Babies: intestinal flora influences tendency to allergies

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MunichBabies with a healthy intestinal flora develop allergies less often. The good news: which bacteria settle in the intestine can be influenced - for example by breastfeeding or contact with pets.

Allergies, neurodermatitis and asthma - an overzealous immune system is the cause of many so-called atopic diseases. The immune system also takes action against harmless proteins such as pollen.

The body's defenses are mainly shaped in the months after the birth. Christine Cole Johnson and her colleagues from the Henry Ford Hospital examined the factors that play a role here by evaluating several independent studies.

Intestinal flora forms the immune system

The investigations focused on the microorganisms in the intestines or in the stool of infants - one month and six months after birth. The intestinal flora plays an important role in the development of the immune system. For example, certain intestinal inhabitants promote the formation of T cells that regulate the immune system. If the body's defenses are not properly trained, the children are prone to allergies and asthma.

The scientists found that the intestinal flora varies greatly depending on whether the child was breastfed or not. They suspect that the different composition of the microorganisms in the intestine influences the development of the immune system. This could be the reason why breastfed children, for example, are less likely to develop allergies.

Pets as immune trainers

But the babies' contact with animals also influenced their intestinal flora. The researchers found that toddlers who have contact with pets in the first year of life are less likely to develop allergies. Johnson even believes that the mother's contact with various germs also plays an important role. For example, the mother's contact with animals affects the level of Ig-E antibodies in the child at the time of birth.

Another factor that affects the composition of the intestinal flora in newborns is the birth canal. “During a caesarean section, the newborns absorb typical skin bacteria, but not the usual intestinal bacteria that occur during natural birth. It therefore takes longer for cesarean section children to develop a stable intestinal flora, ”Johnson explains to

The body expects germs

"Contact with microorganisms or bacteria in the first few months after birth helps to stimulate the immune system," reports Johnson. The body's own defenses have the task of rendering a wide variety of pathogens harmless. In order to be able to fulfill this complex task in the best possible way, it has to train. This requires training partners such as bacteria. If these are missing, the immune system cannot develop optimally, adds the researcher. It is then more difficult to differentiate between harmless intruders and dangerous pathogens.

Tobacco smoke also had a negative impact on the children's intestinal flora. However, the scientists are not yet able to explain the mechanism behind this phenomenon.

A trained immune system prevents allergies and asthma

"The results suggest that frequent contact with various germs and the associated intestinal flora stabilize the immune system and thus provide better protection against allergies and asthma," says Dr. Johnson. Breastfeeding, a natural birth and an environment that is not too clean seem to be beneficial, adds the researcher.

The research is part of the longstanding Henry Ford Wayne County Health, Enivromental, Allergy and Asthma Longitudinal Study (WHEALS) initiated by the National Institute of Allergy and Infectious Diseases. The aim of the study is to uncover the influence of external factors on the development of allergies and asthma.

More and more people in this country are developing allergies. Why this is so has not yet been clarified. But other atopic diseases are also increasing steadily. In Germany, around five percent of adults and up to ten percent of children suffer from asthma - it is the most common chronic disease for them. And the number of atopic dermatitis patients is also increasing. Ten to 15 percent of German children will develop it by the time they start school. In adulthood, the proportion falls back to 1.5 to three percent.

Source:

Henry Ford Health Systems press release dated 02/21/2015

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