Juice-only diets have been touted to clean the bowel and improve health. However, limiting your food intake for a few days or longer to fruit juices for this purpose can remove most of the insoluble fiber in the gut.
Insoluble fiber in whole fruits and vegetables have health benefits. This led researches to study the microbiome in the mouth and the gut in research subjects on a juice-only diet.
The microbiota plays a role in metabolism, the immune system, and brain health. The research mentioned above was done by Sardaro and colleagues and published in Nutrients 2025; 17(3).
The research compared 3 different diets, one of which was a juice-only diet. At the end of 3 days, the gut microbiome “… showed an increase in taxa (types of microorganisms) associated with gut permeability, inflammation, and cognitive decline.”
My suggestion is to include whole vegetables along with juice in your diet. If you are not a vegetarian, including limited amounts of meat is not unreasonable. All things in moderation is good advice.
Peter M. Hartmann, MD
Family Medicine & Psychiatry
