Bifidobacterium adolescentis has been investigated for its potential immunomodulatory effects, including impacts on Peyer’s patches, which are important lymphoid tissues in the gut-associated lymphoid tissue (GALT) system. Peyer’s patches play a critical role in the initiation of immune responses in the intestine. Several animal studies have shown that oral administration of B. adolescentis can enhance the number and activity of immune cells within Peyer’s patches. For example, research in mice has demonstrated that B. adolescentis can stimulate IgA production and increase the presence of dendritic cells and lymphocytes in Peyer’s patches, suggesting an upregulation of mucosal immunity (Yasui et al., 1999, Immunology; Nakayama et al., 2004, Microbiology and Immunology). These effects are thought to be mediated by the interaction between microbial-associated molecular patterns and immune cells in the gut mucosa.

However, direct human evidence is limited. While studies in humans support the general role of bifidobacteria in gut and immune health, specific data linking B. adolescentis supplementation to enhanced function of Peyer’s patches in humans is lacking. Therefore, while preclinical evidence is moderately supportive, clinical validation remains incomplete. The overall evidence base justifies a mid-level score for scientific support of this application.