Synergistic action of naringenin and amikacin in the treatment of avian colibacillosis

Avian colibacillosis is an infectious disease caused by pathogenic Escherichia coli (E. coli) and is one of the significant causes of economic losses in the global poultry industry. The overuse of antibiotics has led to the emergence of resistant strains, and the presence of antibiotic residues in chickens and eggs poses a threat to human health. Therefore, exploring safe adjuvants to enhance the efficacy of existing antibiotics is one of the critical issues in poultry farming and public health research. Naringenin (NG), a naturally occurring flavonoid, has been extensively studied as a therapeutic agent for various diseases, but its efficacy in combination with antibiotics for treating avian colibacillosis has not yet been explored. In this study, we established a model of avian colibacillosis and treated it with NG and amikacin (AMK) alone or in combination. Compared with monotherapy, the combination of NG and AMK significantly decreased bacterial loads in the heart, liver, spleen, lung, and kidney by 5.0–6.0 log 10 CFU/g ( p < 0.01). Histopathological analysis revealed that the combination treatment markedly alleviated pathological damage in the lung and duodenum compared to the AMK alone group. Furthermore, the combination therapy significantly exerted anti-inflammatory and antioxidant effects, as evidenced by reduced serum levels of tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), and malondialdehyde (MDA), alongside increased superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities ( p < 0.05). 16 S rRNA sequencing demonstrated that the combination treatment significantly modulated the gut microbiota composition, decreasing the relative abundance of Proteobacteria from 44% in the infection group to 1.2% ( p < 0.01), while increasing Firmicutes and Bacteroidetes to levels comparable to healthy controls. The research results provides evidence for the therapeutic potential of NG as an effective antibiotic synergist when combined with AMK against avian colibacillosis.