Clinical trials
Microbiota clinical trials
Below are recruiting microbiota clinical trials, each written for real people, not researchers. We’re tracking 409 recruiting studies, each written for real people, not researchers, below.
Recruiting studies
- NCT06896240Recruiting
Fiber smoothie trial for knee replacement patients
This trial tests if drinking a special fiber smoothie for 2 weeks before knee revision surgery can reduce inflammation and improve recovery. It is for people who are scheduled for knee replacement and have certain chronic health conditions.
New York, New YorkAges 40–80 - NCT07718555Recruiting
Gut bacteria study for autoinflammatory diseases
This study looks at the gut bacteria (microbiome) in people with autoinflammatory diseases. It may help researchers understand how bacteria in the gut affect inflammation and find better ways to treat these conditions.
ParisAges 12 years+ - NCT07704255RecruitingPhase 4
Fecal transplant for stubborn H. pylori infection
This study tries a fecal microbiota transplant (placing healthy donor stool into your gut) to get rid of stubborn H. pylori infection that hasn't been cured by standard treatments. It's for people who have failed several rounds of therapy and have a stomach condition that makes eradication important.
Chengdu, SichuanAges 18–80 - NCT07592975Recruiting
Food with Fiber and B-Vitamins for Gut Health in Older Adults
This study tests whether adding special fibers (prebiotics) and B-vitamins to food can improve your gut bacteria, reduce inflammation, and support mental health. You'll eat fortified foods for several weeks while researchers track changes in your digestion and wellbeing.
Coleraine, County LondonderryAges 50 years+ - NCT06754319Recruiting
Gut bacteria and brain connection in child OCD
This study looks at how the bacteria in your gut might affect OCD in children and teens. It tests a possible link between your gut, brain, and OCD symptoms.
Shanghai, Shanghai MunicipalityAges 7–17 - NCT06481852RecruitingPhase 1
Gut bacteria transplant for pulmonary arterial hypertension
This trial tests whether a special combination of antibiotics, fecal transplant (gut bacteria from healthy donors), and a fiber supplement can help people with pulmonary arterial hypertension (PAH). It aims to see if improving gut health can improve PAH symptoms and overall well-being.
Minneapolis, MinnesotaAges 18–75 - 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 - NCT06801184Recruiting
Gut bacteria study for constipation-predominant IBS with methane
This study looks at the gut bacteria in people with irritable bowel syndrome (IBS) who have constipation and produce high levels of methane gas. It aims to understand how methane relates to symptoms and may guide future treatments.
LyonAges 18 years+ - NCT07686835RecruitingPhase 2
High-fiber diet to help immunotherapy work better in advanced melanoma
This trial tests if adding extra dietary fiber before and during immunotherapy can change gut bacteria to make the treatment more effective. It is for people with advanced melanoma who are about to start their first immunotherapy.
Nijmegen, GelderlandAges 18 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+ - NCT07724990Recruiting
Probiotic for gut health in mild-to-moderate colitis
This trial tests a specific probiotic (a type of beneficial bacteria) to see if it can help people with mild to moderate ulcerative colitis by improving the balance of gut microbes. It may be an option if you have not used many advanced treatments before.
Roma, RMAges 18–80 - NCT06478823Recruiting
Healthy stool donors for fecal transplant studies
This trial is looking for healthy stool donors to provide samples for fecal microbiota transplantation, a treatment that uses healthy bacteria from stool to help people with certain gut diseases. As a donor, you would give stool samples regularly to help others.
Paris, ParisAges 18–49 - 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 - NCT07715955Recruiting
Can probiotics help control appetite in adults with overweight or obesity?
This study tests whether taking probiotics can help regulate appetite in people who are overweight or have obesity. It aims to understand if these supplements can support weight management by affecting hunger and fullness signals.
Maastricht, LimburgAges 20–70 - NCT07264985Recruiting
Gut bacteria and diarrhea in breast cancer patients on pyrotinib
This study looks at how gut bacteria relate to diarrhea in breast cancer patients who are taking a drug called pyrotinib. By understanding this link, doctors hope to better manage side effects in the future.
Wuhan, HubeiAges 18–75 - NCT03250091Recruiting
Stomach precancer check-up study after scope
This study follows people who have had an upper endoscopy (a camera test through the mouth to look at the stomach) to monitor precancerous stomach changes. It may help doctors learn the best way to watch these spots over time and catch problems early.
RigaAges 18 years+ - NCT03298334RecruitingPhase 1/Phase 2
Testing vaginal bacteria transfer to newborns after C-section
This study looks at whether they can safely place “healthy vaginal bacteria” from the mother into the newborn after a scheduled C-section, and whether it improves the baby’s health. It only enrolls certain mothers and babies based on infection testing and other health factors.
Falls Church, VirginiaAges birth–50 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 - NCT03787771Recruiting
Fecal transplant registry for donors and recipients
This is a registry that collects information from adults who either receive fecal microbiota transplant (FMT) or plan to receive it, and from people who have donated—or plan to donate—stool for FMT. It helps researchers understand who participates in these gut-microbiome treatments in real life.
Hong KongAges 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+ - NCT03841799Recruiting
Study of gut bacteria and immune changes in colon tissue
This study looks at how gut bacteria and immune activity differ in normal, pre-cancer, and cancer colon tissue. It may help researchers understand what changes in the body are linked to colon growth and how they could be targeted in the future.
Lyon, LyonAges 18 years+ - NCT03855657Recruiting
Biobank study of gut microbes, genes, and blood chemistry
This study collects samples to learn how gut microbes, genetics, and body chemistry may relate to Crohn’s disease or ulcerative colitis. Your information and samples may help researchers understand disease patterns, but it does not test a new drug.
Hong KongAges 18 years+ - NCT04022109Recruiting
Check gastric cancer using breath chemical signals
This study looks at chemical signals in your breath to help screen for or understand gastric (stomach) cancer. It may help doctors improve earlier detection, or better sort out who may need further tests.
São PauloAges 18 years+ - NCT04026360Recruiting
Study early lung, virus, and gut changes in children with cystic fibrosis
This study looks at how a child’s early lung function, viral infections, and gut (microbiome) changes affect cystic fibrosis over time. It may help doctors understand what predicts how lung disease develops, which could improve future care.
BernAges birth–18 years
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Common questions
- Are there clinical trials for microbiota?
- Yes. Clin2 currently lists 409 recruiting microbiota 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 microbiota 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 microbiota 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.