Mushroom β-glucans as immunomodulators: Elucidation of structure-function relationship

Mushrooms are the fruiting bodies of fungi and are recognized as abundant sources of essential nutrients and bioactive molecules. β-Glucans are naturally occurring fungal cell wall polysaccharides identified as non-toxic modulators of the immune system, making them ideal candidates for natural immunotherapy, and a promising dietary intervention through their application as a functional food. Notably, there is a vast structural diversity among β-glucans isolated from various fungal species, resulting in differences in their immunomodulatory activities. This structural heterogeneity has led to the unsolved question - which β-glucan/s have the most potent biological and/or immunological properties. While there is extensive literature on the structure and function of mushroom β-glucans, their structure-function relationships remain unclear. In this report we will consolidate the insights related to the diversity of mushroom β-glucan structure and immunomodulatory activity with specific emphasis on structure-function relationships, as well as the effect of extraction and purification techniques on β-glucan structure and immune activity.