In vitro fermentation of raffinose to unravel its potential as prebiotic ingredient

Until now the prebiotic potential of pure trisaccharide raffinose on human health assessed through high-throughput sequencing remains poorly investigated. In this work, an in vitro model using human fecal inocula of two healthy volunteers (D1 and D2) was used to study the prebiotic potential of raffinose and compare it with the well-stablished and commercial prebiotic lactulose. The intestinal microbiota showed preference for raffinose as substrate showing the highest consumption value at 48 h (96.0 +/- 0.9% D1 and 95.3 +/- 0.7% D2). The fermentation of raffinose decreased the medium pH, the ammonia concentration and the relative amount of Proteobacteria, while increasing the total production of lactate and short chain fatty acids (129.9 +/- 2.6 mmol/L D1 and 179.6 +/- 0.6 mmol/L D2), CO2 (10.8 +/- 0.8 mmol/L-medium D1 and 5.2 +/- 0.3 mmol/L-medium D2) and the relative amount of Bifidobacterium and Lactobacillus. This study suggests that raffinose holds potential functional properties for human health.