Roles of the Polyphenol–Gut Microbiota Interaction in Alleviating Colitis and Preventing Colitis-Associated Colorectal Cancer

Abstract

Accumulating evidence indicates that the gut microbiota can promote or inhibit colonic inflammation and carcinogenesis. Promotion of beneficial gut bacteria is considered a promising strategy to alleviate colonic diseases including colitis and colorectal cancer. Interestingly, dietary polyphenols, which have been shown to attenuate colitis and inhibit colorectal cancer in animal models and some human studies, appear to reach relatively high concentrations in the large intestine and to interact with the gut microbial community. This review summarizes the modulatory effects of polyphenols on the gut microbiota in humans and animals under healthy and diseased conditions including colitis and colitis-associated colorectal cancer (CAC). Existing human and animal studies indicate that polyphenols and polyphenol-rich whole foods are capable of elevating butyrate producers and probiotics that alleviate colitis and inhibit CAC, such as Lactobacillus and Bifidobacterium. Studies in colitis and CAC models indicate that polyphenols decrease opportunistic pathogenic or proinflammatory microbes and counteract disease-induced dysbiosis. Consistently, polyphenols also change microbial functions, including increasing butyrate formation. Moreover, polyphenol metabolites produced by the gut microbiota appear to have anticancer and anti-inflammatory activities, protect gut barrier integrity, and mitigate inflammatory conditions in cells and animal models. Based on these results, we conclude that polyphenol-mediated alteration of microbial composition and functions, together with polyphenol metabolites produced by the gut microbiota, likely contribute to the protective effects of polyphenols on colitis and CAC. Future research is needed to validate the causal role of the polyphenol–gut microbiota interaction in polyphenols’ anti-colitis and anti-CAC effects, and to further elucidate mechanisms underlying such interaction.

The inhibitory effects of probiotics on colon cancer cells: in vitro and in vivo studies

“…This suggests that there is a special connection between probiotics and CRC. In fact, numerous studies have demonstrated the anti-tumor effects of probiotics such as L. acidophilus, L. casei, L. plantarum, and B. longum (13,14). However, before a specific probiotic strain can be considered part of a cancer treatment regimen, its function needs to be assessed in detail (15).…”

Alisol B 23-Acetate Ameliorates Azoxymethane/Dextran Sodium Sulfate-Induced Male Murine Colitis-Associated Colorectal Cancer via Modulating the Composition of Gut Microbiota and Improving Intestinal Barrier

“…Many current studies have shown that the intestinal flora plays an important role in the formation of the inflammatory microenvironment and the promotion of tumor growth ( Brennan and Garrett, 2016 ). The gut microbiota of CAC mice is characterized by reduced microbial diversity and reduced abundance of probiotics (including Bacteroides, Lactobacillus ) ( Zhao and Jiang, 2020 ), and Alloprevotella ( Wei et al., 2018 ), and the expansion of pathogenic bacteria, such as Proteobacteria ( Shin et al., 2015 ; Litvak et al., 2017 ), Muribaculaceae ( Pereira et al., 2020 ), Akkermansia ( Ijssennagger et al., 2015 ), Klebsiella ( Olm et al., 2019 ), and Citrobacter ( Collins et al., 2014 ). Gut microbiome dysbiosis leads to changes in cytokine activity, inflammatory signaling pathway activation (e.g., TLR4, TLR5, NF-κB, and MAPKs), and intestinal barrier function weakening, all of which provide a pro-inflammatory microenvironment for tumor promotion ( Fukata et al., 2009 ; Choi et al., 2013 ; Waldner and Neurath, 2015 ).…”

Pu‐erh tea extraction alleviates intestinal inflammation in mice with flora disorder by regulating gut microbiota

“…These components may help to improve the structure of the intestinal flora. Many studies have shown that polyphenols can decrease proinflammatory microbes and counteract disease‐induced dysbiosis in colitis models (Zhao & Jiang, 2021 ). Moreover, the bioactive phenol is considered to be the main component of Pu‐erh tea responsible for its health‐promoting function (Etxeberria et al., 2013 ).…”