Clinical trials
Microbiome clinical trials
Below are recruiting microbiome clinical trials, each written for real people, not researchers. We’re tracking 349 recruiting studies, each written for real people, not researchers, below.
Recruiting studies
- NCT05121025Recruiting
Study of stomach bacteria and gut microbes in Helicobacter infection
This study looks at how stomach bacteria (Helicobacter pylori) interact with the normal microbes in your gut. You may be asked to provide tissue, stool, and blood samples to help researchers understand infection and the body’s response.
Freiburg im Breisgau, Baden-WurttembergAges 18 years+ - NCT07184684RecruitingPhase 2/Phase 3
Nasal bacteria transplant for chronic sinusitis
This trial tests if transplanting healthy nasal bacteria from a donor can help people with chronic sinusitis. It aims to restore a healthy microbiome in the nose to reduce symptoms like congestion and discharge.
HelsingborgAges 18 years+ - NCT06738329Recruiting
How seaweed additive carrageenan affects gut bacteria
This study tests whether carrageenan, a seaweed-based food ingredient, changes the balance of bacteria in your gut. It could help us understand how common food additives affect digestion and overall health.
Reading, ReadingAges 18–55 - NCT07730229Recruiting
Plant-based drink study for healthy adults
This trial looks at how plant-based drinks affect the bacteria in your gut. You would drink a plant-based beverage daily and provide stool samples to see how your gut microbiome changes.
Lund, Skåne CountyAges 18–65 - NCT06954675Recruiting
Ketone drink study: how it affects gut bacteria in healthy adults
This study tests how a ketone ester drink changes the bacteria in your gut. You'll drink the supplement and fill out questionnaires online. It's for healthy adults who want to help researchers understand gut health.
San Francisco, CaliforniaAges 18–40 - NCT07575529Recruiting
Senior Milk Powder and Gut Health in Healthy Aging
This study tests whether a special milk powder containing beneficial bacteria and fiber (called synbiotics) can improve gut health in adults aged 40–65. You'll use a smartphone app and Apple Watch to track your health and provide samples over several weeks.
SingaporeAges 40–65 - NCT07481578Recruiting
Exercise and gut health study for active men
This study looks at how your training load affects your gut bacteria and how that relates to exercise performance and muscle health. It may help understand overreaching in healthy men.
Leuven, Vlaams BrabantAges 18–45 - NCT07736547Enrolling by invitation
AI-guided supplement for weight loss
This study tests a nutritional supplement (guided by your gut bacteria) to help with weight loss, along with lifestyle advice. It might be a good fit if you are overweight but not diabetic and have not used weight-loss medications recently.
IstanbulAges 18–65 - NCT07735182Recruiting
Gut bacteria and organ damage in sepsis
This study looks at how bacteria in your gut and other signs in your body affect liver and kidney damage in people with sepsis. It also compares findings to healthy volunteers to see what is different.
Hangzhou, ZhejiangAges 18 years+ - NCT07453212Enrolling by invitation
Food supplement for dry eye caused by meibomian gland issues
This trial tests a food supplement designed to improve dry eye symptoms by targeting the microbiome. It may help if you have dry eye due to meibomian gland problems and are not using contact lenses or certain other eye treatments.
IstanbulAges 18–65 - NCT07622628Recruiting
AI-Guided Microbiome Nutrition for Better Blood Sugar Control
This trial tests whether a personalized nutrition plan based on your gut bacteria (microbiome) can help improve blood sugar control in type 2 diabetes. Researchers will use artificial intelligence to match you with a diet tailored to your unique gut bacteria.
IzmirAges 18–65 - NCT04359836Recruiting
Study of gut bacteria in early COVID-19
This trial studies how gut bacteria (“gut flora”) may affect COVID-19 after a recent infection. If you test positive for COVID-19 soon enough, the study may help researchers understand why some people get better faster or have different symptoms.
Ventura, CaliforniaAges 18 years+ - NCT04410003RecruitingPhase 1
Stool-sample capsules to study gut microbiome in unexplained atherosclerosis
This early-phase study tests whether taking stool-based capsules can change gut bacteria in people with severe atherosclerosis that can’t be explained by usual risk factors. Researchers also measure related metabolic (body chemistry) and microbiome (gut bacteria) changes to see how this approach might help.
London, OntarioAges 18 years+ - NCT04658238Recruiting
Dry eye study of the eye microbiome and immune system
This trial looks at how changes in the eye’s normal germs (microbiome) and the immune response may relate to dry eye. It may help researchers better understand what drives symptoms and how to improve care.
BernAges 18 years+ - NCT04957511Recruiting
Testing gut bacteria in gynecologic cancer patients on immunotherapy
This study looks at how gut bacteria may relate to how well immunotherapy works in people with advanced or returning gynecologic cancer. You may be asked to give stool samples several times so researchers can measure changes in your gut microbiome.
Orlando, FloridaAges 18 years+ - NCT05032768Recruiting
Study links between skin bacteria and radiation skin reactions
This study looks at how changes in the skin’s normal bacteria (microbiome) relate to getting redness, irritation, or rash after breast radiation. It may help doctors predict who is more likely to have skin side effects after reconstruction and radiation.
Shanghai, Shanghai MunicipalityAges 18–70 - NCT05127252Recruiting
Study how gut bacteria may affect time to pregnancy
This study looks at whether differences in the gut (microbiome) are linked to how long it takes to get pregnant and pregnancy outcomes. It may help researchers understand who might benefit from future microbiome-focused approaches.
Stockholm, HuddingeAges 18–40 - NCT05405270Recruiting
Testing how well imiquimod works for abnormal cervix cell changes
This study looks for ways to predict who will respond to imiquimod cream for precancerous cervical cell changes (CIN2 or CIN3). Results may help doctors choose the best treatment approach and better plan follow-up.
BredaAges 18 years+ - NCT05412758Recruiting
Breath and blood tests to study stomach and food-pipe cancer
This study looks at how certain “volatile” substances in breath change in people with stomach or food-pipe (oesophageal) cancer, compared with people who have other non-cancer stomach/food-pipe conditions. It may help researchers find better, earlier ways to assess cancer—especially in people who have not started treatment yet.
LondonAges 18–90 - NCT05514899RecruitingPhase 2
Cannabidiol and THC study for gut health and brain inflammation in HIV
This Phase 2 study tests whether cannabidiol (CBD) and tetrahydrocannabinol (THC) change the gut microbiome and brain-related inflammation in people with HIV. It may help researchers understand new ways to reduce inflammation, but you would need strict cannabis and CBD/THC avoidance during the study.
San Diego, CaliforniaAges 21–70 - NCT05670288Recruiting
Studying how gut bacteria affect digestion after spinal cord injury
This study looks at how changes in gut bacteria may affect bowel function and metabolism during the first year after a spinal cord injury. You may be asked about bowel symptoms and other factors, and your results may help guide future care for digestion problems after injury.
Birmingham, AlabamaAges 18–85 - NCT05692024RecruitingPhase 1/Phase 2
Coffee and gut bacteria study after colon or rectal cancer
This early-phase study tests whether a coffee-related approach can change gut bacteria and blood “metabolites” after treatment for stage I–III colon or rectal cancer. The goal is to learn if these changes could help improve health after standard cancer treatment.
Boston, MassachusettsAges 18 years+ - NCT05830591Recruiting
Gut microbiome study in autism in children
This trial studies differences in the gut bacteria (microbiome) between children with autism and healthy children. It may help researchers understand what roles the gut may play in autism and guide future treatments.
TriesteAges 1–17 - NCT05963711Recruiting
Study penis microbiome in partners during vaginal microbiome treatment
This study looks at how the bacteria on a man’s penis may change during a woman’s vaginal microbiome transplant (VMT) for recurrent bacterial vaginosis (BV). You may be asked to follow condom and “decolonization” steps to help the researchers understand what works and why.
JerusalemAges 18 years+
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Common questions
- Are there clinical trials for microbiome?
- Yes. Clin2 currently lists 349 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.