The preliminary study of prebiotic potential of Polish wild mushroom polysaccharides: the stimulation effect on Lactobacillus strains growth

PURPOSE: According to the vast body of evidence demonstrating that the intestinal microbiota is undoubtedly linked with overall health, including cancer risk, searching for functional foods and novel prebiotic influencing on beneficial bacteria is necessary. The present study aimed to investigate the potential of polysaccharides from 53 wild-growing mushrooms to stimulate the growth of Lactobacillus acidophilus and Lactobacillus rhamnosus and to determine the digestibility of polysaccharide fractions. METHODS: Mushroom polysaccharides were precipitated with ethanol from aqueous extracts. Determination of growth promoting activity of polysaccharides was performed in U-shaped 96-plates in an ELISA reader in relation to the reference strain of L. acidophilus and two clinical strains of L. rhamnosus. The digestibility of mushroom polysaccharides was investigated in vitro by exposing them to artificial human gastric juice. RESULTS: Obtained results revealed that fungal polysaccharides stimulate the growth of Lactobacillus strains stronger than commercially available prebiotics like inulin or fructooligosaccharides. Moreover, selected polysaccharides were subjected to artificial human gastric juice and remain undigested in more than 90%. CONCLUSION: Obtained results indicate that mushroom polysaccharides are able to pass through the stomach unchanged, reaching the colon and stimulating the growth of beneficial bacteria. Majority of 53 polysaccharide fractions were analysed for the first time in our study. Overall, our findings suggest that polysaccharide fractions from edible mushrooms might be useful in producing functional foods and nutraceuticals. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00394-017-1436-9) contains supplementary material, which is available to authorized users.