Effects of Dairy Fat and Fermentation on Gut Microbiome and Heart Disease Risk
Effect of Full-Fat and Fat-Free Dairy, With and Without Fermentation, on Fecal Microbiome, Fecal and Serum Metabolome, and Host Cardiometabolic Risk Status
This study is testing whether eating full-fat or fat-free dairy products affects gut health and heart disease risk in people over 50.
Quick facts
| Phase | Not applicable |
|---|---|
| Study type | Interventional |
| Enrollment | 20 (estimated) |
| Ages | 50 Years and up |
| Sex | All |
| Sponsor | Tufts University Academic / other |
| Locations | 1 site (Boston, Massachusetts) |
| Trial ID | NCT05840081 on ClinicalTrials.gov |
What this trial studies
This study investigates how consuming full-fat versus fat-free milk and yogurt affects gut microorganisms and their metabolic products, as well as heart disease risk factors. Participants over 50 years old will follow a randomized-controlled cross-over design, consuming two servings of dairy products daily across four diet phases, each lasting three weeks. The study will measure various health metrics, including weight, waist circumference, blood pressure, and collect blood and stool samples to analyze changes in the gut microbiome and cardiometabolic risk factors. The findings aim to refine dietary guidelines for reducing cardiovascular disease risk.
Who should consider this trial
Good fit: Ideal candidates are men and postmenopausal women over 50 years old with a BMI between 25 and 35 who consume dairy products.
Not a fit: Patients under 50 years old, pre- or peri-menopausal women, or those with certain health conditions or dietary restrictions may not benefit from this study.
Why it matters
Potential benefit: If successful, this study could provide insights into how dairy fat content and fermentation influence heart disease risk, potentially leading to improved dietary recommendations.
How similar studies have performed: While studies on dairy consumption and heart disease exist, this specific approach comparing fat content and fermentation effects on gut microbiota is relatively novel.
Eligibility criteria
Show full inclusion / exclusion criteria
Inclusion Criteria: 1. Age \>50 years 2. Men and postmenopausal women 3. BMI \>25 and \<35 kg/m2 4. No milk allergy, lactose intolerance or adherence to vegan or other dietary pattern that excludes dairy products 5. Non-smoker 6. Usual pattern of bowel movements at least every other day. Exclusion Criteria: 1. Women and men \<50 years 2. Women, pre- or peri-menopausal 3. BMI \<25 and \>35 kg/m2 4. Current smokers or former smoker who quit \< 6 months 5. Use of nicotine replacement products within last 6 months 6. Replacement or gender affirming hormonal therapy use 7. Weight gain of \>15 pounds within last 6 months 8. Infrequent bowel movements 9. History of anemia within past 2 years or confirmation of anemia at first study visit 10. Blood donation within last 2 months 11. Untreated hypertension 12. Oral antibiotics use within 2 weeks of study entry 13. Steroid use (including dental prophylaxis use within 2 wks prior to or during study, except non-prescription topical and nasal steroids, e. g. Flonase) 14. Use of lipid lowering medications 15. Chronic use of aspirin, non-steroidal anti-inflammatory medications (NSAIDS), laxatives, anti-diarrheal medication 16. Regular use (\>2 times per week) of acid lowering medication: antacids, proton pump inhibitors, or H2 Blockers. 17. Use of dietary supplements other than multi-vitamins, including pre- and probiotics, within 2 months of study entry 18. Milk allergy, lactose intolerance or adherence to vegan or other dietary patterns that exclude dairy products 19. Colonoscopy within 3 weeks of study entry or during study period 20. Diagnosis of malabsorption, inflammatory bowel disease (ulcerative colitis or Crohn's Disease), cirrhosis, history of gastrointestinal resection (other than appendectomy), chronic pancreatitis or any other chronic GI disease that in the opinion of the study physician would alter the study results 21. Chronic heart, liver, thyroid, renal or kidney disease 22. Type I or type II diabetes 23. Alcohol consumption \>7 drinks/week for women and \>14 drinks/week for men 24. Inadequate refrigerator storage capacity to store 21 8-oz containers of milk or yogurt 25. Participation in other dietary intervention research study during the same time 26. No social security number 27. Not willing to commit to adhering to the protocol
Where this trial is running
Boston, Massachusetts
- Jean Mayer Human Nutrition Research Center on Aging — Boston, Massachusetts, United States (Recruiting)
Study contacts
- Principal investigator: Alice H Lichtenstein, D. Sc. — Tufts University
- Study coordinator: Alice H Lichtenstein, D. Sc.
- Email: alice.lichtenstein@tufts.edu
- Phone: (617) 556-3127
How to participate
- Review the eligibility criteria above with your treating physician.
- Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
- Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.