Fecal calprotectin concentrations are higher in exclusively breastfed infants compared to those who are mixed-fed.

BACKGROUND Previous studies have shown that giving other foods while breastfeeding increases the risk of mother-to-child transmission of human immunodeficiency virus (HIV) type 1. The mechanism is speculated to be increased inflammation of the gastrointestinal tract. METHODS In a prospective longitudinal study, we compared fecal calprotectin, a marker of intestinal inflammatory disease, in healthy U.S. infants 0-6 months of age who were exclusively breastfed compared to those given additional liquids or solids. RESULTS In comparison to infants who were mixed-fed, fecal calprotectin was significantly higher in the exclusively breastfed group (p = 0.01) by a mean of 60 mg/kg (SE = 23). CONCLUSIONS Introducing complementary food does not increase intestinal inflammation according to this marker. Studies to assess fecal calprotectin levels in breastfeeding and mixed-fed infants born to HIV-infected mothers living in resource-constrained settings, and to evaluate potential protective effects of calprotectin in early infancy, are recommended in the continuing effort to elucidate the mechanisms responsible for increased risk of HIV transmission through mixed-feeding.