch in the diet could significantly reduce that risk.
Publisher: Springer Science and Business Media LLC
Date: 24-03-2020
DOI: 10.1038/S41467-020-14552-1
Abstract: In mice, the maternal microbiome influences fetal immune development and postnatal allergic outcomes. Westernized populations have high rates of allergic disease and low rates of gastrointestinal carriage of Prevotella , a commensal bacterial genus that produces short chain fatty acids and endotoxins, each of which may promote the development of fetal immune tolerance. In this study, we use a prebirth cohort ( n = 1064 mothers) to conduct a nested case-cohort study comparing 58 mothers of babies with clinically proven food IgE mediated food allergy with 258 randomly selected mothers. Analysis of the V4 region of the 16S rRNA gene in fecal s les shows maternal carriage of Prevotella copri during pregnancy strongly predicts the absence of food allergy in the offspring. This association was confirmed using targeted qPCR and was independent of infant carriage of P. copri . Larger household size, which is a well-established protective factor for allergic disease, strongly predicts maternal carriage of P. copri .
Publisher: Elsevier BV
Date: 12-2015
Publisher: Elsevier BV
Date: 02-2002
DOI: 10.1093/JN/132.2.145
Abstract: The relationship between nutritional status and insulin-like growth factor binding protein-2 (IGFBP-2) gene expression in chickens was studied. Chickens (6 wk old) were food deprived for 2 d and then refed. IGFBP-2 mRNA in the brain was significantly decreased by food deprivation and levels did not increase when birds were refed for 24 h. Gizzard and hepatic IGFBP-2 mRNA levels were significantly increased by food deprivation and decreased by refeeding. Any nutrients tested decreased hepatic IGFBP-2 gene expression. In kidney, IGFBP-2 mRNA was detected but not influenced by food deprivation and refeeding. In another study, the influence of dietary protein source [isolated soybean protein vs. casein crude protein (CP) 20%] and the supplementation of essential amino acids on IGFBP-2 gene expression of young chickens (5 wk old) was examined. The influence of feeding a low soybean protein diet (CP 5%) on tissue IGFBP-2 gene expression was also investigated. Hepatic IGFBP-2 mRNA was not detected in any group. Feeding the low protein diet for 7 d decreased brain IGFBP-2 mRNA level and increased gizzard IGFBP-2 level compared with chickens fed 20% protein diets. A significant interaction between protein source and amino acid supplementation was observed in gizzard IGFBP-2 mRNA level. In both casein-fed groups and in chickens fed 20% soybean protein diet without supplemental amino acids, the levels did not differ from one another or from the low protein diet-fed birds. The level was lower in chickens fed the amino acid-supplemented, 20% soybean protein diet. In conclusion, the response of IGFBP-2 gene expression to variations in nutritional status was rapid and different in several tissues of young chickens, which would help modulate the growth-promoting effect of circulating IGF-I by making the IGF-IGFBP complex.
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: Wiley
Date: 05-08-2018
Abstract: Dietary supplementation with polyphenol-rich propolis can protect against experimentally induced colitis. We examined whether different polyphenol compositions of Chinese propolis (CP) and Brazilian propolis (BP) influence their ability to protect against dextran sulfate sodium (DSS)-induced colitis in rats. HPLC-DAD/Q-TOF-MS analysis confirmed that polyphenol compositions of CP and BP were dissimilar. Rats were given CP or BP by gavage (300 mg kg Despite the dissimilar polyphenol compositions of CP and BP, their ability to protect against DSS-induced colitis is similar. Nevertheless, some different physiological impacts were observed.
Publisher: AMPCo
Date: 10-2014
DOI: 10.5694/MJA14.01196
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: Oxford University Press (OUP)
Date: 07-09-2007
Abstract: Human population studies show that dietary red and processed, but not white, meats are associated with increased risk of colorectal cancer but dietary fibre appears to be protective. We examined whether dietary cooked red or white meat had differential effects on colonic DNA damage in rats and if resistant starch (RS), a dietary fibre component, provided protection. Rats were fed diets containing approximately 15, 25 or 35% of cooked beef or chicken, both with or without 20% high-amylose maize starch (HAMS) as a source of RS, for 4 weeks. DNA single-strand breaks (SSB) and double-strand breaks (DSB) were measured in isolated colonocytes (by comet assay) along with apoptosis levels, colonic mucus thickness and large bowel short-chain fatty acids (SCFA). Both red and white meat increased colonocyte SSB and DSB dose dependently but damage was substantially greater with red meat. Dietary HAMS prevented these increases. Apoptotic cell numbers were increased dose dependently by red meat irrespective of HAMS feeding, whereas white meat only increased apoptotic cell numbers in the presence of HAMS. Red meat induced greater colonic mucus layer thinning than white meat but HAMS was protective in both cases. HAMS induced increases in large bowel SCFA, including butyrate, and significantly lowered concentrations of phenols and cresols. We have demonstrated that dietary red meat causes greater levels of colonic DNA SSB and DSB than white meat, consistent with the epidemiological data. Dietary RS protects against this damage and also against loss of the mucus barrier, probably through increased butyrate production.
Publisher: Wiley
Date: 18-10-2014
DOI: 10.1002/JSFA.6919
Abstract: Rats used in nutritional studies are often kept in wire-based cages to prevent ingestion of bedding and minimise ingestion of faeces. However, wire-based cages are criticised because of potential negative animal welfare implications. This study investigated the effects of wire and solid-based cages with corncob bedding on large bowel fermentation and microbiota. Rats were group housed in wire or solid-based cages and fed either a low-fibre (LF) diet or a high-fibre (HF) diet composed of resistant starch for 4 weeks. Bedding material was observed in faeces of rats housed in solid-based cages. Caging type and diet altered large bowel fermentation variables and bacterial populations. Caecal digesta weight was lower in rats fed HF diet and maintained on bedding than in HF-fed rats maintained on wire. Bacteria abundance associated with fibre fermentation was higher in LF-diet fed rats maintained on bedding compared with LF-fed rats housed on wire. Maintaining rats in solid-based cages with corncob bedding alters large bowel fermentation and bacterial communities owing to ingestion of bedding. These changes may confound outcomes of nutritional studies, particularly those investigating the health effects of fibres. The use of wire-based caging may be justified in research of this type.
Publisher: Springer Science and Business Media LLC
Date: 29-08-2013
DOI: 10.1007/S10620-013-2844-1
Abstract: Although a genetic component has been identified as a risk factor for developing inflammatory bowel disease, there is evidence that dietary factors also play a role in the development of this disease. The aim of this study was to determine the effects of feeding a red meat diet with and without resistant starch (RS) to mice with dextran sulfate sodium (DSS)-induced colitis. Colonic experimental colitis was induced in Balb/c mice using DSS. The severity of colitis was evaluated based on a disease activity index (based on bodyweight loss, stool consistency, rectal bleeding, and overall condition of the animal) and a histological score. Estimations were made of numbers of a range of different bacteria in the treatment pools of cecal digesta using quantitative real-time PCR. Consumption of a diet high in red meat increased DSS-induced colitis as evidenced by higher disease activity and histopathological scores. Addition of RS to the red meat diet exerted a beneficial effect in acute DSS-induced colitis. Subjective analysis of numbers of a range of bacterial targets suggest changes in the gut microbiota abundance were induced by red meat and RS treatments and these changes could contribute to the reported outcomes. A dietary intake of red meat aggravates DSS-induced colitis whereas co-consumption of resistant starch reduces the severity of colitis.
Publisher: Wiley
Date: 19-01-2007
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: American Medical Association (AMA)
Date: 15-01-2019
Publisher: MDPI AG
Date: 14-08-2017
DOI: 10.3390/NU9080875
Publisher: MDPI AG
Date: 23-09-2013
DOI: 10.3390/NU5093740
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: 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: Informa UK Limited
Date: 2006
Publisher: Bioscientifica
Date: 1995
Abstract: The effects of continuous 14 day infusion of recombinant human IGF-I (104 or 260 μg/day) or IGF-II (104, 260 or 650 μg/day) via s.c. implanted osmotic pumps were compared in young female rats in order to establish the relative efficacies of these two growth factors. Significant increases in body weight gain and feed conversion efficiency were achieved by 260 of IGF-I or 650 μg/day of IGF-II. These treatments were associated with increased nitrogen retention and increases in the fractional weights of kidneys, spleen, total gut and in idual gut regions. There was an increase in the size of villi and muscularis lining the jejunum, suggesting an increased absorptive capacity of the gut. However there was no significant change in the amount of faecal nitrogen excretion when expressed as a percentage of nitrogen intake. Interestingly, IGF-II was at least as potent as IGF-I in increasing the depth of jejunal crypts. Infusion of equivalent doses of either IGF-I or IGF-II resulted in similar increases in circulating concentrations of the respective peptides, though IGF-II infusion dosedependently decreased plasma IGF-I concentrations from those of the controls. Plasma IGF-binding protein levels were increased by both IGF-I and IGF-II treatments, though IGF-I elicited greater responses. In summary, IGF-II can promote the growth of young female rats, although generally less potently than IGF-I. Journal of Endocrinology (1995) 144, 91–98
Publisher: Royal Society of Chemistry (RSC)
Date: 2016
DOI: 10.1039/C6FO90009G
Abstract: Guest editors Michael Conlon and David Topping introduce this themed collection on foods, the large bowel microbiota and health outcomes.
Publisher: Hindawi Limited
Date: 14-11-2018
DOI: 10.1155/2018/7862782
Publisher: MDPI AG
Date: 28-02-2020
DOI: 10.3390/NU12030644
Abstract: Oil palm fruit is widely used for edible oils, but the health benefits of other components are relatively unknown. We examined if consuming a polyphenol-rich extract of the fruit, from a vegetation by-product of oil processing, which also contains fibre, has gastro-intestinal benefits in rats on a Western-type diet (WD). The oil palm preparation (OPP) was added to food (OPP-F) or drinking water (OPP-D) to provide 50 mg of gallic acid equivalents (GAE)/d and compared to effects of high amylose maize starch (HAMS 30%) in the diet or green tea extract (GT 50 mg GAE/d) in drinking water over 4 wk. OPP treatments induced some significant effects (P 0.05) compared to WD. OPP-D increased caecal digesta mass, caecal digesta concentrations of total SCFA, acetate and propionate (OPP-F increased caecal butyrate concentration), the numbers of mucus-producing goblet cells per colonic crypt, and caecal digesta abundance of some bacteria which may provide benefit to the host (Faecalibacterium prausnitzii, Akkermansia muciniphila and Ruminococcus gnavus). HAMS induced similar effects but with greater potency and had a broader impact on microbe populations, whereas GT had minimal impacts. These results suggest dietary OPP may benefit the large bowel.
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: Bioscientifica
Date: 02-1993
Abstract: The presence of insulin-like growth factor-I (IGF-I)-related molecules and IGF-binding factors in blood from golden perch, Macquaria ambigua , an Australian native freshwater fish, was investigated. Serum was acidified to dissociate IGF and IGF-binding protein complexes that might be present, and fractionated by size-exclusion high-performance liquid chromatography at pH 2·8. Fractions were neutralized and their activities assessed by (i) an immunoassay for mammalian IGF-I which also detects chicken IGF-I but in which all known forms of IGF-II react very poorly, (ii) a receptor assay for IGF-II in which all known forms of IGF-I react poorly, and (iii) a type-I IGF receptor assay in which mammalian IGF-I and IGF-II polypeptides are almost equivalent. No IGF-II-like activity was detected. Three peaks of IGF-I-like activity were detected by IGF-I immunoassay and type-I IGF receptor assay. The major peak of activity was similar in molecular size to human IGF-binding protein-3, 45–55 kDa ('large IGF'), and a minor peak of activity which was similar in size to mammalian IGFs, 7·5 kDa. A third peak of activity was observed eluting at a time which indicates that it is a smaller molecule than any previously described IGF. The large IGF was temperature-sensitive, but was not a binding protein for 125 I-labelled human IGF-I (hIGF-I). This material therefore was able to bind to anti-hIGF-I antibodies and to human type-I IGF receptors, and may represent the fish equivalent of mammalian prepro-IGFs. The two smallest forms of IGF activity identified by IGF-I radioimmunoassay and type-I radioreceptor assay following acidic size-exclusion chromatography were able to stimulate protein synthesis by L-6 myoblasts in culture, although large IGF did not. When fresh (but not frozen and thawed) golden perch serum was incubated with 125 I-labelled hIGF-I and then fractionated by size-exclusion liquid chromatography at pH 7·4 through Sephadex G-100, the radioactivity became associated with a complex, intermediate in size between free IGF-I and the major IGF-binding protein in human serum. The association of 125 I-labelled hIGF-I with the complex was inhibited by the presence of unlabelled hIGF-I in the incubation. These studies show that receptor-active, immunoreactive and bioactive IGF-I-like activity is present in golden perch serum, and demonstrate the presence of an IGF-I-binding factor in this species. Journal of Endocrinology (1993) 136, 191–198
Publisher: American Association for Cancer Research (AACR)
Date: 11-2011
DOI: 10.1158/1940-6207.CAPR-11-0176
Abstract: Population studies have shown that high red meat intake may increase colorectal cancer risk. Our aim was to examine the effect of different amounts and sources of dietary protein on induction of the promutagenic adduct O6-methyl-2-deoxyguanosine (O6MeG) in colonocytes, to relate these to markers of large bowel protein fermentation and ascertain whether increasing colonic carbohydrate fermentation modified these effects. Mice (n = 72) were fed 15% or 30% protein as casein or red meat or 30% protein with 10% high amylose maize starch as the source of resistant starch. Genetic damage in distal colonocytes was detected by immunohistochemical staining for O6MeG and apoptosis. Feces were collected for measurement of pH, ammonia, phenols, p-cresol, and short-chain fatty acids (SCFA). O6MeG and fecal p-cresol concentrations were significantly higher with red meat than with casein (P & 0.018), with adducts accumulating in cells at the crypt apex. DNA adducts (P & 0.01) and apoptosis (P & 0.001) were lower and protein fermentation products (fecal ammonia, P & 0.05 phenol, P & 0.0001) higher in mice fed resistant starch. Fecal SCFA levels were also higher in mice fed resistant starch (P & 0.0001). This is the first demonstration that high protein diets increase promutagenic adducts (O6MeG) in the colon and dietary protein type seems to be the critical factor. The delivery of fermentable carbohydrate to the colon (as resistant starch) seems to switch from fermentation of protein to that of carbohydrate and a reduction in adduct formation, supporting previous observations that dietary resistant starch opposes the mutagenic effects of dietary red meat. Cancer Prev Res 4(11) 1920–8. ©2011 AACR.
Publisher: Informa UK Limited
Date: 05-2012
DOI: 10.4161/GMIC.19579
Publisher: Bioscientifica
Date: 08-1995
Abstract: We have tested whether an animal with substantial amounts of both IGF-I and IGF-II in circulation, such as the guinea pig, would respond to chronic IGF infusion in the same manner as the adult rat, which has negligible amounts of IGF-II in blood. Female guinea pigs of 350 g body weight were continuously infused for 7 days with recombinant guinea pig IGF-I or -II (120 or 360 μg/day) or long R 3 IGF-I (LR 3 IGF-I) (120 μg/day), an analogue which has much reduced affinities for IGF binding proteins. IGF-I or IGF-II infusion led to substantial increases in plasma IGF-I or IGF-II respectively in comparison with vehicle-infused animals. Nevertheless, body weight gain, feed intake, feed conversion efficiency and carcass composition were not significantly affected by any treatment (significance was deemed to be P ·05). Amongst the tissues examined only the fractional weight (g/kg body weight) of the adrenals was increased, and that only by the higher dose (360 μg/day) of IGF-I. However, the fractional weight of adrenals, gut, kidneys and spleen were significantly increased by LR 3 IGF-I, but again overall growth was not stimulated. A possible explanation for the lack of IGF-I effects is that total circulating IGF concentrations were not increased by these treatments. IGF-II significantly raised total IGF concentrations at the higher dose only. Plasma IGF-I was reduced by IGF-II infusion, as was plasma IGF-II by IGF-I infusion. LR 3 IGF-I treatment lowered both plasma IGF-I and IGF-II concentrations, a response probably related to a reduction in total plasma IGF binding protein (IGFBP), especially IGFBP-3, concentrations. We conclude that although the guinea pig is responsive to IGF treatment, the effects differ markedly from those elicited in rats. Journal of Endocrinology (1995) 146, 247–253
Publisher: SAGE Publications
Date: 04-2011
Abstract: This qualitative study is part of a broader study that explored how adjunct foreign English-language teachers (AFELT) in the Japanese university sector conceptualize their role against the backdrop of internationalization. Forty-three teachers across a range of universities participated in this study. The results report on AFELT perceptions of higher education in Japan, teaching English and the role of AFELT in that context, and reveal a discontinuity between the governmental rhetoric of internationalization concerning English-language education and how this is enacted at the institutional level.
Publisher: Springer Science and Business Media LLC
Date: 02-2006
DOI: 10.1007/S10620-006-3121-3
Abstract: We have shown independently that dietary fiber and n-3 fatty acids can affect gut function. This study investigated the interactive effects of resistant starch (RS) (as high amylose maize starch [HAMS]) and tuna fish oil on ileal contractility. Four-week-old male Sprague Dawley rats were fed 4 diets that contained 100 g/kg fat as sunflower oil or tuna fish oil, with 10% fiber supplied as alpha -cellulose or HAMS for 6 weeks. Fish oil feeding led to higher ileal n-3 fatty acid levels (mainly as DHA) and higher agonist-induced maximal contractility with an RS effect noted for carbachol. HAMS-containing diets resulted in lower colonic pH and higher total short-chain fatty acids (SCFA), but not for butyrate with fish oil. Low prostanoid responses in young rats were enhanced by fish oil independent of RS. The order of muscarinic receptor subtype responses were different compared to older rats fish oil feeding altered the sensitivity of the M(1) receptor subtype. Although little interactive effects were demonstrated, these data suggest developmental changes in ileal receptor systems with independent effects of RS and fish oil on some bowel properties in juvenile rats.
Publisher: American Association for Cancer Research (AACR)
Date: 08-2014
DOI: 10.1158/1940-6207.CAPR-14-0053
Abstract: High red meat (HRM) intake is associated with increased colorectal cancer risk, while resistant starch is probably protective. Resistant starch fermentation produces butyrate, which can alter microRNA (miRNA) levels in colorectal cancer cells in vitro effects of red meat and resistant starch on miRNA expression in vivo were unknown. This study examined whether a HRM diet altered miRNA expression in rectal mucosa tissue of healthy volunteers, and if supplementation with butyrylated resistant starch (HRM+HAMSB) modified this response. In a randomized cross-over design, 23 volunteers undertook four 4-week dietary interventions an HRM diet (300 g/day lean red meat) and an HRM+HAMSB diet (HRM with 40 g/day butyrylated high amylose maize starch), preceded by an entry diet and separated by a washout. Fecal butyrate increased with the HRM+HAMSB diet. Levels of oncogenic mature miRNAs, including miR17–92 cluster miRNAs and miR21, increased in the rectal mucosa with the HRM diet, whereas the HRM+HAMSB diet restored miR17–92 miRNAs, but not miR21, to baseline levels. Elevated miR17–92 and miR21 in the HRM diet corresponded with increased cell proliferation, and a decrease in miR17–92 target gene transcript levels, including CDKN1A. The oncogenic miR17–92 cluster is differentially regulated by dietary factors that increase or decrease risk for colorectal cancer, and this may explain, at least in part, the respective risk profiles of HRM and resistant starch. These findings support increased resistant starch consumption as a means of reducing risk associated with an HRM diet. Cancer Prev Res 7(8) 786–95. ©2014 AACR.
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: 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: 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: Springer Science and Business Media LLC
Date: 12-10-2015
Publisher: Informa UK Limited
Date: 28-04-2010
DOI: 10.1080/01635580903532382
Abstract: Dietary red and processed meats may increase risk of colorectal cancer (CRC), whereas fiber may be protective. Recently, we demonstrated that dietary beef causes greater colonic DNA strand breakage than equivalent levels of chicken in rats and that resistant starch (RS) as 20% high amylose maize starch (HAMS) attenuated the damage. From that study, we now report measures of circulating factors that may influence CRC initiation or progression including malondialdehyde (MDA), leptin, insulin-like growth factor-I (IGF-I), insulin, matrix metalloproteinase-2 (MMP-2), tissue inhibitor of MMP-2 (TIMP-2), interleukins (IL), and short chain fatty acids. MDA levels were increased by beef diets relative to the chicken diets. Leptin concentrations, which were lower for chicken than beef at the 35% level in the absence of HAMS, were lowered by HAMS. Higher dietary chicken (but not beef) increased IGF-I irrespective of HAMS feeding. Higher levels of chicken resulted in greater insulin concentrations than for beef in rats fed HAMS. Without dietary HAMS, TIMP-2 concentration increased in response to both meats but was highest for chicken. MMP-2 and TIMP-2 concentrations were higher for HAMS diets. IL-1beta and IL-12 concentrations were lowered by HAMS feeding. Colonic DNA strand breakage was positively associated with circulating leptin and MDA concentrations as well as tissue MDA concentrations and negatively associated with plasma TIMP-2 concentration. MMP-2 and TIMP-2 positively correlated with hepatic portal butyrate levels but leptin concentrations correlated negatively. These results suggest diets high in meat or RS could influence cancer initiation or progression by changes in circulating levels of hormones and other factors.
Publisher: Wiley
Date: 2003
Publisher: Elsevier BV
Date: 05-2011
Abstract: Butyrate and other SCFA produced by bacterial fermentation of resistant starch (RS) or nonstarch polysaccharides (NSP) promote human colonic health. To examine variation in fecal variables, especially butyrate, among in iduals and the response to these fibers, a randomized cross-over study was conducted that compared the effects of foods supplying 25 g of NSP or 25 g of NSP plus 22 g of RS/d over 4 wk in 46 healthy adults (16 males, 30 females age 31-66 y). Fecal SCFA levels varied widely among participants at entry (butyrate concentrations: 3.5-32.6 mmol/kg butyrate excretions: 0.3-18.2 mmol/48 h). BMI explained 27% of inter-in idual butyrate variation, whereas protein, starch, carbohydrate, fiber, and fat intake explained up to 16, 6, 2, 4, and 2% of butyrate variation, respectively. Overall, acetate, butyrate, and total SCFA concentrations were higher when participants consumed RS compared with entry and NSP diets, but in idual responses varied. In idual and total fecal SCFA excretion, weight, and moisture were higher than those for habitual diets when either fiber diet was consumed. SCFA concentrations (except butyrate) and excretions were higher for males than for females. Butyrate levels increased in response to RS in most in iduals but often decreased when entry levels were high. Fecal butyrate and ammonia excretions were positively associated ((2) = 0.76 P < 0.001). In conclusion, fecal butyrate levels vary widely among in iduals but consuming a diet high in RS usually increases levels and may help maintain colorectal health.
Publisher: Informa UK Limited
Date: 2008
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: 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: MDPI AG
Date: 24-12-2015
DOI: 10.3390/NU7010017
Publisher: Elsevier BV
Date: 2018
Publisher: Wiley
Date: 10-2013
Abstract: Red meat is considered a risk factor for colorectal cancer (CRC). Heme is considered to promote colonic hyperproliferation and cell damage. Resistant starch (RS) is a food that ferments in the colon with studies demonstrating protective effects against CRC. By utilizing the western diet model of spontaneous CRC, we determined if feeding heme (as hemin chloride) equivalent to a high red meat diet would increase colonic DNA adducts and CRC and whether RS could abrogate such effects. Four groups of mice: control, heme, RS and heme + RS were fed diets for 1 or 18 months. Colons were analyzed for apoptosis, proliferation, DNA adducts "8-hydroxy-2-deoxyguanosine" and "O(6) -methyl-2-deoxyguanosine" (O(6) MeG), and neoplasms. In the short term, heme increased cell proliferation (p < 0.05). Changes from 1 to 18 months showed increased cell proliferation (p < 0.01) and 8-hydroxy-2-deoxyguanosine adducts (p < 0.05) in all groups, but only heme-fed mice showed reduced apoptosis (p < 0.01) and increased O(6) MeG adducts (p < 0.01). The incidence of colon neoplasms was not different between any interventions. We identified heme to increase proliferation in the short term, inhibit apoptosis over the long term, and increase O(6) MeG adducts in the colon over time although these changes did not affect colonic neoplasms within this mouse model.
Publisher: American Chemical Society (ACS)
Date: 29-04-2011
DOI: 10.1021/JF200859Z
Abstract: This study examined the role of degree of polymerization (DP) of inulin-fructans in modulating the interaction between lactic acid bacteria and IgA cecal secretion. Rats were fed a control diet or a diet containing one of the fructans with different DP. Consuming fructans increased the cecal IgA concentrations in the order DP4 > DP8 > DP16. Cecal lactobacilli counts were higher in DP4, DP8, and DP16, whereas bifidobacteria were higher in DP8, DP16, and DP23. Cecal IgA concentrations were correlated with cecal lactobacilli counts (P < 0.01). DP4, DP8, and DP16, but not DP23, significantly increased IgA-producing plasma cells in the cecal mucosa. IFN-γ and IL-10 production in the cecal CD4(+) T cells was enhanced solely in DP4. The results show that fructans with lower DP enhance cecal IgA secretion and increase the plasma cells and suggest that the increased lactobacilli may contribute to the stimulation of cecal IgA secretion.
Publisher: Springer Science and Business Media LLC
Date: 27-04-2017
Publisher: Informa UK Limited
Date: 2005
DOI: 10.1207/S15327914NC5101_7
Abstract: Epidemiologic studies suggest that dietary complex carbohydrates are protective against colorectal cancer but dietary protein may increase risk. However, experimental data to support these relationships are scant. We have shown in rats that consumption of a high-protein (25% casein) diet for 4 wk resulted in a twofold increase in damage to colonocyte DNA compared with a low-protein (15% casein) diet. This was associated with thinning of the colonic mucous barrier and increased levels of fecal p-cresol. Addition of resistant starch as a high-amylose maize starch to the diet increased cecal short-chain fatty acid pools and attenuated DNA damage, suggesting protection against genotoxic agents. In humans, this could translate to altered risk of colonic cancer.
Publisher: Springer Science and Business Media LLC
Date: 03-02-2023
Publisher: Springer International Publishing
Date: 2016
Publisher: American Medical Association (AMA)
Date: 11-06-2019
Publisher: Springer Science and Business Media LLC
Date: 22-08-2018
DOI: 10.1038/S41467-018-05619-1
Abstract: Honeybee caste development is nutritionally regulated by royal jelly (RJ). Major royal jelly protein 1 (MRJP1), the most abundant glycoprotein among soluble royal jelly proteins, plays pivotal roles in honeybee nutrition and larvae development, and exhibits broad pharmacological activities in humans. However, its structure has long remained unknown. Herein, we identify and report a 16-molecule architecture of native MRJP1 oligomer containing four MRJP1, four apisimin, and eight unanticipated 24-methylenecholesterol molecules at 2.65 Å resolution. MRJP1 has a unique six-bladed β-propeller fold with three disulfide bonds, and it interacts with apisimin mainly by hydrophobic interaction. Every four 24-methylenecholesterol molecules are packaged by two MRJP1 and two apisimin molecules. This assembly dimerizes to form an H-shaped MRJP1 4 -apisimin 4 -24-methylenecholesterol 8 complex via apisimin in a conserved and pH-dependent fashion. Our findings offer a structural basis for understanding the pharmacological effects of MRJPs and 24-methylenecholesterol, and provide insights into their unique physiological roles in bees.
Publisher: Hindawi Limited
Date: 2017
DOI: 10.1155/2017/6134909
Publisher: Informa UK Limited
Date: 12-1998
Abstract: 1. We examined the influence of refeeding after 2 d of fasting on plasma insulin-like growth factor-I (IGF-I) concentration and hepatic IGF-I gene expression in chickens at 6 weeks of age. 2. Hepatic IGF-I mRNA was measured by ribonuclease protection assay and plasma IGF-I concentration was determined by radioimmunoassay. 3. Plasma IGF-I concentration decreased following fasting, increased to the level of fed controls after 2 h of refeeding but then fell back to the level of fasted chickens after 6 h of refeeding. 4. Fasting reduced hepatic IGF-I mRNA concentrations to less than half of those in the fed controls. Refeeding increased IGF-I mRNA sharply at 2 h after refeeding, but by 6 h after refeeding they had taller back again to levels significantly lower than at 2 h. 5. A significant correlation between plasma IGF-I concentration and hepatic IGF-I gene expression was found, suggesting that when chicks are refed after 2 d of fasting, the short-term increase in plasma IGF-I concentration may be partly regulated by the alteration in hepatic IGF-I mRNA.
Publisher: Elsevier BV
Date: 06-2016
Publisher: Cambridge University Press (CUP)
Date: 28-06-2009
Publisher: MDPI AG
Date: 07-05-2016
DOI: 10.3390/NU8050272
Publisher: Bioscientifica
Date: 03-1991
Abstract: The relationship between plasma concentrations of normally secreted GH and insulin-like growth factor-I (IGF-I) was investigated in pigs after weaning. Frequent blood s ling for between 12 and 24 h showed that plasma GH was pulsatile in pigs of 10, 20 and 35 kg liveweight. Pulses were brief in duration, low in litude and variable in frequency. Basal and average daily plasma concentrations of GH changed significantly with development, increasing by about 50% between 10 and 20 kg liveweight. Concentrations of IGF-I in plasma showed little or no evidence of diurnal periodicity and were not increased by GH pulses. Average daily concentrations of both IGF-I and IGF-II in plasma progressively increased between 10 and 35 kg liveweight, as did the total desaturated IGF-binding protein (IGFBP) activity of plasma. A strong positive correlation was observed between the total concentration of IGFs (IGF-I plus IGF-II) in the circulation and plasma IGFBP activity. The developmental rise in IGFBP activity of plasma was associated with increased labelling with 125 I-labelled human IGF-II in ligand blots of binding proteins of apparent molecular masses 200, 50, 43 and 29 kDa. One class of binding proteins of 34·5 kDa decreased with development. This study of young growing pigs shows that normally secreted endogenous GH exerts no significant immediate control over plasma IGF-I concentrations, and that plasma levels of IGF-I and IGF-II increase with maturation in this species. The close relationship between the concentrations of IGFs and IGFBPs in plasma is consistent with recent evidence indicating that binding proteins partially regulate the levels of IGF-I and IGF-II in blood by controlling their rates of clearance from the circulation. Journal of Endocrinology (1991) 128, 439–447
Publisher: Wageningen Academic Publishers
Date: 02-04-2010
Publisher: Elsevier BV
Date: 10-2002
Publisher: Wiley
Date: 11-08-2015
DOI: 10.1111/APT.13366
Abstract: Faecal microbial transplant (FMT) for recurrent Clostridium difficile infection (rCDI) is greatly facilitated by frozen stool banks. However, the effect of frozen storage of stool for greater than 2 months on the viability of stool bacteria is unknown and the efficacy of FMT is not clear. To evaluate the viability of bacteria in stool frozen for up to 6 months, and the clinical efficacy of FMT with stool frozen for 2-10 months, for the treatment of rCDI. Viability of six representative groups of faecal bacteria after 2 and 6 months of storage at -80 °C, in normal saline (NS) or 10% glycerol were assessed by culture on plate media. The clinical outcomes of 16 consecutive patients with rCDI treated with aliquots of stool frozen in 10% glycerol and stored for 2-10 months were also examined. Viability at both 2 and 6 months was similar to baseline, in specimens stored in 10% glycerol and at 2 months in stool stored in NS, but was reduced by >1 log at 6 months for Aerobes (P < 0.01), total Coliforms (P < 0.01) and Lactobacilli (P < 0.01) in NS. Using stool frozen for 2-10 months in 10% glycerol, the cure rate for rCDI was 88% with one FMT and 100% after repeat FMT in those who relapsed. Stool for faecal microbial transplant to treat rCDI can be safely stored frozen in 10% glycerol for at least 6 months without loss of clinical efficacy or viability in the six bacterial groups tested.
Publisher: Cambridge University Press (CUP)
Date: 03-2007
DOI: 10.1017/S0007114507336817
Abstract: Feeding higher levels of dietary animal protein (as casein or red meat) increases colonic DNA damage and thins the colonic mucus barrier in rats. Feeding resistant starch (RS) reverses these changes and increases large bowel SCFA. The present study examined whether high dietary dairy (casein or whey) or plant (soya) proteins had similar adverse effects and whether dietary RS was protective. Adult male rats were fed diets containing 15 or 25 % casein, whey or soya protein with or without 48 % high amylose starch (as a source of RS) for 4 weeks. DNA damage was measured in isolated colonocytes using the comet assay. Higher dietary casein and soya (but not whey) increased colonocyte DNA damage. DNA damage was highest with soya when fed at 15 or 25 % protein without RS. Dietary RS attenuated protein-induced colonocyte DNA damage in all groups but it remained significantly higher in rats fed 25 % soya compared with those fed 15 % protein. Dietary protein level did not affect colonic mucus thickness overall but the barrier was thinner in rats fed high dietary casein. This effect was reversed by feeding RS. Caecal total SCFA and butyrate pools were higher in rats fed RS compared with digestible starch. Caecal and faecal SCFA were unrelated to genetic damage but correlated with mucus thickness. The present data confirm that higher dietary protein affected colonocyte DNA and colonic mucus thickness adversely but that proteins differ in their effects on these indices of colon health. The data show also that these changes were reversed by RS.
Publisher: Cambridge University Press (CUP)
Date: 24-11-2011
DOI: 10.1017/S0007114511004338
Abstract: Population studies show that greater red and processed meat consumption increases colorectal cancer risk, whereas dietary fibre is protective. In rats, resistant starches (a dietary fibre component) oppose colonocyte DNA strand breaks induced by high red meat diets, consistent with epidemiological data. Protection appears to be through SCFA, particularly butyrate, produced by large bowel carbohydrate fermentation. Arabinoxylans are important wheat fibre components and stimulate large bowel carbohydrate SCFA production. The present study aimed to determine whether an arabinoxylan-rich fraction (AXRF) from wheat protected colonocytes from DNA damage and changed colonic microbial composition in pigs fed with a diet high (30 %) in cooked red meat for 4 weeks. AXRF was primarily fermented in the caecum, as indicated by higher tissue and digesta weights and higher caecal (but not colonic) acetate, propionate and total SCFA concentrations. Protein fermentation product concentrations (caecal p- cresol and mid- and distal colonic phenol) were lower in pigs fed with AXRF. Colonocyte DNA damage was lower in pigs fed with AXRF. The microbial profiles of mid-colonic mucosa and adjacent digesta showed that bacteria affiliating with Prevotella spp. and Clostridial cluster IV were more abundant in both the mucosa and digesta fractions of pigs fed with AXRF. These data suggest that, although AXRF was primarily fermented in the caecum, DNA damage was reduced in the large bowel, occurring in conjunction with lower phenol concentrations and altered microbial populations. Further studies to determine the relationships between these changes and the lowering of colonocyte DNA damage are warranted.
Publisher: Oxford University Press (OUP)
Date: 12-2008
DOI: 10.1111/J.1574-6941.2008.00527.X
Abstract: To further understand how diets containing high levels of fibre protect against colorectal cancer, we examined the effects of diets high in nonstarch polysaccharides (NSP) or high in NSP plus resistant starch (RS) on the composition of the faecal microbial community in 46 healthy adults in a randomized crossover intervention study. Changes in bacterial populations were examined using denaturing gradient gel electrophoresis (DGGE) of 16S rRNA gene fragments. Bacterial profiles demonstrated changes in response to the consumption of both RS and NSP diets [analysis of similarities (ANOSIM): R=0.341-0.507, P<0.01]. A number of different DGGE bands with increased intensity in response to dietary intervention were attributed to as-yet uncultivated bacteria closely related to Ruminococcus bromii. A real-time PCR assay specific to the R. bromii group was applied to faecal s les from the dietary study and this group was found to comprise a significant proportion of the total community when in iduals consumed their normal diets (4.4+/-2.6% of total 16S rRNA gene abundance) and numbers increased significantly (+/-67%, P<0.05) with the RS, but not the NSP, dietary intervention. This study indicates that R. bromii-related bacteria are abundant in humans and may be significant in the fermentation of complex carbohydrates in the large bowel.
Publisher: Elsevier BV
Date: 02-2012
DOI: 10.1016/J.CLNU.2011.09.003
Abstract: Population studies indicate that greater red meat consumption increases colorectal cancer risk while dietary fibre is protective. Previous work in rats showed that diets high in protein, including red meat, increase colonocyte DNA strand breaks and that this effect is attenuated by resistant starches (RS). Telomeres are long hexamer repeats that protect against spontaneous DNA damage which would lead to chromosomal instability. Telomere shortening is associated with greater risk of colorectal cancer. The current study aimed to determine the effects of cooked red and white meat intake on colonocyte telomere length in rats and whether dietary RS modified their effects. After four weeks of feeding cooked beef or chicken at 15, 25 and 35% of diet with or without RS, colonocyte telomere length was measured. Telomere length decreased in proportion to red meat content of the diet. A similar trend was observed in the white meat group. Colonocyte telomere shortening due to increased dietary meat was attenuated by the inclusion of RS. These data support previous findings of increased colonocyte DNA damage with greater red and white meat intake and also the protective effect of dietary fibre.
Publisher: Elsevier BV
Date: 09-2001
Publisher: F1000 Research Ltd
Date: 16-05-2016
DOI: 10.12688/F1000RESEARCH.8090.1
Abstract: Intravital imaging is providing new insights into the dynamics of tumor progression in native tissues and has started to reveal the layers of complexity found in cancer. Recent advances in intravital imaging have allowed us to look deeper into cancer behavior and to dissect the interactions between tumor cells and the ancillary host niche that promote cancer development. In this review, we provide an insight into the latest advances in cancer biology achieved by intravital imaging, focusing on recently discovered mechanisms by which tumor cells manipulate normal tissue to facilitate disease progression.
Publisher: Elsevier BV
Date: 12-2017
Publisher: Informa UK Limited
Date: 02-2007
DOI: 10.4161/CBT.6.2.3627
Abstract: Previous studies have shown increased levels of colonocyte DNA damage (as measured by the comet assay) and thinning of the colonic mucus layer in rats fed higher dietary protein as casein or red meat with highly digestible starch. Feeding resistant starch (RS) as high amylose maize starch (HAMS) opposed these changes. However, the dietary level of HAMS was relatively high (48% by weight) so this study was conducted to establish whether HAMS had the same effects at lower dietary levels. Adult male rats were fed a diet containing 25% casein with 0%, 10%, 20%, 30% or 40% HAMS for 4 wk. DNA single strand breaks and 8-hydroxyguanosine levels were measured in isolated colonocytes by the comet assay. As expected, comet tail moment was greatest and the mucus barrier thinnest in rats fed 0% HAMS. DNA damage was reduced and the mucus barrier thickened in a logarithmic dose-dependent manner by HAMS. There was no significant difference in 8-hydroxyguanosine between dietary groups. Caecal and fecal short chain fatty acid (SCFA) pools rose with the increased level of dietary HAMS. DNA damage of colonocytes correlated negatively with caecal SCFA but the strongest correlation was with caecal butyrate, which is consistent with the proposed role of this SCFA in promoting a normal cell phenotype. These data show that HAMS prevents protein-induced colonic DNA damage in a dose-dependent manner. Inclusion of 10% HAMS was found to be sufficient to oppose colonocyte DNA damage, and to increase caecal and fecal SCFA pools.
No related grants have been discovered for Michael Conlon.