Yeast Mannans and Stool Frequency

NCT06911177 | Active Not Recruiting

• 1 other identifier: IRB202500359
• Study Type: interventional
• Target: 70
• Locations: 1 country
• Sites: 1

Brief Summary

Findings from an open-label pilot study of 20 adults suggested that supplementation with 15 g/day of yeast mannans was highly tolerable and demonstrated specific modulation of the microbiota and increased stool frequency in a subset of subjects reporting ≤1 stool per day at baseline. The primary aim of this randomized, double-blind, controlled trial is to determine if yeast mannan supplementation at 12 g/day will increase stool frequency in generally healthy adults reporting ≤1 stool per day. Secondary aims will determine the effect of yeast mannans on intestinal transit time, gastrointestinal symptoms, fecal microbiota composition, and urinary and fecal metabolomics.

Conditions

Defecation Frequency

Keywords

yeast mannan; stool frequency; transit time; microbiota

Outcome Measures

Primary Outcomes (1)

• Defecation frequency

  Mean daily defecation frequency

  From enrollment to the end of treatment at 6 weeks.

Study Arms (2)

Yeast mannan supplementation

EXPERIMENTAL

Yeast cell wall fraction obtained from Saccharomyces cerevisiae containing mannan-oligosaccharides and mannoproteins will be supplemented at 12 g/day.

Dietary Supplement: Yeast mannan

Control supplementation

PLACEBO COMPARATOR

The control supplement, containing yeast protein, yeast extract, and maltodextrin, will be provided at 12 g/day.

Dietary Supplement: Control (placebo)

Interventions

Control (placebo) DIETARY_SUPPLEMENT

A supplement containing yeast protein, yeast extract, and maltodextrin, provided at 12 g/day.

Control supplementation

Yeast mannan DIETARY_SUPPLEMENT

Yeast cell wall fraction of manno-oligosaccharides and mannoproteins supplemented at 12 g/day.

Also known as: yeast cell wall fraction

Yeast mannan supplementation

Eligibility Criteria

• Age: 18 Years - 90 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Adults who report a stool frequency of ≤ 1 per day.
• Able to provide written informed consent in English.
• Willingness to consume 1 supplement (12 g of yeast mannans or control) daily for 28 days.
• Willingness to maintain their usual diet and physical activity patterns throughout the study and refrain from the consumption of any yeast-based foods (e.g. Marmite or Vegemite) or yeast extract supplements.
• Willing to comply with study procedures, including stool and urine colle

You may not qualify if:

• Stool frequency of \< 3 per week
• Yeast allergy
• Vegan dietary pattern
• Self-reported kidney disease
• Elite athletes or long-distance runners
• Use of antibiotic drugs within 1 month of screening
• Current use of laxatives or antidiarrheal medications
• Use of other investigational products within 3 months of the screening
• Previously or currently being treated for intestinal diseases or conditions, including irritable bowel disease (i.e., IBS-D or IBS-mixed), Crohn's disease, ulcerative colitis, celiac disease, or gastrointestinal cancer.
• Previous gastrointestinal surgery (e.g., gastric bypass, fundoplication, bowel resection).
• Current cancer treatment.
• Currently pregnant.

Sponsors & Collaborators

• University of Florida: lead

Study Sites (1)

Department of Food Science and Human Nutrition

Gainesville, Florida, 32611, United States

Location

MeSH Terms

Interventions

bleomycin-mannan conjugate

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: OTHER
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: March 28, 2025
• First Posted: April 4, 2025
• Study Start: July 17, 2025
• Primary Completion: March 16, 2026
• Study Completion (Estimated): December 31, 2026
• Last Updated: April 15, 2026

Record last verified: 2025-08

Locations

US (1)