Beta-d-(1 → 4)-galactan-containing side chains in RG-I regions of pectic polysaccharides from Biophytum petersianum Klotzsch. contribute to expression of immunomodulating activity against intestinal Peyer's patch cells and macrophages

► Immunomodulating activities of pectins from Biophytum petersianum is demonstrated. ► Hairy region is most important for immunomodulating activity on Peyer's patches and macrophages. ► 1,4 linked galactose first time shown to be important for effect on Peyer's patches and macrophages. ► Both 1,4 and 1,3 linked galactose enhance production of IL-6.