Comparative analysis of gut microbiota content from 97 wild Arvicola terrestris

The ground vole Arvicola terrestris is a rodent considered as an agricultural pest endemic of European mid-mountain regions where it causes extensive damage to meadows and so on for grass-based breeding. The factors that drive its reproductive cycle are still poorly understood, but whose populations undergo travelling waves on a 6-year cycle with four successive phases: low density, population growth, high density and population decline This study analyzed the gut bacterial compositions of voles from Massiac and Volvic clumps at different reproductive cycle stages (represented as low, medium, and high-density levels). The luminal content samples from the large intestine of 97 ground voles (55 samples from Massiac and 42 samples from Volvic) were collected. Sequence analysis of the V3-V4 regions of the bacterial 16S rRNA gene was performed to investigate the composition of the gut microbiome of A. terrestris using the Illumina MiSeq platform. Measurements of alpha and beta diversity showed significant differences between microbial diversity between Massiac and Volvic clumps. Three gut bacterial community structures were observed and matched a differentiation according to the density variation patterns of the vole populations in both sites. Globally, the taxonomic composition was similar, but the abundance was different. Our results suggest that the specific bacterial composition of the vole's gut microbiome appears to be influenced by both the cyclic vole population and their spatial distribution. Its implication as a potential vector and reservoir of emerging pathogenic bacteria was discussed.