Abstract
Salmonella pullorum infection in chicks poses a significant threat to poultry farming. Given the growing limitations of conventional antibiotics, there is an urgent need to explore safe and effective alternatives. Purslane (Portulaca oleracea L.), a natural botanical rich in bioactive compounds, has emerged as a promising candidate. This study aimed to evaluate the protective efficacy of purslane extract against S. pullorum infection in chicks. A total of 200 one-day-old Wenchang chicks were randomly assigned to four experimental groups: an uninfected control group (CON) and three groups orally challenged with S. pullorum. Among the infected groups, one received no supplementation (SP), another was treated with 150 mg/kg neomycin sulfate as a positive control (SP-N), and the third was supplemented with 250 mg/kg purslane extract (SP-P). The results demonstrated that purslane extract significantly decreased bacterial colonization in the jejunum, ileum, and liver. Moreover, it markedly mitigated S. pullorum-induced adverse effects, including reduced feed intake, impaired growth performance, and altered immune organ indices. Histopathological analysis revealed that purslane extract restored intestinal architecture. Serological assessments further showed that purslane extract effectively suppressed the elevation of serum diamine oxidase activity and d-lactate levels-key biomarkers of intestinal barrier dysfunction. At the molecular level, purslane extract counteracted the infection-induced downregulation of tight junction proteins, thereby reinforcing the intestinal barrier. Interestingly, no significant changes were observed in the expression of key inflammatory cytokines. Additionally, 16S rRNA sequencing of cecal contents indicated that purslane supplementation specifically enriched beneficial bacterial taxa such as Oscillibacter, Anaerobiclostridium, and Romboutsia, suggesting a microbiota-mediated mechanism of action. In conclusion, purslane extract alleviates systemic infection, intestinal damage, and growth retardation in S. pullorum-challenged chicks by restoring gut barrier function and modulating the cecal microbiota. These findings highlight its potential as a natural, antibiotic-free strategy for both the prevention and treatment of pullorum disease in poultry production.