[Intestinal permeability in the first year of life. The effect of diarrhea].

OBJECTIVE

The permeability of the intestinal mucosa to lactulose and mannitol was explored longitudinally in infants at 1, 3-4 and 11-12 months of age. This was also evaluated during the episodes of diarrhea that they suffered during follow-up.

PATIENTS AND METHODS

Sugar excretion was measured by gas chromatography in five-hour urine samples.

RESULTS

A decrease in lactulose excretion was observed, which became significant at 11-12 months of age (p = 0.02). No changes were detected in mannitol excretion, although this showed a tendency to decrease. The lactulose/mannitol (L/M) ratio remained unchanged. During the 15 episodes of diarrhea observed in these infants during the 12 month follow-up, a considerable increase in this ratio was seen, due mainly to increased lactulose excretion.

CONCLUSIONS

It is hypothesized that the decrease in lactulose excretion between one and 11-12 months of age is part of the maturational process of the intestinal barrier, while diarrhea results in increased permeability due to damage to the absorptive epithelium.