81 Clinical Trials for Various Conditions
The overall objective of this three-arm randomized controlled trial is to compare a dietary fiber-focused behavioral intervention to standard weight loss education for improving eating-related behavior and cognition, weight, and metabolic markers of chronic disease risk in a population of adults with obesity.
The goal of this clinical trial is to understand varying in responses to different dietary patterns in healthy people who are getting a health screening colonoscopy. The main questions it aims to answer are: * What is the variability in the change of the microbes in the gut of (1) a provided diet that is high in fiber vs (2) a diet of the participant's choice. * What is the magnitude of fasting changes in glucose and lipids following the short-term, high-fiber feeding period and identify candidate predictive factors (short-chain fatty acids, BMI, sex, starting glucose level) for these changes Participants will be in one of two groups: 1. High-fiber diet group: These participants will have a series of measurements that include: blood biochemistries, body composition measured via DEXA, anthropometrics, surveys and questionnaires, and collection of fecal samples. 2. Normal diet group: These participants will eat a diet that is of their choosing (ad libitum) and will have a series of measurements that include: fecal samples, and questionnaires/surveys including food records.
This clinical trial tests whether daily fiber supplementation will change the mucosal microbiome of the colon. The microbiome are microorganisms that live in the human gut. They serve a vital role in maintaining health. Certain microbial strains are associated with the growth of colon polyps, which eventually could go on to form colon cancer. Giving dietary fiber supplements may help prevent precancerous polyps from ever developing.
To learn if diet can enhance the microbes (such as bacteria and viruses) found in your gut and improve the body's immune response to the influenza (flu) vaccine.
This phase I trial studies how well fecal microbiota transplant and dietary fiber supplementation work in treating patients with gut graft versus host disease. Fecal microbiota transplant entails inoculating donor stool into a recipient's gastrointestinal tract. Changing the gut microbiome by fecal microbiota transplant and fiber supplementation may help treat gut graft versus host disease.
Strong evidence supports the association between high fiber (HiFi) diets (e.g. legumes, nuts, vegetables) and a reduced risk for chronic conditions such as cardiovascular disease (CVD), type 2 diabetes and some forms of cancer. However, the current U.S. average consumption of dietary fiber of 17g/day is significantly below the recommendation level of 25g/d for women and 38g/d for men. Furthermore, fiber fermentation to produce short chain fatty acid (SCFA) products and alterations in microbial composition and activity may be mechanisms linking a HiFi diet to improved health. Importantly, much of the data, including findings supporting a beneficial role of SCFA have been derived from animal studies. Human studies are now needed to advance the understanding of the translational significance of rodent studies and the potential benefit of fiber on microbial metabolites and cardiometabolic health, glucose regulation, appetite and satiety. The central hypothesis is that that the mechanisms by which dietary fiber provides metabolic benefit include direct physical effects in the upper gastrointestinal tract to slow nutrient absorption, and indirect effects to reduce food intake mediated by SCFA-induced secretion of intestinal hormones resulting in increased satiety. Design: Using fiber derived from peas, Aim 1 will test the effect of a HiFi diet on appetite, satiety, and cardiometabolic health and whether elevated SCFA concentration mediates improved satiety in 44 overweight/obese subjects randomly assigned to receive either a high fiber or a low fiber dietary intervention for four weeks in a parallel arm-repeated measures design. Aim 2 will quantitate the changes in microbial composition and colonic SCFA production rate during HiFi feeding and whether any changes are potential mediators of observed benefits on satiety and cardiometabolic risk factors in 26 subjects assigned to receive a high fiber intervention for 3 weeks in a repeated measures design. Relevance: These studies will significantly expand the understanding of mechanisms by which dietary fiber improves satiety and cardiometabolic health in humans.
A double-blind, randomized, placebo-controlled clinical trial examining the efficacy and safety of Fecal Microbiota Transplantation (FMT) and high fiber supplementation in patients with active mild to moderate Ulcerative Colitis (UC). All enrolled subjects will provide serological, stool and mucosal specimen at each clinic visit to help further define the alterations in microbial profiles and immune cell function in response to psyllium fiber after FMT treatment.
This randomized, crossover study will include four clinic visits: one screening (day -7) and three test visits (days 0, 2, 4). The objective of this study is to assess the effects of dietary fiber-containing bars, at two doses of fiber, compared to a control product, on postprandial glucose and insulin responses in healthy adult men and women.
The objective of this project is to conduct a randomized-order, double-blinded cross-over trial in 20 participants to test the effects of a dietary fiber formulation on gut microbiota composition and short chain fatty acid production, lipid profiles, glucose sensitivity, intestinal permeability, overall gut health, and markers of inflammation.
The purpose of this pilot study is to assess the feasibility of a 3-month dietary fiber intervention: 1) engaging adolescents in regularly consuming a dietary fiber preparation (psyllium powder) and obtaining their parents' support, 2) recruit into a clinical pilot trial with liquid meal challenge test to study the metabolic effects of the dietary fiber preparation. A study modification will be submitted to add additional study arms for feasibility (strength training, coaching).
This study will investigate the effects of different fermenting fibers on liking of foods.
There is a need to assess the LDL-C-lowering abilities of a dietary fiber ingredient, in order to confirm the product's efficacy. Thus, the objective of this study is to assess the effect of 3g dietary fiber on lowering serum LDL-C in otherwise healthy men and women.
Loss of kidney function results in accumulation in the blood of molecules that are either excreted or metabolized by the kidney. Collectively, these molecules are termed Uremic Retention Molecules (URMs) or toxins. It is increasingly recognized that colonic bacterial metabolites like p-cresyl sulfate and indoxyl sulfate that are absorbed from the colon and excreted by the kidney may contribute to the pool of compounds implied in uremic toxicity. Indeed, these URMs have been linked to increased levels of inflammation markers, chronic kidney disease (CKD) progression, cardiovascular disease and overall mortality in CKD and/ or hemodialysis patients. Therefore, interventions that target the production or absorption of URMs from the gut might decrease inflammation and oxidative stress that are commonly seen in the uremic milieu. The National Health and Nutrition Examination Survey III (NHANES III) data show that high dietary fiber intake is associated with decreased serum levels of C-reactive protein (CRP) in those with and without CKD and these associations are much stronger in the CKD population. A possible explanation of this effect is that a high fiber diet in CKD patients modulates the bacterial production, intestinal absorption and finally the serum levels of URMs like p-cresyl sulfate and indoxyl sulfate, which in turn results in decrease in inflammation. OBJECTIVES: Hypothesis: 1. Higher serum levels of markers of inflammation such as high sensitivity C-reactive protein (hsCRP), interleukin 6 (IL-6) and tumor necrosis factor (TNF) -α seen in stage 4 CKD (estimated Glomerular Filtration Rate 15-29 ml/min/1.73 m2) compared to stage 2 CKD (estimated Glomerular Filtration Rate 60-89 ml/min/1.73 m2) is partly explained by the higher circulating levels of URMs (p-cresyl sulfate and indoxyl sulfate) in stage 4 CKD, and 2. Dietary supplementation in stage 4 CKD with 30g/d of a soluble fiber Psyllium (brand name-Metamucil TM) will decrease circulating URMs levels and thereby, decrease serum levels of inflammation markers and urinary levels of transforming growth factor (TGF)-β, a marker of kidney fibrosis.
The primary aim of this study was to compare the effects of supplementation with one of three dietary fibers (gum arabic, carboxy-methylcellulose, or psyllium) or a placebo on fecal incontinence (FI), symptom intolerance, and quality of life in community-living individuals who have incontinence of loose or liquid feces. A secondary aim was to explore the possible mechanism(s) underlying the supplements' efficacy (i.e., improvements in stool consistency, water-holding capacity or gel formation).
This study will examine the effects of a dietary fiber on insulin sensitivity in overweight and obese women. The fiber will be added to snack foods and women will consume the foods for four weeks. In one four-week period, 15 g of fiber will be added, and 30 g will added in another period. In a third period, no fiber will be added to the snack foods. Insulin senstivity will be measured at the end of each treatment period.
The purpose of the study is to examine how a dietary fiber affects metabolism in healthy overweight and obese adults. The fiber will be added to foods that participants will consume for two, three-week periods. The fiber will be given in two doses -- 15 g per day during one period, and 30 g per day in the other. In another three-week period, they will consume the same foods, but with no fiber added. Major outcomes will include fermentability of the fiber, as assessed by measurement of breath hydrogen, as well as shifts in fecal bacteria. The caloric value of the fiber will be determined and metabolic measures related to blood glucose control and inflammation will also be taken.
The objective of this study is to provide evidence for its fermentability of a dietary fiber and to collect information regarding potential health opportunities for glucose control as well as tolerability when being consumed over 7 days.
The purpose of the study will be to assess the gastrointestinal effects of a dietary fiber in healthy, adult volunteers.
Dietary fiber is known to influence bowel function. The investigators hypothesize that the addition of a mixture of fibers to liquid diets will improve bowel function as measured by stool weight.
Studies have found a relationship between dietary fiber consumption and body weight regulation. This relationship may stem from enhanced satiety through fermentation of certain fibers in the large intestine. The objective of this study is to determine and compare satiety ratings, changes in food intake, and gastrointestinal effects for four fibers: fructooligosaccharide, inulin, soluble corn fiber, and resistant starch.
Dietary fibers have previously been shown to affect laxation and satiety. Due to differences in structure and physical properties of dietary fibers, these effects may not be consistent across all fibers. Therefore as new dietary fibers are created or discovered the laxative and satiating effects should be investigated in order to verify these effects.
The purpose of this study is to determine whether 6 months of fiber supplementation will improve ovulation in women with polycystic ovary syndrome (PCOS).
The study evaluates high fiber diet intake in patients with hyperlipidemia.
Monitoring dietary intake and digestion is important for both medical monitoring and assessing the wellness of individuals. Fiber is an important nutrient that is not focused on enough, despite it being an essential nutrient for the bacteria and other micro-organisms that reside in our GI Tracts, known as the microbiome. Ingestion of fermentable soluble and insoluble dietary fiber has been shown to result in the production of short-chain fatty acids (SCFA) by the colonic microbiome. These SCFAs are volatile organic compounds (VOCs) and can be detected in the atmosphere of a bowel movement. We have developed an e-Nose device that once placed in the bathroom records volatile organic compounds (VOCs) from the ambient air. We have demonstrated in an "N of 1" study a strong correlation between the eNose output and grams of daily fiber intake. The current study is being proposed to validate the e-Nose device on a larger population. This is a nonmedical device that is not regulated by the FDA. A total of 40 subjects are invited to participate in this 3-week study. Participants will be asked to complete questionnaires and provide stool and blood samples. The subjects will place the eNose device in their bathroom and record their daily food intake over a 3-week period.
This is a small-scale study of the effects on microbes in the human gut of adding high-fiber snack foods to usual diet. The snack foods are being provided by Mondelez International, Inc. Eight pairs of dizygotic twins, discordant or concordant for obesity, will participate in the study. They will complete 3 successive experiments in which their regular diet is supplemented by consumption, over a 6-week period, of high-fiber snack foods. Each experiment will involve (i) two weeks consuming regular diet (fecal sample collected weekly); (ii) one week consuming one snack food per day (approximately 7 g fiber, collection of all fecal samples), (iii) one week consuming two snack foods per day (approximately 14 g fiber, collection of all fecal samples), (iv) four weeks consuming three snack foods per day (approximately 20 g fiber, collection of all fecal samples); and (v) two weeks consuming only regular diet (weekly collection of fecal sample). For each experiment, participants will also provide a fasting blood sample during the free diet phase at the end of the week just before initiation of snack consumption, and a fasting blood sample at the end of the last week of snack consumption. Participants will also collect one first morning urine sample weekly throughout the study. During week 2, participants will also collect first morning urine samples for 3 consecutive days. Similarly, they will collect first morning urine samples for the last 3 consecutive days of the last week of snack consumption. The study will test the effects of the different fiber-rich snacks on the composition and metabolic properties of the gut microbial community in lean and obese subjects.
The purpose of this research was to investigate 5 different formulations of whole grain barley and refined white rice against a control of white bread on post-prandial glycemic response, as well as self-reported hunger/satiety in a randomized cross-over trial.
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.
The purpose of this study is to see how adding avocado to a breakfast meal affects blood sugar control and signals of hunger and fullness after eating. The investigators will test the effects of 3 breakfast meals on blood sugar control and signals of hunger and fullness after eating: 1. Whole-wheat bread and strawberry jam 2. Whole-wheat bread, strawberry jam, and avocado 3. Whole-wheat bread and strawberry jam (meal enriched with fat and fiber to mimic that of an avocado) Participants will undergo 3 test periods, each separated by a week. Each test period consists of one day with set meals that the investigators will provide (breakfast, lunch, and dinner), and then the next morning, participants will eat a breakfast meal and have blood drawn several times over 4 hours.
The carbohydrate inulin (from chicory root) is a healthy prebiotic ingredient found in dietary supplements and fortified foods (Nagy et al). Inulin is representative of a broader class of typically health-associated, yet fermentable carbohydrates called fructans that occur naturally in many vegetables, fruits, and wheat. Fructans, or long chains of fructose units, are resistant to human digestive enzyme hydrolysis and transit intact to the small intestine and colon where they undergo rapid fermentation by intestinal microbes. This microbial metabolism of fructans produces gas and other fermentation byproducts that can lead to excess gastrointestinal (GI) symptoms like abdominal bloating, cramping, stomach rumbling, and flatulence (Bonnema et al; Briet et al; Bruhwyler et al), especially in individuals with irritable bowel syndrome (Van den Houte et al). A new digestive enzyme called fructanase was developed to help with GI symptoms associated with fructan consumption. Positive findings from in vitro digestion simulations (Guice et al) and a first-in-human safety trial (Garvey et al) helped define the fructanase dose for this clinical trial-the primary objective of which is to investigate the effect of oral fructanase administration on GI symptoms in healthy adults after consuming oatmeal with added inulin (25 grams). Secondary outcomes include breath hydrogen and methane levels, which serve as biomarkers of intestinal microbial fermentation. The investigators hypothesize that fructanase administration will lower the severity of GI symptoms after inulin consumption, as well as lower breath biomarkers of intestinal microbial fermentation, compared to placebo.
The goal of this randomized, crossover, clinical trial is to link: 1) gastrointestinal motility patterns induced by acute consumption of whole and refined grains, 2) enteric microbial production of bioactive metabolites, and 3) circulating postprandial appearance of metabolites important to cardiometabolic health including glucose, triglycerides, and cholesterol. Participants will be asked to consume a Smartpill monitoring device that records metrics of gastrointestinal motility in response to whole or refined grains, monitor cardiometabolic metabolties over an 8 hour postprandial window, and provide a fecal sample for microbiome-related analyses.