Tongbian decoction restores intestinal microbiota and activates 5-hydroxytryptamine signaling: implication in slow transit constipation.

Slow transit constipation (STC) is a type of functional constipation. The detailed mechanism of STC, for which there is currently no effective treatment, is unknown as of yet. Tongbian decoction (TBD), a traditional Chinese medicinal formula, is commonly used to treat STC in clinical settings. However, the potential impact of TBD on the management of STC via modulation of the gut microbiota remains unclear. Pseudo-germ-free rats were constructed after 6 days of treatment with bacitracin, neomycin, and streptomycin (abbreviated as ABX forthwith). Based on the successful construction of pseudo-germ-free rats, the STC model (ABX + STC) was induced using loperamide hydrochloride. After successful modeling, based on the different sources of donor rat microbiota, the ABX + STC rats were randomly divided into three groups: Control → ABX + STC, STC → ABX + STC, and STC + TBD → ABX + STC for fecal microbiota transplant (FMT). Body weight, fecal water content, and charcoal power propelling rate of the rats were recorded. Intestinal microbiota was detected by 16S rRNA sequencing, and the 5-hydroxytryptamine (5-HT) signaling pathway was examined by western blots, immunofluorescence, and immunohistochemical analysis. After treatment with fecal bacterial solutions derived from rats treated with Tongbian decoction (TBD), there was an increase in body weight, fecal water content, and the rate of charcoal propulsion in the rats. Additionally, activation of the 5-hydroxytryptamine (5-HT) signaling pathway was observed. The 16S rRNA sequencing results showed that the fecal bacterial solution from TBD-treated rats affected the intestinal microbiota of STC rats by increasing the proliferation of beneficial bacteria and suppressing the expansion of harmful bacteria. Our study showed that TBD alleviated constipation in STC rats by modulating the structure of the intestinal microbiota.

Li H ，Lv N ，Li D ，Qian Y ，Si X ，Hua Y ，Wang Y ，Han X ，Xu T ... -  《Frontiers in Microbiology》

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》

Yunpi Tongbian Fang alleviates slow transit constipation induced by loperamide by regulating intestinal microbiota and short-chain fatty acids in rats.

Xu W ，Xu S ，Feng R ，Zeng L ... -  《-》

Correlation between slow transit constipation and spleen deficiency, and gut microbiota: a pilot study.

Zeyue YU ，Liyu H ，Zongyuan LI ，Jianhui S ，Hongying C ，Hairu H ，Xiaoqin LI ，Zhongchao S ，Hongmei LI ... -  《-》

Xiao Cheng Qi Decoction, an Ancient Chinese Herbal Mixture, Relieves Loperamide-Induced Slow-Transit Constipation in Mice: An Action Mediated by Gut Microbiota.

Tuohongerbieke A ，Wang H ，Wu J ，Wang Z ，Dong T ，Huang Y ，Zhu D ，Sun D ，Tsim KWK ... -  《-》