Anti‐inflammatory activity of β‐glucans from different sources before and after fermentation by fecal bacteria in vitro

Abstract

BACKGROUNDBeta‐glucan is widely sourced and has various physiological activities including anti‐inflammation. However, the strength of the anti‐inflammatory activity of β‐glucans from different sources remained elusive due to the lack of rapid and effective biomarkers. Therefore, this study aimed to screen out the β‐glucan with strong anti‐inflammatory activity from 5 different sources and to further screen out possible biomarkers in metabolites after fermented the β‐glucans by gut microorganisms.RESULTSThe results showed that all five β‐glucans inhibited the production of LPS‐induced pro‐inflammatory mediators and suppressed the mRNA expression level of TLR4/MyD88. Their anti‐inflammatory mechanisms involved the inhibition of intracellular ROS production and suppression of mRNA expression of the NF‐κB pathway and JNK pathway. Among them, barley β‐glucan exhibited the strongest anti‐inflammatory effect, followed by Ganoderma lucidum β‐glucan. Enhanced anti‐inflammatory activity of β‐glucan after fermentation was found and may be related to the increased abundance of metabolites such as the vanillin, dihydroxyphenylacetic acid, caffeic acid, acetic acid, butyric acid, and lactic acid. They are strongly positively correlated to the abundance of beneficial bacteria such as Blautia, suggesting that the production of those metabolites may be responsible for the flourishing of the beneficial bacteria.CONCLUSIONIn conclusion, barley was a preferred raw material for the preparation of β‐glucans with high anti‐inflammatory activity. Vanillin, dihydroxyphenylacetic acid, caffeic acid, acetic acid, butyric acid, and lactic acid were the possible biomarkers that could be utilized to evaluate the anti‐inflammatory effect of β‐glucans.This article is protected by copyright. All rights reserved.