Auricularia auricula polysaccharides attenuate obesity in mice through gut commensal Papillibacter cinnamivorans

Auricularia auricula is a well-known traditional edible and medical fungus with high nutritional and pharmacological values, as well as metabolic and immunoregulatory properties. Nondigestible fermentable polysaccharides are identified as primary bioactive constituents of Auricularia auricula extracts. However, the exact mechanisms underlying the effects of Auricularia auricula polysaccharides (AAP) on obesity and related metabolic endpoints, including the role of the gut microbiota, remain insufficiently understood.

The effects of AAP on obesity were assessed within high-fat diet (HFD)-based mice through obesity trait analysis and metabolomic profiling. To determine the mechanistic role of the gut microbiota in observed anti-obesogenic effects AAP, faecal microbiota transplantation (FMT) and pseudo-germ-free mice model treated with antibiotics were also applied, together with 16S rRNA genomic-derived taxonomic profiling.

High-fat diet (HFD) murine exposure to AAP thwarted weight gains, reduced fat depositing and enhanced glucose tolerance, together with upregulating thermogenesis proteomic biomarkers within adipose tissue. Serum metabolome indicated these effects were associated with changes in fatty acid metabolism. Intestine-dwelling microbial population assessments discovered that AAP selectively enhanced Papillibacter cinnamivorans, a commensal bacterium with reduced presence in HFD mice. Notably, HFD mice treated with oral formulations of P. cinnamivorans attenuated obesity, which was linked to decreased intestinal lipid transportation and hepatic thermogenesis. Mechanistically, it was demonstrated that P. cinnamivorans regulated intestinal lipids metabolism and liver thermogenesis by reducing the proinflammatory response and gut permeability in a JAK-STAT signaling-related manner.

Datasets from the present study show that AAP thwarted dietary-driven obesity and metabolism-based disorders by regulating intestinal lipid transportation, a mechanism that is dependent on the gut commensal P. cinnamivorans. These results indicated AAP and P. cinnamivorans as newly identified pre- and probiotics that could serve as novel therapeutics against obesity.