Study On Intestinal Microbiome During Development Of The Asian Particolored Bat(Vespertilio Sinensis)

The intestinal tract of animals coexist with a large number of complex microbial communities,which are closely related to the host's physiological functions and play an important role.Many studies have shown that gut microbiota can promote the digestion and absorption,metabolism,intestinal tissue development,and immune function of many key physiological activities during animal ontogeny.However,most previous studies have focused on captive animals?fish,chicken and pigs,etc.?and a few wild animals?birds,primates,etc.?,and it is unclear about the changes of gut microbiota during the development of bats and the relationship of gut microbiota between the female and infants in natural habitats.The Asian particolored bat?Vespertilio sinensis?belongs to Vespertilio genus?Chiroptera,Vespertilionidae?,and goes out before dawn and at dusk to feed on insects twice.In this study,the faeces of infant bats from different ages were collected,and the 16S r RNA amplicon sequencing technology was used to explore the changes in the structure and function of gut microbiota during the individual development of V.sinensis.We combined with factors such as environment temperature,age,and body mass index,to reveal the effects of V.sinensis on the composition of gut microbiota community during development.And the relationships of gut microbiota between newborn infants and female bats were explored.The findings are as follows:1.During the development process of infant bats,the diversity of gut microbiota changed.Alpha diversity of gut microbiota gradually increased from the week 1 to the week 4(R²=0.2285,P_adj=0.01),and decreased significantly at the weeks 5 and 6,and then remained stable thereafter?ANOVA;P<0.05?.2.The beta diversity of gut microbial communities changed significantly during the entire development process of V.sinensis(PERMANOVA;P_adj=0.001).Most individuals from the week 1 to the week 4 clustered together,and the weeks 5 and 6 differed from the samples from the weeks 1 to 4.The clustering of newborn infants was slightly different from other periods.3.The gut microbiota in V.sinensis were relatively stable at the phylum level during ontogeny,with Firmicutes and Proteobacteria constituting most of the community.The results of heatmap analysis at the genus level showed that the gut microbiota with high abundances were similar from week 1 to week 4,but the gut microbiota were composed of relatively low abundances for weeks 5 and 6.Unexpectedly,the community composition on day 1 differed from that during the other periods with high abundances of Lactococcus,Pseudomonas,and Brochothrix.However,the high-abundance bacteria in the other periods were relatively rare on day 1.4.The dietary transition period of V.sinensis during the individual development period was the week 4.And the results of diet identification indicated that the food composition mainly consisted of Coleoptera and Lepidoptera?38%and 26%of the total OTU,respectively?.However,the results from functional analysis by PICRUSt showed that all functions of the gut microbiota before and after week 4 had no significant difference at level 2 and level 3 after Benjamini-Hochberg correction(P_adj>0.05).No useful information of predicted functional profiles obtained in this study might be due to qualitative and quantitative differences between our data and the existing databases used by PICRUSt.5.Redundancy analysis showed that all factors could account for 19.6%of the variation in the bacterial community structure.Age and body mass index?BMI?significantly affected the community structure of the gut microbiota in V.sinensis(age:P_adj=0.006;BMI:P_adj=0.024),while the environmental temperature did not significantly influence the gut microbiota(P_adj>0.05).Age had the greatest effect,accounting for 12.1%of the community variation while BMI accounting for 9.5%.6.The alpha diversity of newborn infant bats was significantly higher than that of female bats(Kruskal-Wallis test;P_adj<0.05)and they have significantly different gut microbiota communities(PERMANOVA;P_adj=0.001).This may suggest that the source of gut microbiota in newborn infant bats is primarily determined by the environment.In general,this study characterized the changes of intestinal microbiota in the development of V.sinensis,and explored the changes of gut microbiota communities and their influencing factors,which is helpful to reveal the changes of gut microbiota in each stage of the development of wild bats.And it provides new insights for studying and protecting the population reproduction and development of wild bats.