Gut Microbial Diversity In Two Insectivory Bats And Comparisons Of Different Sampling Sources

More and more studies have showed that gut microbiota is closely associated with the physiology and health of mammals.Compared with humans and other model animals,relatively few studies have been conducted on the gut microbiota in bats.Previous studies of gut microbiota in mice suggest that faecal samples cannot be used as a proxy of microbiota in other gut regions to study the gut microbial diversity of the host.Our work used two sympatric and insectivorous bats as the study system.Firstly,we characterized the gut microbiota of these two bats,and then the results were compared with those of other bats and mammals.Secondly,we assessed the difference of gut microbial diversity between faecal samples and other gut region samples as well as the differences of the same sampling source between two bats.Gut microbiota of three sampling sources(small intestine,large intestine and faeces)were characterized by high-throughput sequencing of the V3-V4 region of the 16 S rRNA gene.The sequencing data were analyzed by quality control,splicing,assigning,classifying,? analysis and ? analysis to compare microbiota difference among three sampling sources in each of the two bats species and between each of the three sampling sources in two bat species.The results showed that Proteobacteria,Firmicutes and Bacteroides were the dominant phyla of the three sampling sources in two bats.Combining with published studies in bats,this work reveals that Gammaproteobacteria may be a dominant class in the whole Chiroptera and Fusobacteria is less observed in two insectivorous bats although it has been proven to be dominant in other carnivorous mammals.The results revealed that the sampling sources influence alpha diversity of the microbial community in each of two studied species although no significant variations of beta diversity were observed.Our results suggest that faecal samples can not be used as a proxy of the microbiota in other gut regions in studying the gut microbiota of the host.Another important finding of this study is that genetic divergence between hosts has little effect on microbial communities of the small intestine,which suggests that microbiome in the small intestine might represent an ancient and common group occurring in the ancestors of bats.This study has characterized the microbial diversity differences of three sampling sources(the small intestine,large intestine and faeces)in two insectivorous bat species,which adds to the list of a growing number of studies on the gut microbiota in bats.Our work highlights the importance of selecting proper gut region in gut microbiota-related researches.Future investigations will continue to assess the relative effects of genetic divergence of hosts,sex,the gut region and diet on gut microbial communities...