A comparative evaluation of new prebiotic candidates. Part 2: In vitro assays using faecal inoculum from IBD patients

This study evaluated the prebiotic potential of three novel carbohydrate mixtures (i.e. sugar beet pectooligosaccharides (SBPOS) enriched in arabinooligosaccharides; pine-derived galactoglucomannooligosaccharides (GGMOS); and lemon-derived pectooligosaccharides enriched in oligogalacturonides (LPOS)) in comparison with oligofructose (C⁺), using faecal inoculum from ulcerative colitis (UC) and Crohn's disease (CD) patients predominantly in remission. Microbial composition (16S rRNA), short-chain fatty acids (SCFAs) production, gas generation, and polyphenol metabolism were assessed. SBPOS was the most efficiently fermented substrate, reaching carbohydrate consumption of 75.82% in CD and 63.58% in UC, clearly exceeding the positive control. Metabolically, SBPOS showed enhanced acetate production in comparison to the controls, particularly in CD (32.96 mM), whereas oligofructose led to pronounced lactate accumulation, especially in UC (60.27 mM). Total net organic acid production was higher in CD than in UC for SBPOS (80.95 vs 63.06 mM). In terms of microbiota modulation, carbohydrate supplementation limited the dysbiotic profile observed in negative controls dominated by Proteobacteria. C⁺ mainly promoted Lactobacillus, while SBPOS selectively enriched Bifidobacterium and Blautia. Additionally, the tested formulations showed improved fermentation efficiency, with SCFA-to-gas ratios of 3-6 compared with ∼1 for C⁺, indicating reduced gas production per unit of substrate consumed. LPOS fermentation markedly increased hesperetin bioavailability, accounting for ∼70% of the final polyphenolic fraction. Overall, these novel prebiotics, especially SBPOS, demonstrate enhanced modulation of IBD-associated microbiota and metabolic activity.