Lactobacillus rhamnosus is a well-studied probiotic bacterium, and there is scientific evidence suggesting that it can modulate the immune system, including effects on Peyer’s patches. Peyer’s patches are specialized lymphoid follicles in the small intestine that play a central role in mucosal immunity by sampling antigens and facilitating immune responses. Several animal studies have demonstrated that administration of L. rhamnosus can enhance the function of Peyer’s patches, primarily by increasing the production of secretory IgA and stimulating dendritic cells and T cells within these lymphoid tissues (see: Kaila et al., 1992; Gill et al., 2000). These immunomodulatory effects are believed to contribute to enhanced gut barrier function and resistance to intestinal pathogens.

However, much of the evidence for direct support of Peyer’s patches by L. rhamnosus comes from animal models or in vitro research. Human studies tend to examine broader outcomes such as immune function or resistance to infection, with indirect implications for Peyer’s patches. While the mechanistic rationale is strong and there are consistent findings in preclinical models, direct clinical validation in humans is limited, which is why the evidence is rated as moderate (3/5). Overall, the use of L. rhamnosus to support the immune functions of Peyer’s patches is scientifically plausible, but more targeted human studies are needed for stronger validation.