Early exposure to food contaminants reshapes maturation of the human brain-gut-microbiota axis

Abstract

Early childhood growth and development is conditioned by the consecutive events belonging to perinatal programming. This critical window of life will be very sensitive to any event altering programming of the main body functions. Programming of gut function, which is starting right after conception, relates to a very well-established series of cellular and molecular events associating all types of cells present in this organ, including neurons, endocrine and immune cells. At birth, this machinery continues to settle with the establishment of extra connection between enteric and other systemic systems and is partially under the control of gut microbiota activity, itself being under the densification and the diversification of microorganisms’ population. As thus, any environmental factor interfering on this pre-established program may have a strong incidence on body functions. For all these reasons, pregnant women, fetuses and infants will be particularly susceptible to environmental factors and especially food contaminants. In this review, we will summarize the actual understanding of the consequences of repeated low-level exposure to major food contaminants on gut homeostasis settlement and on brain/gut axis communication considering the pivotal role played by the gut microbiota during the fetal and postnatal stages and the presumed consequences of these food toxicants on the individuals especially in relation with the risks of developing later in life non-communicable chronic diseases.

Keywords: Perinatal repeated low-level exposure; Gut homeostasis; Brain gut microbiota axis; Food contaminants; Non-communicable chronic diseases; Epigenetics

Core tip: Increase of non-communicable chronic disease in the world is now clearly associated to environmental factors exposure during life and more especially during fetal and postnatal life. This review outlines the actual understanding of the consequences, on pregnant women, babies and infants, of repeated exposure to low level food contaminants on the settlement and maturation of the gut with specific focus on gut homeostasis, brain gut axis exchanges and the pivotal role played by the microbiota. However, their exact mechanisms of action on health, and particularly the molecular ones including epigenetic regulations still need to be clarified.