Allergies are a growing concern across the UK, affecting millions of people each year. From hay fever and food allergies to eczema and asthma, allergic conditions can have a major impact on quality of life. But what many don’t realise is the potential link between allergies and the gut microbiome, the community of trillions of bacteria and other microbes that live in our digestive tract.

In this article, we explore how allergies might influence the microbiome and vice versa, with insights provided by Vivere's Head of Nutrition, Yusra Serdaroglu Aydin. Yusra is a registered dietitian with a background in nutrition, food engineering and culinary arts. Her approach is grounded in science and shaped by a strong understanding of personalised nutrition and the human microbiome, making her uniquely placed to explain the complex relationship between gut health and immune function.

Here are the five biggest takeaways from this article about allergies and the gut microbiome.

• The gut microbiome plays a vital role in the development and regulation of the immune system, which is central to allergic responses.

• Individuals with allergies often have less microbial diversity in their gut, especially during early life.

• Diet, antibiotic use and birth method can all influence both the microbiome and the likelihood of developing allergies.

• Supporting the microbiome through prebiotics, probiotics and a varied diet may help reduce allergy risk and severity.

• More research is needed, but emerging evidence suggests that gut health and allergy management are closely linked.

The microbiome refers to the collection of bacteria, fungi, viruses and other microorganisms that live in and on the human body, particularly in the gut. These microbes are not just passive passengers, they help digest food, produce essential nutrients and play a critical role in immune system development.

A healthy gut microbiome is diverse and well-balanced. When this balance is disrupted, it may lead to a range of health issues, including digestive problems, chronic inflammation and potentially an increased risk of allergic disease.

An allergy is an overreaction of the immune system to substances that are normally harmless, such as pollen, certain foods or dust mites [1]. Common allergic conditions include:

• Hay fever (allergic rhinitis)

• Food allergies (e.g. to peanuts, eggs or shellfish)

• Eczema (atopic dermatitis)

• Asthma

The immune system mistakenly identifies allergens as threats and launches a defensive response, leading to symptoms such as sneezing, rashes, breathing difficulties and, in some cases, life-threatening reactions.

The gut is the largest immune organ in the body and is home to around 70% of the body’s immune cells. The microbiome trains these immune cells to respond appropriately to potential threats while tolerating harmless substances.

In early life, the microbiome helps shape how the immune system develops. A healthy microbial environment encourages the immune system to build tolerance to allergens. If the gut microbiome lacks diversity or is disrupted, often called dysbiosis, it may lead to an imbalance in immune responses, increasing the likelihood of allergies [2] [3] [4].

Numerous studies have found that children who go on to develop allergies often show differences in their gut microbiota compared to those who do not [5] [6]. For example, lower levels of beneficial bacteria such as Bifidobacteria and Lactobacillus have been observed in infants who later develop eczema or food allergies [7].

Animal studies also show that altering the gut microbiome can influence allergic responses [8] [9]. While human studies are ongoing, the evidence so far suggests that maintaining a healthy gut microbiome may help reduce the risk of developing allergies.

The first few years of life are especially important for both immune development and microbiome formation. Several key factors during this period can affect both:

Babies born vaginally are exposed to beneficial microbes from the mother’s birth canal, which helps seed the gut microbiome. On the other hand, babies born via caesarean section are more likely to have an altered gut microbiota and may be at greater risk of developing allergies.

Breastfeeding supports the growth of beneficial bacteria and contains immune-modulating compounds. Formula-fed babies tend to develop a different microbial profile and may have a higher risk of allergic disease, although formula options are improving [10] [11] [12].

Antibiotics can disrupt the balance of the gut microbiome by killing both harmful and beneficial bacteria. Frequent or early use of antibiotics has been associated with an increased risk of allergies, including asthma and eczema.

Children raised in more sterile environments or those exposed to fewer microbes (for example, due to less time spent outdoors or lack of interaction with animals) may miss out on important microbial exposures that help train the immune system. This is sometimes referred to as the ‘hygiene hypothesis’ [13].

Diet is one of the most powerful ways to shape the gut microbiome throughout life. A fibre-rich, plant-based diet supports the growth of diverse and beneficial gut bacteria, which can in turn help regulate immune responses.

Prebiotics are types of fibre that feed beneficial gut bacteria. These are found in foods such as garlic, onions, bananas, leeks, asparagus and wholegrains.

Probiotics are live beneficial bacteria found in fermented foods like yoghurt, kefir, sauerkraut and kimchi. Some supplements also contain probiotic strains.

Research suggests that prebiotics and probiotics may reduce the risk or severity of allergic conditions, especially when introduced early in life [14]. However, not all products are the same, and the benefits may depend on the specific strains and individual needs.

Polyphenols, natural compounds found in colourful fruits, vegetables, tea and dark chocolate, may also support microbial diversity and reduce inflammation. Similarly, nutrients like vitamin D, omega-3 fatty acids and zinc play roles in immune regulation and gut health [15].

While improving gut health is not a guaranteed cure for allergies, it may help support the immune system and reduce inflammation, which can make allergic reactions less severe.

Some people report reduced allergy symptoms after dietary changes or the introduction of specific supplements, although results can vary. Personalised nutrition, like we offer at Vivere, can help identify the most suitable approach.

It’s also important to note that those with food allergies must continue to avoid allergens and follow medical guidance, even if pursuing strategies to improve gut health.

If you or your child is experiencing allergic symptoms, speak to a GP or allergy specialist for diagnosis and treatment. While gut health can support overall wellbeing, it should never replace professional medical advice or emergency care in the case of severe allergic reactions.

“The link between allergies and the gut microbiome is a rapidly developing area of science. What we do know is that a healthy, diverse gut microbiome plays a vital role in supporting the immune system and may help reduce the risk or severity of allergic conditions. Nurturing gut health through diet, lifestyle and informed choices can make a meaningful difference. As research progresses, we hope to uncover even more ways to support those living with allergies through microbiome-focused approaches.”

Vivere helps you take control of your health with personalised insights from state-of-the-art gut microbiome testing, nutritional guidance, science-backed supplements and expert support. Sign up today and start living better, for longer.

[1] Overview: Allergies - NIH

[2] Microbiome and Immunity: Role & Interaction | StudySmarter

[3] Editorial: The early life window of opportunity: role of the microbiome on immune system imprinting - PMC

[4] Childhood Development and the Microbiome: The Intestinal Microbiota in Maintenance of Health and Development of Disease During Childhood Development - PMC

[5] Relationship between Gut Microbiota and Allergies in Children: A Literature Review - PMC

[6] Gut microbiota of one-and-a-half-year-old food-allergic and healthy children - ScienceDirect

[7] Probiotics in the Treatment and Prevention of Allergy in Children - ScienceDirect

[8] The Microbiome and Development of Allergic disease - PMC

[9] Influence of microbiome and diet on immune responses in food allergy models - PMC

[10] Breastmilk Feeding Practices Are Associated with the Co-Occurrence of Bacteria in Mothers’ Milk and the Infant Gut: the CHILD Cohort Study - ScienceDirect

[11] Gut microbiome and breast-feeding: Implications for early immune development - Journal of Allergy and Clinical Immunology

[12] Breastfeeding and the Microbiome | OHSU

[13] Natural environments in the urban context and gut microbiota in infants - ScienceDirect

[14] The Role of Prebiotics and Probiotics in Prevention of Allergic Diseases in Infants - PMC

[15] Polyphenols—Gut Microbiota Interrelationship: A Transition to a New Generation of Prebiotics - PMC