Antidiabetic Effects of Gegen Qinlian Decoction via the Gut Microbiota Are Attributable to Its Key Ingredient Berberine

Gegen Qinlian Decoction(GQD),a traditional Chinese medicine(TCM)formula,has long been used for the treatment of common metabolic diseases,including type 2 diabetes mellitus.However,the main limitation of its wider application is ingredient complexity of this formula.Thus,it is critically important to identify the major active ingredients of GQD and to illustrate mechanisms underlying its action.Here,we compared the effects of GQD and berberine,a hypothetical key active pharmaceutical ingredient of GQD,on a diabetic rat model by comprehensive analyses of gut microbiota,short-chain fatty acids,proinflammatory cytokines,and ileum transcriptomics.Our results show that berberine and GQD had similar effects on lowering blood glucose levels,modulating gut microbiota,inducing ileal gene expression,as well as relieving systemic and local inflammation.As expected,both berberine and GQD treatment significantly altered the overall gut microbiota structure and enriched many butyrate-producing bacteria,including Faecalibacterium and Roseburia,thereby attenuating intestinal inflammation and lowering glucose.Levels of short-chain fatty acids in rat feces were also significantly elevated after treatment with berberine or GQD.Moreover,concentration of serum proinflammatory cytokines and expression of immune-related genes,including Nfkb1,Stat1,and Ifnrg1,in pancreatic islets were significantly reduced after treatment.Our study demonstrates that the main effects of GQD can be attributed to berberine via modulating gut microbiota.The strategy employed would facilitate further standardization and widespread application of TCM in many diseases.

Of genes and microbes： solving the intricacies in host genomes

Microbiome research is a quickly developing field in biomedical research, and we have witnessed its poten- tial in understanding the physiology, metabolism and immunology, its critical role in understanding the health and disease of the host, and its vast capacity in disease prediction, intervention and treatment. However, many of the fundamental questions still need to be addressed, including the shaping forces of microbial diversity between individuals and across time. Microbiome research falls into the classical nature vs. nurture sce- nario, such that host genetics shape part of the micro- biome, while environmental influences change the original course of microbiome development. In this review, we focus on the nature, i.e., the genetic part of the equation, and summarize the recent efforts in understanding which parts of the genome, especially the human and mouse genome, play important roles in determining the composition and functions of microbial communities, primarily in the gut but also on the skin. We aim to present an overview of different approaches in studying the intricate relationships between host genetic variations and microbes, its underlying philos- ophy and methodology, and we aim to highlight a few key discoveries along this exploration, as well as current pitfalls. More evidence and results will surely appear in upcoming studies, and the accumulating knowledge will lead to a deeper understanding of what we could finally term a ＂hologenome＂, that is, the orga- nized, closely interacting genome of the host and the microbiome.