Immunomodulatory effects and mechanisms of polysaccharides from plant-based functional foods and edible Fungi: A scoping review

Background Polysaccharides from medicinal and edible plants, as well as edible fungi, have garnered attention for their immunomodulatory potential due to their multi-target activity and high safety profiles. However, existing evidence remains fragmented and lacks integration. This scoping review mapped evidence on their effects, mechanisms, and research gaps. Methods Following the Arksey and O'Malley framework and PRISMA-ScR guidance, seven Chinese and English databases were searched for studies published from January 1, 2020 to March 1, 2026. The protocol was registered in INPLASY (INPLASY202610102). Data were synthesized by study type, disease category, polysaccharide type, immune effects, mechanisms, and safety. Results Of 294 studies, animal (37.07%) and in vitro studies (30.61%) predominated, with few clinical studies (4.08%). Polysaccharides showed context-dependent immunomodulation, mainly via TLR/MyD88/NF-κB, MAPK, and NLRP3 pathways. Conclusions Plant and edible fungal polysaccharides show potential, but evidence remains largely preclinical, heterogeneous, and clinically limited. Future studies should prioritize clinical validation, standardized preparations, mechanistic verification, and safety monitoring.