Clinical trials
Microbiome clinical trials
Below are recruiting microbiome clinical trials, each written for real people, not researchers. We’re tracking 350 recruiting studies, each written for real people, not researchers, below.
Recruiting studies
- NCT07567794Recruiting
Gut-Brain Connection Study in Parkinson's Disease
This research examines how the gut and brain are connected in Parkinson's disease and aims to better understand the disease. You'd participate in visits and tests over three years, including some involving your digestive system.
Stanford, CaliforniaAges 21–80 - NCT05135351Recruiting
Prebiotics to help your gut health after cancer cell treatment
This trial tests whether taking prebiotics (food for helpful gut bacteria) can improve gut microbiome diversity after your own cancer-cell treatment, like autologous stem cell transplant or CAR-T. It may help your gut ecosystem recover during and after therapy.
Omaha, NebraskaAges 19 years+ - NCT06845527Recruiting
Gut bacteria testing in a clinic study
This study looks at people who visit a special gut bacteria clinic. It aims to learn more about their health by testing their gut bacteria as part of regular care.
Rome, RMAges 18 years+ - NCT07365514RecruitingPhase 1
Blackcurrants study for bone health in postmenopausal women
This trial tests if taking a blackcurrant supplement can help maintain bone density and reduce osteoporosis risk in postmenopausal women. You will take daily capsules and provide blood, stool, and bone scan samples over the study period.
Storrs, ConnecticutAges 45–70 - NCT07457723RecruitingPhase 2
Gut health and metabolism study
This study tests whether a supplement can improve metabolic health by changing the bacteria in your gut. It looks at how your body processes food and energy.
Brisbane, QueenslandAges 18 years+ - NCT02890342Recruiting
Studying Propionic Acidemia, gut bacteria, and body chemistry over time
This study follows people with propionic acidemia to better understand how the body, diet, gut bacteria, and blood chemistry change over time. It may help researchers learn more about the condition and how pregnancy, transplant, and daily life affect health.
Bethesda, MarylandAges 1 month–100 years - NCT03293758Recruiting
Study of food and gut bacteria changes over time
This study looks at how your diet affects the mix of gut bacteria over time. It may help researchers understand links between food, microbiome (gut bacteria), and health outcomes.
New York, New YorkAges 40 years+ - NCT03325855Recruiting
Fecal transplant registry for patients and donors
This study is a national “registry” that collects information from people who get fecal microbiota transplant (a stool-based treatment) and from people who donate stool. It helps researchers understand who receives these treatments and how they do over time.
Phoenix, ArizonaAges Any age - NCT03331133Recruiting
Study of twins born in Guangzhou
This study focuses on twins who were born at Guangzhou Women and Children’s Medical Center. It aims to use pregnancy and baseline information to learn about twin outcomes and care, and it may help local doctors improve guidance for families in Guangzhou.
Guangzhou, GuangdongAges Up to 18 years - NCT03373721Recruiting
Compare gut microbes in preterm vs full-term babies
This study looks at differences in the gut bacteria of babies born early (preterm) compared with babies born full-term. It may help researchers understand how early birth affects early health and gut development.
ShanghaiAges 1 day–4 months - NCT03437005RecruitingPhase 1
Testing how common skin creams change gut microbes
This study looks at whether commonly used topical (skin) medications change your skin and gut microbial “ecosystem.” It’s an early (Phase 1) pilot study, mainly to see how these treatments affect samples over time.
Sacramento, CaliforniaAges 18 years+ - NCT03577327Recruiting
Study gut and skin germs in vitiligo progression
This study looks at differences in the gut and skin microbiome (the germs living in and on the body) in people with vitiligo and in people without vitiligo. It aims to understand what might be linked to how vitiligo spreads over time.
Chicago, IllinoisAges 18–89 - NCT03589183Recruiting
Gut microbiome study for ulcerative colitis and Crohn disease
This study looks at how changes in gut bacteria (the microbiome) relate to inflammatory bowel disease, including ulcerative colitis and Crohn disease. It may help researchers understand what might improve symptoms or disease control.
SeoulAges Any age - NCT03612193Recruiting
Study how gut bacteria relates to complex regional pain
This study looks at differences in gut bacteria (from a stool sample) in people with complex regional pain syndrome (CRPS) and in people who live with them. The goal is to understand whether gut microbes might play a role in CRPS and improve understanding of the condition.
St Louis, MissouriAges 18 years+ - NCT03633162Recruiting
Study about maternal grandmothers’ effects on babies
This study looks at whether what maternal grandmothers know, do, or influence during a pregnancy is linked to outcomes for grandchildren. You may be included if your grandchild was born at the study hospital and key pregnancy details are available.
Guangzhou, GuangdongAges 36–100 - NCT03668327Recruiting
Study of babies born early in Guangzhou
This study follows babies who were born early (before 37 weeks) to learn more about health outcomes over time. It may help doctors better understand and support families after an early birth.
GuangzhouAges Up to 18 years - NCT03819296RecruitingPhase 1
Fecal transplant to treat cancer immunotherapy bowel side effects
This early-phase study tests whether changing your gut bacteria with a fecal transplant can improve diarrhea or colitis caused by cancer immunotherapy. It may help people whose symptoms have not fully settled with standard treatments like steroids and other immune-blocking medicines.
Houston, TexasAges 18 years+ - NCT03932279Recruiting
Study skin microbiome in certain skin diseases
This study looks at the bacteria (microbiome) living on the skin in people with specific skin conditions, and in healthy volunteers. The results may help researchers understand what skin microbes have to do with these diseases.
Chicago, IllinoisAges 18–89 - NCT03941080Recruiting
Study gut bacteria changes in advanced colorectal cancer
This study looks at how gut bacteria (the microbiome) change during treatment for colorectal cancer that has spread or cannot be removed. Researchers hope the findings may help improve understanding of how treatment works and how to tailor care.
AssenAges 18 years+ - NCT04305808Recruiting
Study of gut, bladder, and vaginal bacteria in recurrent UTIs
This study looks at the bacteria living in the vagina, urine tract, and stool to learn why some women get repeated urinary tract infections (UTIs). The results may help doctors better prevent or treat UTIs in the future.
Jerusalem, JerusalemAges Any age - NCT04529889Recruiting
Study of gestational diabetes during pregnancy and child outcomes
This study follows pregnant people with gestational diabetes to see how it affects mothers and babies over time. The team may use this information to better understand risks and care for both you and your child.
Guangzhou, GuangdongAges Any age - NCT04567446Recruiting
Study cancer microbes to find test markers
This trial looks at the microbes in your body (mostly from samples) to find clues—called biomarkers—that may help doctors understand or track cancer. You might be asked to share health information and provide samples before or around the time you start cancer treatment.
Villejuif, Val De MarneAges Any age - NCT04579900Recruiting
Study how gut microbes affect type 2 diabetes risk
This study looks at how differences in gut microbes may relate to risk of developing type 2 diabetes. It may help researchers understand who is more likely to develop diabetes, and why.
Québec, QuebecAges 18–60 - NCT04590690Recruiting
Gut microbes and sex risks for kidney stones after weight surgery
This study looks at how gut bacteria (microbes), along with sex, may affect the chance of getting kidney stones after bariatric (weight-loss) surgery. It may help doctors understand who is at higher risk so prevention can be improved.
Chicago, IllinoisAges 18–130
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Common questions
- Are there clinical trials for microbiome?
- Yes. Clin2 currently lists 350 recruiting microbiome studies from the U.S. registry, each rewritten for real people, not researchers, so you can see what it’s testing and who it’s for.
- How do I know if I qualify for a microbiome trial?
- Each study lists its eligibility criteria — rules about age, diagnosis, and prior treatments. On every Clin2 trial page we explain these in words written for real people and offer a short, optional pre-screen for a fit read. The study team makes the final decision.
- Does it cost anything to join a microbiome trial?
- Using Clin2 is always free. Many trials cover the cost of the study treatment and related visits; some reimburse travel. The study team explains exactly what’s covered before you decide.
Related conditions
Clin2 helps you find and understand clinical trials and does not provide medical advice. Study data comes from ClinicalTrials.gov. Talk with your doctor about whether a specific trial is right for you.