Amelioration of Metabolic Syndrome by Co-Administration of Lactobacillus johnsonii CRL1231 and Wheat Bran in Mice via Gut Microbiota and Metabolites Modulation

TL;DR

Combining a specific Lactobacillus strain with wheat bran improves metabolic syndrome in mice by altering gut bacteria and metabolites.

Contribution

The study demonstrates a synergistic dietary approach using Lactobacillus johnsonii and wheat bran to alleviate metabolic syndrome through gut microbiota and metabolite modulation.

Findings

Co-administration of Lactobacillus johnsonii and wheat bran reduced adiposity and improved cholesterol levels in mice.

The treatment increased beneficial gut bacteria and decreased harmful ones, while also reducing inflammation and liver damage.

Colonic feruloyl esterase activity and FA-derived metabolites were elevated, contributing to metabolic improvements.

Abstract

Background/Objectives: Lactobacillus johnsonii CRL1231 (Lj CRL1231) is a strain with feruloyl esterase (FE) activity that enhances ferulic acid (FA) release from wheat bran (WB) and has potential as a probiotic for metabolic syndrome (MS). Given the potential health benefits of FA and its microbial metabolites, this study aimed to evaluate the therapeutic effect of Lj CRL1231 co-administered with WB in a mouse model of metabolic syndrome (MS) induced by a high-fat diet (HFD). Methods: Mice were divided into three groups and fed for 14 weeks as follows: the Control group (standard diet), the MS group (HFD+WB), and the MS+Lj group (HFD+WB and Lj CRL1231-dose 108 cells/day). Specifically, we analyzed the changes in the intestinal microbiota (IM), colonic FE activity, generation of FA-derived and fermentation metabolites, and metabolic and inflammatory parameters. Results: Improvements in the MS+Lj group compared to the MS group included the following: a—a 38% increase in colonic FE activity, leading to elevated levels of FA-derived metabolites (e.g., dihydroferulic, dihydroxyphenylpropionic, and hydroxyphenylpropionic acids); b—a significant shift in the IM composition, with a 3.4-fold decrease in Firmicutes and a 2.9-fold increase in Bacteroidetes; c—a decrease in harmful bacteria (Desulfovibrio) by 93%, and beneficial bacteria like Bifidobacterium increased significantly (6.58 log cells/g); d—a 33% increase in total SCFAs; e—a 26% reduction in the adiposity index; f—a 12% increase in HDL cholesterol and a 19% reduction in triglycerides; g—normalized glucose and insulin resulting in a 2-fold lower HOMA-IR index; h—an improved inflammatory profile by decreasing TNF-α, IFN-γ, and IL-6 (3-, 5-, and 2-fold, respectively) and increasing IL-10 by 2-fold; i—alleviation of liver damage by normalizing of transaminases AST (19.70 ± 2.97 U/L) and ALT (13.12 ± 0.88 U/L); j—evidence of reduced oxidative damage. Conclusions: The co-administration of L. johnsonii CRL1231 and WB exerts a synergistic effect in mitigating the features of MS in HFD-fed mice. This effect is mediated by modulation of the gut microbiota, increased release of bioactive FA-derived compounds, and restoration of metabolic and inflammatory homeostasis. This strategy represents a promising dietary approach for MS management through targeted microbiota–metabolite interactions.

Figures