Leaky gut, also known as permeable gut, describes a disorder of the intestinal barrier in which tiny gaps develop in the intestinal mucosa. These allow unwanted substances such as bacteria, toxins and undigested food components to enter the bloodstream. The body reacts to this with inflammation and immune reactions. The development of leaky gut is favored by factors such as poor nutrition, stress, environmental toxins, medication (e.g. antibiotics or chemotherapy), alcohol, nicotine and a disturbed intestinal flora. These causes lead to damage to the protective mucous membrane and increased permeability of the intestinal wall.