Intestinal flora

What kind of image does the term "intestinal flora" conjure up for you? Intestinal flora consists of a complex of microorganisms that colonise our gastrointestinal tract, the large intestine in particular. These useful bacteria help our bodies to defend themselves against pathogens, preventing harmful germs from spreading and causing damage.

Colonisation of the various sections of the intestine is highly varied. Just a few bacteria are to be found in the stomach and small intestine, for example, while the large intestine is particularly densely populated. Can you imagine that there are more than 10 billion microorganisms in every millilitre of fluid in the large intestine? There is also a huge diversity of bacteria, with some 400 - 500 different species to be found here.

If our intestinal flora is "in balance", the useful bacteria have the upper hand. Bifidus bacteria are one example, and protect us from disease by producing acid to ensure an acidic environment in the large intestine. This acidic environment forms a kind of barrier for germs, which are no longer able to multiply. We can help to increase the amount of "good" bacteria in our bodies by eating a high-fibre diet with lots of fruit and vegetables, pulses and whole-grain products. This is important because fibre that passes undigested into the large intestine is used by the bacteria as a source of energy and thus helps them to grow.

Perhaps you're wondering how the intestinal bacteria enter our bodies? After all, an unborn child in its mother's womb does not yet have any intestinal flora -  the intestines are sterile, so  to speak. The first microorganisms do not start with colonisation until the baby encounters them on its way through the birth canal. And then it's up to the food:  the intestinal flora of a breastfed baby consists of 99% bifidobacteria, which provide particularly effective protection against infections by, as described above, producing acids that inhibit the growth of harmful microorganisms . Babies fed with formulas based on cow's milk develop a mixed flora that also contains bifidobacteria, but much fewer than in breastfed babies. Added to this are further microorganisms such as enterobacteria and streptococci. The intestinal flora stabilises during the weaning process and approaches that of an adult over time, with the composition changing again once the individual reaches old age. Minor variations in the composition can also be attributed to changes in eating habits.

Intestinal flora can be "thrown out of balance" by illness or medication such as antibiotics, for example. This is no cause for alarm, however, as the intestines are generally able to compensate for temporary stress or change. The composition of intestinal flora is only affected permanently by longer-term illness or treatments.