Anti-inflammatory activity of Boletus aereus polysaccharides: Involvement of digestion and gut microbiota fermentation

Boletus aereus, an edible mushroom, has gained popularity as a medicinal and functional food. This study aimed to investigate the digestive characteristics of B. aereus polysaccharide (BAP) and its effects on gut microbiota. In vitro digestion results indicated partial degradation of BAP. Furthermore, the digested BAP displayed significantly enhanced antioxidant ability. The 16S rRNA sequencing data revealed that BAP positively influenced the abundance of Phascolarctobacterium, Prevotella, and Bifidobacterium in the gut microbiota. Additionally, BAP promoted the production of short-chain fatty acids (SCFAs). Metabolites of BAP utilized by the gut microbiota effectively reduced the concentration of TNF-α, IL-1β, and NO in an LPS-stimulated RAW 264.7 cell inflammation model. Mantel tests demonstrated a strong correlation among fermentation indicators, gut microbiome composition, SCFAs, and inflammatory cytokines. Overall, this research revealed the underlying digestive and fermentation mechanisms of BAP and provided new insights into the usage of edible mushroom polysaccharides in functional food.