Data from: Hierarchical social networks shape gut microbial composition in wild Verreaux's sifaka

In wild primates, social behaviour influences exposure to environmentally acquired and directly transmitted microorganisms. Prior studies indicate that gut microbiota reflect pairwise social interactions among chimpanzee and baboon hosts. Here, we demonstrate that higher-order social network structure—beyond just pairwise interactions—drives gut bacterial composition in wild lemurs, which live in smaller and more cohesive groups than previously studied anthropoid species. Using 16S rRNA gene sequencing and social network analysis of grooming contacts, we estimate the relative impacts of hierarchical (i.e. multilevel) social structure, individual demographic traits, diet, scent-marking, and habitat overlap on bacteria acquisition in a wild population of Verreaux's sifaka (Propithecus verreauxi) consisting of seven social groups. We show that social group membership is clearly reflected in the microbiomes of individual sifaka, and that social groups with denser grooming networks have more homogeneous gut microbial compositions. Within social groups, adults, more gregarious individuals, and individuals that scent-mark frequently harbour the greatest microbial diversity. Thus, the community structure of wild lemurs governs symbiotic relationships by constraining transmission between hosts and partitioning environmental exposure to microorganisms. This social cultivation of mutualistic gut flora may be an evolutionary benefit of tight-knit group living.

针对野生灵长类动物而言，社会行为会影响其接触经环境途径获得以及直接传播的微生物的概率。既往研究表明，肠道菌群能够反映黑猩猩与狒狒宿主之间的成对社交互动。本研究证实，相较于仅关注成对互动，高阶社交网络结构才是驱动野生狐猴肠道细菌组成的核心因素——相较于此前研究过的类人猿物种，野生狐猴的种群规模更小且群体凝聚力更强。我们依托16S核糖体RNA（16S rRNA）基因测序技术与理毛行为社交网络分析方法，针对由7个社交群体组成的野生维氏冕狐猴（Propithecus verreauxi）种群，评估了层级（即多层级）社交结构、个体人口统计学特征、饮食、气味标记以及栖息地重叠度对细菌获得过程的相对影响。研究结果显示，社交群体归属能够清晰地反映在个体狐猴的微生物组中；且理毛网络更密集的社交群体，其肠道微生物组成的均一性更高。在社交群体内部，成年个体、社交性更强的个体以及频繁进行气味标记的个体，其微生物多样性最为丰富。由此可见，野生狐猴的群落结构通过约束宿主间的微生物传播、划分宿主接触环境微生物的途径，调控着共生关系。这种对互利共生肠道菌群的社会性培育，或许是紧密型群体生活带来的一项进化优势。