Exploring the Immunomodulatory Potential of Pectins and Polysaccharides as Feed Additives for Poultry: In Vitro Insights and Gut Model Development

Antimicrobial resistance in poultry has become a global public health threat, hence the need for alternatives in poultry production is warranted. Carbohydrate compounds have shown promising effects in promoting gut health in poultry as they escape enzymatic digestion in the upper gastrointestinal tract (GIT) and reach the colon to promote growth of beneficial gut microbiota and produce short chain fatty acids (SCFA). In addition to altering the gut microbiota composition, carbohydrate compounds can directly interact with immune cells such as NK cells, a major intraepithelial lymphocyte (IEL) population, and macrophages that are present in the lamina propria and modulate the immune response. This way carbohydrate compounds can promote gut health and thereby reduce the required use of antimicrobials in poultry production. In this thesis we have determined the direct interaction of several pectins and polysaccharides, that may be used as feed additives in poultry production, with chicken macrophages and NK cells and describe their immunomodulatory properties. In addition, an in vitro chicken gut model “chicken intestinal organoids” was also developed. This in vitro model can be used for large screening of several drugs, carbohydrate compounds, and for disease modeling.