Oyster powder supplementation enhances immune function in mice partly through modulating the gut microbiota and arginine metabolism.

Oysters are well-known for their health benefits such as immuno-modulatory functions. The intestinal microbiome serves as a key mediator between diet and immune regulation. This study aimed to investigate whether oyster consumption could alleviate cyclophosphamide (Cy)-induced immunosuppression by promoting intestinal homeostasis. In mice treated with Cy, a significant decrease in immune cells and cytokines was observed. In contrast, mice supplemented with oyster powder demonstrated elevated numbers of immune cells in the spleen and small intestine, as well as enhanced serum production of IL-1β, IL-2, TNF-α, and IFN-γ. Furthermore, oyster consumption improved the composition of the gut microbiota by promoting beneficial bacteria and inhibiting harmful ones. Metabolomics analysis revealed that oyster powder treatment significantly enhanced the arginine biosynthesis pathway, and further analysis found that the consumption of oysters led to increased arginine levels. Correlation analysis showed a significant positive correlation between L-arginine and immune-related markers. Collectively, these findings suggest that oyster consumption may enhance immunity by modulating the gut microbiota and boosting arginine biosynthesis pathways. Dietary oyster consumption could be an effective strategy to support immune health.