When analysing the association between each gene of cagA, vacA and babA2 and gastroduodenal diseases by multivariable logistic regression adjusted by gender and age group, we found that only the cagA (+) genotype was associated with a 13.00-fold increase in the odds of peptic ulcer (95% CI 1.41–120.09, P=0.024), while the vacA s1m1, s1m2 genotypes and the babA2 (+) gene showed no association with clinical outcomes (Table 4). This evidence concerns the gene S100A8 and Peptic ulcer.