Nutrients: Low-gluten diets disrupt gut health by depleting key bacteria

The study, published in the journal Nutrients, found that long-term reduction of gluten in the diet - as a “healthy choice” option - can actually disrupt the balance of gut microflora, reduce the population of beneficial bacteria and increase ethanol levels linked to inflammation and metabolic risks.

In the study, researchers enrolled 40 healthy adults in France who typically consumed about 160 g of bread and pasta per day (~14-15 g of gluten).

The participants switched to a low-gluten diet for two periods of 8 weeks. Fecal analysis was performed before starting, after 8 weeks, and after 16 weeks of diet.

Main Results: 

Decrease in α-diversification of microflora - especially after 16 weeks, indicating a decrease in diversity of beneficial bacteria.

Changes in β-diversification: microbial communities after the low-gluten diet were significantly different from baseline.

The metabolic activity of the gut also changed: the ability to break down carbohydrates was reduced, and the metabolism of several micronutrients (glutamate, zinc, iron, etc.) was altered.

Participants who switched to a diet higher in rice and corn showed these changes more clearly.

Continuous gluten reduction can lead to dysbiosis, progressive deterioration of microflora and accumulation of metabolites that can provoke inflammation and increase metabolic risks, the researchers concluded

The authors emphasize the need for further long-term studies to understand the impact of such diets on immunity, metabolism and general health.