Prebiotic and immunomodulatory potential of Heimioporus sp. polysaccharides: An in vitro study

The increasing awareness of the importance of a healthy lifestyle has encouraged individuals to consume functional food rich in bioactive components. Mushroom polysaccharides, particularly those extracted from edible Heimioporus sp., have been reported to exhibit antioxidant, antibacterial and hypoglycemic activity. Nevertheless, the prebiotic and immunomodulatory potential of Heimioporus sp. remains underexplored. This study aimed to evaluate the prebiotic and immunomodulatory potential of Heimioporus sp. polysaccharide (HP) extracted using ultrasound-assisted hot water extraction. The prebiotic potential was evaluated using L. acidophilus IFO 13951 and B. breve ATCC 15700 for its prebiotic score, pH changes, and production of short-chain fatty acids (SCFAs). Furthermore, its immunomodulatory potential was assessed via nitric oxide (NO) in lipopolysaccharide-induced RAW 264.7 cells followed by HP composition analysis using HPLC. The results demonstrated that HP exhibited high prebiotic scores in L. acidophilus (56.01) and B. breve (55.53) after 48 h of incubation. HP fermented by B. breve was shown to have a lower pH than L. acidophilus, whereas SCFAs produced mainly acetic acid with a concentration of 42.66 mM and 24.08 mM, respectively. The immunomodulatory activity proved HP could modulate the immune system by increasing the NO level in non-LPS-induced macrophage similar to positive control (28.52 ), although its inflammatory mechanism requires further study. Most of the HP composition was fructooligosaccharide, which confirms its potential. Thus, HP show potential as prebiotics for gut health and functional food applications. © 2025