Gut microbiome composition, not alpha diversity, is associated with survival in a natural vertebrate population

Abstract

Background: The vertebrate gut microbiome (GM) can vary substantially across individuals within the same natural population. Although there is evidence linking the GM to health in captive animals, very little is known about the consequences of GM variation for host fitness in the wild. Here, we explore the relationship between faecal microbiome diversity, body condition and survival using data from the long-term study of a discrete natural population of the Seychelles warbler ( Acrocephalus sechellensis ) on Cousin Island. To our knowledge, this is the first time that GM differences associated with survival have been fully characterised for a natural vertebrate species, across multiple age groups and breeding seasons. Results: We identified substantial variation in GM community structure among sampled individuals, which was partially explained by breeding season (7% of the variance), and host age class (up to 1% of the variance). We also identified significant differences in GM community membership between individuals that survived, versus those that had died by the following breeding season. Individuals that died carried reduced abundances of beneficial taxa in the bacterial order Clostridiales , but increased abundances of taxa that are known to be opportunistic pathogens (e.g. members of the Chloroflexi and Propionibacteriales ). However, there was no association between GM alpha diversity (the diversity of bacterial taxa within a sample) and survival to the next breeding season, or with individual body condition. Additionally, we found no association between GM community membership and individual body condition. Conclusions: These results demonstrate that components of the vertebrate GM can be associated with host fitness in the wild, although whether changes in bacterial abundance contribute to, or are only correlated with, the differential survival observed remains unclear. Importantly, it suggests that components of the GM may be under selection, and, thus, could have the potential to influence the evolution of host species living in natural populations.

Prenatal arsenic exposure stymies gut butyrate production and enhances gut permeability in post natal life even in absence of arsenic deftly through miR122-Occludin pathway

“…Although not significant, Chao1 alpha diversity of the microbiome showed a trend of decrease in pAs-mice compared to control-mice. In some cases, microbial compositions rather than diversity seems to be the key player to determine the phenotype as it was shown earlier with the survivality of wild vertebrate population (Worsley et al 2021).…”

Growing and maintaining a network for early career researchers through the Animal Microbiome Research Group

“…Dr. Sarah Worsley (University of East Anglia, UK) demonstrated a link between host survival and the gut microbiome composition of the Seychelles warblers. 12 Lifetime data also offer the possibility to investigate the link between host aging and the gut microbiome. Despite being a dynamic system, the gut microbiome might stabilize with host age as suggested by Dr. Alice Risely's results (Ulm University, Germany) on the stability and repeatability of wild meerkats' gut microbiomes.…”

“…Mason Stothart (University of Calgary, Canada) presented his work linking environmental variation and gut microbiome variation in feral horses, 11 and reported correlates between the microbiome and host survival. Dr. Sarah Worsley (University of East Anglia, UK) demonstrated a link between host survival and the gut microbiome composition of the Seychelles warblers 12 . Lifetime data also offer the possibility to investigate the link between host aging and the gut microbiome.…”

Gut microbiota individuality is contingent on temporal scale and age in wild meerkats

“…Inter-individual differences in gut microbiota composition can lead to variation in host health [1], pathogen susceptibility [2–4] and measures of fitness such as survival [5,6]. Although the mechanisms underpinning these relationships remain poorly understood, one possibility is that hosts maintain individualized and stable microbial symbionts that are disproportionally important for mediating long-term physiological and behavioural phenotypes [7].…”