ORCID Profile
0000-0002-8194-936X
Current Organisation
Universität Ulm
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Publisher: Authorea, Inc.
Date: 13-05-2022
DOI: 10.22541/AU.165244698.86280644/V1
Abstract: Daily light-dark cycles shape the activity patterns and physiology of nearly all organisms. Many biological processes undergo circadian rhythms, yet rhythms in immunity and metabolism are particularly important for the maintenance of biological homeostasis. Recent evidence that food intake and the gut bacterial microbiota synchronise system-wide circadian rhythms spanning immunity, metabolism, and behaviour point towards gut microbial oscillations being a crucial component of microbiome function. Findings from model systems suggest that gut microbial oscillations are likely widespread across species and pivotal for shaping immune and metabolic responses, yet their prevalence and functional significance are rarely tested in natural populations. Here we summarize results from experimental studies on how circadian interactions between the gut microbiota and the host act to synchronise rhythms in host metabolism and immunity. We outline how these circadian interactions are likely to mediate erse biological processes, including host pathogen susceptibility and seasonal switches in metabolism, and discuss how the breakdown of these interactions, for ex le during senescence and urbanisation, can lead to dysbiosis and declines in health. Lastly, we provide practical guidelines for the measurement of microbial oscillations in wildlife, highlighting that whilst wild animals are rarely available over a 24-hour period, characterising even parts of the cycle can be informative. Light-dark cycles are an almost universal environmental cue that provide a rare opportunity to generalise gut microbial responses across species, yet to fully appreciate their ecological relevance an understanding of how microbial rhythms manifest in wildlife is essential.
Publisher: Hindawi Limited
Date: 29-08-2022
DOI: 10.1111/TBED.14679
Abstract: Infections with Tuberculosis (TB)-causing agents of the Mycobacterium tuberculosis complex threaten human, livestock, and wildlife health globally due to the high capacity to cross trans-species boundaries. Tuberculosis is a cryptic disease characterized by prolonged, sometimes lifelong subclinical infections, complicating disease monitoring. Consequently, our understanding of infection risk, disease progression, and mortality across species affected by TB remains limited. The TB agent Mycobacterium suricattae was first recorded in the late 1990s in a wild population of meerkats inhabiting the Kalahari in South Africa and has since spread considerably, becoming a common cause of meerkat mortality. This offers an opportunity to document the epidemiology of naturally spreading TB in a wild population. Here, we synthesize more than 25 years-worth of TB reporting and social interaction data across 3,420 in iduals to track disease spread, and quantify rates of TB social exposure, progression, and mortality. We found that most meerkats had been exposed to the pathogen within eight years of first detection in the study area, with exposure reaching up to 95% of the population. Approximately one quarter of exposed in iduals progressed to clinical TB stages, followed by physical deterioration and death within a few months. Since emergence, 11.6% of deaths were attributed to TB, although the true toll of TB-related mortality is likely higher. Lastly, we observed marked variation in disease progression among in iduals, suggesting inter-in idual differences in both TB susceptibility and resistance. Our results highlight that TB prevalence and mortality could be higher than previously reported, particularly in species or populations with complex social group dynamics. Long-term studies, such as the present one, allow us to assess temporal variation in disease prevalence and progression and quantify exposure, which is rarely measured in wildlife. Long-term studies are highly valuable tools to explore disease emergence and ecology, and study host-pathogen co-evolutionary dynamics in general, and its impact on social mammals. This article is protected by copyright. All rights reserved.
Publisher: Wiley
Date: 20-01-2023
Abstract: Daily light–dark cycles shape the circadian physiology and behaviour of nearly all organisms, with variation in circadian phenotypes having cascading effects on in idual fitness, species interactions and species co‐evolution. Recent evidence that circadian rhythms in host immunity and metabolism are synchronised by the gut microbiota suggest that the circadian dynamics of gut microbes are a crucial component of their function. However, there remains little knowledge or understanding of the diurnal dynamics of gut microbiomes in natural populations or the consequences for host physiology and ecology. Here, we summarise the hallmarks of gut microbiota oscillations reported to date and the mechanisms by which they synchronise rhythms in host immunity and metabolism. We outline the consequences for erse biological processes such as host pathogen susceptibility and seasonal switches in metabolism, and discuss how the breakdown of these circadian interactions, for ex le during senescence or because of light pollution, may affect wildlife infection risk and disease. We also provide practical guidelines for the measurement of microbial oscillations in wildlife, highlighting that whilst faecal s les of wild animals are rarely available over a 24‐h period, characterising even parts of the gut microbial cycle can be informative. An improved understanding of how gut microbial diurnal rhythms manifest in wildlife is essential to fully comprehend their role in shaping variation in host circadian phenotypes and the consequences for host physiology and ecology. Read the free Plain Language Summary for this article on the Journal blog.
Publisher: Authorea, Inc.
Date: 23-05-2022
DOI: 10.22541/AU.165244698.86280644/V2
Abstract: Daily light-dark cycles shape the physiology and activity patterns of nearly all organisms. Recent evidence that gut microbial oscillations synchronise circadian rhythms in host immunity and metabolism indicate that diurnal dynamics is a crucial component of microbiome function. However, their prevalence and functional significance are rarely tested in natural populations. Here we summarize the hallmarks of gut microbiota oscillations and the mechanisms by which they synchronise rhythms in host immunity and metabolism. We discuss the consequences for erse biological processes such as host pathogen susceptibility and seasonal switches in metabolism, and outline how the breakdown of these circadian interactions, for ex le during senescence and as a consequence of urbanisation, may affect wildlife infection risk and disease. Lastly, we provide practical guidelines for the measurement of microbial oscillations in wildlife, highlighting that whilst wild animals are rarely available over a 24-hour period, characterising even parts of the cycle can be informative. Light-dark cycles are an almost universal environmental cue and provide a rare opportunity to generalise gut microbial responses across species. An improved understanding of how microbial rhythms manifest in wildlife is essential to fully comprehend their ecological significance.
No related grants have been discovered for Nadine Müller-Klein.