Colorectal cancer (CRC) is a significant global health burden, ranking third in incidence and second in cancer mortality. Metagenomics analyses of fecal microbiomes have identified microbial biomarkers associated with chronic inflammation and gut dysbiosis, which are prognostically important to CRC. The interplay between intestinal microbiota and gastrointestinal epithelial inflammation is linked to colorectal carcinogenesis, progression, and metastasis. Recent research also suggests a role for gut microbes in early conventional adenoma development.

Bowel lavage, a standard practice for colonoscopies, alters gut microbiota composition for about 14 days, contributing to minor complications. Opportunistic and potentially pathogenic bacteria become more abundant during this period, impacting gut health. Diet intervention post-lavage may mitigate side effects by promoting microbial diversity restoration and reducing inflammation. Studies show that a Standard American Diet induces a pathobiont, while a high-fiber, low-saturated fat diet can reverse the inflammatory phenotype.

While a randomized controlled trial with probiotics post-colonoscopy showed a reduction in pain duration, dietary fiber and polyphenol-rich foods, such as a whole food, plant-based (WFPB) diet, may offer more comprehensive benefits. A proposed study aims to track gut microbiome changes pre- and post-lavage, with participants randomized to a WFPB diet intervention. The study will investigate how bowel lavage promotes microbial dysbiosis and assess the potential of dietary intervention to alter this process, focusing on microbial profiles and tumor markers.



  1. Track and profile gut microbes of colonoscopy patients pre- and post-bowel lavage.
  2. Randomize participants to receive a WFPB diet intervention.
  3. Evaluate the impact of bowel lavage on microbial dysbiosis development.
  4. Assess the potential of dietary intervention to alter the process.
  5. Investigate the relationship between microbial profiles and tumor markers.

The progress

Achieved Milestones



Study Launch

Study Launch
Pre-clinical Testing
Data Analysis
Wrap up
Current status

Gilbert Lab

Jack Gilbert

Principal Investigator

Joshua Tran