In life, people often see such phenomena, some people eat fish, shrimp and other food, will occur raw abdominal pain, diarrhea, vomiting, or itchy skin; some people inhale pollen or dust, will occur rhinitis or asthma; some people inject penicillin will occur after shock. These are all signs of allergic reactions. So, what is an allergic reaction?
An allergic reaction is a reaction that occurs when an organism that has been immunized receives the stimulus of the same substance again. The reaction is characterized by rapid onset, strong reaction, and rapid fading; it does not usually destroy tissue cells or cause tissue damage, and there are obvious genetic tendencies and individual differences.
The substances that cause allergic reactions are called allergens, such as pollen, house dust, fish, shrimp, milk, eggs, penicillin, sulfonamide, quinine, etc. When some people are exposed to allergens, antibodies are produced by effector B cells under the stimulation of the allergen. Some antibodies adsorb to the surface of the skin, respiratory or digestive tract mucosa, and certain cells in the blood. When the same allergen enters the body again, it binds with the corresponding antibodies adsorbed on the cell surface, causing the release of histamine and other substances from the above cells, causing capillary dilation, increased permeability of the blood vessel wall, smooth muscle contraction and increased glandular secretion. If these reactions occur in the skin, redness and swelling, hives, etc.; if they occur in the respiratory tract, vomiting, abdominal pain, diarrhea, etc.. In severe cases, death may occur due to bronchospasm, asphyxia or anaphylaxis.
There are 2,000-3,000 common antigenic substances that cause allergic reactions, and close to 20,000 in the medical literature. They cause allergy in the organism by inhalation, ingestion, injection or contact.
Common allergens are as follows.
(1) Inhaled allergens: such as pollen, willow wool, dust, mites, animal dander, oil fumes, paint, car exhaust, gas, cigarettes, etc.
(2) Ingested allergens: such as milk, eggs, fish and shrimp, beef and mutton, seafood, animal fat, allogeneic proteins, alcohol, drugs, antibacterial agents, anti-inflammatory drugs, fragrance oil, flavoring, onion, ginger, garlic, and some vegetables and fruits, etc.
(3) Contact allergens: such as cold air, hot air, ultraviolet light, radiation, cosmetics, shampoo, detergent, hair dye, soap, chemical fiber products, plastic, metal jewelry (watches, necklaces, rings, earrings), bacteria, mold, viruses, parasites, etc.
(4) Injectable allergens: such as penicillin, streptomycin, heterologous serum, etc.
(5) Self-tissue antigens: Self-tissue antigens that have changed in structure or composition due to mental stress, work stress, infection by microorganisms, ionizing radiation, burns and other biological and physicochemical factors, as well as self-hidden antigens released due to trauma or infection, can also be allergens.
It is well known that smoking, alcohol and drug abuse are very harmful to the fetus. The effects of allergic food consumption by pregnant women on fetal development have not yet attracted much attention. In fact, the consumption of allergic foods by pregnant women can not only lead to miscarriage, premature birth, fetal malformation, but also cause a variety of diseases in infants. According to American scholars, about 50% of foods have an allergenic effect on the human body, but there is a difference between recessive and dominant. Pregnant women with allergies may be allergic to certain foods, which, after digestion and absorption, can enter the fetal blood circulation from the placenta and hinder the growth and development of the fetus, or directly damage certain organs, such as the lungs and bronchi, resulting in fetal malformations or diseases.
In the second trimester, the mother’s placental barrier protection is reduced, making it easier for allergens to pass through, and the fetal immune system is just beginning to develop, so it is possible to delay the onset of possible allergic symptoms in the infant if the fetus is protected from allergens as much as possible. Although, there is not enough scientific research to conclusively prove that prevention during pregnancy is truly effective in protecting the infant, pregnant women need to maintain an attitude of prevention and take the necessary measures.
Pregnant women with allergies can be allergic to certain foods that, after digestion and absorption, enter the fetal circulation through the placenta, hindering the growth and development of the fetus or directly damaging certain organs, such as the lungs and bronchi, leading to miscarriage, premature birth, fetal malformation or grammatical diseases.
Pregnant women can prevent from the following 5 aspects.
(1) Allergic reactions to certain foods in the past should be prohibited during pregnancy.
(2) Do not eat food that you have never eaten in the past or moldy food.
(3) If itching, hives or panic, shortness of breath, abdominal pain or diarrhea occur after eating certain foods, food allergy should be considered and the food should be stopped immediately.
(4) Do not eat or be careful with allergic foods, such as seafood, shrimp, crab, shellfish and spicy and irritating foods. Eat small amounts of seafood first to see if there is an allergic reaction before deciding whether to eat it later.
(5) Consumption of heterogeneous protein foods, such as animal meat, liver, kidney, eggs, milk, fish should be cooked thoroughly to reduce allergies.
Pregnant women should avoid allergy-prone foods such as peanuts and peanut products during pregnancy to reduce the risk of allergies in the fetus. Since alcohol can cause fetal hypoxia and affect fetal brain development, and this damage is often irreversible. Thus, all alcohol should be included in the list of forbidden foods. In addition, excessive tea consumption can make the baby thin and weak, and it is best to avoid tea as well.
In general, pregnant women should try to avoid medication or supplementation of certain substances unless there have been clear findings that the benefits of doing so outweigh the harms to the fetus. Pregnant women should always consult with their doctor before taking medication or supplementing with certain substances.
Breast milk is the best source of food for infants, but it is still an unknown quantity in the prevention of allergic diseases. The presence of allergic diseases in the mother is an obvious risk factor for eczema in infants. The infants who benefit most from their mothers taking probiotics are those with high concentrations of cord blood IgE (an immunoglobulin). Therefore, probiotics given to mothers during pregnancy and lactation are a safe and effective way to enhance the immunoprotective effects of breast milk and can be effective in preventing infant eczema during the first two years of life.
There is a strong genetic component to the development of allergic diseases, especially in the mother, which affects the infant. However, genetic factors do not explain the recent rise in allergic diseases in developed countries. There is an urgent need for effective measures to prevent this disease at its root. Of all the previously studied prevention methods, only breastfeeding is still recommended as beneficial.
In addition to providing optimal nutrition for infant growth and development, breast milk also provides immune protection during critical life stages when the infant’s own immune defense mechanisms are not well developed. Transforming growth factor-β (TGF-β) is considered a key immunomodulatory factor that promotes the production of IgA (an immunoglobulin) and oral immune tolerance. At birth, the infant’s intestine produces little TGF-β on its own, and breast milk is an important source at this time. A recent study showed that in exclusive breastfeeding, the concentration of TGF-β in maternal colostrum was positively associated with infant production of specific IgA antibodies against food allergy and for the prevention of allergic diseases. And the conflicting data on the preventive effect of breast milk may be due to the different composition of breast milk in different studies.
Probiotics are live, edible microorganisms with health benefits. They have been found to control inflammatory responses and reduce symptoms associated with eczema and food allergies, one reason being that they promote the production of TGF-β. We then investigated whether the immunoprotective effects of breast milk could be enhanced by giving probiotics to pregnant and nursing mothers with or without allergic diseases.
First, infants with allergic diseases may have defects in allergen-suppressing mechanisms, and probiotics may improve these immunomodulatory mechanisms. Allergic infants who are ineffective on probiotics may not respond to the immunomodulation provided by probiotics or TGF-β.
Second, administration of probiotics to pregnant and lactating mothers is a safe and effective way to improve the immunoprotective effects of breast milk and prevent infant allergy. Infants who have high cord blood IgE concentrations benefit most from the administration of probiotics to their mothers.
Therefore, it is now generally accepted that mothers who are in a high risk group for allergy should avoid exposure to important allergens or non-allergenic irritants in the environment (including air and food) from the 7th week of pregnancy, and should also take care to control the environment after the baby is born, then the probability of developing allergic diseases in the future will be significantly reduced, or the onset of disease will be later, or the symptoms of the disease will be milder. Proper supplementation with probiotics is also beneficial.