Synchronous seasonality in the gut microbiota of wild wood mouse populations

Abstract

1. The gut microbiome performs many important functions in mammalian hosts, with community composition shaping its functional role. However, what factors drive individual microbiota variation in wild animals and to what extent these are predictable or idiosyncratic across populations remains poorly understood. 2. Here, we use a multi-population dataset from a common rodent species (the wood mouse, Apodemus sylvaticus), to test whether a consistent set of 'core' gut microbes is identifiable in this species, and to what extent the predictors of microbiota variation are consistent across populations. 3. Between 2014 and 2018 we used capture-mark-recapture and 16S rRNA profiling to intensively monitor two wild UK mouse populations and their gut microbiota, as well as characterising the microbiota from a laboratory-housed colony of the same species. 4. Although broadly similar at high taxonomic levels and despite being only 50km apart, the two wild populations did not share a single bacterial amplicon sequence variant (ASV). Meanwhile, the laboratory-housed colony shared many ASVs with one of the wild populations from which it is thought to have been founded decades ago. Despite strong taxonomic divergence in the microbiota, the factors predicting compositional variation in each wild population were remarkably similar. We identified a strong and consistent pattern of seasonal microbiota restructuring that occurred at both sites, in all years, and within individual mice. While the microbiota was highly individualised, seasonal convergence in the gut microbiota among individuals occurred in late winter/early spring. 5. These findings reveal highly repeatable seasonal gut microbiota dynamics across distinct populations of this species, despite divergent taxa being involved. Providing a platform for future work to understand the drivers and functional implications of such predictable seasonal microbiome restructuring, including whether it might provide the host with adaptive seasonal phenotypic plasticity.

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

“…Dr. Kevin Kohl presented results from experimental approaches demonstrating that the gut microbiome contributes to diet selection in mice 3 . Dr. Sarah Knowles found seasonal shifts in the gut microbiome composition of wild wood mice, 4 likely driven by diet. She also showed that social interactions are a strong predictor of the gut microbiota 5 …”

Gut microbiota of homing pigeons shows summer-winter variation under constant diet indicating a substantial effect of temperature

“…Hence, the gut microbiota is expected vary seasonally, as it does in some wild animals [13][14][15][16]. This seasonal variation in gut microbiota seems to be primarily driven by seasonal variation in diet [17]. In North American red squirrels (Tamiasciurus husonicus), for example, seasonal rhythms in the relative abundances of Oscillospira and Corpococcus genera were associated with seasonal variation in food availability [13].…”