A Study to Evaluate the Influence of Diet on GI Health

Not Applicable

Completed

• Conditions: Healthy
• Interventions: Other: Low-fiber, high-protein diet; Other: High-fiber, low-protein diet

• Registration Number: NCT04783142
• Lead Sponsor: Mayo Clinic

Brief Summary

The purpose of this study is to understand the potential of protein and psyllium fiber to manipulate gut microbial densities, intestinal permeability, and inflammation in humans.

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2021-02-23
• Study First Submitted QC: 2021-03-02
• Study First Posted: 2021-03-05
• Study Start: 2021-06-11
• Primary Completion: 2023-03-27
• Study Completion: 2023-03-27
• Status Verified: 2023-05
• Last Update Submitted: 2023-05-12
• Last Update Posted: 2023-05-15

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 20

Inclusion Criteria

• Adults ≥ 18 years old
• On a baseline diet characterized by: Fiber intake of </= 20g/day, > 18% of daily calories from protein

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Exclusion Criteria

• Prior history of gastrointestinal surgeries (except appendectomy and cholecystectomy)
• Known diagnosis of inflammatory bowel disease (Crohn's or ulcerative colitis), microscopic colitis, celiac disease, or other inflammatory GI condition
• Use of tobacco products within the past 6 months (since nicotine may affect intestinal permeability)
• Use of NSAIDs or aspirin and unable or unwilling to stop taking two weeks prior to permeability test and for the duration of the study
• Use of osmotic laxatives and unable or unwilling to stop taking one week prior to permeability test and for the duration of the study
• Use of oral corticosteroids and unable or unwilling to stop use of oral corticosteroids within the previous 6 weeks and for the duration of the study
• Multiple dietary restrictions or unable/unwilling to alter dietary protein or dietary fiber.
• Unwilling to stop ingestion of alcohol and artificial sweeteners such as Splenda™ (sucralose), Nutrasweet™ (aspartame), sorbitol, xylitol, lactulose, or mannitol 2 days before and during the permeability testing days, e.g. foods to be avoided are sugarless gums or mints and diet beverages
• Unwilling to stop stenuous exercise (running >5 miles or equivalent) one week prior to the permeability tests
• Bowel preparation for colonoscopy less than one week prior to completion of the first stool kit and permeability test and flexible sigmoidoscopy and upper endoscopy
• Pregnancy or plan to become pregnant during the study time frame
• Vulnerable adult
• Known bleeding disorders or takes medications that increase risk of bleeding from mucosal biopsies
• Use of oral antibiotic(s) within the past 4 weeks (can be enrolled after 4-week washout period)
• Use of commercial probiotic formulations and unwilling to stop for the duration of the study
• Diagnosis of diabetes
• Any other disease(s), condition(s) or habits(s) that would interfere with completion of study, or in the judgment of the investigator would potentially interfere with compliance to this study or would adversely affect study outcomes

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Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Low-fiber, high-protein diet	Low-fiber, high-protein diet	Participants will consume a low-fiber, high-protein diet for at least 4 weeks. All meals will be provided free of charge. No substitutions will be permitted.
High-fiber, low-protein diet	High-fiber, low-protein diet	Participants will consume a high-fiber, low-protein diet for at least 4 weeks. All meals will be provided free of charge. No substitutions will be permitted.

Primary Outcome Measures

Name	Time	Method
Urinary Excretion of Lactulose and 13C-Mannitol	4 weeks	Small Bowel and Colonic Permeability by Urinary Excretion of Lactulose and 13C-Mannitol after Oral Ingestion of lactulose and 13C mannitol (5:1 ratio by mass). The 0-2h urine most closely reflects small intestinal permeability and 8-24h urine reflects colonic permeability. HPLC-tandem mass spectrometry will be used for detection of the sugars. The results will be expressed as the ratio of percentage excretion of the ingested dose of lactulose and mannitol in urine.

Secondary Outcome Measures

Name	Time	Method
Change in gut microbial alpha diversity based on Shannon index	4 weeks	Stool samples will be processed to extract DNA, followed by metagenomic sequencing and assessment of alpha diversity using Shannon index. Comparison will be made using ttest.

Trial Locations

Locations (2)

Mayo Clinic in Rochester; 🇺🇸 Rochester, Minnesota, United States

Mayo Clinic; 🇺🇸 Rochester, Minnesota, United States