Gut microbiota regulation and prebiotic properties of polysaccharides from Oudemansiella raphanipes mushroom.

Oudemansiella raphanipes is a type of fungus used as both medicine and food. Fungal polysaccharides have demonstrated various bioactivities, involving the adjust and control of gut microbiota, but no such studies on O. raphanipes polysaccharides (OrPs) have been reported. It is by extracting and purifying that OrPs was obtained from O. raphanipes crude polysaccharide and study their effects in mice. The sample contents of total sugar was 97.26%, and the monosaccharide content comprised mannose, rhamnose, glucose, and xylose in a molar ratio of 35.2:2.8:21.2:40.8. The effects of OrPs on body weight (BW), gut microbiota, fecal short-chain fatty acids (SCFAs), and the correlation between fecal SCFAs and gut microbes, in mice were investigated. The results of the experiment found that OrPs significantly (P < 0.01) inhibited the increase in BW, altered the constitution of the gut microbiota, and significantly (P < 0.05) enhanced the content of fecal SCFAs in mice. Moreover, among the top ten bacteria in terms of relative abundance, the Lachnospiraceae and Lachnospiraceae NK4A136 groups were positively associated with the increased production of SCFAs. Other bacteria, such as Atopobiaceae and Bifidobacterium of Actinobacteriota, and Faecalibaculum, Dubosiella, and Clostridium sensu stricto 5 of Firmicutes, were also positively associated with higher content of fecal SCFAs. The results of the experiment suggest that OrPs have a potential prebiotic effect on gut microbiota and may prevent BW gain. Furthermore, the major producers of SCFAs were Firmicutes and Actinobacteriota.