Campylobacter jejuni is the leading cause of bacterial foodborne diarrheal disease worldwide. Despite its microaerophilic nature, C. jejuni is ubiquitous in aerobic environments and must possess specific adaptation mechanisms against oxidative stress. Here, we identified a novel role for FlhF, a GTPase essential for proper flagellar assembly, in promoting resistance to hydrogen peroxide (H2O2). Comparative transcriptomic analysis under H2O2 stress revealed that deletion of flhF leads to significant downregulation of oxidative stress-related genes. FlhF directly interacts with TonB2, an iron transport-associated protein, via its B and N domains. Codeletion of flhF and tonB2 leads to increased sensitivity to H2O2, suggesting a synergistic interaction. Moreover, the FlhF-TonB2 interaction promotes H2O2 detoxification, potentially by modulating intracellular iron homeostasis and influencing redox processes. Together, these findings reveal a novel function of FlhF in the oxidative stress response of C. jejuni, offering new insights into flagella-associated defense mechanisms in this pathogen.
BACKGROUND
The intensification of food production systems highlights the need for poultry gut health strategies aligned with One Health goals. Central to this is a balanced gut microbiota, which supports nutrient absorption, immunity, and disease resilience.
RESULTS
We applied integrative multi-omics, combining untargeted LC-MS metabolomics and shotgun metagenomics, to explore the caecal responses of commercial Ross-308 broilers to two widely used gut health interventions: ionophore supplementation (T1) and anticoccidial vaccination (T2). Across 7,554 detected metabolites, we identified candidate metabolic signatures: T1 was marked by trends in prenol lipids, including multiple soyasaponins, and enrichment of cellular stress-related pathways (e.g. glutathione pathway). T2 instead was associated with shifts in aromatic amino acid metabolism, elevating tryptophan-derived indoles such as 5-methoxyindole. While global metabolic profiles did not differ significantly (PERMANOVA p > 0.05), supervised integration (DIABLO algorithm) identified 405 potential metabolite-MAG correlations. Bacteroides fragilis emerged as a dominant associate, correlating positively with a diverse range of metabolites (n = 271). Functional gene analysis suggested a link between Mediterraneibacter spp. and soyasaponin deglycosylation, while Ruminococcaceae UBA3818 showed genomic potential for tryptophan utilisation and indole-linked metabolic steps.
CONCLUSION
Our exploratory findings suggest that prophylactic interventions impact the gut microbiome, resulting in divergent subsets of metabolic features. This highlights the potential of microbiome-informed strategies to improve enteric disease management and advance gut health centred approaches in both veterinary and human contexts.
G. Pangga, A. Richmond, C. Hughes et al.· Animal Microbiome· 0 citations