Most of us are familiar with the term “food allergy.” Case in point, children with an allergy to peanuts can experience allergic reactions ranging from hives to coma, or even death. Sensitized children must have medication with them at all times to immediately treat reactions.
Strict avoidance of peanuts is their sole option to stay well. Schools have tried to create awareness for students and their parents to avoid bringing foods like peanut butter to school if there is a child with a peanut allergy.
In the last two weeks, there have been a number of news reports on the dramatic increase in food allergies experienced by children.
In the June issue of the medical journal Pediatrics(1), a study found that about eight percent of children under the age of 18 (almost 6 million) suffer from one or more food allergies. These numbers are twice as high as reported by the CDC in 2007, which reported a rate just below four percent. Additionally, the severity of the episodes has increased.
The lead author of the June study, Dr. Ruchi Gupta, reported that “based on our data, about one in 13 children has a food allergy. We are seeing a lot more cases in schools than we used to see. It does seem that food allergy is on the rise.” In addition, Dr. Gupta noted, “What’s more, nearly two out of every five affected children suffer from a severe food allergy. For these children, accidental ingestion of an allergenic food may lead to difficulty breathing, a sharp drop in blood pressure, and even death.”
With the growing severity of food allergies, how can probiotics help? There are some very interesting studies that suggest probiotics may lessen the risk of food allergies in children.
To get a better understanding of this topic, this newsletter will discuss:
- What is a “food allergy”
- What is the cause
- How to diagnose a food allergy
- How is a food allergy treated
- Can probiotics help lessen the risk of developing a food allergy
What is food allergy?
Food allergy is a term used to describe an adverse immune response to a protein in some foods.
When we are born, our intestinal immune cells have to constantly survey what is being ingested. The immune cells determine if they have to mount a protective reaction to a potentially harmful virus, bacteria, parasite or toxin.
Sometimes, the immune cells react to harmless proteins in our food and produce antibodies that can result in allergic reactions like hives, eczema, asthma, rhinitis and gastrointestinal symptoms of cramps, nausea, vomiting and diarrhea.
The most serious reaction is called anaphylaxis, which causes severe breathing difficulty and a major drop in the blood pressure. Oxygen, epinephrine injections and IV fluids can be lifesaving.
Anaphylactic reactions due to food allergies account for 30,000 episodes annually and possibly 200 deaths each year.(2)
The CDC estimates that eight types of foods are responsible for 90 percent of all food allergies in children: milk, eggs, peanuts, tree nuts, fish, shellfish, soy and wheat.
What is the cause of a food allergy?
The exact cause of food allergies is not known. However, there have been several proposed explanations why food allergies occur and have been on the increase over the last 20-30 years.
Factors thought to contribute to food allergies include genetic predisposition and the introduction of foods too early in infancy.
The other major factor is the “Hygiene Theory”.(3) This theory is based on the idea that in the Western developed countries the exposure to harmful bacteria, parasites, viruses and other toxins has decreased due to our efforts at keeping everything sanitized. As a result, our immune system has more time to spend mounting a reaction to harmless proteins in our diet and other allergens like pollens.
Epidemiologic studies have found that the prevalence of allergies is highest in developed countries.
Over the last 30 years there has been a two-to-three fold increase in childhood allergies in developed countries when compared to those less developed.(4)
There have been a number of reports that have found children growing up on a farm have less allergies.(4) Playing with animals and in the dirt may actually be healthy.
How to diagnose food allergies?
A child might have a food allergy, if he/she has recurrent swelling of lips and face, hives, eczema, wheezing, stuffy nose, abdominal pain, diarrhea.
The best method for diagnosing food allergy is to be evaluated by an allergist. The allergist will review the patient’s history and the symptoms or reactions that have been noted after food ingestion. If the allergist feels the symptoms or reactions are consistent with food allergy, special tests can be performed.
Skin testing can aid in detecting the antibody(IgE) to the suspected food protein.
Blood tests can measure IgE antibodies
Sometimes it is necessary to perform a food challenge while being observed by the physician
How is a food allergy treated?
The only proven therapy is food elimination. All patients at risk for anaphylaxis must be trained to identify early symptoms and be prepared to use an auto-injectable epinephrine pen.
Can Probiotics lessen the risk of developing a food allergy?
To understand how probiotics may lessen the risk of food allergies requires a little primer on how the immune system in the intestines works.
Seventy percent of our immune system is in the intestines. Since the intestines serve as our window to our environment, it is important that the intestines monitor our exposure to harmful infections and toxins.
The lymphocytes (immune cells) in the intestines are of several types:
Th1 helps to fight infections due to bacteria and viruses
Th2 responds to infections caused by parasites
If an infant is not exposed to infectious bacteria and viruses, then Th1 will be less active, causing a shift in the balance of activity in favor of the Th2 lymphocytes, producing antibodies to parasites and also to harmless allergens.
Recently, another lymphocyte called a regulatory cell (Treg) has been identified(5). This lymphocyte can regulate the activity of both Th1 and Th2 lymphocytes.
Probiotics can modulate the immune response by acting on the Treg cells. Studies have shown that probiotics can decrease or down regulate the activity of the Th2 cells and lessen the immune reaction against proteins in foods. (6,7) The term “oral tolerance” is used to describe the process when the immune cells don’t mount a reaction.
Mice raised in a germ-free environment do not develop oral tolerance to food protein.(8) But when a mixture of oral probiotics were given to the mice, the IgE antibodies were not produced.
Since 1997, probiotics have been used in the management of food allergy. Infants with eczema due to cow’s milk had improvement when given a probiotic in their formula.(8)
In another study, either probiotics or a placebo were given to mothers during the last 4 weeks of their pregnancy. Their newborn infants were breast fed and given a probiotic supplement or a placebo for 6 months. The children who were exposed to probiotics had a 50% reduction in allergies compared to the placebo group.(9)
Not all clinical studies have shown that probiotics are able to lessen allergic diseases in children.(10) The good news is that the probiotics seem very safe. No serious adverse effects have been reported in the clinical studies.
There is no question that probiotics can influence the intestinal immune system to lessen allergic responses. Some of the future challenges include determining the most effective:
- Probiotic strains
- Combination of bacterial species and strains
- Dose of bacteria in a serving size
- Timing of introducing the probiotic to the infant/child
- Duration of probiotic therapy
Take Home Message
If you don’t live on a farm or your child doesn’t include dirt in their diet, you might consider giving your child a probiotic. For women who are allergy prone, taking a probiotic like EndoMune may help prevent eczema in their offspring. In addition, giving EndoMune Junior to your child during infancy may help to lessen the risk of developing allergies. It is always recommended that you talk with your doctor before taking new medications and supplements.
Eat healthy, exercise and live well!
(1) The Prevalence, Severity, and Distribution of Childhood Food Allergy in the United States.Gupta RS, Springston EE, Warrier MR, Smith B, Kumar R, Pongracic J, Holl JL.Pediatrics. 2011 Jun 20
(2) Epidemiology of anaphylaxis in Olmsted County: A population-based study. Yocum MW, Butterfield JH,Klein JS, Volcheck GW, Schroeder DR, Silverstein MD.Yocum MW,Butterfield JH, Klein JS, Volcheck GW, Schroeder DR, Silverstein MD.
(3) The hygiene theory: fact or fiction? Sheikh A, Strachan DP.Curr Opin Otolaryngol Head Neck Surg. 2004Jun;12(3):232-6. Review.
(4) Exposure to environmental microorganisms and childhood asthma. Ege MJ, Mayer M, Normand AC, Genuneit J, Cookson WO, Braun-Fahrländer C, Heederik D, Piarroux R, von Mutius E; GABRIELA Transregio 22 Study Group. N Engl J Med. 2011 Feb 24;364(8):701-9.
(5) Hygiene theory and allergy and asthma prevention. Liu AH.Paediatr Perinat Epidemiol. 2007 Nov;21 Suppl 3
(6) Probiotics, prebiotics, and synbiotics: impact on the gut immune system and allergic reactions.Gourbeyre P, Denery S, Bodinier M. J Leukoc Biol. 2011 May;89(5):685-95.
(7) Food allergy and probiotics in childhood. del Giudice MM, Leonardi S, Maiello N, Brunese FP. J Clin Gastroenterol. 2010 Sep;44 Suppl 1:S22-5.
(8) Probiotics: a novel approach in the management of food allergy.Majamaa H, Isolauri E.J Allergy Clin Immunol. 1997 Feb;99(2):179-85
(9) Probiotics and prevention of atopic disease: 4-year follow-up of a randomised placebo-controlled trial.Kalliomäki M, Salminen S, Poussa T, Arvilommi H, Isolauri E. Lancet. 2003 May 31;361
(10) Probiotics in prevention of IgE-associated eczema: a double-blind, randomized, placebo-controlled trial.Abrahamsson TR, Jakobsson T, Böttcher MF, Fredrikson M, Jenmalm MC, Björkstén B, Oldaeus G.J Allergy Clin Immunol. 2007 May;119(5)