Overweight and Obesity
Conditions
Keywords
Almond, Gastrointestinal microbiota, Metabolic health, Bile acid profiles
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.
Interventions
Sponsors
Almond Board of California
University of Illinois at Urbana-Champaign
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
BASIC_SCIENCE
Masking
SINGLE (Investigator)
Eligibility
Sex/Gender
ALL
Age
30 Years to 60 Years
Healthy volunteers
Yes
Inclusion criteria
* 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
Exclusion criteria
* 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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| 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 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 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. |
| 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. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| 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. |
| 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. |
Other
| Measure | Time frame | Description |
|---|---|---|
| Changes in markers of systemic inflammation & metabolism | Baseline & 12-week mark | Determine the impact of daily consumption of almonds on inflammation and metabolism compared to control (pretzels) by measuring biomarker concentrations with ELISA. Specifically, we will look at TNF, CRP, & LPS-BP (inflammatory) and NEFAs (metabolism). |
| Changes in subjective measures of gastrointestinal health. | Baseline & 12-week mark | Determine the impact of daily consumption of almonds on subjective measures of gut health compared to control (pretzels) using stool records. The questionnaire addresses questions related to gastrointestinal health including bloating, flatulence, and stool consistency. |
| Changes in adiposity. | Baseline & 12-week mark | Determine the impact of daily consumption of almonds on adiposity compared to control (pretzels) using a DXA scan. |
Countries
United States
Outcome results
None listed