Hayfever, asthma, and eczema are collectively known as atopic diseases. Seemingly unrelated, these conditions share some common connections, with links to gut health and the microbiome.
What is atopy?
Defined as an allergic reaction to an environmental trigger such as dust mites, pet hair, or pollen, or to certain foods, atopic diseases often begin in childhood and can occur together. Around 80% of people with allergic asthma for example also have a related atopic condition like hayfever, eczema or food allergies.
What causes atopic conditions?
The exact cause of atopic conditions isn’t clear, however there appears to be genetic predispositions towards atopy, and the likelihood of developing one or more of these conditions is stronger if there is a family history of atopy.
Gut health and atopic disease
The gut microbiota is strongly associated with atopic conditions. The billions of bacteria, yeasts, and fungi living in the digestive system, respiratory system and on our skin play a key role in regulating the immune response and inflammation. Research increasingly shows that dysbiosis (an imbalance between beneficial microbes and those that are potentially pathogenic) can skew the immune response and increase the risk of atopy.
Antibiotics are a frequent trigger for dysbiosis as the medication cannot clearly distinguish between beneficial and harmful bacteria. This is particularly concerning during infancy when the gut microbiota and immune system are still being established.
Probiotics and atopic disease
Defined by the World Health Organisation as “live microorganisms that when administered in adequate amounts confer a health benefit on the host” probiotics are increasingly associated with reducing the risk of atopic diseases.
Several randomized controlled trials have examined the use of probiotic supplements in pregnant women, breastfeeding mothers, babies, and young children. The results indicate that certain probiotic strains can reduce the risk of developing infant eczema – the most common childhood atopic disease.
Recent studies have highlighted a microbiome “signature” in food allergy, especially in children, suggesting that dysbiosis in early life may increase the risk of a food allergy persisting through childhood. In one study, the gut microbiota of 3–6 months’ infants were proven to affect milk allergy resolution at age 8 years.
Managing atopic conditions
Supporting the balance and diversity of the gut microbiota is a key step in managing atopic conditions. The gut microbes thrive on a diverse range of foods, so including a rainbow spectrum of vegetables and fruits is vital.
Fermented foods may be helpful if histamine intolerance isn’t a concern. Including sauerkraut, kefir, kimchi, live yoghurt, miso, and tofu regularly helps to ‘top up’ the numbers of beneficial bacteria in the gut.
Vitamin C and quercetin may help manage the inflammation and excess histamine caused by atopic conditions. Sources of vitamin C include watercress, berries, citrus fruit, cauliflower, kiwi, peppers, and parsley. Quercetin is found in apples, cherries, onions, shallots, and broccoli.
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