Carbohydrate-dependent inhibition of Helicobacter pylori colonization using porcine milk

Breast milk has a well-known anti-microbial effect, which is in part due to the many different carbohydrate structures expressed. This renders it a position as a potential therapeutic for treatment of infection by different pathogens, thus avoiding the drawbacks of many antibiotics. In a previous study, we showed that pigs express the Helicobacter pylori receptors, sialyl Lewis x ( Le(x)) and Le(b), on various milk proteins. Here, we investigate the pig breed- and individual-specific expression of these epitopes, as well as the inhibitory capacity of porcine milk on H. pylori binding and colonization. Milk proteins from three different pig breeds were analysed by western blotting using antibodies with known carbohydrate specificity. An adhesion assay was used to investigate the capacity of pig milk to inhibit H. pylori binding to neoglycoproteins carrying Leb and sialyl-di-Le(x). alpha 1,3/4-fucosyltransferase transgenic FVB/N mice, known to express Leb and sialyl Lex in their gastric epithelium, were colonized by H. pylori and were subsequently treated with Le(b)- and sialyl Le(x)-expressing or nonexpressing porcine milk, or water ( control) only. The degree of H. pylori colonization in the different treatment groups was quantified. The expression of the Leb and sialyl Lex carbohydrate epitopes on pig milk proteins was breed- and individual specific and correlated to the ability of porcine milk to inhibit H. pylori adhesion in vitro and H. pylori colonization in vivo. Milk from certain pig breeds may have a therapeutic and/or prophylactic effect on H. pylori infection.