Yeast mannans promote laxation and specifically modulate microbiota composition in older adults: An open-label pilot study

Melissa L Moreno; Pieter Van den Abbeele; Aurélien Baudot; Thomas A Tompkins; Diana H Taft; Runzhe Yao; Jeremie Auger; James Colee; Wendy J Dahl

doi:10.1016/j.nutres.2025.02.004

Yeast mannans promote laxation and specifically modulate microbiota composition in older adults: An open-label pilot study

Nutr Res. 2025 Apr:136:15-27. doi: 10.1016/j.nutres.2025.02.004. Epub 2025 Feb 26.

Authors

Melissa L Moreno¹, Pieter Van den Abbeele², Aurélien Baudot², Thomas A Tompkins³, Diana H Taft¹, Runzhe Yao¹, Jeremie Auger⁴, James Colee⁵, Wendy J Dahl⁶

Affiliations

¹ Department of Food Science and Human Nutrition, University of Florida, Institute of Food and Agricultural Sciences (IFAS), Gainesville, FL, USA.
² Department of Research and Development, Cryptobiotix SA, Ghent, Belgium.
³ Department of Research and Development, Lallemand Bio Ingredients, Montreal, QC, Canada.
⁴ Department of Research and Development, Lallemand Health Solutions, Montreal, QC, Canada.
⁵ Institute of Food and Agricultural Sciences (IFAS) Statistics Department, University of Florida, Gainesville, FL, USA.
⁶ Department of Food Science and Human Nutrition, University of Florida, Institute of Food and Agricultural Sciences (IFAS), Gainesville, FL, USA. Electronic address: wdahl@ufl.edu.

PMID: 40117931
DOI: 10.1016/j.nutres.2025.02.004

Abstract

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).

Keywords: Gastrointestinal symptoms; Mannoproteins; Metabolomics; Microbiota; Older adult; Prebiotic; Stool frequency; Yeast mannans.

Publication types

Clinical Trial
Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

Aged
Aged, 80 and over
Constipation* / drug therapy
Constipation* / microbiology
Feces / microbiology
Female
Fermentation
Gastrointestinal Microbiome* / drug effects
Humans
Inulin
Laxatives* / pharmacology
Male
Mannans* / pharmacology
Middle Aged
Pilot Projects
Prebiotics*
RNA, Ribosomal, 16S
Yeasts* / chemistry

Substances

Inulin
Laxatives
Mannans
Prebiotics
RNA, Ribosomal, 16S

Associated data

ClinicalTrials.gov/NCT05939336

Grants and funding

HATCH 1022000/USDA