Allergies in children: the role of the intestinal microbiota
Respiratory (allergic rhinitis , allergic asthma), skin (atopic dermatitis, urticaria, etc.) and food allergies have dramatically increased in recent decades.
According to the most recent research, this increase seems to be linked to the presence of alterations in the intestinal, skin and lung bacterial flora , i.e. the population of microorganisms which today is referred to as the microbiota.
This fact seems quite plausible, considering that the microbiota plays an important role in the development and regulation of the immune system , both innate and acquired.
Microbiota and allergies: what link?
From the first days of life, the intestinal microbiota plays a decisive role in the prevention of allergies . This complex system of microorganisms, in fact, “educates” the child’s immune system to coexist peacefully with many foreign substances , especially food , which come into contact with the body in the intestine.
In more technical terms, the microbiota allows our body to develop a tolerance towards numerous antigens , i.e. the particles that are recognized by the immune system as not belonging to our body.
The opposite mechanism is allergy , a defense reaction in which the body identifies the antigen as an “intruder” and unleashes a powerful immune response against it, aimed at neutralizing and eliminating it.
In doing so, however, it activates inflammatory mechanisms that produce alterations and symptoms of food allergy , both at the intestinal level (diarrhoea, vomiting and reduced absorption of nutrients, with poor growth), and at the level of other organs, such as the skin ( urticaria, angioedema, atopic dermatitis) and the respiratory tract (allergic rhinitis, asthma).
Furthermore, in more serious situations, the reaction can involve the body as a whole and, in particular, the cardiovascular system , with potentially very serious consequences such as anaphylactic shock .
Allergies in children: the importance of intestinal health
As we have seen, under normal conditions (eubiosis), the intestinal microbiota acts as a sort of “gate”, or “switch”, which can direct the immune system towards a tolerant attitude towards antigens.
However, this action can be compromised in the event of dysbiosis (i.e. an imbalance in the intestinal bacterial flora), which can favor the development and occurrence of allergic pathologies .
Among the factors that can negatively influence the state of eubiosis/dysbiosis of the gastrointestinal microbiota, we mention delivery by caesarean section (compared to natural delivery), a diet low in fiber and antibiotic treatments in the early stages of life, while an effect protective is carried out by breastfeeding .
Microbiota and respiratory allergies
The presence of intestinal dysbiosis is usually associated with similar alterations of the pulmonary microbiota, demonstrating that there is a close connection between the intestinal and respiratory mucosa and between the two respective bacterial populations, mediated by the immune system.
In particular, the alterations of the pulmonary microbiota in the first days and years of life compromise its role as a “firefighter” towards allergic respiratory diseases (allergic rhinitis and asthma), which therefore end up developing more easily, frequently and more importantly.
Microbiota and skin allergies
A similar situation occurs in the skin , where the dysbiosis of the skin microbiota increases the risk of chronic diseases such as atopic dermatitis and psoriasis .
Kathryn Barlow is an OB/GYN doctor, which is the medical specialty that deals with the care of women's reproductive health, including pregnancy and childbirth.
Obstetricians provide care to women during pregnancy, labor, and delivery, while gynecologists focus on the health of the female reproductive system, including the ovaries, uterus, vagina, and breasts. OB/GYN doctors are trained to provide medical and surgical care for a wide range of conditions related to women's reproductive health.