Gut microbes and the transmission of behavior between generations

Inheritance is traditionally understood as the transmission of genetic information. Animals, however, are composite systems whose physiology and behavior critically depend on microbial communities. We show that a behavioral trait in mice can be transmitted exclusively via the gut microbiome, without changes to the host genome. Through microbiome transfer and unidirectional selection for activity, stable behavioral changes can be generated across generations. Mechanistically, this is associated with the enrichment of Lactobacillus and the microbial metabolite indolelactate.