Study of the impact of edible mushroom biomass obtained from by-products upcycling on the human intestinal microbiota

• Autor(a) principal: Cima, Arlindo André e André
• Data de Publicação: 2023
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10400.14/43306
• topic: P. ostreatus; Dietary fibre; Gastrointestinal digestion simulation; Gut microbiota; In vitro human fecal fermentation; Mushroom by-products; Prebiotics; Short-chain fatty acids (SCFAs); Fibra alimentar; Simulação da digestão gastrointestinal; Microbiota intestinal; Fermentação fecal humana in vitro; Subprodutos de cogumelos; Prebióticos; Ácidos gordos de cadeia curta (SCFAs); Domínio/Área Científica::Ciências Naturais::Ciências Biológicas

In recent years, the association between prebiotics and human health has been increasingly strong, becoming a major focus due to their ability to positively modulate the composition and metabolism of the intestinal microbiota and favorably impact consumer health. Mushroom consumption has increased in recent years and so the production of available by-products, which may represent a potential new source of dietary fibre that is directly correlated with prebiotic potential. This study aimed to evaluate the potential prebiotic effect of mushroom biomass obtained from by products using a human feces fermentation model. The composition of 4 flours derived from aqueous extraction (2 extraction methods – M1 and M2) of by-products from 2 mushrooms: Pleurotus ostreatus and Pleurotus eryngii, was characterized. Subsequently, two Pleurotus ostreatus flours (chosen for the best carbohydrate profile) were subjected (together with positive and negative controls) to a simulated digestive process, and tested in an in vitro human fecal fermentation model, being evaluated at 5 fermentation times for 5 groups of bacteria: Firmicutes, Bacteroidetes, Lactobacillus, Bifidobacterium and Clostridium, as well as the formation of short-chain fatty acids (SCFAs) and other relevant fatty acids representative of microbiota metabolism. Regarding the characterization, the main focus was to evaluate mainly the nutritional composition and in particular the fibre, the structural carbohydrates including the glucans that are directly related to the prebiotic potential knowing in advance that the bacterial groups use them as a substrate to grow and generate metabolites. This characterization showed that P. ostreatus had a slight advantage over P. eryngii in the case of fiber (P. ostreatus: 36.39 – 41.01 g/100 g DW, P. eryngii: 35.19 – 39.69 g/100 g DW). In the case of β-glucans, P. ostreatus flours were higher (50.92 – 52.29 g/100 g DW) than for P. eryngii (41.96 – 43.64 g/100 g DW). Comparing the flours, it was observed that the M2 extraction method generated a flour with higher concentrations of fibre and structural carbohydrates. The results showed that the Firmicutes: Bacteroidetes ratio over time remained stable and close to one, a positive indicator for M1 and M2 flours. The production of SCFAs (acetate, butyrate and propionate), lactic and succinic acid revealed a positive modulation of the microbiota metabolism, with evidence of an increase in all metabolites (except lactic acid) in relation to controls, which is a very positive indicator of the prebiotic potential of the flours. Although the results of bacterial communities are not directly correlated with the metabolites produced, it is possible to suggest that the range of bioactive properties associated with P. ostreatus biomass may be associated with the potential prebiotic activity displayed in the human intestinal microbiota. Also, the valorization of mushroom by-products allowed to obtain functional ingredients for the development of new health-promoting foods.