Apples increased the bifidobacteria population in human in vitro colonic gut model – preliminary results

A major proportion of apple polyphenols escape absorption in the stomach and small intestine, and together with apple non-digestible polysaccharides reach the colon and may serve as substrates for bacterial fermentation(1). Animal studies suggest a synergistic interaction between apple polyphenols and pectin which could increase their biological activity and beneficial effects compared to the individual compounds(2). Bacterial populations (log10 cells/ml batch culture fluid) determined by RT-PCR in anaerobic, stirred, pH and temperature controlled faecal batch cultures (n = 3 healthy adults). (*) Mean value was significantly different from that at 0 h: P < 0.05. (#) Mean value was significantly different from Blank at 24 h: P < 0.05. (§) Mean value was significantly different from inulin at 24 h: P < 0.05. (°) Mean value was significantly different from cellulose at 24 h: P < 0.05 Bifidobacteria Treatment Blank sd Inulin sd Cellulose sd Gold rush sd Renetta sd Golden delicious sd Pink lady sd T0 7.33 0.3 7.43 0.2 7.36 0.2 7.51 0.1 7.39 0.2 7.55 0.2 7.39 0.3 T5 7.56 0.3 7.80 0.4 7.66 0.4 8.05* 0.4 8.29 0.8 8.52* 0.1 8.23 0.2 T10 7.71 0.5 7.74 0.6 7.77 0.6 8.37* 0.2 8.38* 0.2 8.65* 0.2 8.34* 0.1 T24 7.42 0.1 7.84 0.5 7.56 0.1 8.49*#° 0.1 8.62*#§° 0.1 8.51#° 0.3 8.47*#° 0.1 Four commercial apple varieties – Gold Rush, Renetta, Golden Delicious and Pink Lady – were digested(3) and fermented in vitro using a batch culture model (pH 5.5–6.0, 37°C), inoculated with human faeces from 3 healthy donors.