Is There a Link Between Food Allergies and Gut Bacteria?
Food allergies are serious. Without proper care and attention to avoid the offending food, illness, hospitalization, and even death may occur. According to the Canadian Institute for Health Information, approximately 7% of Canadians self-report a food allergy, with young children (under three years of age) being some of the most affected. 1,2
Although there is a growing public concern around food allergies, what causes them in the first place remains unclear. Research, however, is looking to the role the microbiome plays in the etiology of food allergies and what we can do to reduce their prevalence in our society.
Defining a Food Allergy
It is important to have a proper understanding of the vocabulary we use to talk about our different reactions to food. Over the past few years, there has been a growing awareness of not only food allergies, but also food intolerance. While many people may use these terms interchangeably, it is crucial to understand the difference between the two.
Food Allergy: an abnormal reaction of the immune system to a protein contained within a type of food. It is an instant response, irrespective of how much of the food has been consumed. Any contact or ingestion of the food must be avoided.
Food Intolerance: a reaction to a food that does not involve the immune system. While the symptoms of a food intolerance may resemble a food allergy, food intolerances typically involve the digestive system and the body’s inability to digest or absorb a portion of the food (think lactose intolerance). Food intolerances are not life-threatening.
Chemical Sensitivity: an adverse reaction to chemicals that are found naturally, or added to, foods. Examples of this would be sensitives to Monosodium glutamate (MSG) or caffeine.
Food Sensitivity: this is an umbrella term that encompasses food allergies, food intolerances, and chemical sensitivities.
What Causes Food Allergies: The Microbiome Theory
Understanding what causes a food allergy is complex. To date, we still don’t have a clear picture of what is at the root of their development, but many theories have been put forward trying to explain the increased prevalence of allergies that we are seeing.
The onset of food allergies typically occurs at a young age. During the early stages of childhood, the gut microbiota and immune system are still developing. As we also know that 80% of immune system lives in the gut and allergies are a disproportionate immune response, you can see why looking to the microbiome is of interest to researchers.
While more work is still needed in this area, there are a few studies that corroborate this thinking. A review by Burbank et al. reported that children who go on to have allergy later in life (versus those who do not) do in fact show differences in their microbiome in the first few months of life: Reduced diversity of stool flora at age 1 month was predictive of atopic eczema at age 2 years and allergic rhinitis at age 6 years.3
The development of the microbiome happens in utero and continues with maternal transmission after birth. Exposure to antibiotics at a prenatal or postnatal stage, the method of childbirth (vaginal or C-section) and the baby’s diet (breastfeeding, infant formula or solid foods) all have an impact on the microbiome.
A meta-analysis of 26 studies has established a link between the method of childbirth and six types of allergies: food, atopic, respiratory, dermatitis, rhinitis and asthma. In each of these cases, there was a significant positive correlation between mothers who had C-sections and a moderate risk of developing an allergy.4
Despite this promising evidence, as Burbank and others point out, we still can’t be sure whether such changes in an infant’s microbiota increase their chances of developing an allergy or if this is a sign of a deregulated immune system in early life that may lead to allergies.
Can Food Allergies be Prevented?
With a greater understanding of the connections between allergies, the immune system and the microbiota, can allergies be prevented by bolstering good gut bacteria? Unfortunately, we are not quite there yet, and broader studies need to be conducted before we can definitively answer that question.
Nonetheless, we do know that increasing beneficial gut bacteria and promoting the microbiota diversity of mothers, babies and children does have a beneficial impact on health and well-being, and bolstering the immune system.6 Given what we currently know about the connections between gut health, the immune system, and allergy, supporting our microbiome may be a tool in helping to safeguard us from adverse health issues like the development of allergies.
With that in mind, a probiotic such as Bio-K+ can be an excellent addition to your daily diet as it provides your body with three unique strains of probiotics bacteria (L. acidophilus CL1285®, L. casei LBC80R®, L. rhamnosus CLR2®) that have been clinically proven to keep bad bacteria in check, create a healthy environment for good bacteria to grow, help maintain gut integrity, and promote the immune system. Bio-K+ also offers a product range designed to nurture a healthy gut microbiota in children: every bottle of Bio-Kidz contains 12.5 billion probiotic bacteria.
Beyond Probiotics: Promoting Diversity in the Microbiome
In addition to your daily probiotics, lifestyle factors can either enhance or hinder the growth of beneficial bacteria. A healthy diet, full of fibre-rich vegetable sources, will help sustain your beneficial gut bacteria.6 As part of a study published in 2018, researchers successfully demonstrated that a high-fibre diet boosts specific bacteria groups that promote the production of a particular metabolite, short-chain fatty acids, which have a positive impact on intestinal permeability. It therefore serves as a better barrier and allows our immune systems to function optimally.7
When possible, try to avoid antibiotic use if it is not medically necessary and cut down on antibacterial household and health products that sterilize your day-to-day environment.
Whether you already have a diagnosed allergy, food intolerance or food sensitivity or wish to live healthily at any age, it is essential to look after the bacteria in your digestive system. These bacteria continuously work to optimize several of our internal processes, because, as we have learned, our guts play a significant role in our bodies’ immune responses.
Do you have any other questions about allergies or gut health? Ask us in the comments below! You will find Bio-K+ products in your local pharmacies, grocery stores and health food stores. Check our store locator. For more information about Bio-K+, probiotics and digestive health, get in touch, follow us on Facebook and Instagram or join our community.
References
2. http://foodallergycanada.ca/connect-with-us/media/media-kit/
3. Burbank AJ, Sood AK, Kesic MJ, Peden DB, Hernandez ML. Environmental determinants of allergyand asthma in early life. J Allergy Clin Immunol. 2017 Jul;140(1):1-12. doi: 10.1016/j.jaci.2017.05.010.
4. Bager P, Wohlfahrt J, Westergaard T. Caesarean delivery and risk of atopy and allergic disease: meta-analyses. Clin Exp Allergy. 2008 Apr;38(4):634-42. doi: 10.1111/j.1365-2222.2008.02939.x. Epub 2008 Feb 11.
5. Jenmalm, M C. The mother-offspring dyad: microbial transmission, immune interactions and allergy development. Journal of internal medicine [0954-6820] An.:2017 Vol. :282 iss :6 pg :484 -495Park HJ, Lee SW, Hong S. Regulation of Allergic Immune Responses by Microbial Metabolites. Immune Netw. 2018 Feb 26;18(1):e15. doi: 10.4110/in.2018.18.e15. eCollection 2018 Feb.
6. Fujimura, Kei E., and Susan V. Lynch. “Microbiota in Allergy and Asthma and the Emerging Relationship with the Gut Microbiome.” Cell host & microbe5 (2015): 592–602. PMC. Web. 28 May 2018.
7. Park HJ, Lee SW, Hong S. Regulation of Allergic Immune Responses by Microbial Metabolites. Immune Netw.2018 Feb 26;18(1):e15. doi: 10.4110/in.2018.18.e15. eCollection 2018 Feb.
