Around 800 different types of bacteria live in the human intestine . The organism and the bacteria live together in a form of synergy and commensalism. In the case of synergy, both beings benefit from each other. In the case of commensalism, only one living being, for the second, living together is neutral. There are about a trillion bacteria in one gram of feces. In addition to the gut's own bacteria , pathogens also occur.
Pathogens in the stomach and small intestine
Helicobacter pylori is the most common pathogen occurring in the stomach and causes increased production of gastric acid. It is responsible for B gastritis, 75 percent of all gastric ulcers and nearly all duodenal ulcers. If there is a chronic infection by Heliobacter pylori, the risk of developing gastric carcinoma increases. The bacterium is transmitted via the faecal-oral route , whereby transmission by blowflies is also possible. Vibrio cholerae and enterotoxic Escherichia Coli can occur as pathogens in the small intestine. Vibrio Cholerae releases a toxin that acts on the intestines, causing cholera to become an infectious disease. Infection occurs through contaminated water and food. Escherichia Coli causes watery diarrhea and also enters the intestines through impurities in food. The bacterium accounts for 100 million infections and tens of thousands of deaths every year worldwide. Salmonella, Yersinia and Campylobacter can still occur in the small intestine. Salmonellosis is a zoonotic disease because humans can infect an animal, but an animal can also infect humans. Transmission is often through food, especially raw poultry and undercooked eggs. The contamination in pork is hardly given today. Outside of humans, Salmonella can survive for weeks, for example on wooden cutting boards. However, common disinfectants and an acidic environment cause them to die off quickly. Yersinia can be divided into three dangerous types, one type causing tuberculosis and the second type causing inflammation in the intestines. The third species, Yersinii pestis, is the causative agent of plague. Some Campylobacter are common intestinal dwellers, others cause diarrhea.
pathogens in the colon
Infection with Shigella causes bacterial dysentery. Transmission occurs primarily through contaminated water , but also sometimes through certain flies. Every year, 160 million people worldwide contract bacterial dysentery, of which around a million die as a result. In addition, two other types of coli bacteria are found in the large intestine, which cause diseases similar to the coli type in the small intestine. Aeromonas species can occur like epidemics. Transmitted by water, the pathogen is not uncommon in hospitals. The infections come about via devices and rinsing fluids. Diarrhea and symptoms like gastroenteritis are typical. Another dreaded, so-called hospital germ is Clostridium difficile. Around 20 to 40 percent of all hospital patients, nursing home residents and bath visitors are infected with Clostridium. It is transmitted fecal-orally. However, it only triggers symptoms of the disease when one's own intestinal bacteria are reduced, for example when taking antibiotics. Immune depressants, radiotherapy and chemotherapy and a weakened immune system also make clostridia dangerous. As a rule, however, they are harmless and are successfully fought by the immune system.