van der Wielen NZhang HSchouten PJCMeulenbroeks EStroebinger NHodgkinson SMMensink MHendriks WCapuano E2025-10-272025-10-272025-12-15van der Wielen N, Zhang H, Schouten PJC, Meulenbroeks E, Stroebinger N, Hodgkinson SM, Mensink M, Hendriks W, Capuano E. (2025). Exploring in vitro production of colonic microbial metabolites from diverse protein sources using human ileal digesta. Food Chemistry. 495. Part 3.0308-8146https://mro.massey.ac.nz/handle/10179/73731We explored the relationship between protein fermentation metabolites and ileal digesta composition, using ileal digesta from ileostomates, who ingested nine different protein sources, incubated in the Simulator of the Human Intestinal Microbial Ecosystem (SHIME®). NH3, short-chain fatty acids, branched-chain fatty acids (BCFA), H2S, tryptophan derivatives, and biogenic amines were measured in proximal and distal colon vessels. The relative changes in most metabolites were positively correlated with their amino acid precursors in ileal digesta. In both colon vessels, the relative change of NH3 was a good predictor for the production of other metabolites. Indole was strongly associated with oxindole, 5-HT, and tryptamine and the sum of Trp metabolites in the distal colon. Per gram ingested protein, zein and whey may produce the highest levels of NH3 and BCFA in the proximal colon and BCFA in the distal colon, whereas whey and pigeon peas may result in the highest levels of H2S.(c) The author/shttps://creativecommons.org/licenses/by/4.0/Protein fermentationSHIMEShort chain fatty acidsAmmoniaIn vitro modelsGut microbial metabolitesJournal article10.1016/j.foodchem.2025.1466321873-7072CC BYjournal-article146632S0308814625038841