Metagenomics and metabolomics analysis to investigate the effect of Shugan decoction on intestinal microbiota in irritable bowel syndrome rats

Dangua Fang induces anti-glucolipid metabolism disorder effects similar to those of direct NFIL3 inhibition

Background

Dangua Fang (DGF) is a traditional Chinese herbal formula widely used to regulate glucolipid metabolism. Nuclear factor, interleukin-3 regulated (NFIL3) plays a regulatory role in intestinal fat absorption and energy metabolism. Gut microbiota can modulate NFIL3 expression and affect host metabolism.

Purpose

This study aimed to investigate the effects of DGF or NFIL3 inhibition on the gut microbiota and their metabolites in mice with glucolipid metabolism disorder (GLMD) and explore the relationship between DGF anti-GLMD effects and those of direct NFIL3 inhibition.

Methods

A GLMD mouse model was established by induction with a high-glucose and high-fat diet. The mice were divided into the control group (CG), model group (MG), DGF group (DFG), DGF + siRNA group (DFSG), and siRNA group (SG). The mice were administered sterile water, DGF, and/or intraperitoneal injections of siRNA-NFIL3 or normal saline for 15 weeks, following which glucolipid metabolic indicators, NFIL3 levels, and histopathological alterations in the liver and small intestinal tissues were evaluated. Additionally, the gut microbiota and differential metabolites were analysed, and linear regression analysis was conducted between gut microbial species and metabolic indicators to assess the role of the gut microbiota in metabolic regulation.

Results

Significant differences were observed between the CG and MG groups for various indicators. Compared with that in the MG group, the GLMD in the DFG, DFSG, and SG groups was significantly improved, and the pathological morphology of the liver and small intestine was altered. The NFIL3 mRNA and protein expression levels in the serum, liver, and small intestine were significantly decreased. The relative abundance of Bacteroidota decreased, whereas that of Firmicutes increased, and changes in the gut microbiota significantly correlated with serum total cholesterol (TC), triglyceride (TG), and free fatty acid (FFA) levels. Moreover, lipid metabolism-related pathways were significantly altered in all three intervention groups.

Conclusion

DGF reduced NFIL3 expression in GLMD mice, regulated the gut microbiota and their metabolites, and altered lipid metabolism-related pathways, with anti-GLMD effects similar to those of direct NFIL3 inhibition.

Traditional Chinese medicine for functional gastrointestinal disorders and inflammatory bowel disease: narrative review of the evidence and potential mechanisms involving the brain-gut axis

Functional gastrointestinal disorders (FGIDs) and inflammatory bowel disease (IBD) are common clinical disorders characterized by recurrent diarrhea and abdominal pain. Although their pathogenesis has not been fully clarified, disruptions in intestinal motility and immune function are widely accepted as contributing factors to both conditions, and the brain-gut axis plays a key role in these processes. Traditional Chinese Medicine (TCM) employs a holistic approach to treatment, considers spleen and stomach impairments and liver abnormality the main pathogenesis of these two diseases, and offers a unique therapeutic strategy that targets these interconnected pathways. Clinical evidence shows the great potential of TCM in treating FGIDs and IBD. This study presents a systematic description of the pathological mechanisms of FGIDs and IBD in the context of the brain-gut axis, discusses clinical and preclinical studies on TCM and acupuncture for the treatment of these diseases, and summarizes TCM targets and pathways for the treatment of FGIDs and IBD, integrating ancient wisdom with contemporary biomedical insights. The alleviating effects of TCM on FGID and IBD symptoms are mainly mediated through the modulation of intestinal immunity and inflammation, sensory transmission, neuroendocrine-immune network, and microbiota and their metabolism through brain-gut axis mechanisms. TCM may be a promising treatment option in controlling FGIDs and IBD; however, further high-quality research is required. This review provides a reference for an in-depth exploration of the interventional effects and mechanisms of TCM in FGIDs and IBD, underscoring TCM's potential to recalibrate the dysregulated brain-gut axis in FGIDs and IBD.

Tong-Xie-Yao-Fang strengthens intestinal feedback control of bile acid synthesis to ameliorate irritable bowel syndrome by enhancing bile salt hydrolase-expressing microbiota

ETHNOPHARMACOLOGICAL RELEVANCE

A herbal formula Tong-Xie-Yao-Fang (TXYF) is traditionally used to treat irritable bowel syndrome (IBS), modern pharmacological evidence supports that the formula efficacy is associated with altered gut microbiota. Yet, the mechanistic role of gut microbiota in the therapy of TXYF remains unclear. We previously clarified that gut microbiota-dysregulated bile acid (BA) metabolism contribute to the pathogenesis of IBS, deriving a hypothesis that microbiota-BA metabolic axis might be a potential target of TXYF.

AIM OF THE STUDY

We aim to investigate a new gut microbiota-mediated mechanism underlying anti-IBS efficacy of TXYF.

MATERIALS AND METHODS

We established an IBS rat model with a combination of stressors, compared the herbal efficacy in models undergone gut bacterial manipulations, also examined BA metabolism-related microbiota, metabolites, genes and proteins by 16S rRNA gene sequencing, targeted metabolomics, qPCR and multiplex immunofluorescence staining.

RESULTS

We observed that TXYF attenuated visceral hyperalgesia and diarrhea in IBS rats but not in those underwent gut bacteria depletion. Transferring gut microbiota from TXYF-treated donors also decreased visceral sensitivity and slightly relief diarrhea-like behaviors in IBS recipient rats. Fecal 16S rRNA gene sequencing revealed that TXYF modulated microbial β-diversity and taxonomic structure of IBS rats, with a significant increase in relative abundance of bile salt hydrolase (BSH)-expressing Bacteroidaceae. qPCR and culturing data validated that TXYF had a promotive effect on the growth and BSH activity of Bacteroides species. TXYF-reshaped microbiota upregulated the expression of intestinal Fgf15, a feedback signal to control BA synthesis in the liver. As a result, the BA synthetic and excretory levels in IBS rats were decreased by TXYF, so as that colonic BA membrane receptor Tgr5 sensing and its mediated Calcitonin gene-related peptide (Cgrp)-positive neuronal response were attenuated.

CONCLUSION

This study poses a new microbiota-driven therapeutic action for TXYF, highlighting the potential of developing new anti-IBS strategies from the herbal formula targeting BSH-expressing gut bacteria.

Chaihu Shugan prevents cholesterol gallstone formation by ameliorating the microbiota dysbiosis and metabolic disturbance in mice

Introduction: Cholesterol gallstone (CGS) is a biliary tract disorder requiring treatment in approximately 20% of patients. The efficacy of Chaihu Shugan in preventing CGS recurrence after successful treatment remains uncertain. Methods: We examined the in vivo preventive efficacy of Chaihu Shugan using a CGS mouse model and used multi-omics to study the interplay between gut microbiota, metabolism, and gene expression. Results: The intestinal microbiota was severely dysregulated during the formation of CGS, showing a marked decrease in the abundance of beneficial microbiota, especially Lactobacillus and Akkermansia. Chaihu Shugan prevented CGS formation by restoring the composition of the gut microbiota and reversing the metabolic disturbances caused by dysbiosis. This preventive effect of Chaihu Shugan was paralleled by changes in the expression of metabolism-related genes in the liver. A network pharmacology analysis of Chaihu Shugan revealed that obacunone may be the key active metabolite in regulating bile acid metabolism. Multi-omics and correlation analyses elucidated the interplay between gut microbiota, metabolism, and gene alterations in the dose-dependent effect of Chaihu Shugan. Conclusion: Our data show that Chaihu Shugan can prevent CGS and indicate its mechanisms of action.