A recent study from Northwestern University in Chicago has revealed that detox diets based exclusively on fruit and vegetable juices can negatively impact gut microbiota in as little as three days. These diets, commonly known as "detox" plans, eliminate much of the essential fiber found in whole foods, disrupting the balance of beneficial bacteria in the intestines and potentially increasing inflammation.

How Juices Affect Gut Microbiota

The research, published in the journal Nutrients, analyzed three groups of healthy adults:

1. A group that consumed only juices.
2. A group that combined juices with whole foods.
3. A group that followed a diet based on whole plant-based foods.

The results showed that the group consuming only juices experienced a significant increase in bacteria associated with inflammation and intestinal permeability. In contrast, those who ate whole foods saw an increase in beneficial bacteria that promote the production of butyrate, an anti-inflammatory compound essential for colon health.

Researchers explained that the absence of fiber in juice-based diets can destabilize gut microbiota balance. This happens because fiber is the primary food source for beneficial gut bacteria. Without it, harmful microorganisms thrive, potentially leading to digestive issues and inflammation.

The Importance of Fiber in Diet

Dietary fiber not only supports digestion but also nourishes bacteria that produce short-chain fatty acids, which help reduce inflammation in the body. The removal of fiber during juice extraction promotes the growth of harmful bacteria that feed on sugar, commonly found in juices.

Additionally, juices can cause blood sugar spikes due to the lack of fiber, potentially affecting metabolism and the immune system. In contrast, a balanced diet rich in fiber helps stabilize blood sugar levels and promotes a healthy microbiota.

Recommendations for Maintaining Gut Health

Experts recommend prioritizing whole, fiber-rich foods such as fruits, vegetables, legumes, and whole grains. If juices are included in the diet, blended smoothies that retain the pulp and fiber are a better option. It is also advisable to pair juices with solid foods to balance nutritional intake.

This study highlights how quickly dietary choices can impact gut bacteria and reinforces the importance of a balanced, fiber-rich diet for overall well-being.