Conclusion
Gut microbes are indispensable in the gut, and their metabolic roles
have been widely studied using metabolomics and bacterial profiling. BAs
are metabolized into various configurations by bacteria in the gut and
serve as signaling molecules to regulate immunocytes such as Th17 cells
and Treg cells in the intestine, thereby regulating intestinal immune
balance. The intricate network of relationships among the gut flora,
BAs, immunocytes, and cytokines is closely related to multiple diseases
throughout the body. Therefore, related research will be conducive to
the development of drugs for treating multiple diseases. Research on the
mechanism of the activation effect of TGR5 and FXR in macrophages, DC,
NKT cells, MDSC, B cells, and intestinal epithelial cells contributes to
the development of molecular-targeted drugs. At present, these studies
have mainly focused on liver diseases and ischemia-reperfusion injury.
These results support the possibility of using intestinal microbial
community analysis techniques, metabolomics analysis, and single-cell
sequencing techniques to further explore the immunocyte subgroup
regulated by the intestinal flora in the tumor immune microenvironment.