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Tundra lists 41 Gut Microbiota clinical trials. Each listing includes eligibility criteria, study locations, and direct links to research sites in the Tundra directory.
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NCT07010445
MiCrobiota-gut-brain Axis in Resistant Epilepsy
Epilepsy is one of the most common neurological chronic conditions with a serious burden on patients, their caregivers, and society. Drug-resistant epilepsy (DRE) heightens this burden. New approaches are thus a priority. Studies in animal models and humans have shown the link between gut microbiota (GM) and the central nervous system in health, neurological conditions, and neurodevelopmental disorders. DRE has been linked to GM dysbiosis. Preliminary findings in children with DRE showed GM modifications when responding to a ketogenic diet. The mediator role of GM has not yet been studied in DRE patients undergoing surgery/vagal nerve stimulation. CARE's central hypothesis is that the GM and its metabolic profile could contribute to clinical outcomes following these different therapeutic procedures. Identifying microbial biomarkers will enable us to deepen the knowledge of the role of gut-brain axis in epilepsy and to tailor the intervention to each patient based on GM modulation.
Gender: All
Ages: 3 Years - 50 Years
Updated: 2026-04-09
1 state
NCT06867198
Peanuts for Cardiometabolic, Brain, and Intestinal Health
The overall objective of this 14-month randomized crossover study is to seek evidence demonstrating that daily consumption of peanuts and peanut products improve cardiometabolic, cognitive, and intestinal health in a racially diverse prediabetes population.
Gender: All
Ages: 20 Years - 59 Years
Updated: 2026-03-27
1 state
NCT06735651
Wild Blueberries for Gut, Brain, and Cardiometabolic Health in Prediabetes
The goal of this clinical trial is to determine the effectiveness of using a freeze-dried wild blueberry powder on cardiometabolic health, cognitive function, and gut microbiota composition in adult women with prediabetes.
Gender: FEMALE
Ages: 20 Years - 65 Years
Updated: 2026-03-25
1 state
NCT06136793
HomeStyles-Adults of Chinese Heritage
Individuals of Chinese heritage are the largest and fastest growing segment of the US Asian population. US Chinese have sociodemographic characteristics and culture that differ substantially from other US Asians, and therefore, differ in social determinants of health, health status, and disease risk. US Chinese adults are at increased risk for cardiometabolic disease, related conditions (obesity, type 2 diabetes mellitus, hypertension), and systemic inflammation that promotes disease onset and progression. Immigration to a new country can substantially impact the gut microbiome which may promote systemic inflammation. Pilot interventions indicate a high-fiber diet rich in whole grains reduced inflammation and improved obesity. Additionally, the United States Department of Agriculture (USDA) supported, evidence-based HomeStyles intervention has demonstrated feasibility, acceptability, and efficacy in improving lifestyle behaviors and home environments associated with obesity risk in families. A lack of linguistically, culturally tailored interventions to their specific health needs makes it difficult for US Chinese to implement healthy lifestyle behaviors and reduce health risks. Interventions tailored for US Chinese that could attenuate modifiable cardiometabolic risk factors, understand physiological sequelae, and bridge health equity are not currently available. Thus, the overall goal of this project is to test the efficacy of HomeStyles in improving health outcomes in US Chinese. Project aims are to: A) Culturally adapt the HomeStyles intervention through community-engaged approaches. B) Conduct a 10-week, 2-armed Randomized Controlled Trial (RCT) to test HomeStyles intervention efficacy on health outcomes (dietary intake, physical activity, self-efficacy, HbA1C, waist circumference, and BMI), hypothesizing that participants randomized to the treatment condition will have greater improvements in health outcomes than control comparators. C) Examine associations between intervention participation and gut microbiota/systemic inflammation and test hypotheses that a whole-grain rich diet adopted by those in the intervention group will increase anti-inflammatory gut bacteria, reduce inflammatory gut bacteria, and lower systemic inflammation.
Gender: All
Ages: 30 Years - 70 Years
Updated: 2026-03-25
1 state
NCT07476573
Clinical Trial of Lactiplantibacillus Plantarum Dad-13 on Gut Microbiota Profile and Performance in Adolescent Athletes
The aim of this research is to analyze the effect of a Lactiplantibacillus plantarum Dad-13 supplementation on the gut microbiota profile and performance of adolescent athletes.
Gender: All
Ages: 12 Years - 18 Years
Updated: 2026-03-23
1 state
NCT07471373
Pesticides and Infertility: Oxidative Stress Via Circulating Cell-free DNA and Gut/Genital Microbiome Signatures in Women With Endometriosis
This project PestiEndoMicro aims to provide an innovative approach, studying endometriosis under the genital and gut microbiota scope. To realize this project, the investigators are planning to dose cfDNA to assess the oxidative stress caused by endometriosis and study its epigenetics. At the same time, the investigators will take a pragmatic approach by assessing pesticide exposure in these patients and estimate the correlation between gut or genital dysbiosis and chemical agent exposure. Also, the investigators will take the initiative to use classic culture, qPCR techniques, and NGS to establish signatures in vaginal, endometrial and gut microbiota in patients with endometriosis. With these approaches, the goal is to gain more knowledge about endometriosis and optimize early diagnosis by establishing a signature in the genital and gut microbiota, but also by dosing the cfDNA. By doing so the investigators could open new opportunities to develop new therapeutic strategies for endometriosis.
Gender: FEMALE
Ages: 18 Years - 43 Years
Updated: 2026-03-13
NCT06896240
Fiber Smoothie Supplement
This study aims to assess the feasibility of a 2-week dietary whole-food smoothie intervention and compare outcomes between two groups: patients that integrated a daily whole food plant-based smoothie into their diet for two weeks prior to surgery, and a control group of revision TKA patients that made no nutritional changes to their diet prior to surgery. The main research questions are: 1. Among patients planned for elective TKA revision surgery, what is the feasibility of a 2-week dietary intervention implemented 2 weeks prior to surgery? \[Outcomes will be compliance, noted barriers and/or facilitators, satisfaction with diet\] 2. Determine if the implementation of a daily whole food plant- based smoothie dietary supplement 2 weeks prior to TKA revision surgery will reduce inflammation -measured in plasma levels of IL-6 and CRP- at POD0, POD1, POD2, POD3, and 6 Weeks Post-operative as compared to 1) baseline (prior to dietary intervention initiation) and 2) control patients who did not make changes in their diet prior to surgery. 3. Determine if the implementation of a daily whole food plant-based smoothie dietary supplement 2 weeks prior to TKA revision surgery will result in quantifiable changes in the gut microbiome composition -measured via fecal samples- as compared to control patients who did not make changes in their diet prior to surgery. 4. Determine if the implementation of a daily whole food plant- based smoothie dietary supplement 2 weeks prior to TKA revision surgery will result in improved immediate postoperative pain -measured through numeric rating scale (NRS) pain scores- and opioid use -measured in morphine milligram equivalents (MME)- as compared to control patients. 5. Compare patient satisfaction and adoption of nutritional behavioral changes in patients implementing a whole food plant-based smoothie 2 weeks prior to TKA revision surgery to patients undergoing the same surgery but did not me pre-surgery dietary changes. The researcher's primary outcome is measuring feasibility and patient compliance with smoothie consumption. Secondarily, the investigators are interested in measuring if the preoperative smoothie can alter the gut microbiome and decrease systemic inflammation, leading to lowered post-operative pain and opioid use.
Gender: All
Ages: 40 Years - 80 Years
Updated: 2026-02-12
1 state
NCT07009223
Lifestyle Interventions to Prevent Cognitive Deficits in Subjects With Depressive Symptoms: From Mechanisms to Clinical Practice
The goal of this clinical study is to investigate if lifestyle changes can help prevent cognitive decline and reduce depressive symptoms in people between the ages of 50 and 80 with depressive symptoms or a diagnosis of major depression, but without signs of cognitive decline. The main questions it aims to answer are: * Does regular physical activity improve mood and memory in people who are depressed or have depressive symptoms? * Does cognitive training help prevent mental difficulties in people at risk of cognitive decline? * Do changes in diet and lifestyle alter the composition of the gut microbiota and immuno-related infiammatory factors? Researchers will compare three different treatment groups to see which intervention is most effective in improving mental and cognitive health. The participants: * Will take part to online sessions on healthy eating based on the Mediterranean diet * Some will do regular exercise, supervised by a personal trainer * Others will do weekly cognitive training in small groups at the hospital * They will provide blood and fecal samples and complete cognitive tests and clinical questionnaires at the beginning, at the end of the treatment (12 weeks), and after 3 months.
Gender: All
Ages: 50 Years - 80 Years
Updated: 2026-02-11
NCT07400354
The Efficacy of PD-1 Monoclonal Antibody Combined With Chemotherapy in Metastatic Gastric Cancer Based on Gut Microbiota
This study is designed as a single-center, open-label, phase II exploratory trial. Patients with advanced or locally advanced gastric cancer who have not received chemotherapy or immunotherapy before are eligible for inclusion. They will receive a first-line two-drug combination chemotherapy regimen (FOLFOX, XELOX, or SOX, determined by the attending physician) in combination with a PD-1 monoclonal antibody (nivolumab, sintilimab, tislelizumab, or pembrolizumab, determined by the attending physician). Fruquintinib can be added on this basis (only for patients enrolled in the HMPL-013-SH-GC103 study). The aim is to evaluate whether the gut microbiota has a predictive role in the efficacy of immunotherapy combined with chemotherapy for metastatic gastric cancer. A total of 100 patients will be enrolled in the study. Gut microbiota will be measured at the following three time points: 1. Within 3 days before the first chemotherapy (designated as time 0) 2. Within 3 days before the third chemotherapy (designated as time 1) 3. After the sixth chemotherapy cycle, or within 1 week after disease progression if it occurs within the sixth cycle (designated as time 2)
Gender: All
Ages: 18 Years - Any
Updated: 2026-02-10
1 state
NCT07381140
Bariatric Surgery and Gut Microbiota Changes Over Time
The goal of this observational study is to learn how bariatric surgery affects gut bacteria and gut-related metabolic products over time in adults with obesity. The study includes adults aged 18 to 65 years who are undergoing Roux-en-Y gastric bypass (RYGB) surgery, as well as adults with obesity treated with diet alone and healthy normal-weight adults. The main questions it aims to answer are: How does bariatric surgery change the composition and diversity of gut bacteria over time? How are these changes related to weight loss and improvement of obesity-related health conditions? Researchers will compare people undergoing bariatric surgery with people with obesity treated with diet alone and with healthy normal-weight individuals to see if surgery leads to specific changes in gut bacteria and stool metabolites that are linked to better clinical outcomes. Participants will: Provide stool samples at scheduled time points over 12 months Provide blood samples and undergo routine clinical assessments Take part in follow-up visits to monitor weight, metabolic health, and gastrointestinal symptoms
Gender: All
Ages: 18 Years - 65 Years
Updated: 2026-02-05
1 state
NCT06935435
Effects of Distinct Nebraska-Dry Bean Market Classes on Gut Microbiota
Beans are well known for their health benefits. Many of these benefits relate to gut health, as many of the nutrients found in beans support beneficial microbes that live in the gut. However, beans have a lot of genetic diversity. This diversity has led to different bean market classes with different colors, sizes, and nutrient profiles. Differences between bean market classes may trigger different effects on gut microbes and health, but this is poorly understood. The goal of the pilot clinical trial is to make comparisons (1) between two different bean market classes (pink beans, great northern beans) and (2) between a bean mixture (pinto, kidney, black, pink, and great northern beans) and individual bean market classes. The study will assess whether bean market classes differ in their effects on gut microbes, blood pressure, metabolism, and gut symptoms in adults with and without obesity.
Gender: All
Ages: 19 Years - 50 Years
Updated: 2026-02-04
1 state
NCT07355309
High-Dairy Food Patterns and Gut-Brain Axis
Disturbances in brain insulin sensitivity are associated not only with obesity and type 2 diabetes, but also with brain aging and cognitive decline. Longitudinal studies suggest that dietary patterns, particularly those high in dairy intake, may impact brain function via the gut-brain axis. Indeed, dairy foods are known to modulate gut microbiota and may, through this pathway, not only improve brain insulin sensitivity and cognitive performance, but also mental health and appetite regulation. However, underlying mechanisms remain largely unexplored. The primary objective of this study is to evaluate, in older adults with overweight or obesity, the effects of a high-dairy food pattern (4-5 daily servings of (butter)milk, cheese, yogurt, or cottage cheese) compared to a low-dairy food pattern (≤1 serving daily) on (regional) brain vascular function and insulin sensitivity. These outcomes will be quantified using the non-invasive MRI perfusion technique Arterial Spin Labeling (ASL), which assesses cerebral blood flow (CBF) in response to intranasal insulin, a validated physiological marker of brain insulin sensitivity. Secondary objectives include changes in cognitive performance (via the CANTAB neuropsychological test battery), gut microbiota composition (via shotgun metagenomic analysis of fecal samples), and appetite-related brain reward activity (via BOLD-fMRI with food cues). Exploratory analyses include conventional cardiometabolic risk markers (blood pressure, lipid and glucose metabolism), and perceivable (consumer) benefits.
Gender: All
Ages: 40 Years - 75 Years
Updated: 2026-01-21
1 state
NCT07214428
Effects of Grape Powder on Psychological Distress and Gut Microbiota in College Students
The goal of this trial is to investigate the effect of freeze-dried table grape powder (FTGP) on psychological distress and gut microbiota in college students. The main questions it aims to answer are: Does FTGP reduce anxiety, depression, and perceived stress? Does FTGP improve the gut microbiota? Researchers will compare FTGP to a placebo to see how FTGP affects psychological distress and gut microbiota. Participants will: Drink a daily supplement containing FTGP or a placebo for 4 weeks. Record consumption of grape powder or placebo in a compliance log. Complete surveys and provide stool samples. Three in-person visits.
Gender: All
Ages: 18 Years - 30 Years
Updated: 2026-01-15
1 state
NCT07342621
SMASH: Study to Evaluate the Clinical Efficacy of an Extensively Hydrolysed Infant Formula With Synbiotics and a Human Milk Oligosaccharide (HMO) in Infants With Cow's Milk Protein Allergy (CMPA)
Cow's milk protein allergy (CMPA) is one of the most common food allergies in infants, with an estimated prevalence between 2% and 5%. The number of diagnosed cases has increased in recent years, with clinical manifestations involving the gastrointestinal tract, respiratory system, skin, or systemic reactions. Dietary elimination of cow's milk protein remains the mainstay of treatment, using extensively hydrolyzed formulas (EHF) or amino acid-based formulas (AAF), depending on the severity of the allergy. This study aims to evaluate the clinical effect, as reported by physicians, of an extensively hydrolyzed whey-based formula (Almirón Pepti Syneo®) containing a symbiotic mixture (scGOS/lcFOS 9:1 and Bifidobacterium breve M-16V), the human milk oligosaccharide 2'-fucosyllactose (2'-FL), and a reduced amount of purified lactose, in infants with suspected or confirmed CMPA in a real-world clinical practice setting. This is a prospective, longitudinal, open-label, single-arm, multicenter study including approximately 41 infants under 10 months of age at several primary care centers and one hospital in Valencia, Spain. Each participant will be followed for four weeks. A subgroup of participants will also provide stool samples to explore the effect of the study formula on gut microbiota composition.
Gender: All
Ages: Any - 10 Months
Updated: 2026-01-15
1 state
NCT03620617
Effect of Raspberry on Gut Microbiota and Metabolic Syndrome
There is growing evidence that nutritional intervention with dietary polyphenols can positively modulate the gut microbiota to improve cardiometabolic health. Whether the beneficial effects of raspberry on obesity and the metabolic syndrome can be linked to their potential impact on the gut microbiota and intestinal integrity remains speculative at this time. Moreover, the mechanisms of action underlying health benefits associated to raspberry consumption are still unknown. The investigators are thus proposing to combine the study of metagenomics, transcriptomics and metabolomics to test whether a prebiotic activity of raspberry can play a role in the prevention of obesity-linked metabolic syndrome in a clinical setting.
Gender: All
Ages: 18 Years - 60 Years
Updated: 2025-12-26
NCT03259685
Effect of Non-nutritive Sweeteners of High Sugar Sweetened Beverages on Metabolic Health and Gut Microbiome
Increasing evidence suggest that artificial sweeteners such as saccharin, aspartame and sucralose may not be as metabolically safe as they first appeared, and it has been proposed that their consumption may be linked to important disturbances in the gut microbiome. Some in vitro and in vivo studies suggest that the recently approved sugar substitute Stevia (eg. steviol glycosides) can also influence intestinal homeostasis. However, it is not clear whether this natural non-nutritive sweetener (NNS) could also cause metabolic and microbiome disturbances as proposed for their synthetic counterparts. In fact, steviol glycosides may even have a beneficial impact on glucose homeostasis and lipid metabolism possibly through a positive action on intestinal health and gut microbiome, but this has yet to be experimentally tested in a rigorous study. The main objective of this project is to evaluate whether steviol glycosides sweetened beverages (SGSB) or aspartame/acesulfame K sweetened beverages (AASB) exert beneficial, neutral or detrimental effects on metabolic health of regular consumers of sugar-sweetened beverages (SSBs), and whether modulation of the gut microbiome is involved in the resulting impact of these NNSs on metabolic health. As chronic overconsumption of SSBs is clearly associated with an increased cardiometabolic risk, this study will be the first to determine the metabolic impact of replacing SSBs by potentially "healthier alternatives" such as the increasingly popular stevia-based soft drinks and aspartame-based soft drinks. The investigators will further investigate whether these NNS can cause pernicious effects on intestinal health and the gut microbiome. It is a crucial concern since the importance of this unsuspected key "organ" has been ignored for too long and its important implication in many chronic societal diseases has just been discovered. Results of this study could have a direct influence on health, nutrition and even agricultural policies as well as dietary guidelines around the world. This project is also critically important as an increasing amount of health professionals such as physicians, nurses and registered dietitians seek to provide evidenced-based guidance to individuals looking for healthier alternatives to SSBs including stevia-based or aspartame-based soft drinks.
Gender: All
Ages: 18 Years - 75 Years
Updated: 2025-12-26
NCT03266055
Effects of Blueberry on Gut Microbiota and Metabolic Syndrome
There is growing evidence that nutritional intervention with dietary polyphenols can positively modulate the gut microbiota to improve cardiometabolic health. Whether the beneficial effects of blueberries on obesity and the metabolic syndrome can be linked to their potential impact on the gut microbiota and intestinal integrity remains speculative at this time. Moreover, the mechanisms of action underlying health benefits associated to blueberry consumption are still unknown. The investigators are thus proposing to combine the study of metagenomics, transcriptomics and metabolomics to test whether a prebiotic activity of highbush blueberries can play a role in the prevention of obesity-linked metabolic syndrome in a clinical setting.
Gender: All
Ages: 18 Years - 55 Years
Updated: 2025-12-26
NCT07289581
Effect of Treatment With Butyric Acid in Anorexia Nervosa
This clinical trial aims to evaluate the therapeutic potential of oral butyric acid supplementation in individuals with anorexia nervosa (AN). T The study will assess whether butyric acid, administered alongside standard multidisciplinary care, improves weight restoration and contributes to overall clinical recovery. The primary objectives are to determine: \- Whether butyric acid enhances weight restoration during the first 3 months of treatment. Participants will be randomly assigned to receive either butyric acid or a placebo for 3 months, in addition to treatment-as-usual, which includes nutritional rehabilitation and cognitive-behavioral therapy. Throughout the study, researchers will monitor: * Changes in body weight and Body Mass Index (BMI) * General and eating-disorder-related psychopathology * Blood-based biomarkers related to inflammation, metabolism, and neuroendocrine function * Gut microbiota composition and metabolites, including short-chain fatty acids A total of 50 participants with AN are expected to be enrolled.
Gender: FEMALE
Ages: 18 Years - 65 Years
Updated: 2025-12-17
1 state
NCT07052071
Impact of Transcatheter Aortic Valve Implantation (TAVI) on the Gut Microbiota in Patients With Aortic Valve Stenosis
This study investigates the impact of transcatheter aortic valve implantation (TAVI) on the composition and function of the gut microbiota in patients with severe aortic valve stenosis. The improvement in haemodynamics following TAVI may positively influence gut microbial balance by increasing splanchnic perfusion and reducing intestinal congestion. A total of 40 patients undergoing TAVI at the "Hippokration" General Hospital of Athens will be enrolled, with the aim of analysing stool and blood samples before and after the procedure. The primary endpoint is the change in gut microbiota composition two months post-TAVI, assessed via 16S rRNA sequencing. Secondary endpoints include changes in serum TMAO levels and their association with the severity of aortic stenosis and post-procedural valve haemodynamics. Data will be collected at two timepoints (1 month up to 1 day pre-TAVI and 3 to 4 months post-TAVI), along with dietary questionnaires to account for potential confounding factors. This observational study aims to highlight the potential relationship between cardiac function and the gut microbiome, offering new perspectives for targeted therapeutic strategies in cardiovascular disease.
Gender: All
Updated: 2025-11-18
NCT07220369
Gut Mini-Pill Study
The purpose of this proof-of-concept study in humans is to determine if a noninvasive, ingestible device, called a "mini-pill", can collect gastrointestinal (GI) luminal content samples from 2 different locations along the GI tract after consumption of diets differing in protein source (meat and plant-based meat alternatives). The mini-pills will be recovered in the stool. We will analyze the microbial profile of the mini-pill contents and in stool, and also measure blood biomarkers related to cardiometabolic risk, to better understand the relationship between diet, microbiota and health.
Gender: All
Ages: 50 Years - 75 Years
Updated: 2025-10-30
1 state
NCT07207109
Effect of follow-on Formula on the Gut Microbiota of Healthy Infants.
This study investigates the effects of follow-on formula in infants aged 6-9 months over a 12-week period. After parents give consent, their baby's feeding habits, stool characteristics, and any illnesses or medication use will be recorded. Infants will be randomly assigned to receive either the test or control product. Growth and health data will be collected during study visits. Parents will collect stool samples and complete diaries to help researchers better understand the baby's digestion and overall health. A follow-up phone call will be made to check on the baby's well-being after the study ends.
Gender: All
Ages: 6 Months - 9 Months
Updated: 2025-10-03
2 states
NCT06929845
Organoid Models of Hepatocellular Carcinoma
A promising tool to elucidate the molecular characteristics of HCC are patient-derived organoids (PDOs), three-dimensional cultures of cells that self-organise according to tissue-specific patterns and can be used to test the susceptibility of a specific tumour to anticancer agents. In this study, PDOs for HCC will be developed that closely resemble the tumour microenvironment in vivo and mimic the crosstalk of the gut-liver axis to establish a correlation with patient prognosis and test the efficacy of available systemic therapies.
Gender: All
Ages: 18 Years - Any
Updated: 2025-09-15
NCT07112248
Effects of Soluble Fiber Supplements on Sperm Quality in Males With Obesity: a Randomized Trial
Obesity-related poor sperm quality is a significant public health issue, acting as a major contributor to male infertility. Dietary intervention has emerged as an effective strategy to manage obesity and improve sperm quality. Soluble dietary fiber (SDF), an essential nutritional component, plays a crucial role in regulating host health. Notably, insufficient SDF intake has been associated with both obesity and low sperm motility. However, the effect of SDF supplementation on sperm quality in males with obesity remains unclear. Thus, we conducted a randomized, placebo-controlled study to investigate the effect of SDF supplementation on sperm quality in males with obesity.
Gender: MALE
Ages: 18 Years - 60 Years
Updated: 2025-08-08
NCT06691100
How a Single Workout Affects Gut Bugs in Women With Different Fitness Levels and Body Types
This study aims to elucidate the differences in the gut microbiome functional activity and metabolome in adult premenopausal women with distinctive fitness levels and BMIs (with obesity, w/o obesity). The specific aims are as follows: * Aim 1: To examine the effects of acute aerobic exercise at 60-70% heart rate reserve (HRRmax) for 30 minutes bout on changes in the abundance of SCFA-producing bacteria and their functional downstream metabolic activity. * Aim 2: To examine the effects of acute aerobic exercise at 60-70% HRRmax 30-minute bout on changes in GM-released SCFA concentrations in stool and plasmatic metabolome.
Gender: FEMALE
Ages: 21 Years - 40 Years
Updated: 2025-07-24
1 state