Mushroom polysaccharides and jiaogulan saponins exert cancer preventive effects by shaping the gut microbiota and microenvironment in ApcMin/+ mice

Abstract

The incidence of colorectal cancer (CRC) is alarming among younger peoples. While no effective chemopreventive drug available in the market, researchers have been searching for alternative strategies against CRC that are in demand. Therefore, we tested the cancer-preventive properties of Ganoderma lucidum (Lingzhi) polysaccharides (GLP), along with the saponins extracted from Gynostemma pentaphyllum (GpS), an herbal tea with prebiotic-like effects. Here, we report that saponins from Gynostemma pentaphyllum (GpS) and polysaccharides from Ganoderma lucidum (GLP together with GpS) profoundly improved the inflamed gut barrier of Apc^Min/+ mice by reducing polyps, shifting colonic M1 to M2 macrophages, positively reverting E-cadherin/N-cadherin ratio, and downregulating oncogenic signaling molecules. The treatments also markedly promoted short-chain fatty acids (SCFAs)-producing bacteria and abridged sulfate-reducing bacteria in a time-dependent manner. G-protein coupled-receptors were significantly stimulated in the treated mice, accompanied by the modulated expressions of histone deacetylases, anti-cancer gut hormone PYY, and PPAPγ. These findings suggest that some of the herbal medicinal foods could modulate the relationship between the host and the gut microbiota (GM) to exert their beneficial properties to the host. Our study also implicates that these dietary mushroom polysaccharides and the Gp saponins have the potential to be developed as new preventive medicines against CRC.

Keywords: Apc(Min/+)mice; GPCRs; Gut microbiota; Polysaccharides; SCFAs; Saponins.