Dietary Intervention, Gut Microbiota
Conditions
Keywords
Dry Beans, Gut Microbiota, Nutritional Microbiology
Brief summary
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.
Detailed description
Bean consumption delivers diverse dietary fibers (resistant starches, non-starch polysaccharides), proteins, polyphenols, and other compounds to the colon, where they serve as substrates for the microbial community (microbiota) that colonizes the gut of humans. However, dry beans exhibit high genetic diversity, corresponding with diverse pigments and nutrients across market classes. It remains poorly understood whether targeted effects on the gut microbiota and health measures are possible with distinct dry bean market classes. The overarching study objective is to perform a randomized, crossover pilot intervention trial in adults to determine the effects of consuming distinct dry bean market classes in isolation or combination on the gut microbiota and health. The study will compare the dose-dependent effects of pink beans, great northern beans, and a five-bean mixture (pinto, kidney, black, pink, and great northern beans) on the gut microbiota, health-relevant metabolites, blood pressure, and immunometabolic markers in adults with and without extra body weight. The pilot study will employ a 3-phase, cross-over design with 2-week intervention periods separated by 2-week washout periods.
Interventions
OTHERPink Beans
Pink beans consumed for 2 weeks, at an amount of ½ cup/day for week 1 and 1 ½ cups/day for week 2.
OTHERGreat Northern Beans
Great northern beans consumed for 2 weeks, at an amount of ½ cup/day for week 1 and 1 ½ cups/day for week 2.
OTHERFive-Bean Mixture
Five-bean mixture made of pinto, kidney, black, pink, and great northern beans consumed for 2 weeks, at an amount of ½ cup/day for week 1 and 1 ½ cups/day for week 2.
Sponsors
University of Nebraska Lincoln
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
OTHER
Masking
NONE
Intervention model description
The study intervention will consist of individuals consuming daily, precooked and prepackaged dry beans over three 2-week intervention periods. The amount of beans to consume will be ½ cups/day during week 1 and 1 ½ cups/day during week 2. The three bean interventions will be i) pink beans, ii) great northern beans, and iii) a five-bean mixture (pinto, kidney, black, pink, and great northern beans). The participants will be asked to consume all bean interventions in random order. The beans will be added to the participants' usual diet.
Eligibility
Sex/Gender
ALL
Age
19 Years to 50 Years
Healthy volunteers
Yes
Inclusion criteria
1. Aged 19 to 50 years. 2. Not currently pregnant or planning to become pregnant (Females Only). 3. Stable body mass index (BMI) of either 18.5-24.9 kg/m2 or 27.0-39.9 kg/m2 for the last month. 4. Has not made any major dietary changes in the last month. 5. Able to read and speak English 6. Requires no legally authorized representative (LAR). 7. Not institutionalized (e.g., prison, psychological treatment center, etc.). 8. Able to wear ambulatory blood pressure monitor and limit physical activity over a 24-hr. period. 9. Have a bowel movement at least every other day. 10. Able to collect and deliver stool samples to Innovation Campus within 4 hours of collection. 11. No known allergies or intolerance to beans. 12. Able to avoid consuming beans during the study, except for the provided beans (up to 1.5 cups/day).
Exclusion criteria
1. Has a cardiac device. 2. History of organ transplant 3. History of gastrointestinal surgery or disease diagnosed by a physician that involves the stomach, small, and large intestines (e.g., IBD, IBS, chronic constipation, diverticulosis, gastric bypass). 4. Recent history of cancer (excluding skin cancer) in the last year. 5. Current use of tobacco or vaping. 6. Current or recent use (last 3 weeks) of digestive enzymes, laxatives, dietary fiber, prebiotic, or probiotic supplements. 7. Medication or supplement regimen or dosage changed within the last 2 months or 3 weeks, respectively. 8. Taken antibiotics in the last 2 months. 9. Known allergies or intolerances to beans. 10. BMI 18.5-24.9 kg/m2 (normoweight): Current use of oral or injectable medications for the treatment of most chronic conditions. 11. BMI 27.0-39.9 kg/m2 (overweight): Current use of oral or injectable medications for the treatment of diabetes, hypertension, cardiovascular, liver, kidney, gastrointestinal, or autoimmune.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| 16S rRNA gene amplicon sequencing of the fecal bacterial community | From baseline to end of weeks 1 and 2 of treatment. | Dose-dependent changes in bacterial composition, and precisely the relative abundance of Faecalibacterium, in fecal samples, as assessed by 16S rRNA gene amplicon sequencing. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Fecal short-chain fatty acids assessed by gas chromatography | From baseline to end of weeks 1 and 2 of treatment. | Dose-dependent changes in fecal concentrations of short-chain fatty acids as determined by gas chromatography. |
| Gastrointestinal symptoms assessed by the Gastrointestinal Symptom Rating Scale | From baseline to end of weeks 1 and 2 of treatment. | Dose-dependent changes in gastrointestinal symptoms as assessed by the Gastrointestinal Symptom Rating Scale, where the scale is between 0 and 6 and higher values indicate more severe gastrointestinal symptoms. |
| Bowel movement habits assessed by a Bowel Habits Questionnaire | From baseline to end of weeks 1 and 2 of treatment. | Dose-dependent changes in bowel movement (BM) habits as assessed using a Bowel Habits Questionnaire, which has been previously described by Deehan and colleagues. The questionnaire asks participants to record and describe their BMs over three-days to obtain information on BM frequency (number of BM/day), stool consistency (Bristol Stool Scale, 1 \[hard\] to 7 \[liquid\]), perceived stool hardness (1 \[soft\] to 4 \[very hard\]), straining during bowel movement, discomfort during bowel movement, sensation of incomplete evacuation (1 \[none\] to 4 \[severe\]). |
Countries
United States
Contacts
PRINCIPAL_INVESTIGATOREdward C Deehan, PhD, RD
University of Nebraska Lincoln
Outcome results
None listed