The increasing demand for sustainable and nutritious protein sources has elevated interest in plant-based alternatives like pea protein ( Pisum sativum ), which offers good bioavailability, low allergenicity, high nutritional value, and affordable production costs (1) . While plant proteins contain microbiota-relevant substrates such as lysine and tryptophan, limited research exists on their specific effects on gut microbiota compared to animal- derived proteins (2) . We utilized the MiGut platform, a miniaturized triple-stage in vitro model simulating proximal, medial, and distal regions of the human colon (3) . MiGut’s scalability enabled direct comparison of pea versus whey protein supplementation on microbiota from three human donors under identical conditions. Our design included six models to evaluate both protein types with each donor’s microbiota. Following two-week equilibration, models were dosed daily with pre-digested protein for two weeks (pre-digestion following the INFOGEST protocol), followed by a two-week recovery period. Samples were collected after each phase. Significance between groups was assessed using a paired t-test. Quantitative PCR analysis revealed key differences between protein interventions. In proximal colon, pea protein maintained Bifidobacterium levels (+0.31 log 10 copies/μL) while whey caused notable decreases (-2.36 log). Both reduced Bacteroides, though less with pea (-0.88 vs -2.16 log). Whey more reduced potential pathobionts, decreasing Enterobacteriaceae (-2.9 vs -0.42 log, p<0.05). Prevotella, Faecalibacterium, and C. leptum remained stable with both supplements. Distal colon showed similar but less pronounced trends. 16S rRNA sequencing confirmed higher diversity in distal colon (Shannon index: 2.58±0.21) versus proximal (1.82±0.6), consistent with in vivo patterns. Pea protein caused greater shifts in microbial ecology than whey (Bray-Curtis 0.71 vs 0.45, p<0.05). SCFA analysis showed pea protein significantly increased butyrate and propionate (+590 and +727 μM, p<0.05) with minimal acetate changes, while whey produced no significant SCFA alterations. This data gives an initial overview of the impact of pea and whey protein, and we plan to perform further analysis such as amino acid quantification and tryptophan metabolite profiling. This study demonstrates both the utility of the MiGut platform for nutrition research and the potential benefits of pea protein for gut health. The bacterial changes in the proximal colon and favourable SCFA profile changes suggest plant protein may offer advantages beyond sustainability benefits. The MiGut technology enabled this direct comparison through simultaneous experiments with multiple biological replicates, providing greater statistical power than previously possible with gut model systems. As plant-based proteins become increasingly prevalent in diets, characterising their specific effects on gut health will be crucial for developing evidence-based dietary recommendations that consider both environmental sustainability and human health outcomes. Ethical approval was granted by the University of Leeds Ethics Committee (reference 0624).
Birch et al. (Fri,) studied this question.