Sex,age,and Seasonal Differences Of Gut Bacteria In Wild White-headed Langur(Trachypithecus Leucocephalus)

Gut bacteria are extremely important for host growth,development,survival and reproduction,the two have formed a stable,adaptive and cooperative relationship in the process of long-term evolution.The host adapts to different feeding niches with the assistance of gut bacteria.The diversity and composition of gut bacteria are affected by the age,sex of the host and the seasonal variations of food.Therefore,in-depth study on the interaction between host and gut bacteria under natural conditions can deepen the understanding of host adaptive evolution.From August 2021 to July 2022,fresh feces of white-headed langur(Trachypithecus leucocephalus)in the Botanical Garden were collected in Guangxi Chongzuo White-headed Langur National Nature Reserve.And gut bacteria were detected via16 S r RNA gene high-throughput sequencing technology.The foraging behaviors were recorded by Focal animal sampling and Continuous recording methods.The main findings are as follows:1.Diet: There were 91 known species of T.leucocephalus,which belong to 45 families and 80 genera.51.05% of the plant life types were trees,37.83% were vines,5.59% were shrubs,1.74% were herbs and 3.78% were parasitic plants.Young leaves accounted for 61.05%of the annual foraging time,followed by stems and mature leaves,which accounted for 9.86%and 9.42% of the annual foraging time,respectively.The foraging rates of buds,fruits,flowers,seeds and other plant parts were 4.98%,4.90%,3.71%,2.62% and 0.98%.T.leucocephalus ate 11 more plant species in the dry season than in the wet season(dry season VS wet season = 79 VS 68),but there was no significant seasonal difference.There were significant seasonal differences in the food parts of T.leucocephalus: compared with the dry season,the feeding time of young leaves,fruits and seeds increased significantly in wet season.Compared with wet season,the feeding time of mature leaves and stems increased significantly in dry season.2.Gut bacterial composition: A total of 16,686,271 optimized sequences were obtained in this study,and the number of order elements with definite taxonomic status included 27 phyla,56 classes,124 orders,202 families,415 genera,and 221 species.Firmicutes,Proteobacteria and Bacteroidetes were the three main types of gut bacteria in the phylum with dominant richness.The dominant families included Planococcaceae,Bacillaceae,Enterobacteriaceae,Moraxellaceae and Ruminococcaceae and other bacteria.The dominant genera were Solibacillus,Bacillus,Acinetobacter,Kurthia,Pseudomonas and other bacteria.3.Seasonal,age,and sex differences in gut bacteria:(1)Season(wet season and dry season): There was no significant seasonal difference in α diversity of gut bacteria in T.leucocephalus,but there was a very significant seasonal difference in β diversity.The functional pathway and composition of gut bacteria had significant seasonal differences: The proportions of Cyanobacteria,Micrococcaceae,Muribaculaceae,Kurthia and Streptococcus in the wet season were significantly higher than that in the dry season.These gut bacteria can degrade lipids,pectin,simple sugars and other compounds.At the same time,the relative richness of the second-level functional pathways such as "Carbohydrate metabolism","Lipid metabolism" and "Amino acid metabolism" also increased significantly during the wet season.Compared with the wet season,the relative richness of Bacillaceae,Pseudomonadaceae,Pantoea,Solibacillus,Bacillus and other gut bacteria increased significantly in the dry season.Seasonal differences in gut bacterial composition and function were consistent with seasonal changes of food intake.And seasonal changes of food may be an important reason for seasonal differences in gut bacterial composition and function of T.leucocephalus.(2)Age(juvenile and adult):The α diversity of gut bacteria in adult group was higher than that in juvenile,but there no significant difference,And the β diversity was also not significantly different.There were significant age differences in gut bacterial composition:compared to the juvenile group,the relative richness of Planctomycetes,Streptococcaceae,Lachnospiraceae,Streptococcus,Streptococcaceae,Ruminococcaceae＿UCG-014 and other floras in adult increased significantly.The relative abundance of Weeksellaceae in juvenile was significantly higher than adult.(3)Sex(female and male): The α diversity and β diversity of gut bacteria were significantly different.The ACE,Chao1,Shannon and Simpson of gut bacteria in female were significantly higher than those of males.There were significant sex differences in gut bacterial composition: compared with the male group,the relative richness of gut bacteria in female increased significantly,such as Verrucomicrobia,Actinobacteria,Akkermansiaceae,Streptococcus and UCG genera of Ruminococcaceae.Compared with males,female langurs had a more diverse and complex gut bacterial community.In summary,there were significant seasonal differences in the timing of the T.leucocephalus on food parts.There were significant sex differences in α diversity,and βdiversity varies significantly in different seasons and sexes.There were significant seasonal differences in gut bacterial function.The composition of gut bacteria showed significant differences among different seasons,ages,and sexes.These results enriched the research content of gut bacteria in T.leucocephalus,and provided theoretical basis for the scientific management,protection and follow-up research of T.leucocephalus.