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35 clinical studies listed.

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Microbiome

Tundra lists 35 Microbiome clinical trials. Each listing includes eligibility criteria, study locations, and direct links to research sites in the Tundra directory.

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ACTIVE NOT RECRUITING

NCT05123612

Maternal & Offspring Microbiome Study

The purpose of the study is to learn how different dietary interventions affect microbiota diversity in pregnant women and the transmission of microbiota to their infants during pregnancy, birth, and postpartum.

Gender: FEMALE

Ages: 18 Years - 50 Years

Updated: 2026-04-06

1 state

Pregnancy Related
Microbiome
Immune Function
+1
RECRUITING

NCT07264998

Observational Study of Gut Microbiota in Abemaciclib-Treated Patients With and Without Diarrhea

Why is this study being done? Many patients with a type of breast cancer (called HR-positive) take a medicine called Abemaciclib. While this medicine is effective, a very common side effect is diarrhea, which can be severe enough to disrupt treatment and reduce quality of life. The reason why some patients get diarrhea and others do not is not well understood. This study aims to investigate whether the natural bacteria living in the gut (known as the gut microbiome) play a role in this side effect. Researchers will compare the gut bacteria of patients who develop diarrhea with those who do not. What will happen in the study? This is an observational study, which means that patients will receive their normal cancer treatment and will not be given any new or experimental drugs as part of this initial phase. * Patients who are already being treated with Abemaciclib will be invited to join. * They will be placed into one of two groups: those who experience diarrhea and those who do not. * Participants will be asked to provide stool (feces) samples and may also provide optional blood samples at specific times during their treatment. * Researchers will analyze these samples in the lab to study the types and functions of the gut bacteria. Who can participate? * Adult women (aged 18-75) diagnosed with HR-positive breast cancer. * Currently receiving treatment with Abemaciclib for at least 2 weeks. * Must be willing to provide informed consent and follow the study procedures. What are the potential benefits? Participants will not receive any direct medical benefit from taking part in this study. However, the information learned may help researchers better understand why diarrhea occurs and, in the future, could lead to new ways to prevent or treat this side effect for other cancer patients. How is privacy protected? All personal information and samples collected will be de-identified using a unique code. This means that the data used for analysis cannot be directly linked back to the participant's identity. All data is stored securely according to strict ethical guidelines.

Gender: All

Ages: 18 Years - 75 Years

Updated: 2026-04-03

1 state

Breast Neoplasms
Hormone Receptor-Positive Breast Cancer
Abemaciclib
+4
RECRUITING

NCT07501455

Comparison of the Effects of Oral Hygiene Regimens on Clinical, Immunomodulatory, and Microbial Outcomes and Oral Tolerance in People With Gingivitis

This study is a six-week, double-blind, randomized, parallel-group controlled clinical study. The objective of this study is to evaluate the changes to the oral microbiome, inflammatory mediators, gingival health indices and to assess oral tolerance after 4 weeks of twice daily use of differing oral hygiene regimens including mouthwash compared to a control group. A follow-up assessment will be completed 2 weeks after cessation of treatments.

Gender: All

Ages: 18 Years - 60 Years

Updated: 2026-03-30

1 state

Microbiome
Cytokines
Plaque
+2
NOT YET RECRUITING

NCT07425704

Probiotics, Antibiotics and the Post-Antibiotic Microbiota

Antibiotic therapy can cause gastrointestinal dysbiosis and this study will assess the impact of probiotic supplementation on microbiological composition and functionality pre- and post- antibiotic therapy

Gender: All

Ages: 18 Years - 40 Years

Updated: 2026-03-18

Probiotic
Microbiome
RECRUITING

NCT07439718

The Effects of an Oral Nutritional Intervention on the Small Intestine Microbiome

This is a single-center, single-arm study, aiming at enrolling 25 healthy adult participants to evaluate chronic effects of oil. Specifically, we aim to assess the impact on gut microbiome after a one-month intervention with oil.

Gender: All

Ages: 18 Years - 60 Years

Updated: 2026-03-03

Microbiome Composition
Microbiome
NOT YET RECRUITING

NCT07369869

Evaluating the Effects of Nutritional Interventions on Sleep, the Gut Microbiome, Cognition, and Stress.

This will be a double-blind, placebo-controlled, parallel-group trial. Participants who are poor sleepers will be randomised to receive one of two investigational supplements, or a placebo control supplement, over a 28-day period. At baseline and following 28 days of consumption, sleep quality, gut microbiome profiles, cognitive performance, and mood will be assessed. Sleep outcome measures will also be assessed throughout the supplementation period to monitor the time course of any observed changes. A final data set of at least 66 participants is expected.

Gender: All

Ages: 25 Years - 65 Years

Updated: 2026-03-03

Stress
Sleep
Cognition
+2
RECRUITING

NCT07333482

Flourish: Exploring the Early Infant Gut Microbiome

The goal of this clinical trial is to learn whether microbiome analysis, education, and personalized recommendations can improve gut health and reduce early markers of immune-related conditions in infants aged 0-3 months delivered via Cesarean section. The study aims to determine whether these interventions can increase beneficial bacteria, decrease C-section-associated microbiome signatures, reduce opportunistic pathogens, and improve functional potential for HMO digestion and SCFA production. The study also seeks to assess whether improvements in microbiome composition are associated with a reduced prevalence of early atopic symptoms. Researchers will compare three groups: a full intervention arm that receives microbiome reports, coaching, personalized recommendations, and educational materials; a limited intervention arm that receives simplified reports and basic recommendations; and a control arm that receives no results until study completion. This design allows evaluation of both a comprehensive intervention and a more scalable, minimal-results model. Participants will: 1. Provide six microbiome stool samples over a 24-month period. 2. Provide additional small stool samples at two timepoints for exploratory metabolomic analysis. 3. Receive microbiome reports and guidance according to their assigned study arm. 4. Complete surveys on infant health history, symptoms, diet, and environmental exposures. 5. Participate in standardized eczema assessment(s) administered by a Nurse Practitioner and evaluated by a Pediatric Allergy Specialist if any symptoms are reported. This study seeks to demonstrate that targeted microbiome support can positively shift gut microbial development in C-section infants and may reduce risks linked to the early stages of the atopic march. Findings may inform scalable strategies for delivering microbiome-based support in early life and improve long-term health outcomes for this high-risk population.

Gender: All

Ages: 0 Months - 3 Months

Updated: 2026-02-24

1 state

Microbiota
Gut Microbiome
Eczema
+1
NOT YET RECRUITING

NCT07409870

An Integrated Multi-omics Study on the Molecular Mechanisms of Ureteral Stricture

The goal of this observational study is to investigate the systemic pathogenesis and identify potential diagnostic biomarkers in patients with ureteral stricture and healthy volunteers. The main questions it aims to answer are: What are the systemic differences in the gut microbiome, urine microbiome, and metabolomic profiles (fecal, urinary, and serum) between patients with ureteral stricture and healthy controls? What are the correlations between these microbial/metabolic alterations and clinical phenotypes, such as stricture severity, inflammatory levels, and renal function? Researchers will compare the biological panoramic profiles of patients with ureteral stricture to those of healthy controls to see if specific "microbiome-metabolite-disease" regulatory networks drive the development of the condition. Participants will: Provide stool samples for gut microbiome (16S/Metagenomics) and metabolomic analysis. Provide urine samples for urine microbiome and metabolomic analysis. Provide blood (serum) samples for systemic metabolomic profiling. Undergo clinical assessments, including medical history collection, imaging (e.g., CT/IVP), and laboratory tests (e.g., renal function, inflammatory markers) to evaluate disease severity.

Gender: All

Updated: 2026-02-13

Ureteral Stricture
Ureteral Obstruction
Microbiome
+1
RECRUITING

NCT06606119

The Role of Brain-Bone Marrow-Gut Interaction Following Major Trauma

Traumatic injury followed by critical illness provokes pathophysiologic changes in the bone marrow and the gut that contribute to persistent anemia and changes in the microbiome which significantly impact long-term recovery. This project will define the interactions between the stress, chronic inflammation, bone marrow dysfunction, and an altered microbiome which will provide a strong foundation for future clinical interventions to help improve outcomes following severe trauma.

Gender: All

Ages: 18 Years - 100 Years

Updated: 2026-02-06

1 state

Trauma Injury
Trauma
Critical Illness
+3
NOT YET RECRUITING

NCT07364383

Probiotics for Women

Investigation into the effect of probiotic supplementation on the wellbeing of women with a history of vaginal discomfort and/or irritation, along with any microbiome changes.

Gender: FEMALE

Ages: 18 Years - 40 Years

Updated: 2026-01-23

Probiotic
Microbiome
Wellbeing
NOT YET RECRUITING

NCT07311083

Feasibility of a Lifestyle Intervention for Women With Triple-negative Breast Cancer Under Neoadjuvant Immunotherapy

Triple-negative breast cancer (TNBC) is considered a tumor with a high risk of recurrence and metastasis and requires aggressive systemic therapy combining immunotherapy and chemotherapy. If the therapy leads to complete remission (pCR), this is prognostically beneficial for patients. Studies demonstrating the influence of the microbiome on the development of cancer and on the efficacy and toxicity of immunotherapy and chemotherapy underscore the potential of targeted nutritional interventions. Current data from microbiome research indicate that a high-fiber, gut-healthy diet modulates the microbiota in such a way that the response to and toxicity of immunotherapy and chemotherapy could be improved. The aim of this project is to translate these findings into clinical care. The study will investigate whether an online integrative oncology group training program with mind-body elements supports and is feasible for the implementation of a high-fiber diet in patients with TNBC undergoing neoadjuvant immunotherapy and chemotherapy. The program will be compared with a control group that receives a flyer with nutritional recommendations. If the feasibility of this complementary medicine approach can be demonstrated, a confirmatory study is planned to investigate the expected effect on the pathological complete remission of TNBC.

Gender: FEMALE

Ages: 18 Years - 75 Years

Updated: 2026-01-14

Microbiome
ACTIVE NOT RECRUITING

NCT04552834

Alterations of the Microbiome During Critical Illness With Short and Long Term Clinical Outcomes

This study is designed to study the variations in the microbiome among critically ill patients and the effect of admission to the medical intensive care unit (MICU) at the University of Chicago. Additionally, investigators will examine the downstream clinical effects of dysbiosis in ICU patients and how patients maybe effected long term.

Gender: All

Ages: 18 Years - Any

Updated: 2025-12-19

1 state

Critical Illness
Microbiome
RECRUITING

NCT07250100

The Role of Microbiota in Pancreatic Cancer and Precursor Lesions

This is a prospective observational study aiming to investigate the microbiome in patients suspected of having pancreatic cancer. The purpose is to enhance diagnostic accuracy by developing screening protocols for high-risk individuals, identifying specific microbial biomarkers, and improving prognostic criteria to optimize treatment response. Participants will be asked to complete a questionnaire, provide oral and fecal swabs, and-if clinically indicated-1-2 pancreatic biopsies will be collected.

Gender: All

Ages: 18 Years - Any

Updated: 2025-11-26

1 state

Pancreatic Cancer
Microbiome
RECRUITING

NCT05505110

MOdification Of THe Early-Life Respiratory Microbiome Through Vaginal SEEDing

This is a single-center, parallel-arm, blind, sham-controlled, feasibility randomized controlled trial (RCT) to be conducted in healthy cesarean-born children. Eligible children will be randomized 1:1 to have their nose swabbed with either maternal vaginal secretions or a sterile swab (intervention vs. control group, respectively). The main hypothesis is that conducting an RCT assessing the utility of vaginal seeding in modifying the early-life upper respiratory tract (URT) microbiome of children born by cesarean section (C-section) is feasible and that the intervention is safe.

Gender: FEMALE

Ages: 18 Years - 40 Years

Updated: 2025-11-10

1 state

C-section
Vaginal Seeding
Respiratory
+1
RECRUITING

NCT05852145

Oral Changes With Caloric and no Caloric Sweeteners

The objective of this clinical trial is to compare the effect that the intake of beverages without sweeteners, added with non-caloric sweeteners (stevioside) and caloric sweeteners (sucrose) on oral pH and dental biofilm microbiome in Mexican adolescents. Participants will drink on different occasions a beverage without sweetener, a beverage added with stevioside or a beverage added with sucrose. The researchers will compare the changes that each one causes in salivary pH, dental biofilm pH, dental biofilm bacterial proliferation and dental biofilm microbiome.

Gender: All

Ages: 12 Years - 18 Years

Updated: 2025-10-09

1 state

pH
Microbiome
Dental Plaque
RECRUITING

NCT07209007

Dynamics of Dysbiosis in the Skin and Gut Microbiome of Burn Patients

This prospective observational cohort study aims to investigate the longitudinal changes in the skin and gut microbiome of burn patients after injury and compare them with healthy controls. Burn injuries are known to induce systemic physiological and immune responses that may lead to widespread microbial dysbiosis (microbial imbalance) beyond the injured site. However, the dynamics of microbial community changes in both burned and non-burned skin, as well as the gut, remain poorly understood. In this study, a total of 660 participants will be enrolled, including 600 burn patients and 60 healthy controls. For burn patients, skin swabs from burned scars and matched non-burned skin, stool samples, and physiological skin measurements will be collected at multiple time points (baseline, 3 months, 6 months, 12 months, and 24 months). Healthy controls will provide skin and stool samples at baseline only. Microbial profiling will be performed using 16S ribosomal RNA (rRNA) gene sequencing, and functional prediction will be analyzed using Phylogenetic Investigation of Communities by Reconstruction of Unobserved States 2 (PICRUSt2). Physiological skin-barrier measurements, including transepidermal water loss (TEWL), hydration, pH, erythema, and elasticity, will be assessed using standardized instruments. Blood biomarkers, including C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR), will also be measured. The findings of this study will improve our understanding of burn-related microbial dysbiosis, provide insights into microbiome-driven skin-barrier recovery, and inform potential therapeutic strategies for long-term burn care.

Gender: All

Ages: 19 Years - 65 Years

Updated: 2025-10-06

Burn Injuries
Skin Disease
Microbiome
+1
NOT YET RECRUITING

NCT07195474

Smoothie Program for Achieving and Resilient Kids

The proposed study will examine whether eating yogurt every day can improve brain and gut health in children. Prior research suggests that yogurt may support cognitive functions like self-control, but more studies are needed to confirm this. The study will follow 60 children from Central Pennsylvania, ages 7 to 9, who will be randomly assigned to drink either fruit juice (control group) or yogurt smoothies once or twice a day for four weeks. Researchers will compare how different amounts of yogurt affect children's thinking skills (like memory and focus), brain activity, and gut bacteria. These changes will be measured through brain scans, computer-based thinking tasks, surveys, and stool samples. The study will also collect information about children's overall diet. The goal is to find out if yogurt can support healthy brain and gut development and to determine the right amount to include in a child's daily diet. Results will help guide future research on how nutrition supports children's health.

Gender: All

Ages: 7 Years - 9 Years

Updated: 2025-09-26

1 state

Executive Functions (EF)
Microbiome
Dietary Quality
NOT YET RECRUITING

NCT06734156

CARE-CRC: Microbiome Insights and Correlations for Risk and Outcomes in Colorectal Cancer

Colorectal cancer (CRC) is one of the leading causes of cancer-related deaths globally, with increasing incidence rates. While predominantly affecting older adults, CRC cases among individuals under 50 (early-onset CRC, or EoCRC) are rising. This age group rarely undergoes routine screening, resulting in delayed diagnoses and more advanced disease at presentation. In the USA, EoCRC accounts for 10% of CRC cases and is the leading cause of cancer-related deaths in men under 50. Despite the increase in EoCRC incidence, the causes remain unclear. Only 25% of cases have a CRC family history, suggesting environmental factors. Diets low in fibre and rich in fat and red meat, obesity, alcohol consumption, sedentary lifestyle, stress, and chronic inflammation of the GI tract are estimated to account for 70-90% of CRC risk. According to the World Cancer Research Fund, 47% of all CRC cases could be prevented through lifestyle changes, particularly in diet and physical activity. These lifestyle factors are also strongly linked to changes in the gut microbiome, which differs markedly between CRC patients and healthy individuals. The microbiome may influence tumour development by producing metabolites that regulate immune responses or create anti-tumour environments. Thus, the gut microbiome is a promising target for early CRC detection and prevention. This study aims to develop a non-invasive, microbiome-based diagnostic tool for CRC, identifying biomarkers to improve early detection, personalise treatment, and reduce healthcare costs.

Gender: All

Ages: 40 Years - 74 Years

Updated: 2025-09-03

Colorectal Cancer (CRC)
Microbiome
Early Onset Colorectal Cancer
ENROLLING BY INVITATION

NCT06657001

Enabling Microbiomics- Driven Personalized Nutrition

The goal of this observational research study is to determine how diet contributes to various gastrointestinal related conditions. The main question investigators aim to answer is: Are host genetics, diet, and microbiome all important determinants of GI disorders, and how their relative contribution varies among individuals and populations.

Gender: All

Ages: 18 Years - Any

Updated: 2025-06-25

1 state

Inflammatory Bowel Disease (IBD)
Irritable Bowel Syndrome (IBS)
Celiac Disease
+7
RECRUITING

NCT06778083

STI Prophylaxis and Emergence of Antimicrobial Resistance

The goal of this observational study is to understand the risk of antibiotic resistance and changes in the human microbiome (bacteria that live inside and on us), if people use antibiotics to prevent sexually transmitted infections (STI prophylaxis, doxycycline post-exposure prophylaxis, or 'doxyPEP'). The study will assess how easy and acceptable it is to find antibiotic resistance and microbiome changes in the throats and guts of men-who-have-sex-with-men (MSM) who use STI prophylaxis. The study will recruit 108 MSM who are using and not using STI prophylaxis. Participants will visit the clinic every 6 months. At each visit, they will provide a throat swab and stool sample, and complete a questionnaire. DNA of the bacteria from the samples will be analysed to identify the bacteria and look for antibiotic resistance.

Gender: MALE

Ages: 18 Years - Any

Updated: 2025-03-27

Sexually Transmitted Infection (STI) Prevention
Antibiotic Prophylaxis
Antibiotic Resistance, Bacterial
+2
RECRUITING

NCT04970446

Microbial Restoration in Inflammatory Bowel Diseases

This is a prospective, two-centre, double-blind, parallel-arm, randomised, placebo-controlled trial evaluating the impact of FMT on patients with active Crohn's disease.

Gender: All

Ages: 18 Years - 70 Years

Updated: 2025-02-26

1 state

Fecal Microbiota Transplantation
Crohn Disease
Inflammatory Bowel Diseases
+1
NOT YET RECRUITING

NCT06830824

Supplementation of Inulin + L. Acidophilus in Elders with T2DM

This study investigates the effects of a symbotic supplement (Inulin + Lactobacillus acidophilus) on cognitive impairment in older adults with type 2 diabetes mellitus (T2DM). Diabetes is a chronic disease characterized by insulin deficiency or resistance, leading to hyperglycemia and long-term complications, including cognitive decline. Cognitive impairment in T2DM patients is linked to oxidative stress, neuroinflammation, and disrupted insulin signaling in the brain. The gut-brain axis plays a crucial role in cognition, with gut microbiota influencing neuroinflammatory processes. Dysbiosis, common in T2DM, exacerbates cognitive decline. Probiotics like Lactobacillus acidophilus and prebiotics like inulin can restore gut microbiota balance, reduce inflammation, and promote brain-derived neurotrophic factor (BDNF) production, improving cognitive function. This randomized, crossover clinical trial will enroll 24 patients aged 50-65 with T2DM and mild cognitive impairment. Participants will be divided into control and experimental groups, with an 8-week intervention phase followed by a crossover. The experimental group will receive 8g of inulin and L. acidophilus daily, while the control group will receive a placebo. Cognitive assessments (MMSE, MoCA), PET-CT imaging, gut microbiota sequencing, and butyrate measurements will evaluate the intervention's effects. The study aims to determine whether symbiotic supplementation can improve cognitive function and metabolic brain activity in T2DM patients. If successful, it may offer an accessible, non-pharmacological approach to mitigating diabetes-related cognitive decline. The research is funded by the Universidad Anáhuac Health Sciences Research Center and international diabetes research organizations.

Gender: All

Ages: 60 Years - 90 Years

Updated: 2025-02-19

Diabetes Mellitus
Microbiome
Cognition Disorders
RECRUITING

NCT05514899

Effects of Cannabidiol and Tetrahydrocannabinol on Microbiome and Neuroinflammation in HIV

This study has the potential to contribute to a more complete understanding of the independent and combined effects of cannabis use and HIV on the brain and on inflammation. Such knowledge may inform future strategies for treating brain disease and inflammation. Participants will be randomly assigned to one of two groups, both of which will receive the same treatment in a different order over a period of about 6 weeks. The visits include physical examinations, blood tests, and other procedures designed to monitor subject safety and measure the effects of the study drug.

Gender: All

Ages: 21 Years - 70 Years

Updated: 2025-02-17

1 state

HIV
Cannabis
THC
+3
RECRUITING

NCT05412758

Augmented Response of Volatile Biomarkers in Assessment of Oesophagogastric Cancer (AROMA 1 / BIORESOURCE)

Cancer of the stomach and oesophagus is among the world's top five cancers. Survival rates are very poor as the disease presents late and early symptoms are non-specific. The study team has developed a non-invasive test for cancers of the stomach and oesophagus based on the detection of volatile organic compounds in exhaled breath. These compounds are known to be produced by both cancers as well as cancer associated bacteria within the gut. The proposed innovation is to improve the accuracy of this test by investigating whether simple metabolic substrates can increase the production of these volatile organic compounds by both the tumour and its associated bacteria.

Gender: All

Ages: 18 Years - 90 Years

Updated: 2025-01-31

Volatile Organic Compounds
Microbiome
Microbioata
+7