Evaluation of prebiotic effect and characterization of antioxidant compounds produced in an in vitro gastrointestinal and colonic digestion of Shiitake mushroom (Lentinula edodes)

In the last decade, we have seen the important role that microbiota plays in maintaining health and well-being. There has been growing interest in modulating the gut microbiota through dietary interventions, particularly the consumption of prebiotics. Prebiotics are non-digestible food components that selectively promote the growth and activity of beneficial probiotic bacteria in the gut. Lentinula edodes (Shiitake mushroom) as a potential prebiotic source and phenolic compound content were evaluated. Bromatological and physicochemical analyses were conducted to understand the nutritional composition of Shiitake mushrooms. The mushroom cultivated in the North of México exhibits 45% of dietary fiber and 12% of protein. The prebiotic effect of Shiitake mushroom was evaluated during a fermentation with Lactobacillus plantarum 299v. It should be noted that no prebiotic effect of Shiitake mushroom was observed. However, the carbohydrates from Shiitake serve as a good carbon source, despite containing lower concentrations of simple sugars, similar to MRS medium. Although no prebiotic effect was observed, an increase in antioxidant activity was detected. Antioxidant activities were assessed through various assays including Total Phenol Content (TPC), DPPH free radical scavenging assay, and Metal Chelating Ability (MCA) assay. These procedures were conducted after the fermentation of Shiitake mushroom with Lactobacillus plantarum 299v. An increase in Total Phenol Content (TPC) and radical scavenging abilities was observed after a fermentation with 6 Lactobacillus plantarum 299v, with the highest levels recorded at 24-36 hours, improved the functional properties and benefits of Shiitake mushrooms according to these results. To investigate how intestinal microbiota affects the release of antioxidants from shiitake mushrooms, an in vitro digestion process, including both gastrointestinal and colonic stages, was conducted to assess the stability and bioavailability of phenolic compounds. The quantification of phenolic compounds in mushrooms were determined using Ultra Performance Liquid Chromatography (UPLC). Shiitake mushrooms demonstrated a varied release of phenolic compounds at each phase of the in vitro digestion process. Gallic acid was consistently detected across most stages, albeit in varying concentrations. Additionally, other phenolic compounds were categorized into different families, and the ratios among these compounds were observed. The study concludes that, although Shiitake mushrooms do not demonstrate prebiotic effects, they can release phenolic compounds during in vitro digestion. This release is particularly notable during the colonic stage, indicating an interaction with the intestinal microbiota that facilitates the liberation of these phenolic compounds. This release enhances antioxidant properties, highlighting their potential for promoting gut health and preventing chronic diseases. Further research is needed to understand the specific mechanisms behind these health benefits and to confirm these findings in human clinical trials. This research provides a foundation for future studies on how functional foods can enhance human health by modulating the gut microbiota through diet. Additionally, it explores how this microbiota can aid in increasing the bioavailability of certain phenolic compounds from foods.

https://orcid.org/0000-0001-5580-3108