Bacteria from the gut influence the host micronutrient status

Abstract

Micronutrient malnutrition remains a serious public health problem in most low-and middle income countries, with severe consequences for child physical and psychomotor development. Traditional methods of treatment and prevention, such as supplementation and fortification, have not always proven to be effective and may have undesirable side-effects, including increased growth and virulence of pathogenic gut bacteria, resulting in diarrhea and gut inflammation. Commensal bacteria in the gut have demonstrated the ability to increase the bioavailability of certain micronutrients, notably by removing anti-nutritional compounds, such as phytates and polyphenols, or by the synthesis of vitamins or their derivatives. The intestinal microbiota is also, in symbiosis with the gastrointestinal mucosa, the first line of protection of the internal environment against the external environment. It thus contributes to the reinforcement of the integrity of the intestinal epithelium and to a better absorption of micronutrients. They represent a save alternative to prevent micronutrients deficiencies. However, the metabolic characterization of the intestinal microbiota is not yet complete and its role in micronutrient malnutrition is still poorly understood. The bacterial metabolism is also dependent of micronutrients acquired from the gut environment and resident bacteria may compete or collaborate to maintain micronutrient homeostasis. Gut microbiota composition can therefore be modulated by micronutrient availability. This review brings together current knowledge on this two-Page 2 sur 36 way relationship between micronutrients and gut microbiota bacteria, with a focus on iron, zinc, vitamin A and folate (vitamin B9), which are respectively minerals and vitamins of interest in a global context. key wordsbacteriagut microbiotahumanmicronutrientsdeficiency -prevention 1.

Emergent Functional Organization of Gut Microbiomes in Health and Diseases

“…Non-heme iron in many food matrices is bound to inhibitors like polyphenols, fibers or phytates. Bacterial enzymes can break down these inhibitors, improving iron absorption [42]. The over-representation of P functions may thus reflect the adaptive response of the microbiota to address the unbalance due to loss in functions correlated with cell cycle control and increased demand for iron, possibly due to chronic inflammation or blood loss in the gastrointestinal tract.…”