Clinical trials
Gut Microbiota clinical trials
Below are recruiting gut microbiota clinical trials, each written for real people, not researchers. We’re tracking 158 recruiting studies, each written for real people, not researchers, below.
Recruiting studies
- 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+ - NCT04303325RecruitingPhase 4
Esketamine after breast surgery for depression and gut changes
This trial studies whether esketamine given around the time of breast cancer surgery can improve depression and change gut bacteria. It also monitors your sleep/deep anesthesia level (with a simple monitoring number).
Shenyang, LiaoningAges 18–65 - NCT04730622Recruiting
Studying muscle and bone changes after a hip fracture
This study looks at how bone health and muscle strength (“osteosarcopenia” — loss of both bone and muscle) change after a hip fracture in older adults. It may help doctors understand who is at higher risk and how to better support recovery after hip surgery.
BolognaAges 65 years+ - NCT04791540Recruiting
Rehab study for people with a tracheostomy and low muscle strength
This study looks at how nutrition and muscle health affect recovery during rehabilitation for people who have a tracheostomy (a breathing opening in the neck). It may help the rehab team improve food and care plans to support strength and overall health.
Florence, ItalyAges 18 years+ - NCT04919265Recruiting
Mother and baby health study from early pregnancy
This study follows pregnant people and their babies from the first few months of pregnancy through at least one year after birth. It aims to learn how health and development turn out, especially for mothers who can keep coming to the same clinic for follow-up.
Kajang, SelangorAges 18–45 - NCT05000996Recruiting
Gut microbiome study for people having metabolic surgery
This study looks at your gut bacteria (your “microbiome”) around the time of metabolic surgery. It may help researchers understand how surgery affects gut health and related conditions like diabetes, blood pressure, and cholesterol.
Nashville, TennesseeAges 21–65 - NCT05623007Recruiting
Diet and gut bacteria study for vaccinated teens with COVID
This trial tests whether changing diet can shift gut bacteria in overweight or obese teens after COVID-19 vaccination. The goal is to see if dietary changes can affect health markers related to the gut and immune system.
Jakarta Pusat, DKI JakartaAges 12–17 - NCT05628987Recruiting
Gut bacteria study in men with sperm production problems
This trial looks at whether gut bacteria (microbiome) and lifestyle factors are linked to poor sperm production or sperm quality. You may be asked for stool, urine, and blood samples and to complete questionnaires about diet and habits to help researchers understand possible connections.
Guangzhou, GuangdongAges 18–45 - NCT05638269Recruiting
Study of gut bacteria in people with serious long-term illness
This study looks at the types of gut bacteria in people living in certain parts of China who have serious long-term (chronic) illnesses. The goal is to better understand how gut bacteria differ and may help doctors in the future tailor care.
Chaoyang, Beijing MunicipalityAges 18–75 - NCT05698862Recruiting
Study how gut bacteria affect brain and behavior
This study looks at how gut bacteria may influence brain function and behavior, through a chemical called GABA. It may help researchers understand brain–gut links, though it is not yet a treatment trial.
ReadingAges 18–50 - NCT05723913Recruiting
Test functional foods on blood sugar and gut bacteria
This study looks at how eating specific functional foods affects blood sugar after meals and changes in gut bacteria. It may help people understand ways to support healthy blood sugar and digestion, but it’s not for people with diabetes.
Mexico City, Mexico CityAges 18–60 - NCT05754645Recruiting
Study of gut microbiome in weight-related pregnancy outcomes
This study looks at differences in the gut’s living microbes (microbiome) in people who are trying to conceive or are early in pregnancy, and how that may relate to pregnancy outcomes. It may help researchers understand whether microbiome changes are linked to healthier—or more complicated—pregnancies.
Rotterdam, South HollandAges 18–45 - NCT05930496Recruiting
Exercise after colorectal cancer to change gut bacteria
This study tests whether a structured exercise program can improve the makeup of gut microbiota (gut bacteria) in people who have finished treatment for stage II–III colorectal cancer. It may help learn how exercise supports recovery, and it involves remote or in-person sessions with gut-focused tracking.
Seattle, WashingtonAges 18–70 - NCT05931536Recruiting
How diet, stress, and thinking affect the gut
This study looks at how what you eat and your stress level may change thinking and the bacteria in your gut. It may help researchers understand links between lifestyle, brain function, and gut health.
CorkAges 18–50 - NCT05931562Recruiting
How diet may change gut bacteria and brain signals
This study looks at how changing your diet affects the gut bacteria and how that may influence brain-related signals. It may help researchers understand whether diet could support overall brain and gut health.
CorkAges 18–50 - NCT05946083RecruitingPhase 2
Study links binge drinking, gut bacteria, and brain function
This Phase 2 study looks at how binge drinking may change gut bacteria and how your brain works. You may qualify if you’re a Portuguese-speaking student and your drinking pattern and health history match the study rules.
Braga, Gualtar, BragaAges 18–23 - NCT06001619RecruitingPhase 4
Prostate medication, metabolism, and gut bacteria
This study looks at how prostate medication affects your metabolism and the helpful bacteria in your gut. It may help explain how these drugs work and how they affect your body.
TurkuAges 18 years+ - NCT06116851Recruiting
Prostate health, gut bacteria, and cancer risk
This study looks at how your gut bacteria and prostate health may be connected to cancer risk. It may help find new ways to predict or prevent prostate cancer.
TurkuAges 18 years+ - NCT06146608Recruiting
Iron, gut bacteria, and how the body absorbs iron
This study looks at how different types of iron in food affect your gut bacteria and how well your body absorbs iron. It aims to understand the connection between diet, gut health, and iron levels in healthy adults.
Ithaca, New YorkAges 18–40 - NCT06161896Recruiting
Gut bacteria's role in lymphoma treatment
This study looks at the bacteria living in your gut (your gut microbiome) to see if they affect how well lymphoma responds to treatment. It involves collecting stool and blood samples before and during your standard R-CHOP chemotherapy.
Roskilde, Region SjællandAges 18 years+ - NCT06197698Recruiting
Parkinson's and gut-brain connection study
This study is looking at how the bacteria in your gut might affect your brain in Parkinson's disease. It involves two types of brain scans to see differences between people with Parkinson's and healthy volunteers.
DouliuAges 20 years+ - NCT06265246Recruiting
Milk and yogurt for stronger bones in young adults
This study tests whether adding milk and yogurt to your diet can improve bone health and body composition. If you're a young adult with low calcium intake, you may qualify to join.
Saskatoon, SaskatchewanAges 19–30 - NCT06451913RecruitingPhase 4
Probiotic for gut health during Lyme disease antibiotics
This trial tests if a probiotic (Saccharomyces boulardii) can help maintain healthy gut bacteria while you take antibiotics for the early skin rash of Lyme disease (erythema migrans). You'll take amoxicillin for 14 days, plus either the probiotic or a placebo.
LjubljanaAges 18 years+ - NCT06479928Recruiting
How environment and gut bacteria affect early life
This study looks at how things in the environment (like diet, pollution, or lifestyle) and the bacteria in a baby's gut affect health early in life. It is for pregnant women who are in their last month of pregnancy and their newborns.
BeijingAges 1 day–2 years
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Common questions
- Are there clinical trials for gut microbiota?
- Yes. Clin2 currently lists 158 recruiting gut 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 gut 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 gut 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.