Mol. Nutr. Food Res. 2022, 66, 2200063 DOI: 10.1002/mnfr.202200063 Alpha-cyclodextrin, a low-viscosity soluble dietary fibers, beneficially modified gut microbiota, promoted luminal short chain fatty acids (SCFAs) productions, and enhanced the differentiation of naïve T cells into regulatory T cells, leading to the alleviation of T cell- dependent colonic inflammation. This is reported by Yuka Yamanouchi and co-authors in article number 2200063.
Polyethylene glycol (PEG) is a commonly used dispersant for oral administration of hydrophobic agents. PEG is partly absorbed in the small intestine, and the unabsorbed fraction reaches the large intestine; thus, oral administration of PEG may impact the gut microbial community. However, to the best of our knowledge, no study evaluated the effects of PEG on gut commensal bacteria. Herein, we aimed to determine whether oral administration of PEG modifies the gut microbiota. Administration of PEG400 and PEG4000 altered gut microbial diversity in a concentration-dependent manner. Taxonomic analysis revealed that Akkermansia muciniphila and particularly Parabacteroides goldsteinii were overrepresented in mice administered with 40% PEG. PEG400 administration ameliorated the high-fat diet (HFD)-induced obesity and adipose tissue inflammation. Fecal microbiome transplantation from PEG400-administered donors counteracted the HFD-induced body and epididymal adipose tissue weight gain, indicating that PEG400-associated bacteria are responsible for the anti-obesity effect. Conversely, carboxymethyl cellulose, also used as a dispersant, did not affect the abundance of these two bacterial species or HFD-induced obesity. In conclusion, we demonstrated that oral administration of a high concentration of PEG400 (40%) alters the gut microbiota composition and ameliorates HFD-induced obesity.
Scope The purpose of this study is to compare the impact of four low‐viscosity soluble dietary fibers (DFs) on the intestinal microenvironment, in terms of microbiota composition, short‐chain fatty acid (SCFA) production, proportion of colonic peripherally induced regulatory T cells (pTregs), and experimental colitis in mice. Methods and results Mice are administered 5% w/v low‐viscosity soluble DFs in drinking water for 2 weeks. The gut microbiota composition is determined using 16S rRNA sequencing. Luminal SCFAs are quantified by gas chromatography, and colonic pTregs are analyzed using flow cytometry. All low‐viscosity soluble DFs promote the growth of beneficial bacteria such as Akkermansia muciniphila and Bacteroides acidifaciens , while eliminating pathogenic bacteria such as Clostridium perfringens . Moreover, two low‐viscosity soluble DFs significantly increase the abundance of commensal bacteria and promote the accumulation of propionate and butyrate, leading to marked induction of colonic pTregs. Consistently, these two fibers, in particular α‐cyclodextrin, show remarkable anti‐inflammatory properties in a colitis mouse model. Conclusion Mice administered any low‐viscosity soluble DF show comparable gut microbiota compositions, but differ in terms of bacterial abundance, SCFA concentration, pTreg population, and colitis development. This exploratory study suggests that administration of α‐cyclodextrin may be a possible strategy for the prevention of colitis.
The health benefits of wheat-derived arabinoxylan, a commonly consumed dietary fiber, have been studied for decades. However, its effect on the gut microenvironment and inflammatory bowel disease remains unclear. The objective of this study was to understand the effect of wheat-derived arabinoxylan on gut microbiota, colonic regulatory T cells (Tregs), and experimental colitis. In this study, healthy and chronic colitis model mice were fed chow containing cellulose or wheat-derived arabinoxylan for 2-6 weeks and subjected to subsequent analysis. A 16S-based metagenomic analysis of the fecal DNA revealed that Lachnospiraceae, comprising butyrate-producing and Treg-inducing bacteria, were overrepresented in arabinoxylan-fed mice. In line with the changes in the gut microbiota, both the fecal butyrate concentration and the colonic Treg population were elevated in the arabinoxylan-fed mice. In a T cell transfer model of chronic colitis, wheat-derived arabinoxylan ameliorated body weight loss and colonic tissue inflammation, which may, in part, be mediated by Treg induction. Moreover, wheat-derived arabinoxylan suppressed TNFα production from type 1 helper T cells in this colitis model. In conclusion, wheat-derived arabinoxylans, by altering the gut microenvironment, may be a promising prebiotic for the prevention of colitis.
Soluble oat fiber increased colonic butyrate, peripherally-induced Treg cells and thus alleviated TNBS-induced colitis, which coincided with overrepresentation of F. rodentium (a human analog of H. biformis ) possessing butyrate-producing metagenomes.
Isoliquiritigenin (ILG) has been reported to attenuate adipose tissue inflammation and metabolic disorder; however, the underlying mechanisms remain to be elucidated. The aim of this study is to elucidate whether ILG shows the anti-inflammatory and antimetabolic syndrome effects through gut microbiota modification.Mice are fed a high-fat diet (HFD) with or without ILG for up to 12 weeks. The effect of ILG on body weight, blood glucose level, adipose tissue inflammation, gut barrier function, and gut microbiota composition are investigated. ILG supplementation alleviates HFD-induced obesity, glucose tolerance, and insulin resistance and suppresses inflammatory gene expression in epididymal white adipose tissue (eWAT). Moreover, ILG supplementation modifies gut bacterial composition by increasing the abundance of antimetabolic disease-associated species (e.g., Parabacteroides goldsteinii and Akkemansia muciniphila) and up-regulated genes associated with gut barrier function. Fecal microbiome transplantation (FMT) from ILG-fed donors counteract HFD-induced body and eWAT weight changes, inflammation-related gene expression, glucose tolerance, and insulin resistance, thereby suggesting that ILG-responsive gut bacteria exerts anti-inflammatory and antimetabolic syndrome effects.Alterations in gut bacteria underly the beneficial effects of ILG against adipose tissue inflammation and metabolic disorders. ILG may be a promising prebiotic for the prevention and treatment of metabolic syndrome.
Mol. Nutr. Food Res. 2022, 66, 202101119 DOI: 10.1002/mnfr.202101119 Isoliquiritigenin (ILG), a flavonoid with a chalcone structure derived from Glycyrrhiza uralensis, beneficially modified gut microbiota by increasing the abundance of Akkermansia muciniphila and Parabacteroides goldsteinii. The altered composition of the gut bacteria by ILG restored impaired gut barrier function and prevented metabolic disorder in high fat diet-fed mice. This is reported by Riko Ishibashi and co-workers in article number 2101119.
