On the effect of inheritance of microbes in commensal microbiomes

Abstract

Background. Our current view of nature depicts a world where macroorganisms dwell in a landscape full of microbes. Some of these microbes not only transit but establish themselves in or on hosts. Although hosts might be occupied by microbes for most of their lives, a microbe-free stage during their prenatal development seems to be the rule for many hosts. The questions of who the first colonizers of a newborn host are and to what extent these are obtained from the parents follow naturally. Results. We have developed a mathematical model to study the effect of the transfer of microbes from parents to offspring. Even without selection, we observe that microbial inheritance is particularly effective in modifying the microbiome of hosts with a short lifespan or limited colonization from the environment, for example by favouring the acquisition of rare microbes. Conclusion. By modelling the inheritance of commensal microbes to newborns, our results suggest that, in an eco-evolutionary context, the impact of microbial inheritance is of particular importance for some specific life histories.

The effect of microbial selection on the occurrence-abundance patterns of microbiomes

“…In addition, our model could be extended to include a dynamic external metacommunity and differential immigration to the local communities, similarly to the neutral approach of Harris et al [15]. Although we provided a focused analysis of the occurrence-abundance pattern at equilibrium, future work could study its dynamics [39] and derive exact equations for these and other observables [30]. In fact, it might be necessary to consider observables at the level of types to distinguish between processes leading to equivalent community patterns [15].…”