Bletilla striata oligosaccharides improve metabolic syndrome through modulation of gut microbiota and intestinal metabolites in high fat diet-fed mice

As traditional Chinese medicine, Bletilla striata has been widely applied to clinical treatment for its unique pharmacological profiles. This study aimed to investigate the beneficial role of Bletilla striata oligosaccharides (BO) in improving the metabolic syndrome by regulation of gut microbiota and intestinal metabolites. Treatment of HFD-fed mice with BO prevented weight gain, reversed the glucose intolerance and insulin resistance, and inhibited adipocyte hypertrophy. BO-treated mice also suppressed chronic inflammation and protected intestinal barrier from damage. These effects were linked to the reversal of gut microbiota dysbiosis, which contributed to the homeostasis of intestinal metabolites including bile acids, short-chain fatty acids and tryptophan catabolites. The depletion and reconstitution of intestinal flora from BO- or HFD-treated mice confirmed the significance of gut microbiota in regulation of HFD-induced metabolic disorders. We demonstrated for the first time that BO improved metabolic syndrome through the regulation of gut microbiota and intestinal metabolites. The modulation initiated by BO represents a promising strategy for treatment of obesity and related metabolic diseases.

Gut microbiota, a new frontier to understand traditional Chinese medicines

As an important component of complementary and alternative medicines, traditional Chinese medicines (TCM) are gaining more and more attentions around the world because of the powerful therapeutic effects and less side effects. However, there are still some doubts about TCM because of the questionable TCM theories and unclear biological active compounds. In recent years, gut microbiota has emerged as an important frontier to understand the development and progress of diseases. Together with this trend, an increasing number of studies have indicated that drug molecules can interact with gut microbiota after oral administration. In this context, more and more studies pertaining to TCM have paid attention to gut microbiota and have yield rich information for understanding TCM. After oral administration, TCM can interact with gut microbiota: (1) TCM can modulate the composition of gut microbiota; (2) TCM can modulate the metabolism of gut microbiota; (3) gut microbiota can transform TCM compounds. During the interactions, two types of metabolites can be produced: gut microbiota metabolites (of food and host origin) and gut microbiota transformed TCM compounds. In this review, we summarized the interactions between TCM and gut microbiota, and the pharmacological effects and features of metabolites produced during interactions between TCM and gut microbiota. Then, focusing on gut microbiota and metabolites, we summarized the aspects in which gut microbiota has facilitated our understanding of TCM. At the end of this review, the outlooks for further research of TCM and gut microbiota were also discussed.

The microbiome and its pharmacological targets: therapeutic avenues in cardiometabolic diseases

Consisting of trillions of non-pathogenic bacteria living in a symbiotic relationship with their mammalian host, the gut microbiota has emerged in the past decades as one of the key drivers for cardiometabolic diseases (CMD). By degrading dietary substrates, the gut microbiota produces several metabolites that bind human pharmacological targets, impact subsequent signalling networks and in fine modulate host's metabolism. In this review, we revisit the pharmacological relevance of four classes of gut microbial metabolites in CMD: short-chain fatty acids (SCFA), bile acids, methylamines and indoles. Unravelling the signalling mechanisms of the microbial-mammalian metabolic axis adds one more layer of complexity to the physiopathology of CMD and opens new avenues for the development of microbiota-based pharmacological therapies.