Consumption of polysaccharides from auricularia auricular modulates the intestinal microbiota in mice

Authors: ZHAO, RUIQIU - Nanjing Agricultural University; CHENG, NINGHUI - Children'S Nutrition Research Center (CNRC); Nakata, Paul; ZHAO, LIYAN - Nanjing Agricultural University; HU, QIUHUI - Nanjing Agricultural University

Submitted to: Food Research International
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/30/2019
Publication Date: 5/2/2019
Publication URL: https://handle.nal.usda.gov/10113/6430665
Citation: Zhao, R., Cheng, N., Nakata, P.A., Zhao, L., Hu, Q. 2019. Consumption of polysaccharides from auricularia auricular modulates the intestinal microbiota in mice. Food Research International. 123:383-392. https://doi.org/10.1016/j.foodres.2019.04.070.
DOI: https://doi.org/10.1016/j.foodres.2019.04.070

Interpretive Summary: The mushroom, Auricularia auricular, has been consumed for hundreds of years for its health promoting properties. The exact identity of these health promoting substances and an understanding of how these substances confer health-promoting benefits remain largely unknown. As a step toward identifying these substances and determining how they confer their healthful benefits we report here the extraction of A. auricular polysaccharides (AAP) and study their effect on the microbial community found in the gut of mice. To study this effect mice were fed different amounts of AAP and changes in the pH, short chain fatty acids, and composition of the microbes found in the gut of mice were determined. The measured changes, as a result of the AAP feeding appeared to promote conditions that may be beneficial in regulating body weight. In addition, consumption of AAP boosted the immune system of the mice. Taken together, the results from this study suggest that the polysaccharides present in mushrooms contribute to its healthful properties by modulating the microbial population present in the gut. It is our hope that gained insights into how certain foods promote optimal human health and well-being will lead to the development of new functional foods and/or pharmaceutical products.

Technical Abstract: In vitro studies suggest that edible mushrooms, such as Auricularia auricula, contain substances that can influence the composition and diversity of the intestinal microbial community. The identity of such substances; however, remain unknown. In this study, A. auricular polysaccharides (AAP) were extracted and tested for their ability to modulate the gut microbiota in mice. Different amounts of AAP (40, 80, 160 mg AAP/kg body weight) were administered to mice by gavage feeding over a five- week period. The measurement of the pH value of intestinal contents from the AAP fed mice revealed decreasing pH with increasing doses of AAP. Biochemical measurements showed that the concentration of intestinal short chain fatty acids (SCFAs) increased with increasing doses of fed AAP. In addition, high throughput sequencing revealed an enrichment in the diversity and an alteration in the composition of the fecal microbiota population that may be beneficial in regulating body weight. Moreover, measurement of the secreted cytokines, IgA and IgG, showed increasing serum concentrations of both immune boosting cytokines with increasing doses of fed AAP. Overall, the findings from this study indicate that modulation of the gut microbiota as well as many of the beneficial effects from the consumption of mushrooms such as A. auricular may be due, at least in part, to polysaccharides contained within these edible fungi.