27 Clinical Trials for Various Conditions
This study is designed to examine the shift in gut microbiota and their metabolism after consumption of a dietary supplement (prebiotic) by healthy participants. The investigators will provide participants with a panel of over the counter prebiotics and monitor their gut microbiome response in stool. All prebiotics will be commercially available, over-the-counter food, food additives, or dietary supplements, without any known market-use adverse effects beyond minimal discomfort.
Xla1 Christensenella minuta, phase I, randomized, placebo-controlled double-blind protocol, evaluating safety, tolerability and impact on the gut microbiota in healthy volunteers, overweight and obese adults. This study is designed as a FIH, Phase I, daily oral single dose, clinical trial evaluating safety, tolerability and the impact on the gut microbiota following introduction of Xla1 performed in 2 parts: * Part 1: An open phase in normal weight healthy volunteers (HV) receiving all Xla1. * Part 2: A randomized, parallel, double-blind, placebo-controlled phase in overweight or obese (stage 1) adult patients receiving either Xla1 or placebo.
This exploratory, randomized, open label study aims to explore the safety, tolerability, pharmacokinetics, and effects of increasing intake amounts of two novel glycans on the gut microbiota of healthy subjects.
The purpose of this study is to examine whether the daily consumption of 5 g of milk polar lipids influences serum lipids and gut microbiota composition in healthy adults.
Does the small bowel microbiota in healthy individuals change after consumption of a Western diet?
The importance of the gut microbiota for general health has been recently elucidated, but little is known about the impact of different types of nutrients on the gut microbiota. The soluble fiber in cereal by-products, arabinoxylan (AX), is known to be beneficial for generally promoting gut health. However, it is unclear whether consuming rice bran (RB), the source of AX, is equally helpful or better than consuming the extracted form of AX. This study aims to reveal the potential benefit of insoluble cereal bran fiber ingredients by comparing the effect of soluble arabinoxylan fiber alone and the mostly insoluble rice bran fiber, containing arabinoxylan, on intestinal health and gut microbiota. A placebo (maltodextrin) will be used as a control, with no significant changes expected in this group for the evaluated outcomes. Participants will: * Consume two different fiber supplements (soluble arabinoxylan or stabilized rice bran) as well as a placebo (maltodextrin) for 3 weeks each, separated by a 2-week washout period. * Provide blood and stool samples at six different time points. * Complete a food and gastrointestinal symptom diary during the intervention periods.
Background: Human intestines are home to a complex gut flora, also called microbiome; this is a natural occurring community of bacteria, fungi, yeast, and viruses. Changes in the balances of the gut flora can lead to illnesses, such as diabetes, colorectal cancer, and inflammatory bowel diseases. Synbiotics are dietary supplements people take to maintain proper balances of their gut flora aiming to improve health. Objective: To find out if a synbiotic supplement can increase the type and amount of beneficial gut bacteria in healthy people as well as improve cardio-vascular protection markers. The supplement contains a natural sugar from human milk. Eligibility: Healthy people aged 18 years or older who eat a typical western diet. They must take no medications (with a few exceptions). Design: Participants will have 2 clinic visits. The first visit will start with screening. They will have a blood test and wait around 2 hours for the results of the blood test. The test will determine if they are eligible for the study. Eligible participants will have additional blood drawn during the screening visit. They will be given a kit to collect a stool sample at home with instructions. They may complete a 3-day food diary. They will meet with a nutritionist and a physician by phone, telehealth, or in person. The supplement is a powder that is mixed with water or another noncarbonated drink. Participants will drink 2 doses per day. Each dose will be 1 hour before or after a meal. The second visit will be about 8 weeks after the first. Participants may repeat the 3-day food diary and nutrition visit. The physical exam, blood tests, and stool sample will be repeated.
The main aim of this study is to investigate differences in rate, extent of change and persistence of the gut microbiota in healthy adult volunteers in response to native chicory inulin. Along with investigating the impact of native chicory on bowl habits, mood and appetite. The two main questions this study aims to answer: * To what extent do differences exist in rate of change over time between individuals in gut microbiota response (Bifidobacterium growth) to native chicory inulin supplementation. * To what extent do differences exist between individuals in persistence of the gut microbiota upon stopping supplementation. The effects of native chicory inulin on gut microbiota response will be compared to a maltodextrin placebo to sure changes in gut microbiota result directly from chicory inulin supplementation. Participants will firstly complete a one-week run-in phase to establish baseline data and will then be allocated to either native chicory inulin or maltodextrin supplementation for 6 weeks. Inulin will be delivered at 12 g/day split into 2 x 6g portions. Maltodextrin will be calorie matched at 6 g/day split into 2 x 3g portions. This will then be followed by a 6 week post-supplementation phase. Fecal and blood samples will be collected regularly throughout all phases for analysis of gut microbiota and compounds of interest. Participants will also record any changes in gastrointestinal sensation, bowel habits and mood in a diary. Changes in appetite sensation will also measured.
The researchers will investigate blood and fecal responses in qualified study participants after eating walnuts for 4 weeks compared to not eating walnuts for 4 weeks. The two dietary interventions will be separated by a 4 week washout period. The order of diets will be random; study participants will complete both interventions. Dietary modifications will be part of the study protocol.
To test the feasibility and safety of our designer synbiotic on gastrointestinal symptoms and gut microbiota and fecal metabolomics.
The project will characterize human gut microbiome response to two different diets and the possible physiological and biochemical implications of such response on cardiometabolic risk factors. The study will use controlled-feeding, systems-biology, metagenomic, and metabolomic approaches to examine American dietary patterns.
Edible insects are often considered a nutritious, protein-rich, environmentally sustainable alternative to traditional meat. They represent a new food for North American consumers. While the nutrient composition of several insects is characterized, all potential health impacts have not been evaluated. Crickets contain chitin and other fibers that may influence gut health. In this study, we evaluated the effects of consuming 25 grams/day whole cricket powder on gut microbiota composition, while assessing safety and tolerability. Twenty healthy adults participated in this six-week, double-blind, crossover dietary intervention. Participants were randomized into two treatment arms and consumed either cricket-containing or control breakfast foods for 14 days, followed by a 14-day washout period and assignment to the opposite arm. Blood and stool samples were collected at baseline and after each treatment period to assess liver function and microbiota changes. Results demonstrate that cricket consumption is tolerable and non-toxic at the treatment dose. Cricket powder supported growth of the probiotic bacteria, Bifidobacterium animalis, which increased more than 5.7-fold. Cricket consumption was also associated with reduced plasma TNF-a. These data suggest that eating crickets may improve gut health and reduce systemic inflammation; however, more research is needed to understand these effects and underlying mechanisms.
The purpose of this study is to evaluate the effects of a common over-the-counter medication, omeprazole, on the normal gut bacteria and inflammation in the body in healthy older adults.
The purpose of this study is to investigate the effects of a synbiotic (ProSynbiotic) on the gut microbiota composition, body composition and adiposity-related genes and metabolic markers in healthy overweight adult subjects.
The purpose of this study is to compare and contrast the effects of the probiotic Saccharomyces boulardii, the antibiotic amoxicillin/clavulanate and the combination on the gut microbiota of healthy volunteers.
The purpose of this study is to compare and contrast the effects of a prebiotic (Trametes Versicolor), a probiotic (Saccharomyces boulardii) and an antibiotic (amoxicillin) on the gut microbiota of healthy volunteers. It is expected that treatment will result in the rapid and reproducible alterations in fecal microbiota that will spontaneously reverse in the weeks after treatment is discontinued.
Resistant maltodextrin (RMD) is an indigestible water soluble fiber that increases fecal bulk by enhancing growth of specific microbial populations; however the effect of RMD on bifidobacteria and total fecal weight is not clear. The purpose of this research study is to determine whether incorporating about ¼ cup of a fiber supplement into the diet will induce beneficial changes in gastrointestinal function, the fecal microbiota profile (increased number of healthy bacteria in stool) and immune processes resulting in improved quality of life.
The purpose of this study is to determine whether incorporating almonds into the diets of families with young children will induce beneficial changes in gastrointestinal function, the fecal microbiota profile, and immune and inflammatory processes of the adults and children resulting in improved quality of life. The investigators anticipate finding an increase in beneficial bacteria, improved intestinal function, and decreased inflammation during the almond intervention.
The investigators hypothesis is that daily use of a proton pump inhibitor (PPI) is associated with significant alterations in the healthy fecal microbiome that are similar to those seen in persons with an initial episode of clostridium difficile infection (CDI).
A positive impact of a fermented dairy protein with prebiotic fiber supplement on self-reported GI complaints and wellbeing has been suggested (Wardenaar et al. 2024). The following project aims to further investigate the impact of this supplements in athletes with and without GI complaints in two separate data collections. Part I of the data collection aims to investigate the impact of this supplement vs. a placebo on carbohydrate malabsorption (as a potential cause for GI distress) in athletes that normally don't identify as having GI complaints (randomized double-blind cross over study design covering a total of 9 weeks, including a 3-week washout period). Part II of the data collection aims to confirm the earlier found results in the previous study (Wardenaar et al. 2024) in a group athletes self-reporting GI complaints that will be randomized into an intervention group or a placebo group (randomized double-blind parallel study design covering a total of 3 weeks).
Healthy participants with self-reported GI complaints will consume the protein supplement that they normally use for recovery purposes after exercise during a 3-week baseline period, followed by a 3-week intervention period in which they maintain usage of their product, but replace a part of this product with a fermented dairy protein with prebiotic fiber. In addition, a group of healthy participants without self-reported GI complaints will serve as a reference group by consuming the protein supplement that they normally use for recovery purposes after exercise during a 3-week period.
The purpose of this study is to determine whether healthy older adults, aged 65 to 80 years, consuming a probiotic each day for three weeks will have improved immune strength and digestive health. It is hypothesized that older adults consuming the probiotics will see a shift in their microbiota towards the "healthy" bacteria resulting in a greater proportion of immune cells, decreased inflammation, and better digestive health.
Background: Many kinds of good or normal bacteria live on your skin and inside your stomach and intestines (gut). These bacteria are important to your health. What you eat, where you live, and what medicines you take can affect the bacteria in your gut. Bismuth subsalicylate (BSS) is an ingredient in common medicines for mild diarrhea and stomach pain. Products that contain BSS include Pepto-Bismol, Kao-Tin, and Pink Bismuth. But how BSS affects the bacteria in a person s gut is not fully understood. Objective: To see how BSS affects gut bacteria in healthy people. Eligibility: Healthy people aged 18 to 50 years. Design: Participants will have 6 clinic visits in up to 18 weeks. Only 1 visit must be at the NIH clinic; others may be either in-person or remote. BSS is a liquid taken by mouth. Participants will take a dose of BSS 4 times a day for 2 days. They will take the same amount of BSS as a person would take to treat diarrhea or related problems. Stool samples will be collected at each study visit. For remote visits, participants will be given a collection kit; they will collect the sample at home and send it in. Participants will take surveys at each visit. They will answer questions about their diet and health. Participants may also provide optional samples of blood, saliva, and urine. Participants may have up to 2 optional colonoscopies. A long tube will be inserted via the rectum to collect tissue samples from the intestine. Participants will be sedated or placed under anesthesia for the procedure.
Background: Alcohol use disorder (AUD) affects about 10 percent of people in the U.S. Studies show a relationship between the bacteria (microbiota) in the gut and the brain. Researchers think this may influence AUD. They want to learn more about changes in gut bacteria that may occur in people with AUD. Objectives: To study gut microbiota differences in current drinking versus abstinent people with AUD. Also to test if gut microbiota are related to alcohol cue-induced craving. Eligibility: People ages 21-70 who have AUD (both abstinent and current heavy drinkers) or are healthy, moderate drinkers Design: Participants will be screened in Protocol 14-AA-0181. Participants will have a first visit. They will have 4 more visits within about 10 days. Visits include: Fecal sample collection Physical exam Blood tests Assessment of diet and alcohol use X-rays to test body composition, They will sit under a ventilation hood to measure metabolism. They must fast 12 hours before this test. They will drink a solution. Their urine is collected over 5 hours. Ultrasound of the liver area. They must fast overnight before this test. At 2 visits, they will be in a bar-like setting. They will be exposed to stimuli associated with eating and drinking. They will rate their urge to drink alcohol and their food cravings. Participants will collect their stool throughout the study. They will also record information about their diet and daily activities like sleep and exercise. At the end of the study, participants will discuss their drinking. They will receive counseling if needed. ...
We will sample intestinal microbiota using a microbiome sampling capsule in Healthy, Irritable Bowel Syndrome (IBS), and Functional Gastrointestinal Disease.
The purpose of this study is to determine if supplementing healthy term infants delivered by C-section or vaginal delivery who only consume breastmilk with a probiotic for 21 consecutive days increases levels of bacteria in infants' stool.
This is a prospective, randomized, placebo controlled, double-blind study to assess the effects of a postbiotic blend on exercise induced oxidative stress markers and exercise performance in healthy adult.