Condition

Gut Microbiome clinical trials and research

• 36Clinical trials
• 319NIH research projects
• 12Countries

Newest Gut Microbiome clinical trials

All recruiting trials (36)

• Overnight Temperature Regulation to Test Gut Health, Inflammation, and Circadian Rhythms

  This study tests whether two weeks of using the Eight Sleep Pod at night can improve gut bacteria balance, lower inflammation, and strengthen daily temperature and blood pressure rhythms in postmenopausal women and age-matched men with poor sleep.

  Recruiting Eight Sleep Inc. · Newton Center, Massachusetts · NCT07848594

• Egg intake and gut health, HDL, and immune markers in adults

  This study tests whether daily egg whites or whole eggs affect gut microbiome, HDL function, metabolism, and immune profiles in adults with a range of BMIs.

  Recruiting University of Connecticut · Storrs, Connecticut · NCT07844616

• Tiny Tummies: Milk vs. Oat Milk for Toddlers

  This 12‑month randomized study will test whether 12‑month‑old toddlers who drink daily cow’s milk dairy vs. oat milk dairy have better growth, sleep, neurocognitive outcomes, and gut microbiome by 24 months.

  Recruiting Arizona State University · Phoenix, Arizona · NCT07839156

• Probiotic supplementation to support gut health, immune response, and well-being in adults

  In this 8-week study, healthy adults with mild to moderate stress will take a probiotic supplement or placebo daily to see if it affects gut barrier function, immune markers, and well-being.

  Recruiting Orthomol Pharmazeutische Vertiebs GmbH · Trier · NCT07779265

• Combining 10-day Fasting with Fibre to Boost Gut Health

  This study tests whether adding dietary fibre to a 10-day fast improves gut microbiome function and metabolic health in adults with overweight or obesity.

  Recruiting Buchinger Wilhelmi Development & Holding GmbH · Überlingen, Baden-Wurttemberg · NCT07691736

• Daily kefir during mid-pregnancy to see if it helps prevent gestational diabetes

  Pregnant people will drink kefir daily from mid-pregnancy to see if it improves blood sugar and insulin, reduces gestational diabetes risk, and positively affects gut bacteria.

  Recruiting University of New Brunswick · Fredericton, New Brunswick · NCT07682077

• AGEWISE: Exploring how the gut microbiome and hormones change as women age

  This study will look at how the gut microbiome relates to hormonal changes during menopause in healthy women aged 40–64 in Portugal to see if biomarkers can help predict health risks.

  Recruiting Gulbenkian Institute for Molecular Medicine · Lisbon · NCT07614542

• Gut leakage in dengue: is the intestinal barrier affected during infection?

  Researchers are studying whether dengue infection disrupts the gut barrier and if that contributes to severe disease in adults with dengue who are in hospital.

  Recruiting University of Oxford · Chittagong, Chattogram Division · NCT07602920

• Gut-brain in PD Consortium: understanding gut influences in Parkinson's and prodromal stages

  This study tests how the gut and brain communicate in people with Parkinson's, those without PD, and those at risk, to see if gut factors relate to disease onset and progression.

  Recruiting at 4 sites Duke University · Stanford, California and 6 other locations · NCT07567794

• How different cycling training loads change gut bacteria, butyrate, fitness, and overreaching in healthy men

  This project will test whether supervised moderate or high indoor cycling changes gut bacteria and butyrate levels and whether those changes relate to fitness, muscle health, and signs of overreaching in healthy recreational men aged 18–45.

  Recruiting KU Leuven · Leuven, Vlaams Brabant · NCT07481578

• Blackcurrant supplementation to test bone density changes in postmenopausal women

  This study tests whether taking blackcurrant extract can help improve bone density in postmenopausal women by affecting the gut microbiome.

  Recruiting Phase 1 University of Connecticut · Storrs, Connecticut · NCT07365514

• Flourish: Early infant gut microbiome program for babies born by C-section

  This project tests whether microbiome analysis, education, and personalized recommendations can improve gut bacteria and reduce early immune-related markers in babies born by C-section aged 0–3 months.

  Recruiting Seeding Inc · Austin, Texas · NCT07333482

• Goat milk–derived formula versus undiluted goat milk for infants who cannot be exclusively breastfed: growth and gut health

  This study will test whether a goat milk–derived formula is safe and supports similar growth and gut health for 8–10 week old infants who cannot be exclusively breastfed, compared with undiluted goat milk or breast milk.

  Recruiting Aga Khan University · Matiāri, Sindh · NCT07225153

• Cranberry products and the female vaginal and gut microbiome

  This trial will test whether taking a cranberry-based product changes the vaginal and gut microbiomes and related symptoms in generally healthy premenopausal women.

  Recruiting Ocean Spray Cranberries, Inc. · Chicago, Illinois · NCT07109713

• Kefir versus milk for gut microbiome, sleep, and cardiometabolic markers

  This project will test whether drinking 250 ml of kefir daily for 4 weeks, compared with milk, can improve gut bacteria, sleep quality, and LDL cholesterol in adults aged 40–70 with poor sleep and BMI 25–35.

  Recruiting Sheffield Hallam University · Leeds, West Yorkshire and 1 other locations · NCT07071181

• How TAVI affects gut bacteria in people with severe aortic stenosis

  This will test whether transcatheter aortic valve implantation (TAVI) changes the gut microbiota and related blood markers in people with severe aortic stenosis.

  Recruiting Hippocration General Hospital · Athens · NCT07052071

• Collecting stool samples to study gut microbiota and nutrition

  This study is trying to see how different diets affect the gut bacteria in people to better understand their link to health issues like obesity and diabetes.

  Recruiting Institut National de la Santé Et de la Recherche Médicale, France · Bobigny · NCT06941090

• Daily avocado from 6–12 months and infant gut, growth, and development

  This trial will test whether giving Hispanic infants a daily avocado from about 6 to 12 months changes their gut microbes and supports better growth and motor and cognitive development.

  Recruiting Arizona State University · Phoenix, Arizona · NCT06876935

• Effects of mango and low-fat cookies on gut health and its impact on mental, sexual, and skin health

  This study is testing whether eating fresh mangoes can improve gut health and, in turn, benefit mental, sexual, and skin health in healthy adults compared to eating low-fat cookies.

  Recruiting San Diego State University · San Diego, California · NCT06800833

• Impact of seaweed food additive carrageenan on gut health

  This study tests whether a seaweed food additive called carrageenan can improve gut health in healthy people by changing their gut bacteria and making them feel better.

  Recruiting University of Reading · Reading, Reading · NCT06738329

• Effects of wild blueberries on heart, brain, and gut health in adults with high blood pressure

  This study tests if eating freeze-dried wild blueberries can improve heart health, brain function, and gut health in adults aged 45-65 with high blood pressure.

  Recruiting Georgia State University · Atlanta, Georgia · NCT06735599

• Effects of a Single Workout on Gut Health in Women

  This study is testing how a single workout affects gut health and metabolism in premenopausal women of different fitness levels and body types.

  Recruiting George Washington University · Washington D.C., District of Columbia · NCT06691100

• Exploring how a dietary supplement affects gut fungi in healthy adults

  This study is testing if a dietary supplement called L-Phenylalanine can change the types of fungi in the gut of healthy adults.

  Recruiting Phase 4 Weill Medical College of Cornell University · New York, New York · NCT06433310

• Evaluating storage buffers for gut microbiome samples

  This study is testing different storage solutions to see which one best keeps human gut samples fresh over time for research.

  Recruiting University of Vienna · Vienna, State of Vienna · NCT06423508

• Home-based exercise program for kidney transplant recipients

  This study is testing whether a home-based exercise program can help kidney transplant recipients improve their fitness and overall health compared to different levels of exercise intensity.

  Recruiting at 2 sites KU Leuven · Ghent and 1 other locations · NCT06260579

• Examining the effects of a Mediterranean diet on Parkinson's Disease

  This study is trying out a Mediterranean diet for people with Parkinson's Disease to see if it helps improve their symptoms and overall health compared to a regular diet.

  Recruiting University of British Columbia · Vancouver, British Columbia · NCT06207136

• Exploring the Gut Microbiome's Role in Pain After Kidney Transplant

  This study looks at how the bacteria in the gut might affect chronic pain in people who have had a kidney transplant, and whether diet and stress play a role in this connection.

  Recruiting University of Illinois Chicago · Chicago, Illinois · NCT06206486

• Curcumin supplementation for Alzheimer's disease diagnosis and gut health

  This study is testing if taking curcumin for two weeks can help people with Alzheimer's by checking its effects on brain health and gut bacteria.

  Recruiting Phase 1/2 Texas Tech University Health Sciences Center · Lubbock, Texas · NCT05774704

• Examining the gut microbiome's effects on metabolic and bowel function after spinal cord injury

  This study is trying to see how the gut bacteria of people with a recent spinal cord injury affects their metabolism and bowel function over the first year after the injury.

  Recruiting University of Alabama at Birmingham · Birmingham, Alabama · NCT05670288

• Nutritional support for heart failure patients undergoing LVAD placement

  This study tests if giving heart failure patients a special nutritional shake before their LVAD surgery can help them recover better and avoid complications.

  Recruiting Columbia University · New York, New York · NCT05655910

• Investigating how sex hormones affect gut microbiome and heart health in transgender individuals

  This study tests how sex hormones affect gut health and heart risks in transgender individuals receiving hormone therapy.

  Recruiting Charite University, Berlin, Germany · Berlin · NCT05334888

• Cognitive and gut health interventions for alcohol users with HIV

  This study tests two different approaches to help people with HIV who drink alcohol by using a device to stimulate the nervous system and a probiotic to improve gut health and brain function.

  Recruiting University of Florida · Coral Gables, Florida · NCT05090267

• Exploring the gut microbiome in gynecological cancer patients receiving immunotherapy

  This study is trying to see how the gut bacteria of women with advanced gynecological cancer affects their response to immunotherapy treatment.

  Recruiting Viome · Orlando, Florida · NCT04957511

• Exploring how mothers pass gut bacteria to their babies

  This study looks at how mothers pass their gut bacteria to their babies during birth to see how it affects the baby's health and development.

  Recruiting Chinese University of Hong Kong · Hong Kong, Hong Kong · NCT04117321

• Comparing gut microbiota in preterm and full-term infants

  This study looks at the differences in gut bacteria between preterm and full-term babies from birth to three months to see how things like antibiotic use affect their gut health.

  Recruiting Xinhua Hospital, Shanghai Jiao Tong University School of Medicine · Shanghai · NCT03373721

• National registry for fecal microbiota transplantation

  This study is collecting information from 4,000 patients who are getting fecal microbiota transplants to see how well the treatment works and what effects it has over time.

  Recruiting at 26 sites American Gastroenterological Association · Phoenix, Arizona and 52 other locations · NCT03325855

NIH-funded research (newest 40 of 319)

Early-stage science funded by the US National Institutes of Health. Most of these projects don't enroll patients, but they show what is being worked on.

• Multi-agent AI to annotate enzymes in the human gut microbiome

  A team at a major university will build an AI system that automatically curates and labels the functions of enzymes in the human gut microbiome to speed up understanding their health effects.

  NIH research University of South Florida · Tampa, United States · NIH-11594384

• Mapping how gut bacteria transform drugs

  Scientists will study how the gut microbiome changes thousands of drugs into new forms, which could affect how well a medicine works or whether it causes side effects.

  NIH research Stanford University · Stanford, United States · NIH-11550022

• Aflatoxin exposure and child growth in Guatemala

  A study in rural Guatemala will track how exposure to aflatoxin relates to growth and gut health in young children.

  NIH research Arizona State University-Tempe Campus · Scottsdale, United States · NIH-11513260

• Gut bacteria that can make cancer immunotherapy less effective

  This project will see if reducing chronic inflammation driven by certain gut bacteria can help immunotherapy work better for people whose cancers have stopped responding.

  NIH research University of Tx Md Anderson Can Ctr · Houston, United States · NIH-11478145

• How gut bacteria affect how cancer drugs work

  This project looks at how the bacteria in your gut might change how well and with what side effects fluoropyrimidine cancer drugs like 5-FU work in people.

  NIH research University of California, San Francisco · San Francisco, United States · NIH-11473234

• Gut bacteria and cancer drugs: how your gut may change chemotherapy effectiveness

  This project studies how the gut microbiome might affect how well certain chemotherapy drugs work and their side effects in people with cancer.

  NIH research University of California, San Francisco · San Francisco, United States · NIH-11473233

• Long-term study of NAFLD progression and gut bacteria in diverse groups

  We’re following people over time to see how the gut microbiome and diet relate to fatty liver disease progression in diverse racial/ethnic groups.

  NIH research University of Hawaii at Manoa · Honolulu, United States · NIH-11453729

• Gut microbiome targets to ease sickle cell pain in patients

  Researchers are studying how gut microbes affect chronic pain in people with sickle cell disease and how penicillin prophylaxis in babies might change pain pathways.

  NIH research University of Texas Dallas · Richardson, United States · NIH-11448997

• Estrogen, gut bacteria, and heart health in menopausal hormone therapy

  This study will look at how gut bacteria and estrogen-related recycling affect hot flashes and heart-risk markers in women starting modern menopausal hormone therapy.

  NIH research Albert Einstein College of Medicine · Bronx, United States · NIH-11448536

• Predicting how gut bacteria affect drug breakdown in people

  A study to understand how a common gut bacterium changes how medicines are absorbed and processed in people.

  NIH research University of California, San Francisco · San Francisco, United States · NIH-11447313

• Gut microbiome imbalance linked to brain fog and fatigue after COVID-19

  A study will explore whether shifts in gut bacteria after COVID-19 contribute to brain fog and fatigue and how this relationship could point to new treatments.

  NIH research University of Texas Med Br Galveston · Galveston, United States · NIH-11446349

• How genes, gut health, and cadmium exposure affect brain aging in ApoE carriers

  This grant studies how the gut microbiome and ApoE gene variants influence brain sensitivity to cadmium, a toxin linked to cognitive problems.

  NIH research University of Michigan at Ann Arbor · Ann Arbor, United States · NIH-11446322

• Understanding how antibiotic resistance genes move in the human gut

  A funded project will develop new tools and mouse models to track how resistance genes spread between gut bacteria when people take antibiotics.

  NIH research University of California Berkeley · Berkeley, United States · NIH-11441990

• Gut bacteria and a key fat molecule may shape malaria severity

  A small, patient-friendly study will explore how gut bacteria and a fat signaling molecule called S1P influence how severe malaria can be in children.

  NIH research Hunter College · New York, United States · NIH-11441337

• Gut microbiome and multisensory sensitivity in teen menstrual pain

  A study in adolescent girls with moderate-to-severe menstrual pain will explore how gut bacteria relate to their pain and sensitivity to different senses.

  NIH research Mclean Hospital · Belmont, United States · NIH-11438140

• Gut microbiome in cystic fibrosis and colorectal cancer risk

  Researchers are studying how the gut bacteria in adults with cystic fibrosis influence the development of colorectal cancer.

  NIH research Utah State Higher Education System--University of Utah · Salt Lake City, United States · NIH-11436161

• Intermittent Fasting to Boost Fracture Healing in Obesity and Type 2 Diabetes

  A study tests whether intermittent fasting can improve bone healing in people with obesity and type 2 diabetes by changing the gut microbiome.

  NIH research University of Colorado Denver · Aurora, UNITED STATES · NIH-11434069

• Serological and gut virome profiling in type 2 diabetes

  A study will map how people with type 2 diabetes respond to gut microbes and their viruses, to see how this interaction relates to diabetes.

  NIH research Brigham and Women's Hospital · Boston, United States · NIH-11430219

• New oral gel platform to deliver medicine in the gut

  A new oral inulin gel delivery system is being developed to release medicines in the gut and shape the gut microbiome for better immune balance.

  NIH research University of Michigan at Ann Arbor · Ann Arbor, United States · NIH-11429143

• Gut microbiome and breast cancer risk in postmenopausal women

  A large, long-term study will look at how gut bacteria and their metabolites relate to breast cancer risk in women before diagnosis.

  NIH research Rutgers Biomedical and Health Sciences · Newark, UNITED STATES · NIH-11427932

• Gut microbiome and heart disease risk in Asian American and Pacific Islander adults

  A Johns Hopkins-style patient-friendly summary: this study will look at how the gut microbiome relates to early heart artery changes in AsA-NHPI adults to help prevent heart disease.

  NIH research New York University School of Medicine · New York, United States · NIH-11418013

• Dietary plant diversity and your gut microbiome

  Eating a wider variety of plant foods may shape the bacteria in your gut and influence your health.

  NIH research Duke University · Durham, United States · NIH-11414836

• Gut bacteria, colon state, and early colorectal tumor growth

  This grant looks at how the gut microbiome and the lining of the colon work together to influence the formation and growth of early colorectal tumors, with goals to prevent cancer.

  NIH research Fred Hutchinson Cancer Center · Seattle, United States · NIH-11412578

• How gut bacteria and a 'primed' colon may drive colon polyps

  This project looks at whether certain gut bacteria together with molecular changes in the colon make people more likely to develop colon polyps, especially for those at risk of colorectal cancer.

  NIH research Fred Hutchinson Cancer Center · Seattle, United States · NIH-11412577

• Understanding how early colon lesions grow into colorectal cancer via tissue environment, genetics, and gut microbes

  A study to understand why some early colon lesions progress to colorectal cancer by looking at the tissue around them, their genetic changes, and the gut microbiome.

  NIH research Fred Hutchinson Cancer Center · Seattle, United States · NIH-11412564

• How early antibiotics may shape a child’s airways and asthma risk

  Early antibiotic use in the first year of life may influence a child’s airway health and risk of developing asthma later on.

  NIH research Vanderbilt University Medical Center · Nashville, United States · NIH-11411373

• How infant gut health and breastmilk shape development in babies exposed to HIV

  This project looks at how the tiny gut microbiome and components in breastmilk influence brain development in babies exposed to HIV.

  NIH research University of Washington · Seattle, United States · NIH-11408470

• Understanding how the gut microbiome influences energy use and metabolic health

  A study from Harvard will explore how our gut microbes affect how we get and use energy from food and how lifestyle factors like diet and exercise change this in ways that could impact metabolic health.

  NIH research Harvard University · Cambridge, United States · NIH-11406341

• Role of skin and gut microbes in starting atopic dermatitis in babies

  This grant examines how microbes on the skin and in the gut may influence the development of atopic dermatitis in infants.

  NIH research Washington State University · Pullman, United States · NIH-11406309

• Gut microbiome and intestinal development after fetal growth restriction

  A researcher is studying how gut microbes and intestinal growth interact after fetal growth restriction to influence obesity and type 2 diabetes risk.

  NIH research University of Colorado Denver · Aurora, UNITED STATES · NIH-11400303

• Gut microbes and malaria: how microbiome interactions influence malaria and drug behavior in people

  Researchers will study how the gut microbiome interacts with malaria infection and how it affects antimalarial drugs in people, using samples from an existing trial and observational cohort.

  NIH research Johns Hopkins University · Baltimore, United States · NIH-11399690

• How certain chemicals affect gut bacteria and defense against gut infections

  This grant looks at how exposure to non-drug chemicals changes the gut’s trillions of bacteria and how that affects your chance of getting infections like Salmonella or cholera.

  NIH research University of California Riverside · Riverside, United States · NIH-11399356

• Gut bacteria metabolites linked to memory and thinking in Alzheimer's and vascular dementia

  A study at a major hospital is exploring how tiny molecules produced by gut bacteria relate to brain changes and memory problems in people with Alzheimer’s disease and vascular-related dementia.

  NIH research Massachusetts General Hospital · Boston, United States · NIH-11399345

• Gut microbes, environmental toxins, and host health: how microbiome helps adaptation

  This project studies how gut microbes help the body adapt to toxins like antibiotics and pesticides, using a C. elegans model to understand long-term health effects.

  NIH research University of California Berkeley · Berkeley, United States · NIH-11398943

• Gut bacteria and cancer drugs: how your gut may change 5-FU treatment

  A research team at UC San Francisco studies how the gut microbiome affects how people respond to cancer drugs like 5-FU and capecitabine, aiming to explain differences in effectiveness and side effects.

  NIH research University of California, San Francisco · San Francisco, United States · NIH-11397471

• GLP-1, Alcohol, and Gut Microbes in HIV

  This grant explores how the body's own GLP-1 system, alcohol use, and gut microbes may influence heart health in people living with HIV.

  NIH research Vanderbilt University Medical Center · Nashville, United States · NIH-11395333

• Gut bacteria and blueberry compounds: how your gut shapes blueberry benefits

  This grant studies how your gut microbiome affects how blueberry compounds are absorbed and used in your body to impact health.

  NIH research Colorado State University · Fort Collins, United States · NIH-11394570

• Gut microbes and Parkinson's: how gut chemistry may start harmful protein clumps

  A science project looks at how gut bacteria might trigger the harmful clumps of alpha-synuclein in Parkinson's disease, with potential for early interventions.

  NIH research University of California-Irvine · Irvine, United States · NIH-11394420

• Dietary approach to prevent colorectal cancer by shaping gut bacteria and bile acids

  A long-term study will explore how diet influences gut microbes and bile acids to reduce colorectal cancer risk in people.

  NIH research Massachusetts General Hospital · Boston, United States · NIH-11394379

• Gut microbiome, lifestyle, and colorectal neoplasia

  Researchers will study how gut bacteria, diet, and aspirin use interact to influence the development of colorectal polyps and cancer in diverse groups of people.

  NIH research Harvard University D/b/a Harvard School of Public Health · Boston, United States · NIH-11394025

Related topics

Quick answers

How many Gut Microbiome clinical trials are recruiting right now?

36, as of November 12, 2026. We update this list each time we refresh our data from ClinicalTrials.gov.

Where are these trials running?

In 12 countries. The most sites are in United States (19 trials), Canada (3 trials), Germany (3 trials), China (2 trials), Belgium (2 trials). Each study page lists its sites and which ones are recruiting.

What phases are they in?

Phase 4: 1, Phase 1: 1, Phase 1/2: 1. Trials with no phase listed are usually device, behavioural or observational studies.

How do I join one?

Open a study, check the "Is this trial a fit for you?" section, then contact the study team listed on the page. They will ask a few screening questions. Asking is free and does not commit you to anything. Talk it over with your doctor first.

Find the studies that fit you

A list is a starting point. Tell us your situation in your own words and we'll rank the studies that match and explain why. It's free and needs no account.

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