The effect of dietary level of two inulin types differing in chain length on biogenic amine concentration, oxidant-antioxidant balance and DNA repair in the colon of piglets

Bioaminergic Responses in an In Vitro System Studying Human Gut Microbiota-Kiwifruit Interactions

Whole kiwifruit ('Hayward' and 'Zesy002') were examined for their bioaminergic potential after being subjected to in vitro gastrointestinal digestion and colonic fermentation. Controls included the prebiotic inulin and water, a carbohydrate-free vehicle. The dopamine precursor l-dihydroxyphenylalanine (L-DOPA) and the serotonin precursor 5-hydroxytryptophan were increased in the kiwifruit gastrointestinal digesta ('Hayward' > 'Zesy002') in comparison to the water digesta. Fermentation of the digesta with human fecal bacteria for 18 h modulated the concentrations of bioamine metabolites. The most notable were the significant increases in L-DOPA ('Zesy002' > 'Hayward') and γ-aminobutyric acid (GABA) ('Hayward' > 'Zesy002'). Kiwifruit increased Bifidobacterium spp. and Veillonellaceae (correlating with L-DOPA increase), and Lachnospira spp. (correlating with GABA). The digesta and fermenta were incubated with Caco-2 cells for 3 h followed by gene expression analysis. Effects were seen on genes related to serotonin synthesis/re-uptake/conversion to melatonin, gut tight junction, inflammation and circadian rhythm with different digesta and fermenta from the four treatments. These indicate potential effects of the substrates and the microbially generated organic acid and bioamine metabolites on intestinal functions that have physiological relevance. Further studies are required to confirm the potential bioaminergic effects of gut microbiota-kiwifruit interactions.

Effect of dietary inclusion of 1% or 3% of native chicory inulin on the large intestinal mucosa proteome of growing pigs

Native chicory inulin is one of the promising alternatives to replace antibiotic growth promoters in young animals. Several potential mechanisms of prebiotic action have been proposed, such as modification of the intestinal microbiota composition leading to improved epithelial integrity and gut mucosal immunity of the host. The current study was focused on inulin effect on the large intestinal proteome and its implications for gut barrier functions. Therefore, we used proteomic techniques to determine changes in the large intestinal mucosa proteome of growing pigs after 40-day supplementation with native chicory inulin. The experiment was performed on 24 piglets fed from the 10th day of life an unsupplemented cereal-based diet or inulin-enriched diets (1% or 3%) with an average degree of polymerisation ≥ 10. At the age of 50 days, animals were sacrificed and tissue samples were collected from the cecum, and proximal and distal colon. Feeding diets supplemented with both levels of native inulin increased cecal and colonic expression of molecular chaperones, protein foldases and antioxidant proteins, which are collectively responsible for maintaining mucosal cell integrity as well as protecting against endotoxins and reactive oxygen species. This may confirm the beneficial effect of inulin on the gut health in growing pigs.