Astragaloside IV alleviates mouse slow transit constipation by modulating gut microbiota profile and promoting butyric acid generation.

Gut microbiota and short-chain fatty acids (SCFAs) are associated with the development of various human diseases. In this study, we examined the role of astragaloside IV in modulating mouse gut microbiota structure and the generation of SCFAs, as well as in slow transit constipation (STC). An STC model was established by treating mice with loperamide, in which the therapeutic effects of astragaloside IV were evaluated. The microbiota community structure and SCFA content were analysed by 16S rRNA gene sequencing and gas chromatography-mass spectrometry, respectively. The influence of butyrate on STC was assessed using a mouse model and Cajal cells (ICC). Astragaloside IV promoted defecation, improved intestinal mobility, suppressed ICC loss and alleviated colonic lesions in STC mice. Alterations in gut microbiota community structure in STC mice, such as decreased Lactobacillus reuteri diversity, were improved following astragaloside IV treatment. Moreover, astragaloside IV up-regulated butyric acid and valeric acid, but decreased isovaleric acid, in STC mouse stools. Butyrate promoted defecation, improved intestinal mobility, and enhanced ICC proliferation by regulating the AKT-NF-κB signalling pathway. Astragaloside IV promoted intestinal transit in STC mice and inhibited ICC loss by regulating the gut microbiota community structure and generating butyric acid.

He Q ，Han C ，Huang L ，Yang H ，Hu J ，Chen H ，Dou R ，Ren D ，Lin H ... -  《-》

Astragaloside IV improves slow transit constipation by regulating gut microbiota and enterochromaffin cells.

Purpose: Slow transit constipation (STC) is a common gastrointestinal disorder characterized by altered gut microbiota and reduced number of enterochromaffin cells (ECs). Astragaloside IV (AS-IV), a low drug permeability saponin, has showed beneficial effects on patients with STC. However, the specific mechanism by which AS-IV regulates STC remains unclear. In this study, we aimed to investigate the effect of AS-IV on STC and its associated mechanisms involving gut microbiota. Methods: The effect of AS-IV on STC was evaluated on STC mice induced with loperamide. We measured defecation frequency, intestinal mobility, ECs loss, and colonic lesions in STC mice treated with AS-IV. We also analyzed the changes in gut microbiota and metabolites after AS-IV treatment. Moreover, we investigated the relationship between specific gut microbes and altered fecal metabolites, such as 3-bromotyrosine (3-BrY). We also conducted in vitro experiments to investigate the effect of 3-BrY on caspase-dependent apoptosis of ECs and the activation of the p38 MAPK and ERK signaling pathways induced by loperamide. Results: AS-IV treatment promoted defecation, improved intestinal mobility, suppressed ECs loss, and alleviated colonic lesions in STC mice. AS-IV treatment also affected gut microbiota and metabolites, with a significant correlation between specific gut microbes and altered fecal metabolites such as 3-BrY. Furthermore, 3-BrY may potentially reduce caspase-dependent apoptosis of ECs and protect cell survival by inhibiting the activation of the p38 MAPK and ERK signaling pathways induced by loperamide. Conclusion: Our findings suggest that changes in gut microbiota and ECs mediated the therapeutic effect of STC by AS-IV. These results provide a basis for the use of AS-IV as a prebiotic agent for treating STC. The specific mechanism by which AS-IV regulates gut microbiota and ECs warrants further investigation.

Wan X ，Zhou Q ，Chen H ，Li Z ，Mo M ，Liu Z ，Zhang H ，He Z ，Xiao G ，Zheng Y ，Lin H ，Ren D ... -  《-》

Single-cell RNA sequencing reveals cellular dynamics and therapeutic effects of astragaloside IV in slow transit constipation.

Chen H ，Wan X ，He Q ，Xiao G ，Zheng Y ，Luo M ，Yang C ，Ren D ，Lu L ，Peng H ，Lin H ... -  《-》

Tongbian formula alleviates slow transit constipation by increasing intestinal butyric acid to activate the 5-HT signaling.

Slow transit constipation (STC) is a long-lasting and prevalent intestinal condition, marked by hard, dry feces. The primary cause of STC may be attributed to an imbalance in the gut's microbial community and alterations in its metabolic byproducts. Tongbian formula (TB), a traditional Chinese medicinal formula, has been used to treat STC and shows a great effect on relieving constipation. The role of TB in regulating intestinal microbiota has not been fully elucidated. Herein, we investigated the potential effect of TB on gut microbiota and further explored the potential mechanism behind its effects. Our study demonstrated that TB significantly increased fecal water content and intestinal ink propulsion rate in loperamide (Lope)-induced STC rats. 5-HT signaling was suppressed in STC colon tissue, and the abundance of butyric acid (BA) in colonic contents was significantly down-regulated after Lope treatment. Notably, TB administration led to the restoration of microbial dysbiosis and the up-regulation of BA content, subsequently activating 5-HT signaling pathways. When BA was combined with a tryptophan hydroxylase-1 (TPH1) inhibitor, which is crucial for 5-HT synthesis, its therapeutic efficacy for treating STC was compromised. TB alleviates STC by reversing the intestinal microbiota imbalance and activating the 5-HT signaling in the colon through increasing BA levels. These findings suggest that TB is an ideal candidate for STC treatment.

Li D ，Si X ，Hua Y ，Qian Y ，Li H ，Lv N ，Fang Q ，Han X ，Xu T ... -  《Scientific Reports》

Electro-acupuncture promotes gut motility and alleviates functional constipation by regulating gut microbiota and increasing butyric acid generation in mice.

Abnormalities in the gut microbiota and intestinal short-chain fatty acid (SCFA) levels are implicated in the pathogenesis of functional constipation (FC). Electro-acupuncture (EA) has been shown to improve constipation-related symptoms and rebalance the gut microbiota. However, it is currently unknown whether the gut microbiota is a key mechanistic target for EA or how EA promotes gut motility by regulating the gut microbiota and SCFAs. Therefore, we assessed the effects of EA in FC mice and pseudo-germfree (PGF) mice to address these questions. Forty female Kunming mice were randomly separated into a normal control group (n = 8), an FC group (n = 8), an FC + EA group (n = 8), a PGF group (n = 8) and a PGF + EA group (n = 8). The FC group and FC + EA group were treated with diphenoxylate to establish the FC model; the PGF group and PGF + EA group were given an antibiotic cocktail to initiate the PGF model. After maintaining the model for 14 d, mice in the FC + EA and PGF + EA groups received EA stimulation at the ST25 and ST37 acupoints, once a day, 5 times per week, for 2 weeks. Fecal parameters and intestinal transit rate were calculated to assess the efficacy of EA on constipation and gastrointestinal motility. Colonic contents were used to quantify gut microbial diversity using 16S rRNA sequencing, and measure SCFA concentrations using gas chromatography-mass spectrometry. EA significantly shortened the first black stool defecation time (P < 0.05) and increased the intestinal transit rate (P < 0.01), and fecal pellet number (P < 0.05), wet weight (P < 0.05) and water content (P < 0.01) over 8 h, compared with the FC group, showing that EA promoted gut motility and alleviated constipation. However, EA treatment did not reverse slow-transit colonic motility in PGF mice (P > 0.05), demonstrating that the gut microbiota may play a mechanistic role in the EA treatment of constipation. In addition, EA treatment restored the Firmicutes to Bacteroidetes ratio and significantly increased butyric acid generation in FC mice (P < 0.05), most likely due to the upregulation of Staphylococcaceae microorganisms (P < 0.01). EA-mediated resolution of constipation occurs through rebalancing the gut microbiota and promoting butyric acid generation. Please cite this article as: Xu MM, Guo Y, Chen Y, Zhang W, Wang L, Li Y. Electro-acupuncture promotes gut motility and alleviates functional constipation by regulating gut microbiota and increasing butyric acid generation in mice. J Integr Med. 2023; Epub ahead of print.

Xu MM ，Guo Y ，Chen Y ，Zhang W ，Wang L ，Li Y ... -  《-》