Microbiome-Germline Interactions and Their Transgenerational Implications

It is becoming increasingly clear that most, if not all, animals and plants are associated with a diverse array of resident gut microbiota. This symbiosis is regulated by host-microbiome interactions which influence the development, homeostasis, adaptation and evolution of the host. Recent evidence indicated that these interactions can also affect the host germline and have a potential of supporting transgenerational effects, including inheritance of acquired characteristics. Taken together, the influence of gut bacteria on the host soma and germline could potentially give rise to emergent phenotypes, which may be partially inherited by three distinguishable modes of transgenerational influence of gut bacteria: 1) "soma-to-soma" 2) "soma-to-germline" and 3) "soma-germline-soma". Here, we discuss these possibilities in light of evidence supporting bacterial-mediated modes of transgenerational inheritance.