Propiedades probióticas de Lactobacillus spp aislados de biopsias gástricas de pacientes con y sin infección por Helicobacter pylori

Abstract

Background: Gastric microbiota is a complex ecosystem, composed by diverse microorganisms, where H pylori and Lactobacillus are relevant species. Aim: To study the probiotic properties of Lactobacillus spp isolated from gastric biopsies of subjects bearing or not H pylori. Materials and Methods: Gastric biopsies from 197 individuals that consulted for gastrointestinal disorders were cultivated in media specific for H pylori and Lactobacillus spp. Probiotic properties of lactobacilli isolates and histological diagnosis of H pylori colonized patients were performed. Results: Among 197 individuals evaluated, H pylori was detected in 43%, Lactobacillus spp in 24%, while 8% presented both bacteria simultaneously. Forty one percent of the Lactobacillus spp strains produced hydrogen peroxide, 83% presented a highly hydrophobic surface and 32% had an inhibitory effect upon H pylori ATCC 43504, even greater than Lactobacillus LGG or LAI reference strains. The main pathological diagnosis of patients was chronic non-atrophic gastritis (73%) followed by intestinal metaplasia (19%). A similar proportion of both conditions were observed in patients colonized by Lactobacillus spp, while not colonized individuals developed preferentially chronic non-atrophic gastritis (p =0.002). Conclusions: Lactobacillus spp and H pylori were mutually excluded, suggesting a competitive colonization model between probiotic bacteria and pathogens.