Overweight and Obesity
Conditions
Keywords
Avocado, Gastrointestinal microbiome, Bile acid profile, Inflammation, Thinking, Glycemia
Brief summary
The goal of this clinical trial is to learn about the effects of avocado consumption on gastrointestinal health in adults with overweight and obesity. The main questions is aims to answer are: How does avocado consumption affect the gut microbiome? How does avocado consumption affect thinking? Are there connections between the microbiome and cognition? Participants will be asked to eat provided meals with and without avocados for three 4-week periods. At the end of each 4-week period, participants will be asked to provide stool samples and complete computer games that assess thinking and memory.
Interventions
OTHERAvocado
The intervention treatment will contain avocado
OTHEROil + Fiber
The active comparator will contain a snack with oils and fibers that mimic an avocado
The sham comparator will contain foods/beverages that mimic a standard American Diet
Sponsors
University of Illinois at Urbana-Champaign
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
SINGLE (Investigator)
Eligibility
Sex/Gender
ALL
Age
25 Years to 74 Years
Healthy volunteers
Yes
Inclusion criteria
* Participants must be between the ages of 25 and 74 years old * BMI ≥ 25 kg/m2 * Ability to drop off fecal sample within 15 minutes of defecation * 20/20 or corrected vision
Exclusion criteria
* Avocado allergy or intolerance * Food allergies or intolerances * Prior diagnosis of liver or gastrointestinal disease (primary biliary cirrhosis or gallbladder disease, chronic constipation, diarrhea, Crohn's disease, celiac disease, ulcerative colitis, irritable bowel syndrome, diverticulosis, stomach or duodenal ulcers), diabetes, hepatitis, HIV, or cancer * Women that are pregnant, have given birth in the previous 12 months or are lactating * Individuals that smoke, use tobacco, abuse drugs, or consume \> 2 alcoholic beverages per day. * \> 5% weight change in the past month or \> 10% change in the past six months * Oral antibiotics during the previous 6 weeks. * Currently taking lipid-lowering medications, oral hypoglycemic agents, or insulin. * History of malabsorptive or restrictive bariatric surgeries (e.g., gastric bypass, sleeve gastrectomy, adjustable gastric band) or gall bladder removal surgery. * Are unable to consume the experimental meals/snacks. * Allergic to latex * Concurrent enrollment in another dietary, exercise, or medication study
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Fecal microbial species | 4 weeks | Feacalibacterium spp., bacteria capable of producing SCFA and secondary bile acid synthesis measured using metagenomic sequencing |
| Concentration of fecal SCFA | 4 weeks | Fecal SCFA concentrations using GC-MS in avocado and active comparator vs. control, |
| Concentration of fecal bile acids | 4 weeks | Fecal bile acid concentrations using HPLC in avocado and active comparator vs. control, |
| Fecal microbial genes | 4 weeks | Microbial genes involved in short-chain fatty acids and secondary bile acid synthesis measured using metagenomic sequencing |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Subjective gastrointestinal tolerance via questionnaire | 4 week | Ratings of gastrointestinal symptoms (ease of stool passage, frequency of stools, abdominal pain, bloating, burping, flatulence, nausea, reflux, rumblings assessed using questionnaires |
| Cognitive function | 4 weeks | Neuropshycological function as measured by a clinical cognitive task battery. |
| Digestive health using stool records/Bristol Stool Scale | 4 week | Ratings of stool consistency using Bristol Stool Scale |
Other
| Measure | Time frame | Description |
|---|---|---|
| Inflammation | 4 weeks | LPS-binding protein, a marker of inflammation will be measured using ELISA. (Blood samples) |
| Fecal pH | 4 weeks | Fecal pH will be measured using a pH meter |
| Fecal metabolites | 4 weeks | Proteolytic metabolites will be measures in fecal samples using GC-MS |
| Intestinal permeability | up to 4 weeks | Intestinal permeability will be measured using a orally ingested sugar substitutes. 24-hour urinary appearance of the sugars will be quantified using GC-MS. |
| Fecal microbiome | 4 weeks | Relative abundance of microbial genes, genera, and community structure measured using metagenomic sequencing of extracted fecal DNA to compare abundances between avocado, active comparator, and control. |
Countries
United States
Contacts
Primary ContactHannah D Holscher, PhD, RD
Backup ContactMaggie Oleksiak, MS
Outcome results
None listed