Diet and Domestication Drive Evolution of the Gut Holobiome

Abstract

The host microbiome encompasses all microorganisms of a host. Host and microbiome coevolution in the gut result in differing microbial compositions, functionality, and host diet [1]. Host diet modulates what macromolecules are used for gut microbial metabolism, which can determine digestion, health, and behavior [2, 3]. Microbial composition across animals provides data on how microbiomes segregate between species and diets [4]. Here we show that microbiome data from GenBank can model host evolution, providing a "holobiome" insight to the important roles of diet and domestication. The main findings of this study in respect to microbial composition among species were: (1) herbivores are more similar than hosts with other diets; (2) domesticated species are more similar than wild relatives; and (3) humans are distinct from primates. Microbial composition between diets indicates a difference in functionality, where protein and fiber degradation are seen more in carnivores and herbivores respectively. Additionally, herbivores show the most microbial diversity among the diets. Finally, this analysis informs us of gaps in current microbiome data collection, which is biased toward pathogens. Thus, the host-microbiome relationship depicts a complex web of microbial functionality, composition, and diet that impact coevolution.