Scientists from the Catholic University of Leuven warned of the potential danger of uncontrolled intake of vitamins: they can promote the colonization of harmful bacteria in the intestines and prevent the multiplication of beneficial microbes. Review study published in the journal PLoS Pathogens.
Many vitamins cannot be synthesized by humans and therefore must be obtained from external sources. One such source may be microbes of the gastrointestinal tract. Recent research shows that up to 30% of the recommended daily intake of these vitamins is produced by the gut microbiota. However, the effectiveness of this process largely depends on the individual’s dietary habits and the composition of the microbiome. In a new review, scientists examined factors that could influence vitamin production by the microbiota.
Research has shown that gut bacteria can produce vitamin K and various B vitamins (niacin, riboflavin, and cobalamin). Recent studies also show that up to 65% of human gut microorganisms produce at least one type of B vitamin.
However, the production of vitamins by bacteria can be affected by vitamin supplements and dietary habits. For example, high-carb, low-fat diets have been associated with high urinary riboflavin levels. This may mean that gut bacteria increase vitamin production in response to such a diet.
Overall, the benefit of vitamin supplements remains questionable. For example, excessive consumption of fat-soluble vitamins (A, D, E, and K) can lead to their accumulation in the body and adverse health effects. Additionally, some research suggests that the high doses often used in oral vitamin supplements may inhibit microbial-human interactions. For example, previous studies in mice have shown that vitamin B12 supplementation promotes colonization with harmful bacteria in the intestines of animals. Citrobacter rodentiuminhibiting bacterial activity Lachnospiraceae.