Swine gut microbiota and its interaction with host nutrient metabolism

Abstract

Gut microbiota is generally recognized to play a crucial role in maintaining host health and metabolism. The correlation among gut microbiota, glycolipid metabolism, and metabolic diseases has been well reviewed in humans. However, the interplay between gut microbiota and host metabolism in swine remains incompletely understood. Given the limitation in conducting human experiments and the high similarity between swine and humans in terms of anatomy, physiology, polyphagy, habits, and metabolism and in terms of the composition of gut microbiota, there is a pressing need to summarize the knowledge gained regarding swine gut microbiota, its interplay with host metabolism, and the underlying mechanisms. This review aimed to outline the bidirectional regulation between gut microbiota and nutrient metabolism in swine and to emphasize the action mechanisms underlying the complex microbiome-host crosstalk via the gut microbiota-gut-brain axis. Moreover, it highlights the new advances in knowledge of the diurnal rhythmicity of gut microbiota. A better understanding of these aspects can not only shed light on healthy and efficient pork production but also promote our knowledge on the associations between gut microbiota and the microbiome-host crosstalk mechanism. More importantly, knowledge on microbiota, host health and metabolism facilitates the development of a precise intervention therapy targeting the gut microbiota.

Keywords: Gut microbiota; Host nutrient metabolism; Microbiota diurnal rhythmicity; Microbiota–gut–brain axis.

Fig. 1

The gut microbiota communities of swine are subtle to several endogenous and exogenous factors: host factors, diet, feeding management and environment, and additives.

Fig. 2

The microbiome-host crosstalk via microbiota–gut–brain axis. The mammalian gastrointestinal tract hosts trillions of microorganisms. The symbiotic gut microbiota could promote host nervous system development and neurotransmitter secretion. Besides, the bacterial metabolites might cross the blood–brain barrier and directly modulate signaling in the brain. Meanwhile, the central nervous system in the brain adjust host behavior (e.g. appetite) to change the composition and function of the gut microbiota in turn. The gut affords the nutrients for the microbiota and thus shaping the scenery of its habitat, while the microbiota promotes the differentiation of intestinal epithelial cell, stimulate intestinal peptide secretion, and regulate gut signaling in return. The central nervous system controls the motility and secretion of the gut, while the gut affects the signaling and neurotransmitter expression in the brain. EEC = Enteroendocrine cells; SCFA = short-chain fatty acids.