Butyric acid, a short-chain fatty acid (SCFA) produced by gut microbial fermentation of dietary fiber, has a growing body of scientific evidence supporting its role in gut immune function, including effects on Peyer’s patches, which are important lymphoid tissues in the small intestine that help regulate mucosal immunity. Several animal and in vitro studies have demonstrated that butyric acid can influence the immune environment of the gut by promoting regulatory T cell (Treg) differentiation, modulating cytokine production, and enhancing the integrity of the intestinal barrier.

Specifically, butyrate has been shown to affect the function and development of Peyer’s patches. For example, studies in mice have found that butyrate can increase IgA production, likely through its action on B cells within Peyer’s patches. There is also evidence that butyrate exerts anti-inflammatory effects, reducing gut inflammation and supporting immune tolerance. The mechanism involves histone deacetylase (HDAC) inhibition, which alters gene expression in immune cells. While direct human clinical trials specifically linking butyric acid supplementation to Peyer’s patch function are limited, the mechanistic and animal data provide a rationale for its use to support mucosal immunity associated with these lymphoid tissues.

In summary, while more targeted human studies are needed, there is moderate scientific evidence that butyric acid supports the immune functions of Peyer’s patches, primarily through its immunomodulatory and barrier-enhancing effects in the gut.