Clinical trials
Microbiome clinical trials
Below are recruiting microbiome clinical trials, each written for real people, not researchers. We’re tracking 346 recruiting studies, each written for real people, not researchers, below.
Recruiting studies
- NCT05655910Recruiting
Nutrition support program for people with LVADs in the hospital
This trial tests whether an enhanced nutrition plan can improve care for adults who already have an LVAD (a heart pumping device). It’s designed for hospitalized patients and looks at who can safely eat by mouth while avoiding high-risk situations.
New York, New YorkAges 18 years+ - 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+ - NCT06072976Recruiting
How feeding affects gut health in babies with bowel conditions
This study looks at whether breast milk or formula helps babies with certain bowel problems heal faster and reach full feeds sooner. It compares how different milk affects the bacteria in a baby's gut.
Seattle, WashingtonAges birth–55 years - NCT06044051Recruiting
Severe infant asthma and the lung microbiome study
This study looks at the bacteria (microbiome) in the airways of infants under 2 years old with severe asthma. It aims to understand how these bacteria might affect the disease.
RouenAges Up to 2 years - NCT06050733Recruiting
Gut bacteria and immunotherapy response in solid tumors
This study looks at how the bacteria in your gut may affect how well immunotherapy works for solid cancers that have spread or cannot be removed. It focuses on people who have been on certain immunotherapy drugs (PD-1 or PD-L1 inhibitors) for at least 3 months but less than 2 years.
Galveston, TexasAges 35–75 - NCT06009276Recruiting
Gut bacteria, muscle blood flow, and fitness study
This study looks at how the bacteria in your gut affect blood flow to your muscles and your overall fitness. You will provide samples and do some exercise tests to help researchers understand this link.
Charlottesville, VirginiaAges 18 years+ - NCT05934188Recruiting
Study how gut signals relate to brain aging and diseases
This study looks at how the gut may influence the brain in normal aging and conditions like Alzheimer’s, Parkinson’s, and multiple sclerosis. It may help researchers understand new ways to measure or treat these brain changes over time.
Venice-Lido, VeniceAges 20–90 - NCT05873231Recruiting
Gut microbiome study for diarrhea after anti-cancer treatment
This trial looks at how changes in the gut (microbiome) relate to diarrhea that can happen after starting anti-cancer therapy. It may help doctors better predict and manage treatment-related diarrhea.
GrazAges 18 years+ - NCT05837221Recruiting
Study of the mouth microbiome in oral cancer
This study looks at the types of bacteria in the mouth (the microbiome) in people with oral squamous cell cancer and compares them to people without this cancer. It may help researchers understand what’s different in oral cancer and what could be useful for diagnosis or treatment planning.
Aurora, ColoradoAges 18–100 - NCT05835206RecruitingPhase 2
Drug to reduce antibiotic-resistant gut bacteria
This Phase 2 study tests whether an investigational treatment can help clear or reduce antibiotic-resistant bacteria living in the gut. It may help prevent these germs from causing future infections by targeting specific resistant bacteria found on stool or rectal swabs.
Atlanta, GeorgiaAges 18 years+ - NCT05821309RecruitingPhase 4
Testing how a new enema routine changes gut bacteria
This study looks at how placing an antegrade (forward-flow) continence enema and starting a bowel flush routine may change your gut microbiome (your gut bacteria). It is meant for children who have long-lasting constipation that required a special surgical drainage channel.
Carmel, IndianaAges 2–18 - NCT05774704RecruitingPhase 1/Phase 2
Curcumin eye study for people with retinal amyloid deposits
This early-stage study tests whether curcumin (a natural plant compound) can affect eye changes in people who have amyloid deposits in the retina. It aims to see if the treatment is safe and possibly helpful for vision-related outcomes.
Lubbock, TexasAges 40–89 - NCT05753813RecruitingEarly Phase 1
Study lactic acid gel to change vaginal germs
This early study tests whether placing a lactic acid gel inside the vagina can change the vaginal “microbiome,” the mix of germs, to help reduce repeat BV or yeast infections. You may join if you’ve had at least two recent episodes that needed treatment.
Honolulu, HawaiiAges 18–54 - NCT05732480Recruiting
Studying how gut bacteria affect gallstone disease
This study looks at gut bacteria (your microbiome) in people with gallstones to better understand what’s going on in the body. It includes adults having gallbladder removal surgery, and it may help researchers find better ways to predict or treat gallstone disease.
Ashford, KentAges 18 years+ - NCT05689255Recruiting
Study gut bacteria and gut chemistry after gallbladder treatment
This study looks at how your gut bacteria and gut chemical products change after treatment for gallstones. It may help researchers understand what drives symptoms and recovery after surgery and/or endoscopic procedures.
Singapore, SingaporeAges 21–80 - NCT05656378Recruiting
Storing samples to study how the body interacts with microbes
This study creates a storage bank of biological samples like blood, stool, and tissue. Researchers will use these samples to learn how the body interacts with the natural microbes that live in and on us, which may help improve treatments for many diseases.
Bethesda, MarylandAges Any age - NCT05643859Recruiting
Fiber supplement study for bowel health and gut bacteria
This study tests whether adding a dietary fiber supplement can change the bacteria in your colon (gut microbiome). You may be asked to take the fiber supplement during evaluation for a non-cancer rectal condition.
Portland, OregonAges 18 years+ - NCT05598112RecruitingEarly Phase 1
Oral stool-based microbiome treatment for healthy aging
This early-stage study tests whether changing the gut bacteria using an oral stool-based treatment (called oral FMT) can improve health in older adults. It aims to see if this approach affects aging-related changes, including gut and body function.
Beijing, Beijing MunicipalityAges 70–85 - NCT05603650Recruiting
Mouthwash study for healthy bacteria in your mouth and gut
This study tests how a mouthrinse changes the helpful bacteria in your mouth and stomach/gut. You may need several visits and phone follow-ups to see how your microbiome shifts over time.
Irvine, CaliforniaAges 18 years+ - NCT05417867Recruiting
Tracking gut bacteria changes and nausea during chemo
This study looks at how changes in the gut “microbiome” (your gut bacteria) relate to fatigue and chemotherapy-induced nausea in people with early-stage breast cancer. It may help doctors better understand why nausea and fatigue happen and how to predict or manage them during treatment.
Scottsdale, ArizonaAges 20 years+ - NCT05414409RecruitingPhase 2
Gut microbiome study in young people with type 1 diabetes
This Phase 2 study looks at the gut microbiome (the bacteria in your intestines) in youth with type 1 diabetes, and how metformin may work differently through the gut. It may help researchers understand mechanisms and future treatment options.
Indianapolis, IndianaAges 11–18 - NCT05414994Recruiting
Study eye bacteria in healthy and eye disease
This study compares the tiny living organisms (“ocular microbiome,” meaning eye-surface bacteria) in different eye conditions. It may help researchers understand how these eye bacteria relate to diseases and why some people develop problems with vision.
Nashville, TennesseeAges 18 years+ - NCT05337072Recruiting
Finding the cause of chronic endometritis in IVF patients
This study looks for a possible infection-related cause of chronic endometritis (a long-lasting inflammation inside the uterus) in people preparing for IVF/ICSI, to help find the best treatment. It involves a diagnostic hysteroscopy and may help doctors choose the most effective steps to improve pregnancy chances.
BrusselsAges Any age - NCT05357170Recruiting
Testing gut bacteria changes after severe ICU illnesses
This study looks at changes in the microbiome (gut bacteria) in adults after serious ICU illnesses like sepsis, major trauma, or open heart/abdominal surgery. It may help researchers understand why recovery can be harder in some people and guide future treatments.
Gainesville, FloridaAges 18–110
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Common questions
- Are there clinical trials for microbiome?
- Yes. Clin2 currently lists 346 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.