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Intestinal flora is a diversified and dynamic micro-ecosystem, whose structure and function have become a research hotspot in life sciences and medicine. The close relationship between intestinal flora and metabolic diseases has been verified by numerous studies. Traditional Chinese medicine (TCM) is used for disease prevention and treatment within China and is attracting attention and receiving more and more recognition from other countries all over the world. Consequently, the interaction of the two hotspots deserves further investigation. Although TCM has been put into practice for thousands of years, the study of its specific mechanism of action and related targets for the treatment of endocrine diseases is still at an exploratory stage. For TCM with oral administration as the main usage, the key targets of their active ingredients may be inextricably linked to the decomposition and metabolic effects of certain intestinal bacterium. All these hypotheses need to be tested further.

The composition of gut microbiota plays a critical role in maintaining the host's health, particularly in regulating immune homeostasis and the intestinal immune response. A massive effort has pointed to the importance of these interactions in various intestinal diseases like colorectal cancer (CRC), irritable bowel syndrome (IBS), and inflammatory bowel disease (IBD). Microbiome influences the formation of key components of both the innate and adaptive immune systems, while the immune system is responsible for regulating and maintaining the symbiotic relationship between the host and microbes. Currently, the crosstalk between gut flora and host immunity is not fully revealed in both homeostasis maintenance and disease development. Hence detailed mechanistic studies are needed to further explore the microbial manipulation on host immunity as well as the immune response to microbiome dysbiosis in intestinal diseases. Current evidence indicates a strong bidirectional interaction between microbiome perturbation and immune dysregulation. The aim of this Research Topic is to create a platform for the advancement of research on the causal relationship between the microbiome and immunity. Besides, we would like to define the core microbiota responsible for the initiation and progression of intestinal diseases, the molecular mechanisms of host immune-microbiome interactions, and novel gut-targeted pharmacological interventions to achieve a positive impact on intestinal disease.