Arabinogalactans are polysaccharides found in various plants, especially larch trees (Larix spp.). Their use to support immune function, particularly relating to the gut-associated lymphoid tissue (GALT) and Peyer’s patches, is based on emerging scientific evidence. Peyer’s patches are key lymphoid structures in the small intestine that play a critical role in mucosal immunity.

Some animal studies and in vitro research indicate that arabinogalactans can stimulate immune responses, including the activation of macrophages and natural killer cells, and may enhance the production of cytokines. A few studies suggest that orally consumed arabinogalactan can increase the number and activity of immune cells in the gut, potentially via fermentation by gut microbiota and the subsequent production of short-chain fatty acids, which have immune-modulating effects.

However, direct evidence specifically linking arabinogalactan to enhanced function or structure of Peyer’s patches in humans is limited. Most human clinical studies have focused on broader immune markers, such as the response to vaccines or upper respiratory tract infections, rather than direct effects on Peyer’s patches. Thus, while there is a plausible mechanism and some preclinical support, the clinical evidence remains preliminary and indirect.

In summary, the scientific rationale for using arabinogalactans to support Peyer’s patches exists but is not robustly validated in humans, warranting a modest evidence rating.