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.

Recent studies have emphasized that there is a strong link between the gut microbiome and the brain that affects social behavior and personality in animals. However, the interface between personality and the gut microbiome in wild primates remains poorly understood. Here, we used high-throughput sequencing and ethological methods in primate behavioral ecology to investigate the relationship between gut microbiome and personality in Tibetan macaques (Macaca thibetana). The behavioral assessment results indicated three personality dimensions including socialization, shyness, and anxiety. There was significant variation in alpha diversity only for shyness, with a significantly lower alpha diversity indices (including Shannon, Chao1, and PD) for bold individuals than for shy individuals. Using regression models to control for possible confounding factors, we found that the relative abundance of three genera, Akkermansia, Dialister, and Asteroleplasma, was significantly and positively correlated with the sociability scores in the macaques. In addition, Oscillospiraceae exhibited a positive correlation with scores for Shy Dimension. Furthermore, we found that the predicted functional genes for propionate and pyruvate, porphyrin and chlorophyll metabolic pathways related to animal behavior, were significant enriched in shyness group. We propose that the gut microbiome may play an important role in the formation of personality of Tibetan macaques.

Gut microbiome is critical to the health of mammals. Many previous studies have revealed the gut bacterial microbiomes of mother and infant changed significantly during the weaning period. However, little is known concerning the gut mycobiome of wild primates. Here, we examined the variations on gut mycobiome between weaning and post‐weaning for both mother and infant in wild‐living Tibetan macaques (Macaca thibetana). Our results showed that the gut mycobiomes of mother and infant were dominated by two phyla Ascomycota and Basidiomycota. For both mother and infant, the ASV richness of gut mycobiome remained relatively steady from weaning to post‐weaning periods, while the Shannon indexes increased significant in weaning compared to post‐weaning periods. However, no significant difference between mother and infant ASV richness and Shannon indexes during weaning and post‐weaning periods respectively. Compared to mothers, we found that much more known taxa of gut fungi were enriched in weaning or post‐weaning periods of infants. In particular, we found that the dominant genus Aspergillus was enriched in infants during weaning period. Furthermore, we found that the relative abundance of plant pathogens were significantly higher in the post‐weaning period than in the weaning period for infants. Our results indicated that weaning events could affect the gut mycobiome significantly for both mothers and infant in Tibetan macaques, which had a stronger effect on the gut mycobiome of infant monkeys than on their mothers.

The transmission and dissemination of antibiotic resistance genes (ARGs) have increasingly drawn global attention. However, our knowledge of the antibiotic resistance gene pool in wild primates' gut microbiomes and its influencing factors remains limited. In this study, we focus on a social group of Tibetan macaques ( Macaca thibetana ) in Huangshan, utilizing behavioral and metagenomic data to investigate the effects of host sex, age, and social network on the ARG profiles of the gut microbiome. Our results demonstrate a high diversity of ARGs in the gut microbiota of Tibetan macaques, with multidrug, glycopeptide, and peptide resistance genes being the most prevalent. Although host age, sex, and social networks did not significantly affect the overall diversity of ARGs, these factors were significantly correlated with the relative abundance of several highly abundant ARG types, including gryB , rpoB , macB , novA , efrA , patB , Staphylococcus aureus mupA conferring mupirocin resistance, RanA , and cdeA . Further analysis revealed extensive interactions between gut bacteria and ARGs, with age emerging as a potentially key factor in this covariation process. These findings provide new insights into the formation and transmission mechanisms of antibiotic resistance in the gut microbiome of wildlife, particularly in social primates.