Yeast mannans promote laxation and specifically modulate microbiota composition in older adults: An open-label pilot study
Bibliographic record
Abstract
• 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.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.002 | 0.001 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.002 |
| Insufficient payload (model declined to judge) | 0.004 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".