The Expensive-Tissue Hypothesis in Vertebrates: Gut Microbiota Effect, a Review.

Xin Yu,Wen Bo Liao,Chun Hua Huang

doi:10.3390/ijms19061792

Xin Yu, Wen Bo Liao + Show 1 more

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https://doi.org/10.3390/ijms19061792

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Abstract

The gut microbiota is integral to an organism’s digestive structure and has been shown to play an important role in producing substrates for gluconeogenesis and energy production, vasodilator, and gut motility. Numerous studies have demonstrated that variation in diet types is associated with the abundance and diversity of the gut microbiota, a relationship that plays a significant role in nutrient absorption and affects gut size. The Expensive-Tissue Hypothesis states (ETH) that the metabolic requirement of relatively large brains is offset by a corresponding reduction of the other tissues, such as gut size. However, how the trade-off between gut size and brain size in vertebrates is associated with the gut microbiota through metabolic requirements still remains unexplored. Here, we review research relating to and discuss the potential influence of gut microbiota on the ETH.

Highlights

Vertebrates have coevolved with a diverse range of symbiotic gut bacteria and other microorganisms that populate the intestinal tract, known collectively as the gut microbiota [1,2]
We review how gut microbiota responds to diet quality and how it influences host metabolism by improving energy yield from food and modulating dietary or host-derived compounds that alter host metabolic pathways
Since its original formulation there have been extensions to the hypothesis, the “energy trade-off hypothesis” is one of the proposed extensions of the original Expensive-Tissue Hypothesis (ETH) [44] that suggests that the cost of increased brain size can be compensated by a costly loss of traits including and other than gut size and digestion, such as body maintenance [45], locomotion [47], development [46], and reproduction [43,49]

Summary

Introduction

Vertebrates have coevolved with a diverse range of symbiotic gut bacteria and other microorganisms that populate the intestinal tract, known collectively as the gut microbiota [1,2]. The diversity and composition of the gut microbiota among individuals of a host species often varies topographically and temporally [4,5], with particular bacterial species being associated with the host’s food intake [6] and with consequences for nutrient utilization and energy metabolism [7]. An example result of these interactions are short-chain fatty acids (SCFAs), metabolism products [5] that play an important role in the host’s food intake [6,24], gut nutrient utilization, energy metabolism, and development [21,25,26,27,28,29].

Influences of Gut Microbiota on Host Digestive System

Gut Microbiota Associated with Diet Affects Gut Size

Future Perspectives

Findings

Conclusions