The protective effect of breast feeding in relation to sudden infant deathsyndrome (SIDS). II. The effect of human milk and infant formula preparations on binding of Clostridium perfringens to epithelial cells

Breast feeding is known to protect an infant against gastrointestinal patho gens and epidemiological studies indicate that compared to breast fed infan ts, formula fed infants are at a greater risk of dying from sudden infant d eath syndrome (SIDS). Many SIDS infants have symptoms of gastrointestinal i nfections prior to death and one gastrointestinal pathogen associated with SIDS is Clostridium perfringens. Studies have found that a significantly hi gher number of formula fed SIDS infants have C. perfringens and its enterot oxin in their faeces compared to breast fed infants. The aim of the study w as to compare the effects of human milk and infant formula on binding of C. perfringens to epithelial cells. Two protocols were used to assess the effect of human milk and infant formu la to inhibit binding of C. perfringens to epithelial cells. Binding was as sessed by flow cytometry. For the in vivo protocol which more closely repre sents interactions on the mucosal surface, breast milk enhanced bacterial b inding but infant formula caused inhibition of binding; however for the in vitro method, both human milk and infant formula resulted in consistent enh ancement of binding. Flow cytometry studies indicated that enhancement of b inding was due to the formation of bacterial aggregates. Lewis(a) and Lewis (b) antigens, found in both breast milk and infant formula, inhibited C. pe rfringens binding in a dose dependent manner. The Lewis(a) and Lewis(b) antigens in human milk and infant formula can inh ibit C. perfringens binding to epithelial cells. While infant formula reduc ed binding of C. perfringens to epithelial cells in the experiments carried out with the in vivo protocol, the protective effects of breast feeding in relation to colonisation with C. perfringens are more likely to be due to formation of bacterial aggregates. These findings have implications for imp roving infant formula preparations. (C) 1999 Federation of European Microbi ological Societies. Published by Elsevier Science B.V. All rights reserved.