The functional effects of nutrients on enterocyte proliferation and intestinal ion transport in early infancy.

Nutrition has a key role in the modulation of the developing intestine in early infancy, and nutrients are able to modulate several intestinal functions including nutrient absorption, ion transport, cell growth and differentiation, motility and immunomodulation. Such modulation is exerted in part through a direct interaction between a single nutrient and the enterocyte. Two functions--ion transport and cell growth--are closely connected and appear to be modulated by nutrients. This is supported by the finding that a single nutrient (e.g. zinc) stimulates ion absorption and also promotes enterocyte growth. Interestingly, intracellular signalling for either effect is similar and involves mitogen-activated protein kinase. Other nutrients also modulate enterocyte function and there is evidence that their effect may depend on their side of action (apical or basolateral) and concentration. Knowledge of the interaction between nutrients and enterocytes may be exploited to obtain clinical effects using nutrition as a long-term treatment for intestinal and non-intestinal conditions.