In a healthy intestinal system there is a great variety of natural bacteria.
Today many people have an imbalanced flora of intestinal bacteria. Now a new study, from Lund University in Sweden, shows that children with only a limited variety of bacteria in their feces one week after birth more often developed atopical eczema by the age of 18 months. In the study, published in Journal of Allergy and Clinical Immunology, feces were examined from children in Göteborg, London, and Rome.
“A diversified intestinal flora seems to be better at stimulating the immune defense," says Göran Molin, professor of food hygiene at the Faculty of Engineering, Lund University, who co-directed the study with Siv Ahrné, also a professor of food hygiene.
The composition of a child’s bacterial flora is dependent on the mother’s microflora, since she is the primary source for the child’s bacteria at the outset.
“A healthy vagina is totally dominated by lactobacilli, or lactic acid bacteria. With a vaginal delivery the child will come into close contact with the mother’s bacteria. If the mother has a good flora of bacteria, the contact is an important help for the child to be able to be colonized by bacteria in the proper way. It can be assumed that certain hygiene measures, such as antibiotics given in some countries in connection with deliveries, in normal cases may have a deleterious effect, since the mother then is at risk to get a skewed bacteria flora, which she passes on to the child," Göran Molin reasons.
But today, many women in the U.S. as many as a third of all women of fertile age have bacterial vaginosis. This is a condition in which other bacteria than lactobacilli dominate in the vagina.
Precisely why people have less diversity in their bacteria is not known. But there arespeculations:
“Our intestinal system developed to deal with lots of lactobacilli. But today our groceries are often heat-treated, and the food is kept in refrigerators explains Siv Ahrné. Consumption of live lactobacilli included in lactic acid fermented foods has been a regular part of the food intake of humans for a long time. In fact, there are archaeological signs that mankind has used this technique from the beginning of time as it is the simplest and often the safest way to preserve food, and humans have in this way consumed large numbers of live lactobacilli until modern times.
Foods that promote the existence of lactobacilli are soured vegetables, such as sauerkraut, marinated olives, capers, and salted pickles, as well as cheese. The industry has discovered that certain living microorganisms are good and therefore add them to certain products under the umbrella term of probiotica.