Tundra Space

Tundra Space

Clinical Research Directory

Browse clinical research sites, groups, and studies.

17 clinical studies listed.

Filters:

Gastrointestinal Symptoms

Tundra lists 17 Gastrointestinal Symptoms clinical trials. Each listing includes eligibility criteria, study locations, and direct links to research sites in the Tundra directory.

This data is also available as a public JSON API. AI systems and LLMs are encouraged to use it for structured queries.

ENROLLING BY INVITATION

NCT07471490

Specimen and Data Collection for a Novel Biomarker Combination for the Differential Diagnosis of Inflammatory Bowel Disease and Irritable Bowel Syndrome.

This study will evaluate how well the a new stool test can distinguish inflammatory bowel disease (IBD) from non-IBD conditions compared with standard calprotectin testing and colonoscopy findings. Participants will undergo only routine clinical care, including colonoscopy, and will provide a stool sample for testing. The study will also examine how test results relate to endoscopic, histologic, and ultrasound measures of disease activity. Findings may help determine whether the new test could reduce unnecessary colonoscopies and support future regulatory submissions.

Gender: All

Ages: 2 Years - Any

Updated: 2026-03-13

2 states

IBD (Inflammatory Bowel Disease)
IBS (Irritable Bowel Syndrome)
Gastrointestinal Symptoms
RECRUITING

NCT06937814

The Effect of Humiome® Post LB on Gut COMFort in healthY Adult Volunteers

The goal of this double-blind, randomized placebo-controlled study is to evaluate the effect of an 8-week supplementation of Humiome ® Post LB (170 mg) on bowel movements in healthy adult volunteers compared to Placebo adjusted on baseline. The main question\[s\] it aims to answer \[is/are\]: Does Humiome ® Post LB improve bowel movements with self-reported GI issues? Participants will be provided Humiome ® Post LB (170 mg) for 8 weeks and asked to complete a study diary, questionnaires, and stool samples.

Gender: All

Ages: 18 Years - 75 Years

Updated: 2026-03-09

1 state

GI Issues
Bowel Movements
Gastrointestinal Symptoms
NOT YET RECRUITING

NCT07453823

The Effect of a Synbiotic on Intestinal Barrier Function and Microbiota Modulation in Middle-aged to Elderly Individuals With Excessive Body Weight

The study is a single-center, randomized, double-blind, placebo-controlled study in middle-aged to elderly adults with excessive body weight. The study includes an 8-week intervention period followed by a 2-week follow-up period. The study will evaluate the effect of a synbiotic consisting of two probiotic strains and a prebiotic. The aim is to investigate the effect of the synbiotic on modulating the gut microbiota and improving markers of gastrointestinal permeability and integrity and gastrointestinal discomfort.

Gender: All

Ages: 50 Years - 70 Years

Updated: 2026-03-06

1 state

Gastrointestinal Microbiome (Focus)
Gastrointestinal Symptoms
RECRUITING

NCT07421596

An 8-Week Study Evaluating Gut and Digestive Health After Use of a Dietary Supplement System

This clinical research study is being conducted to evaluate gut and digestive health before and after the use of a dietary supplement system over an eight-week period. Gut and digestive health play an important role in overall health, including digestion, nutrient absorption, immune function, and metabolic balance. Changes in gut microbiota, inflammation, and intestinal barrier function may contribute to digestive symptoms such as bloating, discomfort, altered bowel habits, and reduced well-being. In this study, adult men and women with self-reported gastrointestinal symptoms will consume a dietary supplement system daily for eight weeks. The study will measure changes in gut and digestive health using objective stool-based laboratory biomarkers and validated symptom questionnaires. Stool samples will be collected at baseline and at the end of the study to evaluate markers related to microbial diversity, inflammation, immune activity, digestive function, and intestinal barrier integrity. Participants will also complete questionnaires throughout the study to assess gastrointestinal symptoms and subjective digestive health and well-being. The study will also monitor the safety and tolerability of the dietary supplement system during the study period.

Gender: All

Ages: 18 Years - 80 Years

Updated: 2026-02-24

1 state

Gastrointestinal Symptoms
Digestive Health
Gut Health
NOT YET RECRUITING

NCT07422103

PAN-CLO-BU (PANcreas-CLOstridium-BUtyricum)

This is a prospective, randomized, double-blind, single-center clinical trial designed to evaluate the effects of Clostridium butyricum CBM588 supplementation on postoperative diarrhea, gastrointestinal symptoms, and quality of life in patients undergoing pancreaticoduodenectomy for periampullary neoplasms. Oncological outcomes, including disease-free survival and overall survival, will be monitored as secondary endpoints during follow-up.

Gender: All

Ages: 18 Years - Any

Updated: 2026-02-19

1 state

Pancreatic Cancer
Pancreatic Diseases
Gastrointestinal Symptoms
+3
RECRUITING

NCT07388264

Impact of Weizmannia (Bacillus) Coagulans JBI-YZ6.3 on Gut Health and Fecal Microbiome Changes

This study will evaluate the effects of supplementation with Weizmannia (Bacillus) coagulans JBI-YZ6.3 on gastrointestinal health in healthy, physically active adults. The primary objective is to determine whether daily intake of this probiotic strain improves symptoms of constipation and related gastrointestinal function compared with placebo. Approximately 30 healthy men and women aged 18 to 50 years will be enrolled in a randomized, double-blind, placebo-controlled, crossover trial. Participants will complete two 4-week supplementation periods, one with Weizmannia (Bacillus) coagulans JBI-YZ6.3 and one with placebo, separated by a 4-week washout period. The total duration of participation will be approximately 13 to 14 weeks, including screening and testing visits. Gastrointestinal symptoms will be assessed at baseline and after each supplementation period using validated questionnaires, with particular focus on the constipation domain of the Gastrointestinal Symptom Rating Scale (GSRS). Secondary outcomes will include additional gastrointestinal symptom domains and markers of perceived gut comfort and function. This study is designed to determine whether supplementation with Weizmannia (Bacillus) coagulans JBI-YZ6.3 produces clinically meaningful improvements in gastrointestinal symptoms in physically active adults compared with placebo.

Gender: All

Ages: 18 Years - 50 Years

Updated: 2026-02-05

1 state

Gastrointestinal Symptoms
Constipation
Gut Health
+1
NOT YET RECRUITING

NCT07387991

Evaluating the Ability of a Multi-Strain Postbiotic to Impact Inflammation, Immune Components, Gastrointestinal Symptoms, Recovery, Anxiety, and Intestinal Permeability

This study will evaluate the effects of a multi-strain postbiotic supplement on markers of inflammation, immune function, gastrointestinal symptoms, psychological well-being, and intestinal permeability in healthy adults. The primary objective is to determine whether four weeks of postbiotic supplementation alters physiological and perceptual responses to a standardized bout of moderate-to-high intensity exercise compared with placebo. Approximately 50 healthy men and women aged 18 to 55 years will be enrolled in a randomized, double-blind, placebo-controlled, parallel-group clinical trial. Participants will be randomly assigned to receive either a multi-strain postbiotic supplement or a matched placebo for 28 days. At the end of the supplementation period, participants will complete a 45-minute treadmill exercise bout at 75% of their individually determined maximum heart rate. Blood samples will be collected to assess biomarkers of inflammation, immune activity, and recovery. Gastrointestinal symptoms, intestinal permeability, anxiety, and perceived recovery will be evaluated using validated questionnaires. This study is designed to determine whether postbiotic supplementation modulates physiological stress responses and subjective well-being following prolonged exercise in healthy adults.

Gender: All

Ages: 18 Years - 55 Years

Updated: 2026-02-04

1 state

Inflammation
Gastrointestinal Symptoms
NOT YET RECRUITING

NCT07370740

A Clinical Trial to Investigate the Safety and Efficacy of Bloat on Gas and Bloating in Healthy Women

The goal of this clinical trial is to investigate the safety and efficacy of Bloat on gas and bloating in healthy women. The main question it aims to answer is what is the change in postprandial gas and bloating from pre-dose at t = 60 mins post-dose between Bloat and placebo, as assessed by Gas and Bloating Likert scale at screening/baseline. Participants will be asked to consume one dose of Bloat or Placebo and answer questionnaires on gas and bloating.

Gender: FEMALE

Ages: 18 Years - 65 Years

Updated: 2026-01-27

1 state

Bloating
Gastrointestinal Symptoms
Intestinal Gas
NOT YET RECRUITING

NCT07371013

Fecal Microbiota Transplantation in Children With Autism Spectrum Disorder and Gastrointestinal Symptoms

The aim of the study is to evaluate the effectiveness and safety of fecal microbiota transplantation (FMT) in reducing gastrointestinal (GI) and behavioral symptoms in children with autism spectrum disorder (ASD). Children with ASD often experience GI problems such as constipation, diarrhea, and abdominal pain. These symptoms can negatively affect their daily life and behavior. Recent research suggests that the gut microbiota-the community of bacteria and other microorganisms living in the intestines-plays an important role in digestion, immunity, and communication with the brain through the gut-brain axis. Modifying the gut microbiota may help improve GI symptoms and possibly behavioral functioning. FMT involves giving a preparation containing gut microbiota from a healthy donor after bowel cleansing. The product used in this study is MBiotix HBI Caps, produced by Human Biome Institute. A placebo (inactive substance) will also be used for comparison. Both will be given as frozen oral capsules that look identical. 20 children aged 6-12 years will take part. Participants will be randomly assigned to receive either the microbiota preparation or placebo. The study includes several visits over about 6 months. Before the first dose, every child will undergo bowel cleansing with a special preparation (Polyethylene Glycol, PEG). During the study, participants will be asked to keep a symptom diary, complete questionnaires, and record child's diet. Biological samples (stool, urine, saliva) will be collected at specific time points for analysis. Every child will also be assessed by a psychologist before the study begins and again during the study using standardized tools (Autism Diagnostic Observation Schedule, Second Edition, ADOS-2) to evaluate behavioral functioning and quality of life.

Gender: All

Ages: 6 Years - 12 Years

Updated: 2026-01-27

1 state

Autism Spectrum Disorder
Gastrointestinal Symptoms
NOT YET RECRUITING

NCT07366931

The Effect of Daily Supplementation With Humiome® Post LB on Gastrointestinal Symptoms in Female Athletes

Female athletes are often overlooked in scientific research, including the understanding of their digestive system and its impact on overall health, training, and performance. The gastrointestinal (GI) system plays a critical role in supporting digestion, nutrient absorption, and acting as a protective barrier for the body. While there is some knowledge about the differences in GI structure and function between males and females at rest, there is a lack of understanding regarding how these differences manifest during exercise, especially among female athletes and at different phases of the menstrual cycle. It has been observed that female athletes commonly report a higher prevalence of GI symptoms compared to males, with many experiencing an increase during menstruation. These symptoms, including bloating, abdominal discomfort, and irregular bowel movements, can significantly disrupt an athlete's training and performance. Elite female athletes have acknowledged that GI symptoms associated with the menstrual cycle have led to altered or disrupted training routines. While these symptoms are commonly recognized to affect a large portion of the female population, few interventions have been studied to assist in managing this discomfort. Some clinicians may direct their patients to take pain-relieving medications without any thoughts on the consequences of chronic use. One potential strategy to reduce GI symptoms during endurance exercise is probiotic-postbiotic supplementation. Various probiotic supplements have been shown to effectively decrease diarrhoea, constipation stress, and intestinal permeability, as well as impact immunologic outcomes. Postbiotics differ from probiotics in that they are made from microorganisms that are not alive. They allow the modulation of the composition and function of the gut microbiota and enhance the intestinal barrier to prevent unwanted substances from entering the body proper. While these biotics can relieve lower GI symptoms in irritable bowel syndrome (IBS), there is less consensus regarding their efficacy in modulating exercise-associated GI symptoms. Previous research by Pugh et al., 2019 has demonstrated that four weeks of probiotic supplementation was able to reduce GI symptoms during a marathon race, however this work was predominantly conducted in males and did not take menstrual cycle in consideration. This is important given that symptoms are commonly higher in the early follicular phase when a female experiences their period. Therefore, the aim of this study is to assess the effects of postbiotic supplementation on GI symptomology in female athletes. The aim of this present study is to investigate the influence of postbiotic supplementation on menstrual cycle symptoms and exercise-associated GI symptoms in female endurance athletes while exercising compared to symptoms while taking a placebo.

Gender: FEMALE

Ages: 18 Years - Any

Updated: 2026-01-27

Healthy Adult Females
Gastrointestinal Symptoms
NOT YET RECRUITING

NCT07342972

Gastrointestinal Symptoms and Tolerance in Infants Fed Goat or Cow's Milk-based Infant Formula

This randomized controlled double-blind study will compare the effect of a commercially available goat milk formula to a cow's milk formula on gastrointestinal symptoms and tolerance, and infections in infants.

Gender: All

Ages: 14 Days - 90 Days

Updated: 2026-01-15

Gastrointestinal Tolerance
Gastrointestinal Symptoms
Infections
+2
NOT YET RECRUITING

NCT07272681

Effect of H. Pylori Eradication on The Improvement of Gastrointestinal Symptoms

This study aims to evaluate the effect of Helicobacter pylori eradication on gastrointestinal symptoms in adult patients. H. pylori infection is a common cause of dyspepsia and other upper gastrointestinal complaints. The trial will assess whether successful eradication therapy leads to significant improvement in symptoms compared to baseline. Adult patients diagnosed with H. pylori infection will receive standard eradication treatment, and symptom changes will be monitored using validated questionnaires over a defined follow-up period.

Gender: All

Ages: 18 Years - Any

Updated: 2025-12-16

Helicobacter Pylori Infection
Dyspepsia
Gastrointestinal Symptoms
NOT YET RECRUITING

NCT07280624

Diagnostic PCR Panel in Children With Acute Gastrointestinal Symptoms

This investigator-initiated randomized controlled trial compares the clinical impact of real time PCR of fecal samples in children with acute gastrointestinal symptoms at a pediatric emergency room. Specifically, the trial compares immediate testing of fecal samples using a multiplex PCR panel to a a control group with delayed test results.

Gender: All

Ages: Any - 16 Years

Updated: 2025-12-12

Gastroenteritis Acute
Gastrointestinal Symptoms
Abdominal Pain/ Discomfort
+1
RECRUITING

NCT05972291

Mechanisms of Gulf War Illness

Many veterans with Gulf War Illness developed chronic gastrointestinal symptoms during their deployment to the Persian Gulf. The pathophysiologic mechanisms of these chronic gastrointestinal symptoms are not well understood but cause significant morbidity in veterans. Our proposed studies will provide an innovative and novel treatment trial for chronic gastrointestinal symptoms in veterans with Gulf War Illness that were deployed into war zones. Given that there are currently no specific treatments for these disorders, and that current symptomatic approaches are far from ideal, proof of principle of our trial would be an extremely important advance as it would not only have a beneficial impact on the health of many thousands of our veterans, but also it would substantially reduce the many negative economic effects of this ailment on the VA Health Care System.

Gender: All

Ages: 18 Years - 65 Years

Updated: 2025-12-05

1 state

Gulf War Illness
Irritable Bowel Syndrome
Gastrointestinal Symptoms
ACTIVE NOT RECRUITING

NCT06744699

Assessment of Gastrointestinal Discomfort and Infections in Healthy Term Infants

A retrospective observational medical dossier-based study to assess gastrointestinal discomfort and infections in healthy term infants

Gender: All

Ages: Any - 24 Months

Updated: 2024-12-20

Gastrointestinal Symptoms
Infection
Allergy Symptoms
+1
RECRUITING

NCT04919265

Mother-Infant Cohort Study in Malaysia and China

This mother-infant cohort study aims to determine the geographic differences in the microbial profiles in breast milk from mothers living in Malaysia and China that are potentially important determinants of infant development. It also aims to determine the impact of gut microbiome on infant health (temperament, gastrointestinal symptoms, eczema symptoms, and asthma symptoms).

Gender: FEMALE

Ages: 18 Years - 45 Years

Updated: 2024-12-13

1 state

Gut Microbiota
Gastrointestinal Symptoms
Temperament
+3
RECRUITING

NCT03514784

Combination Probiotic: BB-12 With LGG (Different Doses) in Treating Children With Autism Spectrum Disorder

This protocol is a blinded randomized controlled study of the effects of BB-12 with LGG at different doses in 70 healthy children with autism spectrum disorders at lower and higher doses over an 56-day period and a 28- day observation period. The study is being conducted in order to assess safety and tolerability of the probiotic (BB-12 with LGG) at 2 different doses of BB-12 with LGG. Identifying effects on behaviors in healthy children with ASD using SRS-2 and ABC, GI symptoms using GI symptom severity index, and relevant biomarkers of inflammation, microbiota, and metabolites. Primary testing and procedures will be conducted at the University of Texas Health Science Center at Houston and Memorial Hermann. Biomarker identification includes Integrative analysis of plasma metabolome and stool microbiota will be conducted with the collaboration of Dr. Ruth Ann Luna and Dr. Jim Versalovic at Alkek Center for Metagenomics and Microbiome Research, Department of Molecular Virology \& Microbiology of Baylor College of Medicine.

Gender: All

Ages: 4 Years - 16 Years

Updated: 2024-05-08

1 state

Autism Spectrum Disorder
Gastrointestinal Symptoms