MICROBIAL DIVERSITY AND CATALASE PROFILE OF ORAL MICROORGANISMS IN CHILDREN WITH GASTRITIS AND GASTRODUODENITIS

Abstract

The oral microbiome was compared between 33 children aged 5-18 years with gastritis or gastroduodenitis and multiple dental caries and 20 controls. Culture-based analysis revealed 16 taxa in controls and 20 identified taxa plus unidentified strains in the study group. Shannon diversity was higher in the study group (2.969 vs. 2.614), whereas Simpson dominance was lower (0.055 vs. 0.083). Bray-Curtis dissimilarity reached 0.685, indicating marked restructuring of the microbial profiles. Catalase-positive phenotypes occurred among Neisseria spp., Rothia spp., Staphylococcus spp., and Candida albicans, while isolated streptococci were catalase-negative. These findings demonstrate greater and more even microbial diversity in children with gastroduodenal pathology and multiple caries. The functional contribution of catalase-positive taxa to oxidative-stress tolerance in dental biofilms requires further investigation. Keywords: oral microbiome, gastritis, gastroduodenitis, dental caries, catalase activity.