Effect of Short-chain Fatty Acids on Aerobic Endurance

NCT06054607 | Completed

• 2 other identifiers: 23-13HM-11031
• Study Type: interventional
• Target: 21
• Locations: 1 country
• Sites: 1

Brief Summary

Randomized, double-blind, placebo-controlled crossover study designed to determine the effects of increasing colonic short-chain fatty acid (SCFA) content on aerobic endurance in healthy adults, and to identify underpinning mechanisms. In random order, healthy physically active adults will consume provided diets low in fiber and supplemented with SCFA-enriched high amylose maize starch (a poorly digested resistant starch considered a fermentable fiber) or low amylose maize starch (a rapidly digestible starch) for 1-week separated by a ≥2-week washout. At the end of each intervention period, participants will complete an endurance exercise bout followed by a time trial. Biological samples will be collected to assess muscle and whole body metabolism, gut microbiota, inflammation, and gastrointestinal function.

Conditions

Aerobic Endurance; Metabolism

Keywords

short-chain fatty acid; microbiome; endurance; fiber; resistant starch; gastrointestinal

Outcome Measures

Primary Outcomes (1)

• Run time

  Time to complete a 5km treadmill run

  Phases 1 and 2, day 8

Secondary Outcomes (6)

• Muscle glycogen content

  Phases 1 and 2, day 8

• Plasma glucose turnover

  Phases 1 and 2, day 8

• Whole body substrate oxidation

  Phase 1 and 2, day 8

• Serum short-chain fatty acid concentrations

  Phases 1 and 2, day 8. Measured fasted (-300 minutes) and before (0 minutes) and at the end (80 minutes) of steady state endurance exercise

• Fecal short-chain fatty acid concentrations

  Phases 1 and 2, days 1 and 7

Other Outcomes (15)

• Gastrointestinal symptoms

  Phases 1 and 2, daily on days 1 through 8

• Circulating biomarkers of substrate utilization

  Phases 1 and 2, day 8. Measured before (-300minutes, 0minutes) and during (20, 40, 60, 80minutes) steady state endurance exercise.

• Total protein content in muscle

  Phases 1 and 2, day 8

Study Arms (2)

Low-amylose maize starch

PLACEBO COMPARATOR

Low-amylose maize starch (AMIOCA; Ingredion, Inc).

Other: Low-amylose maize starch

High-amylose maize starch+acetate/butyrate

ACTIVE COMPARATOR

High-amylose maize starch, (Hylon VII; Ingredion, Inc.) to which the SCFA acetate or butyrate has been chemically added.

Dietary Supplement: High-amylose maize starch+acetate/butyrate

Interventions

High-amylose maize starch+acetate/butyrate DIETARY_SUPPLEMENT

High-amylose maize starch (HAMS), commercially available as Hylon VII (Ingredion, Inc.), to which the SCFA acetate or butyrate has been chemically added. Hylon VII is a HAMS containing \~70% amylose and used in a variety of food products. To produce SCFA-enriched HAMS, Hylon VII is chemically modified through esterification with the SCFA acetate or butyrate.

High-amylose maize starch+acetate/butyrate

Low-amylose maize starch OTHER

Rapidly digestible low-amylose maize starch (0% amylose, 100% amylopectin) sold commercially as AMIOCA (Ingredion, Inc).

Low-amylose maize starch

Eligibility Criteria

• Age: 17 Years - 39 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Child (0-17), Adult (18-64)

You may qualify if:

• Men and women aged 18 - 39 years (active-duty personnel who are 17 yr of age will also be allowed to participate).
• In good health.
• Routinely participate in moderate or higher intensity aerobic and/or resistance exercise at least 4 days per week for ≥20 min/d.
• Meet Army weight for height and body composition standards as defined in Army Regulation 600-9.
• Self-reports a usual bowel movement frequency of every other day or more often.
• Willing to refrain from the use of caffeine, alcohol, and nicotine while consuming study diets.
• Willing to refrain from all dietary supplements beginning 2 weeks prior to study start and throughout study participation.
• Willing to refrain from consumption of any foods containing live microorganisms (e.g., yogurt, kefir, kombucha) or added prebiotics (e.g. Fiber One products) beginning 2 weeks prior to study start and throughout study participation.
• Willing to participate in all study procedures.
• Females must have normal menstrual cycles between 26-32 days in duration; 5 menstrual cycles within the past 6 months; or be using an oral/hormonal contraceptive which contains low-dose estrogen/progesterone to maintain continuous levels throughout the 28-day cycle (i.e., no placebos).

You may not qualify if:

• Females who are pregnant, expecting to become pregnant during the study, or breastfeeding.
• Any of the following medical conditions:
• Cardiac disease (including arrhythmia or fast or skipped heart beats) Hypertension Musculoskeletal injuries that compromise exercise capability Metabolic or cardiovascular abnormalities (e.g., kidney disease, diabetes, etc.) Disease of the GI tract including, but not limited to diverticulitis, inflammatory bowel disease, irritable bowel syndrome, peptic ulcer disease, Crohn's disease, and ulcerative colitis Allergy to skin adhesive or Lidocaine (or other local anesthetic being used in place of Lidocaine) Suspected or known strictures, fistulas, or physiological/mechanical GI obstruction History of gastric bezoar Swallowing disorders; severe dysphagia to food or pills Implanted or portable electro-mechanical medical devices (e.g., pacemaker)
• Colonoscopy within 3 months of study participation.
• Any use of antibiotics or antimycotics, except topical antibiotics/antimycotics, within 3 months of study participation.
• Regular (i.e., weekly or more frequent) use of over-the-counter medications (including antacids, laxatives, stool softeners, and anti-diarrheals) unless approved by study PI.
• Use of medication (i.e., diabetes medications, statins, corticosteroids, etc.) that affects macronutrient utilization and/or the ability to participate in strenuous exercise.
• Anemia (HCT \<38 for men and \<34 for women) or Sickle Cell Anemia/Trait.
• Not willing or able to follow all study procedures and diet/exercise restrictions.
• Allergies, intolerances, unwillingness or inability to eat provided foods and beverages.
• Following vegetarian/vegan diet or other highly restrictive diet (e.g., ketogenic diet, very high protein diet, Paleo diet, etc.).
• Any previous blood donation within the previous 8 weeks that when combined with the volume of blood collected for the study within any 8-week period would exceed 550mL.

Sponsors & Collaborators

• United States Army Research Institute of Environmental Medicine: lead

Study Sites (1)

United States Army Research Institute of Environmental Medicine

Natick, Massachusetts, 01760, United States

Location

MeSH Terms

Interventions

Butyrates

Intervention Hierarchy (Ancestors)

Acids, Acyclic; Carboxylic Acids; Organic Chemicals; Fatty Acids, Volatile; Fatty Acids; Lipids

Study Officials

• J. Philip Karl, PhD

  United States Army Research Institute of Environmental Medicine

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: OTHER
• Intervention Model: CROSSOVER
• Sponsor Type: FED
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: August 21, 2023
• First Posted: September 26, 2023
• Study Start: July 21, 2023
• Primary Completion: May 1, 2025
• Study Completion: May 1, 2025
• Last Updated: December 26, 2025

Record last verified: 2025-12

Locations

US (1)