Understanding food allergies and gut health

With a rise in food allergies amongst young children in the UK, and more discussion than ever about the possible link between the community of bacteria in the gut and allergy risk, or avoidance of food allergies, it’s becoming clear that our gut health may play a crucial role in how our bodies respond to the foods we eat. Researchers are now investigating how early-life factors  –  including diet and antibiotic use  – may influence the gut microbiome, potentially promoting immune tolerance or contributing to the development of allergic conditions. In this blog, we’ll take a closer look at the relationship between gut health and food allergies, and what current research suggests about prevention and management.

The role of the gut in immune development

It often surprises people to learn that around 70% of the immune cells within our bodies are located in the gut, which means the overall health of our gut and the community of bacteria that reside there can have a direct influence on how the immune system works.  Early-life nutrition significantly shapes the gut microbiome, and a healthy, diverse community of gut bacteria can play a vital role in how the immune system responds to food. 

Emerging research suggests that certain patterns in the gut microbiome, notably lower bacterial diversity or an imbalance of specific bacteria, may be linked to a higher risk of developing food allergies. However, there is much more to understand about this before specific recommendations can be made regarding how we might alter this to help reduce allergy risk. Factors such as how a baby is born (vaginal birth or caesarean section), breastfeeding, the timing of introducing solid foods, and exposure to antibiotics early in life can all affect how the gut microbiome evolves and develops.  To support a healthy gut microbiome in these critical years and guide the immune system to recognise and tolerate a wide range of foods (therefore reducing allergy risk), here are some things you can consider as a parent that can help reduce allergy risk (based on the current scientific evidence)

Offer a wide variety of foods from weaning onwards 

A number of studies now recognise that dietary variety (or ‘diversity’) has a positive impact on reducing food allergy risk in babies and young children.  Frequent consumption of plant-based foods such as fruits, vegetables, and legumes seems to be particularly helpful for reducing the risk of food allergies, all of which are fantastic sources of fibre, and the preferred fuel of beneficial gut bacteria!  With this in mind, offering your baby plenty of different foods from the start of weaning onwards would be recommended to help reduce food allergy risk – focusing on variety with fruits, vegetables, beans, lentils and some wholegrains (they don’t have to be avoided entirely when weaning).  This is another reason why, with the exception of allergenic foods, there is usually no need to focus on one new food every three days when your baby starts solids!

Don’t delay introducing common allergenic foods.

It is now widely recognised that delaying the introduction of common food allergens can actually increase the risk of food allergy.  The aim is to introduce these foods, such as eggs, peanuts, sesame, wheat (and all other common allergens), proactively once your baby has started solids, to help the immune system recognise them as safe! When introducing these foods, remember to do so one at a time, starting with small amounts and building up gradually.  Once introduced, remember to maintain these foods in your baby’s diet regularly!

Consider the targeted use of probiotic supplements.

I’m often asked whether certain probiotic strains will help prevent food allergies or manage symptoms. Unfortunately, while research is ongoing, we don’t have robust data on this yet,  as food allergy is complex and multiple factors likely affect allergy risk. However, considering the targeted use of specific strains of bacteria for certain conditions may be a helpful approach for overall gut health and maintaining a positive balance of good bacteria in the gut.  For example:

• Recommendations and scientific evidence show that the strain of bacteria L.Reuteri DSM17938 may have beneficial effects for the prevention of infant colic, or symptom management, especially in breastfed babies.
• Antibiotics are often necessary, but can affect the balance of gut bacteria. Current evidence suggests that commencing the strains of bacteria Lactobacillus rhamnosus or Saccharomyces boulardii can help support the gut microbiome during and after antibiotic use. These probiotic strains have been shown in several studies to reduce the risk of antibiotic-associated diarrhoea and may help maintain a more balanced gut environment.

So, if you remember nothing else about supporting your baby’s gut health and allergy risk, remember;

• Focus on variety when it comes to offering foods during weaning, especially with fibre-rich plant-based foods
• Don’t delay the introduction of common allergens such as egg and peanut
• Consider targeted use of probiotic supplements for specific conditions, but remember food first!