Fermented Food Diet for Microbiome Balance

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: Mayo Clinic

Must not be taking: Monoamine oxidase inhibitors

Disqualifiers: Dementia, Schizophrenia, Organ transplant, others

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

Approved in 1 Jurisdiction This treatment is already approved in other countries

Compensation: Varies

Number of Visits: 12

Duration: 12 weeks

40 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial explores whether consuming fermented foods, such as yogurt and kimchi, can aid recovery after serious illnesses, including severe COVID-19. Researchers aim to determine if these foods can enhance gut health and reduce inflammation, potentially improving daily life for these individuals. Participants will either incorporate fermented foods into their diet or maintain their usual eating habits. This trial suits individuals who spent over 48 hours in the ICU due to a critical illness or severe COVID-19, are at risk of long-term symptoms, have a smartphone, and can safely consume fermented foods. As an unphased trial, it offers a unique opportunity to contribute to understanding the potential health benefits of fermented foods.

Will I have to stop taking my current medications?

The trial does not specify if you need to stop taking your current medications, but it does exclude those taking Monoamine oxidase inhibitors (a type of antidepressant).

What prior data suggests that a high fermented food diet is safe for improving gut health after critical illness?

Research has shown that fermented foods are generally safe and beneficial for gut health. A study from Stanford found that consuming a large amount of fermented foods for 10 weeks increased the variety of beneficial gut bacteria and supported the immune system, indicating good tolerance by the body. Another review highlighted that fermented foods contain helpful microbes that promote gut health. However, one study noted that long-term consumption might reduce gut bacteria diversity, though this was not associated with any harm.

Overall, fermented foods are considered safe for most people and can be beneficial. It is advisable to consult a healthcare provider before making significant dietary changes, especially if a medical condition is present. ^{1 2 3 4 5}

Why are researchers excited about this trial?

The Fermented Food Diet is unique because it uses a natural approach to balance the gut microbiome by incorporating foods like yogurt, kimchi, and sauerkraut. Unlike typical treatments for microbiome imbalance, which often involve probiotics or prebiotic supplements, this diet leverages whole foods that are rich in live beneficial bacteria. Researchers are excited about this diet because it could offer a more accessible and holistic way to improve gut health without relying on supplements, potentially leading to better digestive health and enhanced immune function naturally.

What evidence suggests that a fermented food diet might be an effective treatment for improving quality of life after surviving a critical illness?

Research has shown that eating fermented foods can increase the variety of good bacteria in the gut, which may help reduce inflammation. Inflammation is the body's response to injury or illness, and lowering it is often beneficial. In this trial, participants in the Fermented Foods Diet arm will incorporate fermented foods into their diet to potentially boost these good bacteria and reduce inflammation. This diet might improve gut health, which is important for recovering from serious illnesses like COVID-19. ^{1 3 4 5 6}

Who Is on the Research Team?

Lioudmila Karnatovskaia, MD

Principal Investigator

Mayo Clinic

Are You a Good Fit for This Trial?

This trial is for people who've been critically ill, including severe COVID-19 cases, and spent time in the ICU. They should be at risk of long-term mental health issues but can't have dementia or severe cognitive impairment. Participants must speak English, eat normally, not be severely immunosuppressed or on certain medications like MAO inhibitors.

Inclusion Criteria

You have recently been very sick, such as with severe COVID, spent a long time in the intensive care unit, and have ongoing health problems related to your illness.

My cognitive function is good enough to understand and follow study instructions.

Exclusion Criteria

I cannot eat by mouth or have conditions that make certain diets risky.

You are not expected to survive your time in the hospital.

You have a history of memory and thinking problems.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants incorporate a high fermented food diet into their routine to evaluate its effect on microbiome diversity and mental health

12 weeks

Regular follow-ups at baseline and 12 weeks

Follow-up

Participants are monitored for safety and effectiveness after treatment

4 weeks

What Are the Treatments Tested in This Trial?

Interventions

• Fermented Food Diet

Trial Overview

The study tests if a diet rich in fermented foods can improve life quality after critical illness by aiding gut health and reducing inflammation. It's aimed at those recovering from serious conditions such as COVID-19 to see if this dietary change could help with physical and mental recovery.

How Is the Trial Designed?

Group I: Fermented Foods Diet Experimental Treatment 1 Intervention

Subjects will incorporate fermented food into their diet.

Group II: Normal Diet Active Control 1 Intervention

Subjects will continue their regular diet.

Who Is Running the Clinical Trial?

Mayo Clinic

Lead Sponsor

Trials

3,427

Recruited

3,221,000+

Published Research Related to This Trial

Fermented foods have been part of human diets for nearly 10,000 years and contain unique microorganisms that can positively influence gut health.

These foods can impact the gut microbiome both in the short and long term, making them an important component of a healthy diet.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Fermented Foods, Health and the Gut Microbiome. Leeuwendaal, NK., Stanton, C., O'Toole, PW., et al.[2022]

Fermentation processes, both in food production and the gastrointestinal tract, produce compounds that can significantly impact consumer health, highlighting the importance of selecting specific food-fermenting microbes to enhance nutritional value.

The gut microbiota plays a crucial role in generating health-active molecules, and dietary choices can modulate this activity, suggesting that a multidisciplinary approach is essential for understanding how diet and microbes interact to benefit health.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Impact of microbial transformation of food on health - from fermented foods to fermentation in the gastro-intestinal tract. van Hylckama Vlieg, JE., Veiga, P., Zhang, C., et al.[2011]

The global market for fermented foods is approximately USD 30 billion and is growing, highlighting the increasing popularity and demand for these products.

Fermented foods play a crucial role in health, particularly through their impact on the microbiome, which is essential for maintaining human health and could be tailored for specific dietary needs, such as for patients with Crohn's disease.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Fermentative Foods: Microbiology, Biochemistry, Potential Human Health Benefits and Public Health Issues. Voidarou, C., Antoniadou, Μ., Rozos, G., et al.[2021]

A 17-week study with 36 healthy adults showed that a high-fiber diet increased specific enzymes in the gut microbiome but did not change overall immune response, indicating a complex relationship between diet and immune function.

In contrast, a diet rich in fermented foods improved microbiome diversity and reduced inflammation, suggesting that such foods could help combat the negative effects of low diversity and high inflammation common in modern diets.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Gut-microbiota-targeted diets modulate human immune status. Wastyk, HC., Fragiadakis, GK., Perelman, D., et al.[2022]

Traditional fermented foods in Africa play a crucial role in food preservation, enhancing nutritional value, and supporting food security, which is vital for socio-economic growth.

Recent studies using advanced DNA sequencing have uncovered diverse microbial populations in these fermented foods that could be leveraged to improve health, food safety, and overall food quality.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

African fermented foods: overview, emerging benefits, and novel approaches to microbiome profiling. Obafemi, YD., Oranusi, SU., Ajanaku, KO., et al.[2022]

Dietary interventions, particularly through the consumption of fermented foods, may enhance the gut microbiome and improve the immune response to cancer immunotherapies, potentially leading to better cancer treatment outcomes.

The review highlights the need for more research on how fermented food interventions can be effectively implemented in cancer patients to optimize their treatment and survivorship.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Gut microbiome and cancer implications: Potential opportunities for fermented foods. Crowder, SL., Jim, HSL., Hogue, S., et al.[2023]

Most caregivers in the South African community are aware of fermented foods and their benefits, but many struggle to differentiate between fermented and unfermented foods, indicating a gap in knowledge.

There is a need for education and health promotion campaigns to standardize the preparation of fermented foods, as misconceptions about the fermentation process were common among participants.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

South African rural community understanding of fermented foods preparation and usage. Chelule, PK., Mokgatle, MM., Zungu, LI.[2020]

The expert panel defined fermented foods as those made through specific microbial growth and enzymatic processes, aiming to clarify the term 'fermented' and distinguish these foods from probiotics.

The panel highlighted the health benefits and safety of fermented foods, discussing their nutritional value and potential to improve gastrointestinal and overall health, while also advocating for their recognition in national dietary guidelines.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The International Scientific Association for Probiotics and Prebiotics (ISAPP) consensus statement on fermented foods. Marco, ML., Sanders, ME., Gänzle, M., et al.[2021]

Fermentation is a widely used and affordable food preservation method in developing countries, offering benefits like extended shelf life, improved digestibility, and potential health advantages from functional microorganisms.

However, the lack of hygiene standards and quality control in the fermentation process can lead to health risks, including contamination with harmful pathogens, which poses a significant food safety concern, particularly in low-income regions.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Two Faces of Fermented Foods-The Benefits and Threats of Its Consumption. Skowron, K., Budzyńska, A., Grudlewska-Buda, K., et al.[2022]

Citations

1.

pmc.ncbi.nlm.nih.gov

pmc.ncbi.nlm.nih.gov/articles/PMC9003261/

Fermented Foods, Health and the Gut Microbiome - PMC

The fermented food-rich diet resulted in an increase in alpha diversity of the gut microbiome that was not observed with the fibre diet.

2.

med.stanford.edu

med.stanford.edu/news/all-news/2021/07/fermented-food-diet-increases-microbiome-diversity-lowers-inflammation.html

Fermented-food diet increases microbiome diversity ...

Stanford researchers discover that a 10-week diet high in fermented foods boosts microbiome diversity and improves immune responses.

3.

pmc.ncbi.nlm.nih.gov

pmc.ncbi.nlm.nih.gov/articles/PMC9020749/

Gut Microbiota-Targeted Diets Modulate Human Immune ...

Alternatively, the high-fermented food diet steadily increased microbiota diversity and decreased inflammatory markers. The data highlight how coupling dietary ...

4.

sciencedirect.com

sciencedirect.com/science/article/pii/S0149763424000307

Fermented foods: Harnessing their potential to modulate ...

Fermented foods offer themselves as a combined whole food microbiota modulating intervention. Indeed, they contain potentially beneficial microbes.

5.

nature.com

nature.com/articles/s41467-025-56014-6

Fermented foods affect the seasonal stability of gut bacteria ...

Our results associate long-term fermented food consumption with reduced gut microbiota diversity and bacterial load.

6.

pmc.ncbi.nlm.nih.gov

pmc.ncbi.nlm.nih.gov/articles/PMC10886436/

Fermented foods, their microbiome and its potential in ...

This review aims to sum up the knowledge about traditional FFs and their associated microbiomes, outlining the role of fermentation with respect to boosting ...