Table 1:

Study Enrollment Criteria

Inclusion Criteria	Method of Assessment
Male or Female between the ages of 18-65 years, inclusive	Photo Identification
In evaluation for Roux-en-Y Gastric Bypass or Sleeve Gastrecomy as primary procedure	Surgery Department
Planning to be available for two years of follow-up after surgery	Self-report
Exclusion Criteria	Method of Assessment
Alcohol or substance use disorder in the past year	Structured Interview
Severe psychiatric disorder that may affect the ability of the participant’s ability to comply with the protocol	Structured interview
Tobacco use in the prior year	Self-report
Current medication known to significantly influence gastrointestinal transit time (e.g., opioids, glp-1 agonists, metoclopramide) or is being taken routinely for weight loss (e.g., phentermine, topiramate)	Medical History
Use of any oral or injectable antibiotic in the past month	Medical History
Use of commercially available prebiotic or probiotic in the past month	Medical History
History of significant intestinal disease or disorder that would influence the microbiome (e.g., Crohn’s Disease, etc.)	Medical History
History of significant gastrointestinal surgery that would influence the microbiome, not including cholecystectomy or appendectomy	Medical History
Inability to engage in physical activity or dietary monitoring or any medical condition that would put the participant at risk in the study	Self-report
Positive urine drug screen for a non-prescribed medication	Urine drug screen
Pregnancy or breast feeding	Self-report