IDDF2024-ABS-0290 Protective efficacy of human stomach-derived lactobacillus paragasseri strain LPG-9 against acute ethanol-induced gastric ulcer

<h3>Background</h3> Acute Gastric Ulcer represents a prevalent disorder within the digestive system, characterized by the erosion of the gastric mucosa. However, the traditional regimens have several limitations. This study aims to investigate the prophylactic effects of human stomach-derived <i>Lactobacillus paragasseri</i> strain LPG-9 against acute ethanol-induced gastric ulcer (AEGU), with the intention of providing a theoretical foundation and guidance for clinical interventions. <h3>Methods</h3> In this study, mice were orally administered LPG-9 via gavage for 14 consecutive days, followed by induction of an AEGU model using an 85% ethanol solution. The protective efficacy of LPG-9 against AEGU was evaluated through morphological evaluation of gastric tissues, measurement of gastric fluid pH, computation of the ulcer index, histopathological examination of gastric mucosal tissues using hematoxylin and eosin (<i>H&amp;E</i>) staining, and quantification of mucosal barrier protein levels via immunohistochemical analysis. <h3>Results</h3> Compared to the model group and omeprazole group, mice pre-treated with LPG-9 showed significant improvements in ulcer index and gastric mucosal cellular damage, a less pronounced reduction in gastric fluid pH, preservation of tissue architecture, and notable alleviation of edematous and congestive symptoms. Immunohistochemical analysis revealed a significant upregulation in the expression of mucosal barrier proteins, including Occludin and Zonula Occludens-1 (ZO-1), induced by LPG-9 administration (P &lt; 0.05). This effect contributed to the preservation of the structural integrity of the gastric mucosal barrier, and demonstrated superior gastric protective effects when compared to omeprazole. <h3>Conclusions</h3> LPG-9 demonstrates protective effects on the gastric mucosa in mice by preserving the integrity of the gastric mucosal barrier and cytoprotection, thereby mitigating the development of AEGU. LPG-9 originates from the gastric microbiota and is a promising probiotic for acute gastric disease, providing a solution to this global issue.