Juice Cleanses Are Wrecking Your Gut Health

Just three days of being on a juice cleanse can ravage your precious gut microbiome and damage your mouth bacteria. On the surface, it seems like drinking a bunch of liquefied fruits and vegetables would be the perfect way to replenish your gut with beneficial bacteria. It turns out, however, that it might be doing the opposite.

Researchers from Northwestern University found that the juices people drink during a juice cleanse tend to be stripped of their essential fiber. It makes sense considering that the fiber in fruits and vegetables comes in the fibrous parts of the produce, the parts usually filtered out during the juicing process. You’re getting the vitamins, you’re getting the minerals, but you’re not getting the roughage your gut needs to maintain bacterial balance.

And it all happens rather quickly, too. The study, which again, was rather small with only 14 participants, found that just three days’ worth of juice cleansing was found to cause a significant shift in the mouth and gut microbiome of its participants.

After testing three different diets, a whole plant diet, a juicing-only diet, and a combination of juicing and whole foods, the researchers found that participants who had only been on a juice cleanse diet saw a big reduction in beneficial Firmicutes bacteria in the mouth and an increase in Proteobacteria, an evil bacterial linked to inflammation.

In the gut, the researchers found an increase in bacteria commonly associated with gut permeability, inflammation, and cognitive decline. The folks who ate whole plants as a part of their diets did not experience such dramatic negative shifts in their mouth and gut microbiome.

Researchers think that the absence of fiber isn’t the only culprit. Juices are naturally packed with sugar, which can wreak havoc on the body’s beneficial bacteria.

The researchers conclude that the best way to go about a juice cleanse isn’t to fully commit to a diet of 100 percent juice, even if only for a limited time. Mixing in some whole fruits and vegetables is vital to maintaining the delicate balance of your internal flora, which supports everything form your cognitive ability to your athletic ability.