In recent years, fermented products have been gaining space in the management of a good quality of life, and scientific evidence has shown a fairly close relationship between the microbiota and quality of life.
Obviously, one of these fermented foods is milk kefir, which in the day we will analyze against allergic pictures to see if it can really have an impact on health.
Strictly speaking, the scientific evidence in humans regarding kefir and allergies is quite scarce, however, according to animal models we have been able to observe that kefir is proposed as a potential food to treat allergic problems through its contribution to the balance of the intestinal flora.
So if you want to know more about milk kefir and its relationship with allergies, we have a whole guide below.
Relationship between the intestines, the immune system, and allergies
The intestinal immune system is the most extensive and complex part of the immune system, it is an excellent identifier of invading microorganisms and foreign substances, whether physical or chemical or even from food.
Any of these mentioned agents will be rejected by the intestinal immune system activating its defense barrier and releasing antibodies and immunoglobulins such as IgE. 
This intestinal barrier is composed of various elements such as pancreatic digestive enzymes, intestinal epithelium, and bacteria that constitute the intestinal flora and is found in the mucosa of the small intestine, that is, any foreign substance, also called antigen, when it reaches this area of the abdomen can be rejected by the immune system triggering a series of inflammatory responses throughout the body.
When there is an alteration of the intestinal flora, the body will not be able to comply with its first lines of defenses against a toxic antigen this will cause other types of cells such as T lymphocytes (antibodies) and their subtypes of lymphocytes especially Th2 attack these antigens developing different allergic reactions throughout the body. 
There is a hypothesis oriented to Western societies where it is suggested that there is an increasing increase in cases of atopy (eczema, asthma, rhinitis, food allergies, among others), inflammatory bowel diseases and autoimmune disorders (multiple sclerosis, type I diabetes mellitus) triggered by not having a well-developed intestinal flora. 
The lactobacillus Kefiranofaciens of milk kefir, has been shown according to several clinical trials to have an important role in different allergies as an antiallergic effect by decreasing the amount of IgE immunoglobulins and mediator lymphocytes in allergic reactions such as T lymphocytes of Th2 subtype. 
Another aspect that is already known about milk kefir is its property of reestablishing the intestinal flora and thus helping to colonize healthy bacteria in the flora to strengthen it, this will also help prevent allergic reactions.
Next, we will break down in more detail the relationship between the consumption of milk kefir and its effect on allergies.
Can drinking milk kefir help improve allergy symptoms?
The consumption of milk kefir could help you relieve allergy symptoms, there are even in vivo studies (in rodents) with clinical trial of the oral use of the bacterium lactobacillus Kefiranofaciens of kefir granules with positive results in terms of the decrease of antibodies and immunoglobulins that are activated during an allergic process, that is, the inflammatory process of the body is reduced.
Milk kefir, having the possibility of reducing the inflammatory process, reduces symptoms such as skin rashes, itching, allergic rhinitis and could even prevent symptoms of asthmatic processes such as respiratory distress, among others.
However, studies are still being conducted to know with more certainty if bronchial asthma could be prevented with kefir, of the rest of the allergic processes there are more studies suggesting that consuming this product has greater potential to balance the immune system and therefore reduce inflammatory processes. 2
Both the digestive tract and the intestinal microflora are interdependent and their balance between them conditions maintaining a stable and relatively constant internal environment, but when the intestinal flora suffers damage, the immune system is compromised through the decrease of regulatory T lymphocytes causing a cascade of production of inflammatory interleukins (IL).
Milk kefir contains the essential microorganisms to colonize the digestive tract of healthy bacteria that will help balance in terms of quantity and quality of good bacteria in the digestive mucosa managing to maintain an optimal environment with an ideal pH to neutralize in the first instance harmful bacteria or foreign substances.
If milk kefir colonizes the intestinal tract by reestablishing healthy bacteria, the intestinal flora will be able to achieve its balance within its habitat and consequently increase the levels of regulatory T lymphocytes that will be responsible for mediating the immune response without having to activate the antibodies. 
So kefir has a high potential for its mechanisms of action through healthy microorganisms containing the granules in improving the symptoms of allergic reactions.
Can milk kefir be used to prevent all kinds of allergies?
Milk kefir can be consumed to prevent most allergic diseases, for its immunoregulatory effect. Allergic diseases will always be given by an alteration of the immune system, in most cases with a diminished or weak intestinal flora.
When there is normal intestinal flora there are few Th1 and Th2 lymphocytes in the mucosa and regulatory T lymphocytes and IgA immunoglobulins predominate, responsible for protecting the intestinal mucosa from any toxic damage. That is why it is considered important to consume milk kefir to keep this intestinal flora strengthened.
Another aspect to mention is that if we consume milk kefir during any allergic disease, we are also protecting our digestive system. As previously described, the digestive system is the starting point of activation of the immune system so during allergic reactions there will not only be an inflammatory process of the skin or respiratory tract but also will inflame the entire digestive tract.
Although there are few studies regarding the consumption of kefir and its use in allergies, the little evidence existing during the different clinical trials that were carried out in humans, describe that certain probiotic strains can help prevent certain types of allergies, mainly those of dermatological types, that is, related to the skin, as is the case of dermatitis or eczema, acne vulgaris, psoriasis, chronic wounds, seborrheic and skin dermatitis. 
In other publications they found that the use of kefir in rats with bronchial asthma managed to reduce the production of eosinophilia, and therefore improved the symptoms of mucus hypersecretion in these animals. 
As for the allergy caused by food poisoning, there is more variety of study of this topic since the cause in this type of allergy is proportionally direct to an imbalance of the intestinal microbiota and the involvement of the immune system in recognizing through its receptor cells certain foods that are unable to be tolerated by the body. 
In summary, milk kefir can be consumed for certain allergic diseases such as eczema, atopic dermatitis, allergic rhinitis and food poisoning and acne for its anti-inflammatory and antiallergic effect, since in these cases there is more variety of favorable publications in relation to these diseases, however, more experimentation in humans is required to establish definitive conclusions.
How do the probiotics in milk kefir work to achieve their anti-allergic effect?
To understand well how kefir works in the immune system, it is necessary to understand how the process of activation of sensitive cells is during an allergic disease.
Immunoglobulins E (IgE) are responsible for mediating allergic reactions, cellular hypersensitivity reactions. This occurs when the allergen is presented to Th2 cells (T lymphocytes) through the presenting cells of the immune system and these Th2 cells, evolve to activate B cells and therefore the production of IgE (antibodies), in short, they are the defense cells against invading allergens. 
IgE immunoglobulins release into the blood other defense cells such as eosinophils, interleukins (IL4, IL5 and IL3), histamines and leukotrienes, and all these cellular proteins belonging to our immune system trigger inflammation in the airways, skin, and intestinal mucosa.
Milk kefir has three main mechanisms directly related to the immune system as immunoregulatory, antiallergic and anti-inflammatory effect and this is done through two pathways: a local and a systemic pathway. 
In the local route this probiotic, its main effect will be given by its anti-inflammatory action: 
- Decreasing T lymphocytes (Th2).
- Regulating TLR-9 which are sensory receptors when there is presence of an allergen.
- Decreasing immune cell sensitization.
- Increasing the production of TGF-B, a type of protein that has immunosuppressive and anti-inflammatory function. 
- Increasing immunoglobulin type A activity.
In the systemic pathway, its main effect will be given by its protective action this does: 
- Regenerating the integrity of the intestinal barrier, decreasing the permeability of the intestine for allergens or antigens and promotes the secretion of intestinal mucus.
- Increases the production of Immunoglobulin A in distal sites, in order to increase antimicrobial immunity.
Can kefir milk make allergies worse?
If people are allergic to dairy products, it can cause the appearance of allergy symptoms, this would be a food allergy, as explained above, in the same way a hypersensitivity response is activated by the immune cells, in this case if it could increase the symptoms of allergies.
This topic has an extensive source of studies published by different health organizations, annals of pediatrics, British and Spanish societies of clinical immunology regarding allergy. In this scientific research he explains that the allergy to cow’s milk comes from the immune rejection of milk proteins, in its frequency to the casein protein. 
The important thing is that, if you have no previous history of having reactions to cow’s milk proteins, you can consume milk kefir and not worsen allergic processes.
The other case has been people who are lactose intolerant, kefir could become useful as an improvement to increase tolerance to this type of products, although for its part you can also consume the non-dairy variant, that is, water kefir. If you want more information about it, you can consult the article on milk kefir and lactose intolerance.
The milk of kefir we use is lactose as a source of sugar, this substrate helps to carry out the fermentation of kefir granules. In the case of water kefir you can use common sugar and add it to the preparation that ferments it.
And with this we end this article about milk kefir and its relationship with allergies, but it is not time to leave, you can continue reading much more quality content with the following articles.