2025/02/26 by Matías Bedmar Moreno, Melissa L. Moreno, Pieter Van den Abbeele +8
Agricultural and Biological Sciences · Biochemistry, Genetics and Molecular Biology · Nursing · #Food composition and properties #Gut microbiota and health #Probiotics and Fermented Foods
paper · doi:10.1016/j.nutres.2025.02.004
openalex publication_date 2025/02/26 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
• Yeast mannans produced less gas than inulin in ex vivo simulation of fermentation. • Yeast mannans elicit minimal symptoms and potential to increase stool frequency. • Yeast mannan supplementation at 15 g/d specifically modulates fecal microbiota. Yeast mannans (YM) are potential prebiotics that may improve laxation. The aim was to evaluate the effects of YM on gastrointestinal symptoms, with a hypothesis of high tolerance. A secondary aim assessed stool frequency. Fecal microbiota composition (16S rRNA gene amplicon sequencing) and targeted urine metabolites (LC-MS/MS) were explored. An ex vivo simulation of digestion and fermentation (6 donors) compared YM to the reference prebiotic inulin followed by an open-label pilot study, with a 1-week baseline and 2-week intervention of 15 g/d of YM. Ex vivo findings showed increased Bacteroides faecis, B. ovatus, Parabacteroides merdae, P. distasonis, Blautia faecis , and Bifidobacterium spp. in response to YM. Participants ( n = 20, 71.4 ± 11.0 y) reported no change with YM for burping, constipation, diarrhea, flatulence/gas, nausea, reflux/heartburn, or rumblings/noise, rated from 0 for none to 3 for severe symptoms. Cramping/pain marginally increased from baseline (0.02 ± 0.01) to intervention (0.05 ± 0.02; P = .046), as did distention/bloating (baseline, 0.07 ± 0.03; intervention week 2, 0.15 ± 0.05; P = .037). This high tolerability was explained by the ex vivo finding that YM induced less gas production than inulin (–45%). Stool frequency trended higher with YM (1.53 ± 0.15 stools/d) compared to baseline (1.35 ± 0.11) ( P = .079); participants with ≤1 stools/d ( n = 8) showed an increase (0.84 ± 0.14 to 1.19 ± 0.32; P = .016). In vivo compositional changes in fecal microbiota suggest increased B. faecis, B. ovatus, P. merdae, and P. distasonis levels in response to YM. Overall, YM elicited specific microbiota modulation with minimal gastrointestinal symptoms and the potential to increase stool frequency, supporting its prebiotic potential. This trial was registered at clinicaltrials.gov (NCT05939336). Yeast mannan supplementation elicited specific modulation of microbiota composition in older adults with minimal gastrointestinal symptoms (e.g. flatulence) and the potential to increase stool frequency, supporting its prebiotic potential. Microbiota compositional changes were confirmed by ex vivo stimulation of digestion and fermentation.