{
  "abstract": "Background Streptococcus anginosus (S. anginosus) is a recognized pathogen contributing to gastritis and gastric cancer development. Rising antibiotic resistance necessitates the search for novel probiotic-based interventions, yet many common probiotics lack niche-specific efficacy in the stomach.Methods Gastric mucosal biopsies from patients with non- H. pylori gastritis were subjected to metagenomic sequencing, revealing a significant correlation between S. anginosus enrichment and Lactobacillus depletion. To identify a potential probiotic intervention, we isolated Lactiplantibacillus plantarum LPF-01 from healthy human gastric mucosa using selective culture under acidic conditions. The strain was characterized for its exceptional acid resistance via simulated gastric fluid tolerance assays. Whole-genome shotgun sequencing of LPF-01 was performed, followed by de novo assembly and annotation. In silico mining with the BAGEL4 algorithm identified a putative biosynthetic gene cluster encoding the bacteriocin Plantaricin_A. To validate its functional role, synthetic Plantaricin_A was tested against S. anginosus using agar well diffusion and minimum inhibitory concentration assays. Furthermore, an in vivo murine model of S. anginosus-induced gastritis was established, and animals were orally administered LPF-01 or vehicle. Gastric tissues and contents were collected for histopathological scoring, immunofluorescence analysis of tight junction proteins, cytokine profiling, and 16S rRNA gene sequencing to assess microbial compositional changes.Results Genomic analysis confirmed the presence of a complete Plantaricin_A biosynthetic gene cluster in LPF-01. Synthetic Plantaricin_A exhibited potent dose-dependent inhibitory activity against S. anginosus. In vivo, administration of synthetic Plantaricin_A significantly attenuated S. anginosus-induced gastric inflammation, as evidenced by reduced histopathological scores and decreased mucosal levels of IL-6 and TNF-α. Immunofluorescence staining revealed preserved ZO-1 and occludin expression, indicating protection of the gastric mucosal barrier. Moreover, 16S rRNA sequencing demonstrated that LPF-01 treatment restored gastric microbial homeostasis, marked by a significant reduction in S. anginosus abundance and a concurrent increase in endogenous Lactobacillus species. These findings establish Plantaricin_A as a key effector molecule mediating the antagonistic effect of LPF-01 against S. anginosus and highlight its therapeutic potential in non-H. pylori gastritis.Conclusions Our study identifies LPF-01 as a promising gastric-derived probiotic and characterizes Plantaricin_A as a vital antimicrobial agent against S. anginosus, providing a robust theoretical basis for precision probiotic therapy in gastric diseases.",
  "authors": [
    {
      "affiliations": [
        "Department of Microbiology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, China"
      ],
      "name": "Zhenhui Chen"
    },
    {
      "affiliations": [
        "Department of Microbiology, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, China"
      ],
      "name": "Hongying Fan"
    }
  ],
  "title": "IDDF2026-ABS-0135 A novel gastric-derived lactiplantibacillus plantarum LPF-01 alleviates streptococcus anginosus-induced gastritis via antimicrobial peptide secretion and microbiome restoration",
  "uid": "aebfe7ae-75f8-557d-a467-cdf04722326b"
}