Environmental effects rather than relatedness determine gut microbiome similarity in a social mammal

Abstract

Abstract In social species, group members commonly show substantial similarity in gut microbiome composition. Such similarities have been hypothesized to arise either by shared environmental effects or by host relatedness. However, disentangling these factors is difficult, because group members are often related, and social groups typically share similar environmental conditions. In this study, we conducted a cross-foster experiment under controlled laboratory conditions in group-living Damaraland mole-rats (Fukomys damarensis) and used 16S amplicon sequencing to disentangle the effects of the environment and relatedness on gut microbiome similarity and diversity. Our results show that a shared environment is the main factor explaining gut microbiome similarity, overshadowing any effect of host relatedness. Together with studies in wild animal populations, our results suggest that among conspecifics environmental factors are more powerful drivers of gut microbiome composition similarity than host genetics. Abstract Why are gut microbiomes of group members often more similar than non-group members? Is the shared evironment or host relatedness more influential in shaping gut microbiome of social hosts? In this study, we show that the environment overshadowes host relatedness in explaining gut microbiome similarity of experimentally cross-fostered social mole-rats.