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 <i>in vitro</i> gastrointestinal digestion/fermentation and an <i>in vivo</i> rodent model. <i>In vitro</i>, 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 <i>in vivo</i>. Consumption of a low-fiber pork diet without hydrocolloids promoted <i>Akkermansia</i> (29.5 % median abundance) and <i>Tannerellaceae</i> (24.7 %) growth in the colon, whereas κ-carrageenan increased <i>Desulfovibrio</i> (7.95 %) and <i>Alistipes</i> (6.14 %), and xanthan gum enhanced unclassified <i>Muribaculaceae</i> (14.8 %) and <i>Bacteroides</i> (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.