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
- NCT07456579Enrolling by invitation
Alcohol and cannabis use in pregnancy
This study looks at alcohol and cannabis use during pregnancy by asking new mothers about their habits and testing newborn stool samples (meconium). The goal is to understand how common these substances are among pregnant women in Slovenia and how they might affect babies.
LjubljanaAges Any age - NCT06681246Recruiting
How gut bacteria affect weight regain after weight loss
This study looks at how the natural bacteria in your gut (the microbiome) might be linked to regaining weight after losing it. It tests whether a short course of antibiotics or a placebo (a sugar pill) affects this process. The goal is to find new ways to help people keep weight off long-term.
RehovotAges 18–65 - NCT07724522Recruiting
Prebiotic Fiber for Irregular Periods in Women
This study tests whether taking a prebiotic fiber (inulin) can help women who are in the later years of their reproductive life (before menopause) and have irregular periods. You may be eligible if you are overweight, have irregular cycles, sit a lot, and do not exercise much.
Washington D.C., District of ColumbiaAges 40–55 - 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 - 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 - NCT06433115Recruiting
Lean beef and your heart and gut health trial
This study tests how eating lean beef for 4 weeks affects your heart health and the bacteria in your gut. If you qualify, you'll be asked to follow a consistent diet and activity routine during the study.
Columbia, MissouriAges 18–45 - NCT05090267Recruiting
Gut-brain treatments for alcohol use and memory changes
This study tests whether gut-brain–targeted treatments (including probiotics and stimulation of a nerve) can improve thinking and inflammation-related health in people who use alcohol. You may be able to join if you have memory/thinking problems and meet specific medical limits, including HIV immune system levels.
Coral Gables, FloridaAges 35–70 - NCT07602920Recruiting
Understanding Gut Leakage in Dengue Fever
This study investigates whether dengue fever causes the intestinal lining to become leaky, allowing harmful substances to enter the bloodstream. Researchers compare blood markers in dengue patients and healthy volunteers to understand how this happens and why it might make dengue worse.
Chittagong, Chattogram DivisionAges 18 years+ - NCT07750249Enrolling by invitationEarly Phase 1
Short-chain fatty acids for IgA nephropathy
This trial tests whether a daily supplement of short-chain fatty acids (SCFAs) can slow down kidney damage in people with IgA nephropathy. SCFAs are substances made by gut bacteria that may help reduce inflammation and protect the kidneys.
MartinAges 18 years+ - NCT07111455Recruiting
Oral bacteria changes with chemoimmunotherapy for mouth cancer
This study is testing whether a combination of chemotherapy and immunotherapy before surgery can help treat advanced oral cancer. Researchers will also look at how the cancer changes the bacteria in your mouth.
Guangzhou, GuangdongAges 18–80 - 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+ - NCT03962920Recruiting
Personalized care for urologic cancer based on gut and urine bacteria
This study looks at how your body’s bacteria (microbiome in and around the urinary/genital area) may help guide personalized treatment for localized urologic cancers. The goal is to see whether tailoring treatment to your bacteria could improve outcomes.
RoskildeAges 40–70 - NCT04117321Recruiting
Study of mother-to-baby gut germs and baby health
This study looks at how germs in a mother can be passed to her baby and whether that affects the baby’s health. If you join, your baby (and the other parent or legal guardian) may be asked to share consent so researchers can follow the pregnancy and early life.
Hong Kong, Hong KongAges Any age - NCT04264975Recruiting
Using gut microbiome tests and stool transfer in immunotherapy cancer
This trial studies whether changes in gut bacteria can help predict how well immunotherapy works for solid cancers. It also tests whether stool (fecal microbiota) from certain immunotherapy-responding people can improve outcomes for others who are not responding well.
Seoul, SeoulAges 19 years+ - NCT03650829Recruiting
IVF baby study for pregnancies in Guangzhou
This study looks at babies born from IVF (assisted reproductive technology) pregnancies. It may help the hospital better understand outcomes for families who plan to deliver there and stay in Guangzhou for years.
Guangzhou, GuangdongAges Up to 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 - NCT06205862RecruitingPhase 2
Fecal transplant for preventing colon polyp return
This study tests whether taking capsules of healthy bacteria (fecal microbiota transplant) can help prevent colon polyps from coming back after they have been removed. It might be an option for people who have had an adenoma polyp removed and want to reduce the chance of recurrence.
Guangzhou, GuangdongAges 18–75 - NCT03507673Recruiting
Study of vaginal and uterine microbiome after frozen embryo transfer
This study looks at how bacteria in the vagina and lining of the uterus change during the “luteal phase” (the time after ovulation and before a pregnancy test) in people using frozen embryo transfers. It may help researchers understand what conditions support embryo implantation and pregnancy in assisted reproduction.
Saarbrücken, SaarlandAges 18–45 - NCT07437911Recruiting
Can a Supplement Help with Nutrient Gaps for GLP-1 Users?
This study tests whether a daily supplement can help fill nutrient gaps and improve gut health for people who are already taking GLP-1 weight-loss medications (like Ozempic or Wegovy). Participants must be on a stable dose for at least 8 weeks and be generally healthy without other chronic conditions.
Santa Monica, CaliforniaAges 18–59 - NCT06406751Enrolling by invitation
MI Paste and mouth bacteria in older denture wearers
This study tests whether a special paste (MI Paste) used for several months can change the natural bacteria in the mouth of older adults who wear dentures. It may help keep your mouth healthier.
Iowa City, IowaAges 65–105 - NCT06356012RecruitingPhase 4
Imiquimod for high-risk HPV cervical lesions
This trial tests if imiquimod cream can help clear high-grade cervical lesions caused by high-risk HPV. It may be an option for people who want to avoid surgery.
BarretosAges 25–45 - 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+ - NCT06252948Recruiting
Gut bacteria study for POEMS and related plasma cell disorders
This study looks at the gut microbiome (the bacteria living in your digestive system) in people with POEMS syndrome, multiple myeloma, MGUS, amyloidosis, and healthy household members. It may help researchers understand how gut health relates to these conditions.
Rochester, MinnesotaAges 18 years+ - NCT07623902Recruiting
Testing a Tongue Scan to Detect Colorectal Polyps
This study tests whether a new tongue-scanning tool called Gixam can help find advanced colorectal polyps in people with negative stool tests. If it works, it might offer a simpler screening option alongside colonoscopy.
Orlando, FloridaAges 45–84
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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.