Definition: Microthelys is a type of small, round, and often parasitic microorganisms that can colonize in the digestive tract of animals like humans, pigs, and sheep. They feed on bacteria, fungi, or other organisms within their host's gut and are typically found in the lining of the intestines as they grow larger. Microthelys is a significant concern for animal health because it can lead to digestive problems such as diarrhea, vomiting, and malabsorption.