Bacterial colonies that differed markedly in morphology, seen among H. pylori cultured from biopsies from two patients with normal endoscopic gastroduodenal tract appearance (14 and 72 years of age), were used to test for H. pylori DNA level heterogeneity in individual hosts, perhaps equivalent to that seen previously in a European with a mixed cagA+ and cagA- infection [31]. This evidence concerns the gene S100A8 and infection.