Harnessing β-glucans for immune regulation: Bridging structural diversity, therapeutic potential, and functional food...

β-Glucans are natural polysaccharides with significant structural heterogeneity, originating from sources such as grains, mushrooms, yeast, and bacteria. Their diverse immunomodulatory properties are fundamentally governed by this structural complexity. This review comprehensively analyzes structurally diverse β-glucans and their absorption pathways and mechanisms of action following oral or parenteral administration. In addition, it elucidates their interactions with specific receptors including Dectin-1 and Toll-like receptors (TLRs), which play critical roles in mediating their immunomodulatory effects. The review further details their immunomodulatory functions, highlighting their role in enhancing anti-tumor and anti-infection responses through the induction of trained immunity, alongside modulating immunity via alterations in gut microbial composition and regulation of metabolite production. Finally, we discuss the translational potential of β-glucans for diverse biomedical applications, including drug delivery systems, immunoadjuvants, wound dressings and functional foods. These insights underscore β-glucans as versatile immunomodulators, paving the way for innovative strategies in precision nutrition and the development of next-generation adjuvants for oncological, immunological, and metabolic interventions.