Human gut microbiota-fermented asparagus powder protects human epithelial cells from injury and inflammation

Dietary consumption of green asparagus has been associated with several health benefits. These beneficial properties are attributed to the presence of many bioactive compounds in asparagus, including saponins, phenolics, flavonoids, as well as dietary fiber mostly comprising fructans and inulins, which are prebiotics capable of supporting the growth of beneficial members of gut microbiota. In this study, we used the in vitro Human Gut Simulator system to assess the fermentation of oro-gastro-intestinally digested asparagus powder by the human gut microbiota. Microbial community composition differed between communities grown on the asparagus digest and on the Western diet derived medium. Asparagus supported beneficial Ruminococcus but also hydrogen sulfide producing members of Desulfovibrionaceae. Fermentation of asparagus released more antioxidants into the environment compared to the Western diet medium, and supernatant of asparagus-grown cultures protected cultured human epithelial cells against damage and inflammation. We thus showed that asparagus powder has potential to be used as a functional food, offering protection against intestinal damage and inflammation - effects mediated by the gut microbiota.