Diet-related factors strongly shaped the gut microbiota of Japanese macaques

Abstract

Mammals rely on the gut microbiome to process the indigestible plant materials. Through fermentation, the gut microbes transform fiber and the other indigestible materials into short-chain fatty acids and other nutrients, which are then absorbed by the host animals. For nonhuman primates and other animals that depend on plant material as the main component of their diet, the gut microbiome and its digestive function play a vital role in their feeding ecology. Although knowledge on the functions of the gut microbiome has increased greatly over the past few decades, our understanding of the mechanisms governing its ecology and evolution remains obscure. Comparing the gut microbiome of 19 populations of Japanese macaques Macaca fuscata across the Japanese archipelago, we assessed the relative roles of host genetic distance, geographic distance and dietary factors in influencing the macaque gut microbiome. Our results suggested that the macaques may maintain a core gut microbiome, while each population may have acquired some microbes from its specific habitat and diet. Diet-related factors such as season, forest and reliance on anthropogenic foods played a stronger role in shaping the macaque gut microbiome. Among closely related mammalian hosts, host genetics may have limited effects on the gut microbiome since the hosts generally have smaller physiological differences.

Given the close link between host physiology and gut microbiome, an improved understanding of the macaque gut microbiome may advance our knowledge in the ecological flexibility of Japanese macaques and the role of the gut microbiome in mammalian feeding ecology.