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
- NCT02431845Recruiting
Study of OCD genes, proteins, and gut microbes
This study looks at genes, blood/brain proteins, and gut microbes in people with obsessive-compulsive disorder (OCD). It may help researchers understand what drives OCD and how treatments could be better tailored in the future.
SeoulAges 19–70 - NCT02898818Recruiting
Study of interactions between vaginal and oral microbiomes
This study looks at how the bacteria (microbes) in the vagina and in the mouth may affect each other. It may help improve understanding of vaginal health and related conditions.
Turku, TurkuAges 18 years+ - NCT02526901Recruiting
Pregnancy cohort study for women in Guangzhou
This study follows pregnant women from early pregnancy to learn about pregnancy and child health. You may be asked to share health information so researchers can better understand outcomes for babies born in Guangzhou.
Guangzhou, GuangdongAges Any age - NCT02777879Recruiting
Study gut-like lung bacteria and inflammation in early COPD
This study looks at the lung’s tiny bacteria (microbiome) and inflammation in people with early COPD who have a smoking history. It compares them with smokers who have normal breathing tests, to better understand what may drive COPD early on.
New York, New YorkAges 18–70 - NCT03080129Recruiting
Study gut microbes and muscle loss in liver cirrhosis
This study looks at the gut microbiome (the helpful bacteria in your gut) and muscle loss (sarcopenia) in people with liver cirrhosis. It may help researchers understand what changes in the gut and body can go along with getting weaker, so better treatments can be developed.
GrazAges 18–100 - NCT07280091Recruiting
Skin and gut bacteria in Netherton syndrome
This study looks at the bacteria on the skin and in the gut of people with Netherton syndrome, a condition that affects the skin barrier and often causes allergies. It also compares these findings to healthy volunteers to understand how the microbiome might be different.
Paris, Île-de-France RegionAges 10 years+ - NCT07676461Recruiting
Microbiome study in advanced cancer patients starting immunotherapy
This study looks at the bacteria in your mouth, gut, and tumors to see if they affect how well first-line immunotherapy works. It is for people with advanced stomach, colorectal, breast, cervical, or head-and-neck cancer.
Bogotá, Bogota D.C.Ages 18 years+ - NCT07533890Recruiting
Probiotics and gut health in children with inflammatory bowel disease
This study tests whether a multi-strain probiotic supplement can change the gut bacteria in children and teens with inflammatory bowel disease (IBD). Researchers will collect stool samples to see if the probiotics help restore healthy gut bacteria and potentially improve symptoms.
BernAges 5–18 - NCT02636517Enrolling by invitationPhase 1
Fecal microbiome transplant for repeat C. difficile infection
This Phase 1 study tests whether transferring healthy gut bacteria (a fecal microbiome transplant) can help children with repeated or moderate-to-severe C. difficile infection. It focuses on changing gut bacteria to reduce ongoing infection and symptoms.
Philadelphia, PennsylvaniaAges 3–21 - NCT01933620Enrolling by invitation
NIH study of the microbiome using stored body samples
This study looks at the community of microbes in the body (your “microbiome”) using samples like stool, urine, and possibly tissue. It may help researchers understand how these microbes relate to health in hospital patients.
Bethesda, MarylandAges 2–120 - NCT02013284Enrolling by invitation
Stool test to see if gut microbes predict heart risk
This study looks at your gut bacteria (from a stool sample) to see whether they can help predict heart risk in people being checked for blocked heart arteries. Your results may help researchers understand who is at higher risk and why.
Rochester, MinnesotaAges 18 years+ - NCT07402226Recruiting
Diet study for bloating with scleroderma
This study tests whether a special diet can help reduce bloating and stomach discomfort in people with scleroderma (systemic sclerosis). You'll follow a specific meal plan to see if it improves your digestive symptoms.
Ann Arbor, MichiganAges 18 years+ - NCT07414498Recruiting
Bacteria in gum surgery for implant and tooth infections
This study looks at the bacteria living in deep gum pockets around implants or teeth during different types of gum surgery. It may help determine which surgical approach is best for your kind of gum infection.
Münster, North Rhine-WestphaliaAges 18–80 - NCT07424469Recruiting
Leaks in the esophagus or stomach: microbiome role
This study looks at the role of tiny organisms (the microbiome) in leaks from the esophagus or stomach. Researchers will take small tissue samples to learn more about these leaks and how to treat them better.
Dallas, TexasAges 18 years+ - NCT07443917Recruiting
Study of Treponema Parvum in gum disease patients
This study looks for a specific bacteria called Treponema Parvum in the gums of people with periodontitis (severe gum disease). It aims to understand if this bacteria is linked to gum disease and could help improve future treatments.
BaghdadAges 30 years+ - NCT07460687Recruiting
Frequent health check-ups study in Hangzhou
This study collects frequent health samples from healthy volunteers living in Hangzhou to monitor health changes over time. It may help understand how lifestyle, diet, and other factors affect health.
Hangzhou, ZhejiangAges 18–40 - NCT07471373Recruiting
Pesticides and infertility study in endometriosis
This study looks at how pesticides might affect fertility in women with endometriosis, focusing on stress markers and gut/genital bacteria. You will provide samples and answer questions so researchers can compare women with and without endometriosis.
SalouëlAges 18–43 - NCT07477470Recruiting
Fiber supplement for stress and mood
This study tests whether a daily fiber supplement can improve mood, memory, and gut health in stressed adults. It lasts a few weeks and involves questionnaires and samples.
LondonAges 18–50 - NCT07483502Recruiting
Pre-surgery gut health supplement study for heart patients
This trial tests whether taking a gut health supplement (WellBiome) for six weeks before heart surgery can improve recovery and save the NHS money. It compares the supplement to a placebo (a pill with no active medicine).
Hull, East Riding Of YorkshireAges 50–80 - NCT07501455Recruiting
Studying toothpaste and mouth rinse effects on gum inflammation
This study tests whether using a certain toothpaste and mouth rinse can reduce gum inflammation (gingivitis) better than brushing alone. It is for people with mild to moderate gum disease who have not used tobacco or certain medications recently.
Somerville, MassachusettsAges 18–60 - NCT07517029Recruiting
Gut Bacteria Study in Post-Infectious IBS
This study looks at how gut bacteria may change in people who developed irritable bowel syndrome (IBS) after a stomach infection. Researchers hope to understand why some people recover completely while others develop ongoing digestive problems.
RomeAges 18 years+ - NCT07600008RecruitingEarly Phase 1
Probiotics as a supplement for reflux disease management
This early-stage trial tests whether a probiotic supplement can help support treatment of reflux disease (GERD) in patients already taking a standard reflux medication. Researchers want to see if adding probiotics might improve symptoms or overall digestive health.
OlomoucAges 40–55 - NCT07606885Recruiting
Hangzhou Health and Lifestyle Study
This study collects detailed health information from people living in Hangzhou to understand how daily habits affect overall health. Researchers will ask questions and take samples to learn more about what keeps people healthy.
Hangzhou, ZhejiangAges 18–40 - NCT07635732Recruiting
Urine Bacteria as a Test for Melanoma Treatment Response
This study looks at bacteria naturally found in urine to see if they can help diagnose melanoma and predict how well systemic therapy (medicine that spreads throughout the body) will work. Researchers believe the types of bacteria in your urine may reflect how your immune system is responding to melanoma treatment.
Gratwein, StyriaAges 18 years+
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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.