Structural characterization, digestive and fermentative properties of Pleurotus ferulae polysaccharides and their effects on human gut microbiota.

Both WEPP and AEPP from Pleurotus ferulae share a core polysaccharide composition of glucose, galactose, and mannose.

• WEPP was water-extracted and AEPP was alkali-extracted from the medicinal edible mushroom Pleurotus ferulae.
• Structural characterization confirmed glucose (Glc), galactose (Gal), and mannose (Man) as the core monosaccharide constituents of both polysaccharides.
• The two extraction methods yielded polysaccharides with this shared core composition despite differing extraction conditions.

Both WEPP and AEPP resisted gastrointestinal digestion but were readily fermented by human gut microbiota in vitro.

• Gastrointestinal digestive properties were investigated using in vitro digestion assays simulating the human gastrointestinal tract.
• Resistance to digestion indicates the polysaccharides could reach the colon intact, a key characteristic for prebiotic function.
• Fermentative properties were assessed using in vitro fermentation with human gut microbiota.

During fermentation, degradation of WEPP and AEPP selectively utilized glucose, galactose, and mannose linkages, with glucose linkage being the first to be utilized.

• The sequential degradation pattern showed that Glc linkage was preferentially utilized first by gut microbiota.
• Gal and Man linkages were also selectively degraded during the fermentation process.
• This selective degradation pattern was observed for both WEPP and AEPP during in vitro fermentation.

WEPP and AEPP yielded significantly higher propionic acid levels compared with the prebiotic inulin during in vitro fermentation.

• Propionic acid production was used as a measure of fermentative output and potential health benefit.
• The comparison was made against inulin, a well-established prebiotic reference compound.
• Higher propionic acid production suggests potentially distinct or superior metabolic outcomes compared to inulin.

WEPP and AEPP differentially modulated specific gut bacterial genera, with WEPP primarily enhancing Parabacteroides enrichment and AEPP predominantly modulating Paraclostridium enrichment.

• The two polysaccharides exerted distinct effects on gut microbiota composition despite sharing a similar core sugar composition.
• WEPP selectively enriched Parabacteroides, a genus associated with beneficial gut health effects.
• AEPP predominantly modulated Paraclostridium enrichment, indicating extraction method influences the specific microbial communities targeted.
• These differential effects suggest that structural differences between WEPP and AEPP resulting from different extraction methods underlie their distinct microbiota-modulating properties.

WEPP and AEPP are concluded to possess prebiotic potential by supporting gut health through specific modulation of the intestinal microbial community.

• The prebiotic potential is supported by resistance to gastrointestinal digestion, fermentability by gut microbiota, short-chain fatty acid production, and selective modulation of beneficial bacteria.
• The results collectively support classification of both polysaccharides as having prebiotic properties.
• Modulation of gut microbiota composition was specific rather than general, indicating selective prebiotic activity.