Recruiting
Phase 2

Soluble Corn Fiber

Sponsor:

VA Office of Research and Development

Code:

NCT06519877

Conditions

Aging

Eligibility Criteria

Sex: Male

Age: 60+

Healthy Volunteers: Accepted

Interventions

Soluble corn fiber

Study Details

Brief summary:

Osteoporotic fractures are a major but underrecognized problem in men. There is growing evidence that low dietary fiber intake is a modifiable risk factor for age-related bone loss in men. Preclinical and human studies in adolescents and postmenopausal women suggest that dietary fiber intake influences bone metabolism by modulating the gut microbiome to augment intestinal calcium absorption, but it is unclear through what molecular mechanism and whether dietary fiber has the same effects in older men. In this crossover intervention study, the investigators will enroll and follow 30 older male Veterans to evaluate the effects of soluble corn fiber on intestinal calcium absorption and explore the contribution of the gut microbiome.

Conditions

Aging

Study ID

NCT06519877

Start date

Jan 1, 2025

Status verified date

Feb, 2026

Completion date

Jan 1, 2029

Anticipated

Primary completion date

Jan 1, 2029

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: Male

Age: 60+

Healthy Volunteers: Accepted

Inclusion Criteria:

  • Male Veterans 60 years of age

Exclusion Criteria:

  • History of malabsorption
  • Hypercalcemia (corrected Ca > 10.2 mg/dL)
  • Vitamin D insufficiency (25OHD < 30 ng/mL)
  • Chronic kidney disease stage 3B or worse (CrCl < 45 mL/min)
  • Severe hypogonadism (AM fasting serum total testosterone < 150 ng/dL)
  • Daily use of proton pump inhibitor
  • Use of medication(s) known to affect calcium metabolism
  • Use of medications or supplements that could impact gut microbiota in the previous 3 months (antibiotics or commercially available probiotics or prebiotics.
  • Presence of a condition or abnormality that in the opinion of the Investigator that would compromise the safety of the patient or the quality of the data.

Study Design

Enrollment

30 participants

Anticipated

Allocation

Randomized

Intervention Model

Crossover

Primary purpose

Other

Interventions and Outcome Measures

Arms

experimental: Group 1

Soluble corn fiber 20g/day x 4 weeks, washout period for 4 weeks, and placebo (maltodextrin) x 4 weeks.

experimental: Group 2

Placebo (maltodextrin) 20g/day x 4 weeks, washout period for 4 weeks, and soluble corn fiber x 4 weeks.

Interventions

Soluble corn fiber

Soluble corn fiber, also referred to resistant maltodextrin, is a type of dietary fiber made from corn starch. Soluble corn fiber is typically used to thicken processed foods and has been marketed as a prebiotic to improve digestive health.

Primary outcome measure

  • Intestinal fractional calcium absorption [ Time Frame: At week 4 and week 12 of study participation (at the end of each treatment phase x2) ]

Central Contacts and Locations

Central contacts

Karin C Wu, MD

(415) 221-4810karin.Wu@va.gov

Locations

San Francisco VA Medical Center, San Francisco, CA

Recruiting

San Francisco, California, United States, 94121-1563

Contacts

Karin C Wu, MD

415-221-4810karin.Wu@va.gov

Principal Investigator:

Karin C Wu, MD

More Information

Sponsor

VA Office of Research and Development

Last update posted

Feb 17, 2026

Last verified

Feb, 2026

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by VA Office of Research and Development on 2026-02-17.