Dietary regulations of the intestinal barrier function at weaning

Weaning is a complex phase when the mammal suffers the action of different stressors that contribute to negatively affect the efficiency of the intestinal mucosa and of the whole local integrated system, that acts as barrier against any nocuous agent. The components of this barrier are mechanical, chemical, and bacteriological; immunological and not. The development of contact with a saprophyte microflora and the maintenance of feed intake after the interruption of motherly nutrition are essential for the maturation of an equilibrated local immune function and for a functional integrity of villi. Opportunities and limits of some dietary strategies that can contribute to reduce negative effects of weaning on health and performance are discussed. Knowledges on the possible mechanism of action of probiotics are upgraded, particularly for their supposed role in the balance between different immune functions (effectory/regulatory). Some tools to control pathogen microflora are reviewed (acids, herbs, immunoglobulin sources) and practical feeding systems are proposed.