Functions of Gut Microbiota Metabolites, Current Status and Future Perspectives

Abstract

Gut microbiota, a collection of microorganisms that live within gastrointestinal tract, provides crucial signaling metabolites for the physiological of hosts. In healthy state, gut microbiota metabolites are helpful for maintaining the basic functions of hosts, whereas disturbed production of these metabolites can lead to numerous diseases such as metabolic diseases, cardiovascular diseases, gastrointestinal diseases, neurodegenerative diseases, and cancer. Although there are many reviews about the specific mechanisms of gut microbiota metabolites on specific diseases, there is no comprehensive summarization of the functions of these metabolites. In this Opinion, we discuss the knowledge of gut microbiota metabolites including the types of gut microbiota metabolites and their ways acting on targets. In addition, we summarize their physiological and pathologic functions in health and diseases, such as shaping the composition of gut microbiota and acting as nutrition. This paper can be helpful for understanding the roles of gut microbiota metabolites and thus provide guidance for developing suitable therapeutic strategies to combat microbial-driven diseases and improve health.

Dietary compounds in modulation of gut microbiota-derived metabolites

“…When absorbed, gut microbiota metabolites can be transported to target organs and tissues that are remote from gastrointestinal tract, and therefore exert a wide range of activities on hosts. These activities include, but not limited to, regulating the composition and function of gut microbiota, acting as nutrition, influencing nutrition absorption, modulating host metabolism, influencing intestinal barrier and gut motility, impacting the local and systemic immune response, modulating circadian rhythm and nervous system ( 6 ). With these bioactivities, gut microbiota metabolites play important roles in the development and progress of a variety of diseases such as cancer, non-alcoholic fatty liver disease, hypertension, Parkinson's disease, and ulcerative diseases ( 30 , 38 – 40 ).…”

“…Gut microbiota can produce gases (H 2 S, H 2 , CO 2 , CH 4 , NO) ( 6 , 35 ). CH 4 has significant effect on gastrointestinal tract as it is associated with constipation and can slow the colon motility ( 149 ).…”

“…Normally, the gut microbiota is confined within the gastrointestinal lumen by gut barrier and translocation of gut bacteria can lead to local and systematic inflammation ( 5 ). To overcome the spatial limitation, gut microbiota develops a tactic of releasing a large number of gut microbiota metabolites from different chemical classes to exert extensive effects on host organs that are near or far away from gastrointestinal lumen ( 6 ). Gut microbiota contains 5 × 10 6 unique microbial genes collectively, which outnumber the genes of humans ( 7 ).…”

“…These gut microbiota-derived metabolites include, but not limited to, short chain fatty acids (SCFAs), bile acids, vitamins, tryptophan and indole derivatives ( 8 ). These metabolites can exert the functions of regulating of gut microbiota composition, host metabolism, nutrition absorption, gut motility, local and systemic immune response, circadian rhythm, etc., to maintain the health or promote the development of diseases ( 6 ).…”

Study on the Antipyretic and Anti-inflammatory Mechanism of Shuanghuanglian Oral Liquid Based on Gut Microbiota-Host Metabolism

“…Studies have confirmed that human fecal microflora could transform baicalin to baicalein and oroxylin A, which exhibit a more potent anti-scratching behavioral effect than their parent molecule in histamine-treated mice ( Jung et al, 2012 ; Cheng et al, 2021 ). Moreover, the bioavailability of herbal compounds can be further improved by their possible effect on the production of microbial metabolites ( Zhang et al, 2020 ; Liu et al, 2022 ). Therefore, gut microbiota combined with metabolomics is widely used to study the mechanism of Chinese medicine ( Feng et al, 2021 ).…”