Persea Americana for Total Health (PATH)-2 (PATH-2)

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.

Study Overview

• Status: Recruiting
• Conditions: Overweight and Obesity
• Intervention / Treatment: Other: Avocado; Other: Oil + Fiber; Other: Average American Diet

• Study Type: Interventional
• Enrollment (Estimated): 45
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Hannah D Holscher, PhD, RD; Phone Number: 217-300-2512; Email: hholsche@illinois.edu
• Study Contact Backup: Name: Maggie Oleksiak, MS; Email: maggieo4@illinois.edu

Study Locations

• United States
  • Illinois
    • Urbana, Illinois, United States, 61801
      • Recruiting
      • University of Illinois, Urbana Champaign
      • Contact: Maggie Oleksiak, MS; Email: maggieo4@illinois.edu
      • Contact: Hannah Holscher, PhD, RD; Email: hholsche@illinois.edu

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Single

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Avocado; The experimental treatment will contain an avocado. Avocados will be consumed daily for 4 weeks.	Other: Avocado; The intervention treatment will contain avocado
Active Comparator: Fiber + Oil; The active comparator will have a snack that mimics the fiber and fatty acid composition found in avocados and will be consumed daily for 4 weeks.	Other: Oil + Fiber; The active comparator will contain a snack with oils and fibers that mimic an avocado
Sham Comparator: Standard American Diet; The sham comparator contains foods and beverages of a standard American diet and will be consumed daily for 4 weeks.	Other: Average American Diet; The sham comparator will contain foods/beverages that mimic a standard American Diet

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Concentration of fecal bile acids	Fecal bile acid concentrations using HPLC in avocado and active comparator vs. control,	4 weeks
Concentration of fecal SCFA	Fecal SCFA concentrations using GC-MS in avocado and active comparator vs. control,	4 weeks
Fecal microbial species	Feacalibacterium spp., bacteria capable of producing SCFA and secondary bile acid synthesis measured using metagenomic sequencing	4 weeks
Fecal microbial genes	Microbial genes involved in short-chain fatty acids and secondary bile acid synthesis measured using metagenomic sequencing	4 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Cognitive function	Neuropshycological function as measured by a clinical cognitive task battery.	4 weeks
Subjective gastrointestinal tolerance via questionnaire	Ratings of gastrointestinal symptoms (ease of stool passage, frequency of stools, abdominal pain, bloating, burping, flatulence, nausea, reflux, rumblings assessed using questionnaires	4 week
Digestive health using stool records/Bristol Stool Scale	Ratings of stool consistency using Bristol Stool Scale	4 week

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Inflammation	LPS-binding protein, a marker of inflammation will be measured using ELISA. (Blood samples)	4 weeks
Intestinal permeability	Intestinal permeability will be measured using a orally ingested sugar substitutes. 24-hour urinary appearance of the sugars will be quantified using GC-MS.	up to 4 weeks
Fecal metabolites	Proteolytic metabolites will be measures in fecal samples using GC-MS	4 weeks
Fecal microbiome	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.	4 weeks
Fecal pH	Fecal pH will be measured using a pH meter	4 weeks

Collaborators and Investigators

• Sponsor: University of Illinois at Urbana-Champaign
• Investigators: Principal Investigator: Hannah Holscher, PhD, RD, University of Illinois Urbana Champaign

Study record dates

Study Major Dates

• Study Start (Actual): July 11, 2023
• Primary Completion (Estimated): July 1, 2024
• Study Completion (Estimated): July 1, 2024

Study Registration Dates

• First Submitted: June 27, 2023
• First Submitted That Met QC Criteria: July 11, 2023
• First Posted (Actual): July 12, 2023

Study Record Updates

• Last Update Posted (Actual): October 13, 2023
• Last Update Submitted That Met QC Criteria: October 11, 2023
• Last Verified: October 1, 2023

More Information

Terms related to this study

• Keywords: Inflammation; Glycemia; Thinking; Gastrointestinal microbiome; Avocado; Bile acid profile
• Additional Relevant MeSH Terms: Overnutrition; Nutrition Disorders; Body Weight; Overweight
• Other Study ID Numbers: 22788

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No