Simulated gut microbiota fermentation of polysaccharide extracts from Ganoderma lucidum and Ganoderma neo-japonicum

This study compared the chemical composition and effects on the gut microbiota of hot-water extracts from two Ganoderma species: Ganoderma lucidum (GL), a well-studied medicinal mushroom, and Ganoderma neo-japonicum (GN), a lesser-known counterpart. Polysaccharides were identified as the primary active components in both extracts, with comparable concentrations. However, GL had a significantly higher total phenolic content. Monosaccharides such as glucose, galactose, and mannose ratios differed between the two species, though both displayed a β-dominant configuration. Notably, β-1,6-glucopyranose (β-1,6-Glcp) and α-4,6-glucopyranose (α-4,6-Glcp) structures were present in GL but absent in GN. Fermentation experiments revealed that both extracts supported the growth of beneficial bacterial families, including Prevotellaceae, Ruminococcaceae, Lachnospiraceae, Muribaculaceae, and Bifidobacteriaceae, while suppressing the abundance of Enterobacteriaceae. This modulation of gut microbiota led to increased production of short-chain fatty acids (SCFAs), particularly acetic acid, propionic acid, and butyric acid. The effects on microbiota regulation were more pronounced with GL. These findings suggest that hot-water extracts from both Ganoderma species may promote health by positively influencing gut microbial communities, highlighting the potential of G. neo-japonicum as a modulator of gut microbiota.