HenBiota - Investigating the complex interactions among Ascarids, host gut microbiota, Ascarids’ own microbiota, and diet in laying hens with implications for metabolism and immunity

• Applicant: Oyekunle John Oladosu, Ph.D.
• Subject Area: Animal Breeding, Animal Nutrition, Animal Husbandry
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 555620407

Gastrointestinal nematode infections, primarily caused by Ascaridia galli, compromise the intestinal health of chickens by damaging the intestinal mucosa, which subsequently may affect the gut's microbial composition and overall gut function. This infection is frequent in non-cage housing systems where nematodes have higher survival rates due to close contact with faecal matter, facilitating the nematode life cycle. Overall, A. galli infections impair nutrient uptake, reduce feed efficiency, and enhance susceptibility to secondary infections. Inulin, a non-digestible but easily fermentable fibre found predominantly in chicory roots, has been recognized for its prebiotic properties, promoting beneficial gut bacteria and enhancing gut health by producing short-chain fatty acids. This fibre reaches the lower tract undigested, serving as nourishment for gut microbiota, thus fostering a healthy intestinal environment. However, the role of inulin in the context of nematode infections like A. galli is complex. While it generally promotes gut health, studies indicate that inulin may paradoxically enhance the resilience and fecundity of nematodes within the host. For instance, dietary inulin has been shown to increase the prevalence and severity of A. galli infections, leading to poorer feed utilization and reduced growth in chickens. This surprising effect might be due to increased intestinal size and alterations in microbial fermentation products, which could inadvertently facilitate the persistence of nematodes. Moreover, an inulin-rich diet has a dynamic impact on immune response, particularly the polarization of Th1 and Th2 responses, affecting nematode expulsion from the host. This nuanced interaction between diet, particularly inulin supplementation, and intestinal health under nematode stress presents a critical area for deeper investigation. Understanding how inulin influences the dynamics between host responses, gut microbiota, and ascarids could lead to more targeted strategies to enhance poultry health and productivity while mitigating the adverse effects of parasitic infections. The primary hypotheses proposed by this research program are that the promotion of beneficial gut microbiota with an inulin-rich diet has a direct [positive] effect on the host responses and laying performance of chickens but also indirectly [negatively] affects the expulsion rate of worms from the host, spanning from pre-patency to worm maturity during infection with A. galli. The outcomes of this research programme will provide insights into optimizing dietary strategies to enhance gut health and chicken productivity in the face of parasitic challenges. Moreover, this study aims to contribute to more sustainable poultry farming practices. Given the shift towards animal welfare-friendly farming practices, understanding and mitigating health challenges in high-performing chicken genotypes is crucial.

• DFG Programme: Research Grants