Social relationships and microbial ecology in wild baboons

Background/Question/Methods

The microbial composition of the gut has important functional consequences for an individual, ranging from metabolism to mental health. However, the role that social behaviors play in shaping the gut ecosystem is largely unknown. The goal of this study was to use ecological and behavioral data to test the role of social transmission in gut microbiome composition using two troops of wild savannah baboons (Papio cynocephalus). 

Results/Conclusions

Consistent with previous work, social group membership was the most important predictor of microbial diversity for adult female and juvenile baboons. Surprisingly, current social group membership also predicted gut microbiome composition in adult males, even though they disperse between social groups throughout their lives. We also found that length of social group membership predicted how similar a male’s microbiota were to other long-term group residents, suggesting that males acquire gut microbes from conspecifics or objects in the group’s home range. Additionally, we found that dominance rank predicted microbiome composition in adult males and maternal rank predicted microbial diversity in juveniles, illuminating the relationship between behavior, physiology, and microbiota. These results provide evidence that social transmission and interactions between physiology and behaviors are important in microbial acquisition.