New preprint on BiorXiv! Suzuki et al. show that the gut microbiome can drive phenotypic plasticity in a mammal, that a phenotype can then be selected, and the trait passed to a new host without selection on the host genome. We demonstrated this using independently bred germfree inbred mice who received the microbiome of donor mice selected for low levels of behavioral activity. Over 4 rounds of transfer/selection, the overall activity of the mice was reduced.

The reduced activity was associated with more Lactobacilli and indolelactate: transfer of the bacteria or the metabolite to the mouse gut reduced activity.

“Thus, certain members of the gut microbiome can be viewed as non-nuclear mechanisms shaping host ecology and evolution.”