The aim of a study in Israel was to examine the relationship between the presence of H. pylori and the probability of developing infectious diseases accompanied by diarrheal syndrome. In a case-control nesting study of participants selected from cohorts of Israeli military ground units between the ages of 18 and 21, dynamic observation was established to monitor the development of diarrhea. The patients studied (n = 177) sought medical help due to the development of diarrhea and had either a positive laboratory test for Shigella sonnei (n = 66), enterotoxigenic strains Escherichia coli (ETEC) (n = 31), or a negative result on bacterial pathogens (n = 80; diarrhea of unknown etiology). The control group (n = 418) was made up of men from the same military unit and the same year of service who did not observe any development of diarrhea during the observation period. Serum samples obtained from study participants at the start of the field exercises were tested for the presence of anti H. pylori IgG, as well as IgG and IgA against the lipopolysaccharide antigen. Shigella sonnei using ELISA.

The proportion of patients infected with H. pylori was significantly lower in the patients studied with an infection of unknown etiology (36.3%) compared to patients in the control group (56.0% ) (adjusted odds ratio 0.43, 95% confidence interval 0.24-0.77; p = 0.005). The number of H. infected pylori in patients with a confirmed diagnosis of shigellosis caused by S. sonnei, was significantly lower compared to the control group (36.3% vs 56.0%). The identified trend continued after adjustments in socio-demographic indicators and the level of antibodies against the S antigen. sonnei of class IgA (correlated OR 0.37, 95% CI 0.14-0.95, p = 0.03) and IgG (corrected OR 0.38, 95% CI 0.14-0, 99, p = 0.04). A similar pattern of dependence was also observed between H. pylori infection and infection caused by enterotoxigenic strains, although no statistically significant difference between the study and control groups was obtained..

Thus, the data obtained during this study allow the possibility of an active role of H. pylori in protection against infectious diseases accompanied by diarrhea.