Intestinal Microbiota: A Hidden Metabolic and Immune Organ

The gut microbiota, a hidden metabolic organ, is the immune system’s largest and most complex part. It is vital to maintaining the host organisms’ health. The gut microbial community comprises hundreds of trillions of bacteria, viruses, fungi, archaea, and bacteriophages. Generally, the predominant bacterial phyla in chickens include Firmicutes, Proteobacteria, Actinobacteria, and Bacteroidetes. However, each gut compartment may be a distinct ecosystem for specific microbiota. Additionally, various factors such as animal species, breed, age, nutrition, environment, stocking density, stress, and medication can all influence the delicate composition of gut microbiota. Maintaining animal health and enhancing animal performance requires a focus on microbiota, which provides a mutually beneficial and dynamic interaction. This review focuses on the dynamics and functions of the gut microbiota in chickens.