The main objective is to evaluate the impact of intestinal preparation on the composition, diversity and metabolome of the intestinal microbiota.

Based on the limited literature that PEG does not significantly impact the microbiome, certain investigators ascertain that administration of PEG without any subsequent FMT would represents the gold-standard control group. On the other hand, other investigators raised their concern that perturbation of the microbiome with PEG without subsequent replacement with FMT might negatively impact immune checkpoint inhibitor efficacy. Therefore, there is an unmet need to conduct a study using the metagenomic shotgun sequencing to precisely understand the impact of bowel preparation on gut microbiome composition and on the dynamics of recovery of the gut microbiome after bowel preparation to better design microbiome-centered trials.

Inclusion Criteria:

• Healthy volunteer participant cohort:

  1. > 18 years of age
  2. The participant has provided documented informed consent for the participation and to complete PEG bowel preparation and return collected stool samples.

Exclusion Criteria:

• An ileus
• Significant gastric retention
• Suspected or established mechanical bowel obstruction
• Inflammatory or infectious gastrointestinal condition
• Neurologic or cognitive impairment that prevents safe swallowing
• Recent history (<1 year) of cancer that still requires ongoing treatment
• Recent use of antibiotics 1 month prior to participation in the trial
• History of cardiac disease
• History of active renal dysfunction
• Presence of any absolute contraindication to PEG bowel preparation according to manufacturer labeling