Effects of Almond Consumption on the Human Gastrointestinal Microbiota and Metabolic Health
- Conditions
- Overweight and Obesity
- Interventions
- Dietary Supplement: AlmondsDietary Supplement: Pretzels
- Registration Number
- NCT04223323
- Lead Sponsor
- University of Illinois at Urbana-Champaign
- Brief Summary
The proposed work will investigate the effect of almond consumption as a snack on human gastrointestinal microbiota and on metabolic health.
- Detailed Description
This study is a randomized, controlled, investigator-blinded, parallel arm design with two treatment conditions. There will be a phone screening, in person pre-intervention testing, a one-week baseline period devoid of all nuts and seeds followed by a 12-week intervention period, and a post-testing appointment. Participants will be randomized to consume almonds or isocaloric snack for 12 weeks. Participants will provide stool samples during baseline testing and during the 12th week of the intervention.
Recruitment & Eligibility
- Status
- COMPLETED
- Sex
- All
- Target Recruitment
- 40
- Males & Females
- 30-60 years of age
- BMI 25-34.9 kg/m^2
- Ability to drop off fecal sample within 15 minutes of defecation
- Physician diagnosed metabolic or gastrointestinal diseases
- Fasting blood glucose >126 mg/dL
- Blood pressure >160/100 mm Hg
- Anemia
- Elevation in serum transaminases (i.e. >3 times the upper limit of normal)
- Evidence of liver disease, including primary biliary cirrhosis or gallbladder disease, constipation
- Currently taking lipid-lowering medications, oral hypoglycemic agents, or insulin, or medications known to impact bowel function.
- Pregnant, breastfeeding or postmenopausal
- Smoker, tobacco use
- Allergic to nuts
- Consume > 2 alcoholic beverages/day
- Abuse drugs
- Have had > 5% weight change in the past month or > 10% change in the past year
- Have taken antibiotics during the previous 2 months
- Unable to consume the experimental treatments (almonds or pretzels)
- Bariatric surgery
- Gallbladder removal
- Allergic to lidocaine or other topical anesthetics
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- PARALLEL
- Arm && Interventions
Group Intervention Description Intervention Almonds The intervention arm consists of daily consumption of the investigator's intervention snack over the course of 12 weeks. Isocaloric Control Pretzels The control arm consists of daily consumption of an isocaloric snack over the course of 12 weeks.
- Primary Outcome Measures
Name Time Method Changes in gastrointestinal microbial-derived metabolite concentrations Baseline & 12-week mark Determine the impact of daily consumption of almonds on the concentration of microbial-derived metabolites compared to control (pretzels) by using gas-liquid chromatography. These metabolites include butyrate and secondary bile acids.
Changes in abundance of fecal Roseburia spp Baseline & 12-week mark Determine the impact of daily consumption of almonds on the abundance of Roseburia spp. compared to control (pretzels) by using quantitative real-time PCR.
Changes in abundance of fecal Butyryl CoA: Acetate CoA transferase Baseline & 12-week mark Determine the impact of daily consumption of almonds on the abundance of Butyryl CoA: Acetate CoA transferase gene compared to control (pretzels) by using quantitative real-time PCR.
Changes in gastrointestinal microbiota composition Baseline & 12-week mark Determine the impact of daily consumption of almonds on the gastrointestinal microbiota compared to control (pretzels) by sequencing the V4 region of the 16S rRNA gene in fecal samples.
- Secondary Outcome Measures
Name Time Method Changes in glycemic control. Baseline & 12-week mark Determine the impact on oral glucose tolerance within intervention (almond) and control (pretzel) groups by using a mixed meal tolerance test.
Changes in secondary measures of gastrointestinal health. Baseline & 12-week mark Determine the impact of daily consumption of almonds on gastrointestinal health compared to control (pretzels) by measuring fecal pH; other microbial fermentation end products and microbial-derived bile acids using gas-liquid chromatography; and alpha- and beta- diversity measures of the gut microbiota community structure using 16S microbiota analyses.
Changes in liver fat Baseline & 12-week mark Determine the impact of daily consumption of almonds on liver fat percentages compared to control (pretzels) by quantitative liver ultrasound.
Trial Locations
- Locations (1)
University of Illinois at Urbana-Champaign
🇺🇸Urbana, Illinois, United States