Helicobacter pylori, the etiologic agent of chronic-active gastritis and duodenal ulcers in humans, and Helicobacter mustelae, a gastric pathogen in ferrets, bind to phosphatidylethanolamine (PE), a constituent of host gastric mucosal cells, and to gangliotetraosylceramide (Gg4) and gangliotriaosylceramide (Gg3). The effect of a bovine colostrum concentrate (BCC) on the interaction of H. pylori and H. mustelae to their lipid receptors was examined. BCC blocked attachment of both species to Gg4, Gg3, and PE. Partial inhibition of binding was observed with native bovine and human colostra. BCC lacked detectable antibodies (by immunoblotting) to H. pylori surface proteins (adhesins). However, colostral lipid extracts contained PE and lyso-PE that bound H. pylori in vitro. These results indicate that colostrum can block the binding of Helicobacter species to select lipids and that binding inhibition is conferred, in part, by colostral PE or PE derivatives. Colostral lipids may modulate the interaction of H. pylori and other adhesin-expressing pathogens with their target tissues.