Sex and habitat are associated with gut bacterial and fungal variatons in wild yellow baboons (Papio cynocephalus)

Variatons in richness and compositon of mammal gut bacteria and fungi have mainly been related to diet, lifestyle, and habitat; however, less is known about the effect of sex on non-human primate gut microbiota. To understand the associaton of sex and habitat with microbiota diversity, we non-invasively collected and analyzed faecal samples from 40 yellow baboons (Papio cynocephalus) living in well-protected and disturbed forests of the Udzungwa Mountains in Tanzania. Sex determinaton has been performed using the marker genes: SRY (Sex-determining Region Y) and DDX3X (DEAD-Box Helicase 3-X Linked). Molecular investgatons resulted in 34 individuals sexed, including 19 females and 15 males, belonging to 5 social groups. Combining these results with two amplicon-sequencing datasets focusing on bacterial (16S rRNA gene, V1-V3 region) and fungal (ITS1-ITS2) gut communites, we found a signifcantly higher bacterial richness in baboon females compared to males. No signifcant difference in observed fungal richness was detected between sexes; however, beta diversity estmates (Bray-Curts dissimilarity) indicated that fungal and bacterial compositon was signifcantly different between males and females. This was true in both protected and fragmented forest types. Although the sample size is relatvely small, our results highlight the relevant contributon of an intrinsic factor shaping the variaton of both bacterial and fungal communites in wild non-human primates