Browsing by Author "Schreck, Isabell"

Background Short-chain fatty acids (SCFAs), such as butyrate, acetate and propionate, mainly originate from dietary fibre fermentation in the colon. In recent years, additional gastrointestinal (local) and systemic effects of SCFAs have been observed in vitro and in both animals and humans in vivo. Faecal SCFAs have been associated with several conditions and diseases, including irritable bowel syndrome, type 2 diabetes, colorectal cancer, and cardiovascular diseases. Aim(s) The BEAN MAN study was carried out to assess the effects of the partial replacement of red and processed meat with legumes on nutrient intake, nutritional status, and the risk factors of type 2 diabetes, colorectal cancer and cardiovascular diseases. This thesis was part of the BEAN MAN study and investigated the effects of partially replacing red and processed meat with legumes on the concentration and composition of faecal SCFAs in healthy, working-age Finnish men. As a secondary outcome, the intake of dietary fibre and soluble polysaccharides were assessed and correlations between the total and individual SCFAs were analysed. Methods The BEAN MAN study was a 6-week randomized dietary intervention, with two diet groups in a parallel design. The Conventional Finnish diet group (Conventional FIN) was given 760 g/week of red and processed meat, corresponding the average meat consumption of Finnish men. The Flexitarian/Legume group (Flex/Leg) received 200 g/week of red and processed meat, and legume products to provide an equal amount of protein as 560 g of red meat. The faecal samples obtained from the participants before and at the end of the intervention period were freeze-dried, and SCFA were extracted and analysed using gas chromatography. Dietary fibre intake was analysed based on 4-day food records. Results At the endpoint, no significant differences in total (p = 0.560) nor individual SCFAs concentration and composition between the two diet groups were observed (ANCOVA, baseline as a covariate). The dietary fibre intake of the Flex/Leg group was higher (p < 0,001) when compared to the Conventional FIN. This was not the case for soluble polysaccharides. No correlation between the dietary fibre intake and the concentration of total or individual SCFA was found. Conclusion The concentration and composition of faecal SCFAs were not significantly affected by the partial replacement of red and processed meat with legumes during the 6-week intervention. This may highlight a more complex relationship between diet, microbiota and the production of SCFA.