In industrialized countries, allergies are becoming a plague. Whether they are food, respiratory, skin, seasonal or not, allergies affect up to 30% of French people! We now know that good health depends on the quality and diversity of the intestinal microbiota. Researchers then turned to the study of the link between intestinal flora and allergies.
Allergy: reminder
An allergy is a hyper-reaction of the immune system When faced with one or more allergens. The physical manifestations take the form of itching, local or generalized inflammation, irritation, discomfort and even suffocation.
The allergy is triggered when the person has genetic predispositions and is in direct or indirect contact with the allergen.
Then, the allergic process proceeds in 2 phases:
- Sensitization : this is the first contact with the allergenic substance. The body activates Th2 lymphocytes (white blood cells) which in turn activate B lymphocytes. The latter will then release IgE antibodies (immunoglobulin E) which will cling to the mast cells (immune cells) on the skin and mucous membranes.
- Triggering: the immune system encounters for the second time the allergen which activates the release of histamine and other inflammatory molecules by mast cells. This is the allergic reaction.
Microbiota as a regulator of the immune system
One of the main functions of the gut flora is the modulation of the immune response. It is nowadays admitted that the quality and diversity of bacteria in the intestine is a guarantee of good health.
Based on this premise, the researchers studied the effects of gut microbiota on whether or not allergic phenomena occur.
A team from INSERM presented in their September 24, 2018, release a study in mice that shows a relationship between "a virus detection system, the composition of the intestinal microbiota and the development of cutaneous allergies. "
"Several types of epidemiological data suggest a link between changes in the composition of this gut microbiota (or gut flora) and the development of allergic diseases, including eczema, remote from the gut. But the explanation of this relationship remained to be elucidated. "Source: Press release - Inserm Press Room Deciphering the link between intestinal microbiota and skin allergy
Prebiotics to cure allergies?
According to INSERM, studies aimed at modifying the gut microbiota using probiotics have not been successful in combating the progression of allergies...
However, they had the idea to use prebiotics to promote the growth of "good" bacteria.
The goal is to modify the gut flora more subtly than by introducing this or that strain, and to do so very early. The ideal is to intervene before birth and during the first few months of life to successfully prevent therisk of allergies usually occurring in the very early years.
The researchers then administered a daily sugar supplement (galacto-oligosaccharides and inulin) to mice during gestation and then during the lactation phase. Three weeks after weaning, the mice were exposed to
To allergenic wheat proteins. The result was that the mice born to mothers supplemented with prebiotics were less responsive to allergens than the others.
Probiotics or prebiotics?
As a naturopath, my professional experience has shown me that the gut flora in allergic people is greatly disrupted by improper lifestyle, chronic intestinal inflammation, and taking medications.
After calming the inflammation of the mucous membranes, a course of probiotics will reseed and diversify the gut bacteria. Then, it is important to feed this microbial flora. Prebiotics are their main food. They are found mainly in fiber and lacto-fermented foods, which is why it is important to take care of your diet.
To conclude
The gut microbiota is responsible for the reactivity of the immune system. If it is out of balance, the responses will not be effective. In order to take care of your flora, diet must be reviewed and adapted as well as your overall lifestyle. Probiotic supplementation can be considered but will only be beneficial if fed daily with prebiotics.