Metabolic and microbial responses to the complexation of manuka honey with α-cyclodextrin after simulated gastrointestinal digestion and fermentation

Manuka honey (MH), α-cyclodextrin (C) and a formulation containing these two components (MH + C) were subjected to simulated gastrointestinal digestion followed by fermentation with human faecal microbiota. The honey monosaccharides, glucose and fructose were 9- and 3-fold higher respectively in the digesta of MH + C compared with MH. Methylglyoxal (MGO), characteristic of MH was absent after gastric digestion. The precursor of MGO, 1,3-dihydroxyacetone was found to be at a higher concentration in MH + C, compared with MH, after digestion. The MH + C fermenta were more acidic (pH 4.6, p < 0.05), with a higher lactate concentration (p < 0.005). Compared with water control, MH + C fermenta significantly inhibited Salmonella enterica Typhimurium (p = 0.041) and enhanced Lactobacillus reuteri (p = 0.016). These findings suggest that complexation with α-cyclodextrin protects some MH components during digestion. This increases the availability of substrates to faecal bacteria resulting in the generation of metabolites that favour gut health.