Variation of Gut Microbiome in Free-Ranging Female Tibetan Macaques (Macaca thibetana) across Different Reproductive States

SIMPLE SUMMARY: The gut microbiome is expected to adapt to the varying energetic and nutritional pressures in females of different reproductive states. Although the genus Macaca has the widest geographical range of nonhuman primates, few empirical studies are currently available that explore the relationship between female reproductive states and their gut microbiome in this genus. We have examined variation of gut bacterial microbiome in free-ranging female Tibetan macaques (Macaca thibetana) across different reproductive states (cycling, pregnancy and lactation). We found significant changes in gut bacterial taxonomic composition, structure and their potential functions in different reproductive states of our study species. In particular, the relative abundance of Proteobacteria increased significantly during pregnancy and lactation. In addition, the relative abundance of Succinivibrionaceae and Succinivibrio (Succinivibrionaceae) were overrepresented in pregnant females, whereas Bifidobacteriaceae and Bifidobacterium (Bifidobacteriaceae) were overrepresented in lactating females. Furthermore, predicted functional genes of several metabolic pathways related to host’s energy and nutrition, such as metabolism of carbohydrates, cofactors and vitamins, glycans and other amino acids, were overrepresented in pregnancy and lactation. Thus, our results suggest that the gut microbiome may play an important role in the energetic and nutritional strategies of female reproductive ecology in the genus Macaca. Future studies of the “microbial reproductive ecology” of primates that incorporate food availability, reproductive seasonality, female reproductive physiology and gut inflammation are warranted. ABSTRACT: The gut microbiome is expected to adapt to the varying energetic and nutritional pressures in females of different reproductive states. Changes in the gut microbiome may lead to varying nutrient utilizing efficiency in pregnant and lactating female primates. In this study, we examined variation in the gut bacterial community composition of wild female Tibetan macaques (Macaca thibetana) across different reproductive states (cycling, pregnancy and lactation). Fecal samples (n = 25) were collected from ten adult females harvested across different reproductive states. Gut microbial community composition and potential functions were assessed using 16 S rRNA gene sequences. We found significant changes in gut bacterial taxonomic composition, structure and their potential functions in different reproductive states of our study species. In particular, the relative abundance of Proteobacteria increased significantly during pregnancy and lactation. In addition, the relative abundance of Succinivibrionaceae and Succinivibrio (Succinivibrionaceae) were overrepresented in pregnant females, whereas Bifidobacteriaceae and Bifidobacterium (Bifidobacteriaceae) were overrepresented in lactating females. Furthermore, the relative abundance of predicted functional genes of several metabolic pathways related to host’s energy and nutrition, such as metabolism of carbohydrates, cofactors and vitamins, glycans and other amino acids, were enriched in pregnancy and lactation. Our findings suggest that changes in the gut microbiome may play an important role in meeting the energetic needs of pregnant and lactating Tibetan macaques. Future studies of the “microbial reproductive ecology” of primates that incorporate food availability, reproductive seasonality, female reproductive physiology and gut inflammation are warranted.