Screening and characterization of potential Lactobacillus strains with anti-Helicobacter pylori activity through principal component analysis

Helicobacter pylori is considered a causative agent of gastrointestinal diseases. Treatment for H. pylori has caused a significant increase in drug-resistant strains, making it very important to develop new treatment strategies. Lactic acid bacteria are natural microbial species. Owing to their excellent antibacterial activity and probiotic characteristics, they have received significant attention for their ability to suppress H. pylori infection. Nine strains were selected from sixty-four Lactobacillus strains sourced from infant feces and fermented foods to assess the inhibition of H. pylori growth and urease activity. Acid resistance, hydrophobicity, auto-aggregation, and co-aggregation with H. pylori were characterized and integrated with synthetic assessment using principal component analysis to obtain two strains, Scr72 and Scr19. Both strains were identified as Lactiplantibacillus plantarum using 16S rRNA gene sequencing. Moreover, both Lactiplantibacillus plantarum strains significantly reduced the levels of the pro-inflammatory cytokine interleukin 8 in human gastric epithelial cells (GES-1) during H. pylori infection and exhibited harmless γ-hemolysis activity and antibiotic sensitivity. When live cells or cell-free supernatants of both strains were co-cultured with H. pylori, the survival count of H. pylori decreased significantly. Based on these preliminary findings, L. plantarum Scr72 and L. plantarum Scr19 derived from pickled vegetables have the potential to act as probiotics against H. pylori infection.