Chicken intestinal in vitro models to study anti-inflammatory and antioxidant properties of natural bioactive compounds

The gastrointestinal tract constitutes the primary point of contact between the body and the external environment. A healthy intestine is responsible for proper digestion and absorption of nutrients, maintaining a stable microbiota, promoting the development of a mucus layer, ensuring proper barrier function, and supporting mucosal immune responses. However, a variety of factors such as bacteria, parasites, mycotoxins, and diet can negatively impact intestinal health and lead to inflammation and oxidative stress, which can affect production yields and animal growth. To study the effects of these factors and find targeted solutions, in vitro models are necessary. This thesis describes the development and/or optimization of three different in vitro models to study the anti-inflammatory and antioxidant properties of natural bioactive compounds to fight the problems caused by common chicken host-pathogen interactions. Firstly, this thesis describes a novel method to culture and maintain primary chicken enterocytes. They were then used to study a thymol-based blend of botanicals able to fight C. perfringens and that can potentially replace bacitracin in the future. Subsequently, a 3D enteroid model made of epithelial cells and immune cells was used to screen different botanicals and essential oils for their ability to act as anti-inflammatory and antioxidant compounds on chicken intestine and to study the effects of in-ovo delivery of glutamine and sodium butyrate on intestinal health. Lastly, the use of dendritic cells to study the effects of phytonutrients on intestinal immune sentinels’ maturation was also investigated. In conclusion, the project behind this thesis led to the optimization of different chicken intestinal in vitro models, which will serve as reliable platforms to study novel strategies against intestinal inflammation and oxidative stress in chickens.