696 - Lactobacillus fermentum CECT5716 Drives Intestinal Crypt Stem Cell Regeneration in Necrotizing Enterocolitis by Activating Glutathione Metabolism

Publication Number: 1673.696

Juyi Zhao, Department of Pediatrics, the Women's Hospital of Nanjing Medical University, Nanjing, Jiangsu, China (People's Republic); Shushu Li, Nanjing Women and Children's Healthcare Hospital, Nan jing, Jiangsu, China (People's Republic); Shuping Han, Nanjing Women and Children's Healthcare Hospita, Nanjing, Jiangsu, China (People's Republic)

Background: Necrotizing enterocolitis (NEC) is a severe inflammatory disease predominantly affecting preterm and low birth weight neonates, leading to high morbidity and mortality and long-term sequelae. Increasing evidence suggests that impaired gut microbiota establishment and compromised intestinal barrier function are significant causes of NEC. Disrupted intestinal microenvironments due to prematurity, delivery mode, antibiotic use, and NICU exposure elevate NEC risk, highlighting the need for targeted therapeutic strategies based on microbial changes.

Objective: This study aimed to investigate changes in the gut microbiota of preterm infants with NEC and to elucidate the protective mechanism of the probiotic Lactobacillus fermentum CECT5716 (LC40) and its active metabolite against NEC-induced intestinal injury.

Design/Methods: High-throughput sequencing was first performed on fecal samples from preterm infants to assess gut microbiota diversity and composition. LC40, a probiotic isolated from breast milk, was then transplanted into a murine NEC model to evaluate its therapeutic efficacy, focusing on clinical symptoms and intestinal stem cell (ISC) regeneration. Non-targeted metabolomics was used to identify key metabolites produced by LC40. The protective effects of the identified metabolite, gallic acid (GA), were confirmed using in vivo NEC animal models and in vitro organoid models. Finally, RNA-sequencing and subsequent validation were conducted to identify and confirm the underlying protective mechanism.

Results: We found that infants with NEC exhibited reduced gut microbiota diversity and a significant decrease in the abundance of Lactobacillus fermentum. Administration of the probiotic LC40 significantly alleviated NEC clinical symptoms in mice and promoted intestinal stem cell regeneration. Metabolomics identified a significant upregulation of GA by LC40. In vivo and in vitro experiments confirmed that GA effectively drove ISC regeneration, facilitating the repair of NEC-induced intestinal damage. Mechanistically, RNA-sequencing revealed that GA exerts its protective effects by upregulating glutathione (GSH) metabolism, reducing reactive oxygen species generation, and activating the Wnt/β-catenin signaling pathway.

Conclusion(s): We conclude that the breast milk-derived probiotic LC40 and its metabolite GA can effectively drive intestinal stem cell regeneration and repair NEC-induced intestinal damage. This effect was mediated through the GA/GSH/Wnt/β-catenin axis. These findings may provide a novel therapeutic approach for NEC and offer new theoretical support for the health benefits of probiotics.

Mechanism diagram of Lactobacillus fermentum LC40 driving intestinal stem cell regeneration