Tabatha: I have spent years rebuilding my gut after reading your book, The Microbiome Solution. After 4 years of amazing health, I’m afraid of the damage that my next colonoscopy might do to my rebuilt gut microbiome. Should I be concerned and how can I still do my scheduled colonoscopies with the least amount of damage to my gut? Are there other options than a colonoscopy?
Dr. Chutkan: Tabatha, many of my patients, like you, have spent years working on rehabbing their gut microbiome, so your question is a really valid one. Preparing for a colonoscopy requires fasting and cleansing the colon using strong laxatives 24 hours before the procedure. This process can remove many of the microbes that live inside your gut. Let’s take a look at the science: a 2013 study assessed the effect of traditional colonoscopy prep on the gut microbiota in 10 men and 10 women, and took samples one month and one week before prep administration, as well as one week, one month, three and six months after. Results showed that the variations between samples in the colonoscopy prep group were comparable to the variations in the group that did not receive the prep. Researchers concluded that colonoscopy bowel preparation does not have a lasting impact on the gut microbiota. Studies since then have found that the gut microbiota is significantly altered and diminished in both its richness and diversity following colonoscopy bowel prep, yet it seems to bounce back to is prior state within 2 to 4 weeks. Based on the latest research, it can be concluded that while a colonoscopy bowel prep does affect the gut microbiome in adults, the effects are short lived.
As a reminder, the age recommendation for colonoscopy screening, previously 50, changed in 2018 to age 45 after researchers analyzed data and found that new CRC cases are increasing in younger adult populations.