CLEAN-MED Diet for Healthy Gut Microbiome

Overseen By Crystal K Ayensu

Age: 18 - 65

Sex: Any

Trial Phase: Academic

Sponsor: National Institutes of Health Clinical Center (CC)

Must not be taking: Weight control, Antidiabetics, Cholesterol drugs, others

Disqualifiers: Diabetes, Kidney disease, Liver disease, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: 21

1000 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial aims to explore how switching from a Western diet, low in fiber and high in saturated fat, to a Mediterranean-like diet (CLEAN-MED) affects gut health. The CLEAN-MED diet includes plenty of vegetables, fruits, and whole grains, with limited sugar and red meat. Participants will follow this diet for either a short term (4 weeks) or long term (up to 12 months), and researchers will collect various health samples. Healthy adults currently on a Western diet and willing to switch to the CLEAN-MED plan may be suitable for this study. As an unphased trial, this study offers participants the chance to contribute to valuable research on diet and gut health.

Will I have to stop taking my current medications?

The trial requires that you do not use certain medications, such as those for weight control, diabetes, cholesterol, and some others. If you are taking any of these, you may need to stop before joining the study.

Is there any evidence suggesting that this trial's treatments are likely to be safe?

Research has shown that switching to a Mediterranean-like diet with unprocessed foods, such as the CLEAN-MED diet, is generally safe and well-tolerated by healthy adults. This diet, rich in vegetables, fruits, and whole grains, benefits the gut microbiome (the helpful bacteria in the intestines) without causing major side effects.

In previous studies with similar diets, participants followed the Mediterranean diet with few reports of negative side effects. The emphasis on natural, whole foods usually makes this diet a healthy choice for most people. However, as with any diet change, some individuals might experience mild digestive changes as their bodies adjust. These changes are usually temporary.

Participants in earlier research successfully followed the CLEAN-MED diet, indicating it is a manageable and safe way to improve overall gut health. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about the CLEAN-MED Diet because it focuses on enhancing gut health through a Mediterranean-like diet, which is distinct from many current dietary interventions. Unlike standard Western diets, which are often high in processed foods and low in nutrients, the CLEAN-MED Diet emphasizes whole foods rich in healthy fats, fibers, and antioxidants. This approach is believed to foster a diverse and healthy gut microbiome, which can have far-reaching benefits for overall health. The trial aims to determine the effects of different durations and intensities of this diet, providing insights into how dietary patterns can significantly impact gut health and potentially prevent related conditions.

What evidence suggests that the CLEAN-MED Diet could be effective for a healthy gut microbiome?

Studies have shown that following a Mediterranean-like diet, such as the CLEAN-MED diet, can improve overall health. This diet lowers the risk of diseases like diabetes and obesity. Research also suggests it supports a healthier gut, the community of tiny organisms in the intestines. Changes in the gut can lead to better digestion and stronger immunity. Participants in this trial will follow the CLEAN-MED diet, which emphasizes whole foods like vegetables, fruits, and whole grains while reducing sugar and red meat. This eating style has been linked to longer life and fewer metabolic problems. ^{1 2 5 6 7}

Who Is on the Research Team?

Karen M Frank, M.D.

Principal Investigator

National Institutes of Health Clinical Center (CC)

Are You a Good Fit for This Trial?

Healthy adults aged 18-60 who currently follow a Western diet and are willing to switch to a Mediterranean-like unprocessed foods diet (CLEAN-MED) for the study. They must be able to attend clinic visits, provide blood and stool samples, have internet access, and not have any severe health conditions or recent significant weight changes.

Inclusion Criteria

For 10 of the 60 participants in short-term cohort and for 10 of the 50 participants in the long-term cohort: Currently following a Western diet with specific dietary scores and items/week criteria

I can prepare and eat fresh meals.

My gender, race, or ethnicity does not limit my participation.

Exclusion Criteria

I have painful gallstones.

I am currently taking certain medications.

I have not had heart disease or conditions in the last year.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Trial Week

Participants log all food intake and answer dietary questions

1 week

1 visit (in-person)

Short-term Treatment

Participants in the short-term group consume a Western diet for 4 weeks followed by a CLEAN-MED diet for 4 weeks

8 weeks

8 visits (in-person)

Long-term Treatment

Participants in the long-term group consume a CLEAN-MED diet for up to 12 months

12 months

12 visits (in-person)

Follow-up

Participants are monitored for changes in gut microbiome and quality of life

4 weeks

What Are the Treatments Tested in This Trial?

Interventions

• CLEAN-MED Diet
• Western Diet

Trial Overview The trial is testing how changing from a traditional Western diet to a CLEAN-MED diet affects gut microbiome in healthy adults. Participants will either adopt the CLEAN-MED diet short-term (8 weeks) with provided food or long-term (up to 12 months), logging their intake and providing regular biological samples.

How Is the Trial Designed?

Group I: Short-term, Western Diet, low MedDiet score a Intervention: We Experimental Treatment 1 Intervention

Study arm will consume a Mediterranean like diet, while tracking their food intake for 9 weeks. With low MEdDIet score.

Group II: Short-term, Western Diet, low MedDiet score a Intervention: CL Experimental Treatment 1 Intervention

Study arm will consume a western diet eating as they normally would for 9 weeks. With low MEdDIet score.

Group III: Short-term, Western Diet, high MedDiet score a Intervention: W Experimental Treatment 1 Intervention

Study arm will consume a Mediterranean like diet, while tracking their food intake for 9 weeks, With high MEdDIet score.

Group IV: Short-term, Western Diet, high MedDiet score a Intervention: C Experimental Treatment 1 Intervention

Study arm will consume a Mediterranean like diet, while tracking their food intake for 9 weeks, With high MEdDIet score.

Group V: Long-term a Intervention: CLEAN-MED Experimental Treatment 1 Intervention

Study arm will consume a Mediterranean like diet, while tracking their food intake for 12 months

Who Is Running the Clinical Trial?

National Institutes of Health Clinical Center (CC)

Lead Sponsor

Trials

391

Recruited

30,880,000+

Published Research Related to This Trial

The Mediterranean diet (MedDiet) is linked to numerous health benefits, including lower rates of cardiometabolic diseases, cancer, and inflammation, suggesting it plays a significant role in promoting overall health.

Recent research indicates that the MedDiet influences the gut microbiome, which in turn may enhance the diet's health benefits through bioactive compounds, highlighting the potential for personalized nutrition strategies to optimize these effects.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The role of the Mediterranean diet in modulating the gut microbiome: A review of current evidence. Gundogdu, A., Nalbantoglu, OU.[2023]

In a study of 120 adults, those who adhered more closely to the Mediterranean diet showed a healthier gut microbiota profile, including lower levels of harmful E. coli and a higher ratio of beneficial bifidobacteria.

Higher adherence to the Mediterranean diet was associated with increased gastrointestinal symptoms and a greater frequency of bowel movements, suggesting a complex relationship between diet and gut health.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Adherence to the Mediterranean diet is associated with the gut microbiota pattern and gastrointestinal characteristics in an adult population. Mitsou, EK., Kakali, A., Antonopoulou, S., et al.[2017]

A study involving 106 subjects over 2 years found that obese patients with severe metabolic disease (MetS-OB) had significant gut microbiome dysbiosis compared to those without metabolic dysfunction and non-obese individuals.

Both Mediterranean and low-fat diets were effective in partially restoring the gut microbiome in obese patients with severe metabolic disease, indicating that dietary interventions can positively impact gut health based on metabolic status.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Consumption of Two Healthy Dietary Patterns Restored Microbiota Dysbiosis in Obese Patients with Metabolic Dysfunction. Haro, C., García-Carpintero, S., Rangel-Zúñiga, OA., et al.[2018]

The Mediterranean diet (MD) is linked to increased gut microbiota diversity and specific characteristics that differ significantly from those following a Western diet, which is associated with higher gut permeability and metabolic issues.

Adhering to a Mediterranean diet may help prevent chronic diseases like cardiovascular diseases and certain cancers by positively influencing gut microbiota, but more controlled studies are needed to confirm these effects.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Influence of Mediterranean Diet on Human Gut Microbiota. Merra, G., Noce, A., Marrone, G., et al.[2021]

A study involving 27 healthy adults found that adherence to the Mediterranean diet (MD) is linked to a healthier gut microbiome, with higher levels of beneficial bacteria and short-chain fatty acids (SCFA) that can positively influence metabolism.

In contrast, higher intakes of animal proteins, saturated fats, and sugars were associated with reduced gut microbiota diversity and an increased risk of obesity and related diseases, highlighting the importance of dietary patterns on gut health.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Shifts on Gut Microbiota Associated to Mediterranean Diet Adherence and Specific Dietary Intakes on General Adult Population. Garcia-Mantrana, I., Selma-Royo, M., Alcantara, C., et al.[2020]

A 4-week Mediterranean diet (MED) intervention in 20 healthy participants led to significant improvements in dietary adherence, with increased fiber intake and reduced saturated fat, which correlated with beneficial changes in gut microbiota composition.

The MED intervention also resulted in modest reductions in inflammatory markers like fecal calprotectin and white blood cell counts, suggesting potential health benefits related to gut health and inflammation.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Increasing adherence to the Mediterranean diet and lifestyle is associated with reduced fecal calprotectin and intra-individual changes in microbial composition of healthy subjects. Godny, L., Reshef, L., Sharar Fischler, T., et al.[2022]

The Mediterranean diet (MD) is associated with a gut microbiota that promotes an anti-inflammatory environment, which may help prevent colorectal cancer (CRC) and inflammatory bowel diseases (IBD).

In contrast, patients with CRC and IBD have a microbiota profile that is enriched in pro-inflammatory bacteria, suggesting that adopting MD could be a beneficial lifestyle change to improve gut health and reduce disease risk.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Mediterranean Diet to Prevent the Development of Colon Diseases: A Meta-Analysis of Gut Microbiota Studies. Illescas, O., Rodríguez-Sosa, M., Gariboldi, M.[2021]

Citations

1. clinicaltrials.gov clinicaltrials.gov/study/NCT05411120?term=AREA%5BBasicSearch%5D(Mediterranean%20diet)&rank=8

Mediterranean-like Unprocessed (CLEAN-MED) Diet ... This study (called the CLEAN-MED Diet Study) seeks to examine associations between the gut microbiome, well-being, and adherence to a Mediterranean-like ...

2. cc.nih.gov cc.nih.gov/recruit/protocols/000871-CC

Mediterranean-Like Unprocessed (CLEAN-MED) Diet ... A study at the NIH is measuring the changes within the gut environment in healthy adults when switching from a traditional Western diet.

3. clinicaltrials.gov clinicaltrials.gov/study/NCT05411120?cond=Diet&viewType=Table&rank=1

Mediterranean-like Unprocessed (CLEAN-MED) Diet ... Primary Objective: -The primary objective is to measure changes within the gut microbiome in healthy adults who adhere to a Mediterranean-like unprocessed food ...

4. reporter.nih.gov reporter.nih.gov/project-details/11180839

Project Details - NIH RePORTER This study (called the CLEAN-MED Diet Study) seeks to examine associations between the gut microbiome, well-being, and adherence to a Mediterranean-like ...

5. mdpi.com mdpi.com/2072-6643/15/9/2150

The Effects of the Mediterranean Diet on Health and Gut ... Much evidence supports the health benefits of the MD that include improved longevity, reduced metabolic risk of Diabetes Mellitus, obesity, and Metabolic ...

6. clinicaltrials.gov clinicaltrials.gov/study/NCT05411120

Mediterranean-like Unprocessed (CLEAN-MED) Diet ... This study (called the CLEAN-MED Diet Study) seeks to examine associations between the gut microbiome, well-being, and adherence to a Mediterranean-like ...

7. mdpi.com mdpi.com/2072-6643/16/6/793

Impact of the Mediterranean Diet on the Gut Microbiome ... We assessed the influence of the Mediterranean diet on the intestinal microbiome in a rigorously defined cohort of 60 healthy subjects ...