A comprehensive update on the immunoregulatory mechanisms of : insights into active ingredients, metabolites, and nutrient-driven modulation.

() has gained recognition as a pioneering probiotic, exhibiting considerable potential to enhance immune conditions across both humans and animals. The health benefits of are attributed to its various components, including outer membrane proteins (PilQ and Amuc_1100), secreted proteins (P9 and AmTARS), extracellular vesicles, and metabolites such as SCFAs, ornithine lipids, -aminobutyric acid, cobalamin, and inosine. The dynamic control of the mucus layer by plays a crucial role in regulating intestinal mucosal immunity. Furthermore, modulates immune function by interacting with macrophages, dendritic cells, T lymphocytes, and Paneth cells. Increasing the abundance of in the gut through nutritional strategies represents a safe and effective means to augment immune function. Various polyphenols, oligosaccharides, and polysaccharides have been shown to elevate the levels of this bacterium, thereby contributing to favorable immunoregulatory outcomes. This paper delves into the latest research advancements related to the probiotic mechanisms of and provides an overview of the current understanding of how its abundance responds to nutrients. These insights offer a theoretical foundation for the utilization of in immunoregulation.