Gut Flora and the Microbiome

In short: Trillions of tiny microorganisms, mainly bacteria, live in the human gut. This community, the gut flora or gut microbiome, helps with digestion and is in close contact with the immune system.

In more detail: Most gut bacteria live in the large intestine. They make use of food components that the body cannot break down itself and in doing so produce substances that benefit us; the composition is slightly different in every person.

In detail

• A huge community: According to current estimates, the number of bacteria in the body is of a similar order of magnitude to the number of human body cells, with the gut housing the largest share.
• Where they live: There are only a few microbes in the acidic stomach, more in the small intestine and by far the most in the large intestine (verdauungssystem-vom-mund-bis-zum-darm).
• Using dietary fibre: Gut bacteria ferment dietary fibre that our own enzymes cannot break down and, among other things, produce short-chain fatty acids from it, which serve as an energy source for the cells of the intestinal lining.
• Vitamins: Some gut bacteria produce vitamins, including vitamin K and certain B vitamins.
• Protection against pathogens: A stable gut flora takes up space and nutrients and makes it harder for harmful germs to settle (bakterien-und-viren-unterschied).
• Training the immune system: Constant contact with gut bacteria helps the immune system to tell harmless microbes from dangerous ones (immunsystem-grundlagen).
• Colonised from the start: A newborn baby receives its first microbes during and after birth; the gut flora develops particularly strongly in the first years of life.
• Influences: Diet, age, living conditions and medicines such as antibiotics can change the make-up of the gut flora, usually only temporarily.
• A young field of research: Links between the microbiome, metabolism and even the brain are being studied intensively, but many questions remain open; persistent digestive complaints should be checked by a doctor (symbiose-und-parasitismus).