Food hydrocolloids κ-carrageenan and xanthan gum in processed red meat modify gut health in rats.

The food hydrocolloids κ-carrageenan and xanthan gum, used in processed foods including meat products, have unclear effects on gut health. This study investigated the effects of incorporating 1 % κ-carrageenan or xanthan gum into pork on protein digestibility, gut microbiota, oxidative stress, and gene expression using both in vitro gastrointestinal digestion/fermentation and an in vivo rodent model. In vitro, xanthan gum reduced protein digestibility (-11 %) in the simulated small intestine, thus elevating protein fermentation metabolites (up to 4-fold), but this was not observed in vivo. Consumption of a low-fiber pork diet without hydrocolloids promoted Akkermansia (29.5 % median abundance) and Tannerellaceae (24.7 %) growth in the colon, whereas κ-carrageenan increased Desulfovibrio (7.95 %) and Alistipes (6.14 %), and xanthan gum enhanced unclassified Muribaculaceae (14.8 %) and Bacteroides (12.1 %). Unexpectedly, transcriptomic analysis revealed a down-regulation of gut inflammatory pathways, accompanied by lower fecal calprotectin levels, in rats consuming pork with hydrocolloids. While κ-carrageenan notably reduced lipid oxidation in stomach contents, only xanthan gum lowered plasma and colonic oxidative stress. These findings highlight the potential of hydrocolloids to modulate dietary responses, suggesting a role in influencing gut health following high processed meat consumption.