Transfer Factor is a term for low-molecular-weight molecules, primarily oligopeptides, derived from immune cells (often sourced from colostrum or leukocyte extracts). Their use to support the immune system, specifically structures like Peyer’s patches in the gut-associated lymphoid tissue (GALT), has some scientific basis. Peyer’s patches are integral to mucosal immunity, sampling antigens and coordinating immune responses in the intestines. Some studies suggest that orally administered Transfer Factor can modulate immune responses, enhance cellular immunity, and affect cytokine production. Small clinical trials and animal studies have reported immune modulation and improved resistance to certain infections after supplementation with Transfer Factor. However, most research is preliminary, with limited large-scale, well-controlled human trials. There is some in vitro and in vivo evidence that Transfer Factor can facilitate communication between immune cells and potentially prime mucosal immunity, which may indirectly support Peyer’s patch function. Nevertheless, direct evidence specifically linking Transfer Factor supplementation to enhanced Peyer’s patch activity in humans is sparse. Most claims rely on broader immunomodulatory effects rather than specific mechanistic data regarding Peyer’s patches. Therefore, while the scientific rationale exists and some early studies are promising, the strength of evidence is modest and further research is needed to substantiate specific claims.