Oxidized proteins in ready-to-eat beef are likely responsible for oxidative stress, dysbiosis and poor gut health in Wistar rats: underlying biochemical insights.

The global rise in convenience food consumption raises health concerns. This study examined the effects of ready-to-eat beef (RTE-B) versus freshly cooked beef (B) on protein digestibility, oxidative stress, gut microbiota, and colonic metabolome in Wistar rats (n = 14) over 10 weeks. RTE-B increased oxidative stress markers, including colon advanced protein oxidation products (1582 vs. 369 nmol/mg; p < 0.001). Gut microbiota composition shifted significantly, with a marked expansion of Akkermansia (18.5% vs. 0.5%; p < 0.01) and downward trends in several beneficial commensals. Metabolomics revealed elevated protein and lipid oxidation byproducts (e.g., 4-oxo-proline, DL-2,6-diaminopimelic acid) and reduced functional metabolites (e.g., spermidine, fumarate, and TMAO). These findings indicate that RTE-B promotes oxidative stress, impairs protein utilization, disrupts microbial balance, and alters colonic metabolic pathways, highlighting potential risks of oxidized proteins in processed meats for metabolic and intestinal health.