Could Your Gut Influence Your Hay Fever?
Spring arrives, the pollen count rises, and suddenly you’re sneezing, rubbing your eyes and reaching for the tissues.
Hay fever is usually blamed on what’s happening outside. But researchers are also investigating whether the bacteria living inside your gut could influence how your immune system responds to allergens.
The science is promising, although the gut microbiome is not a proven cure for hay fever.
Your Gut and Immune System Are Connected
Your gut contains trillions of microorganisms, collectively known as the gut microbiome.
These microbes help digest food, produce useful compounds and interact with your immune system.
Hay fever, also known as allergic rhinitis, occurs when your immune system reacts to otherwise harmless substances such as pollen, dust mites or animal dander.
This immune response can release chemicals including histamine, leading to symptoms such as:
Sneezing
Runny or blocked nose
Itchy eyes
Watery eyes
Nasal congestion
One of the immune system’s important jobs is tolerance — recognising harmless substances without mounting an unnecessary inflammatory response.
Gut microbes appear to help train and regulate this process, particularly during childhood.
What Does the Research Show?
Studies have found differences in the gut microbiomes of people with allergic rhinitis compared with people without allergies. However, researchers have not identified one consistent bacterial pattern that causes hay fever.
Some of the strongest evidence comes from studies following children from infancy.
Research suggests that early gut microbiome development, along with higher levels of certain microbial metabolites, may be associated with a lower risk of allergic sensitisation and allergic disease later in childhood.
These findings suggest that the microbiome plays a role in immune development.
However, they do not prove that changing your gut bacteria as an adult will eliminate hay fever.
Why Is Fibre Important?
When gut bacteria ferment dietary fibre and resistant starch, they produce compounds called short-chain fatty acids (SCFAs).
One of these, butyrate, is particularly interesting to allergy researchers.
Butyrate helps maintain the intestinal barrier and can influence immune cells involved in controlling inflammation and maintaining immune tolerance.
Studies in children have linked higher levels of butyrate and propionate with lower rates of allergic sensitisation and some allergic conditions.
This provides a plausible reason why a fibre-rich diet might support healthy immune regulation.
However, clinical trials have not yet established that eating more fibre can treat or prevent hay fever.
Do Probiotics Help With Hay Fever?
Probiotics are live microorganisms found in certain supplements and fermented foods.
Several randomised controlled trials have investigated whether probiotics can help people with allergic rhinitis.
Some meta-analyses suggest that certain probiotic preparations may improve nasal symptoms and quality of life. However, the average benefits appear modest, and results vary considerably between studies.
One reason may be that different trials use different:
Bacterial strains
Doses
Treatment durations
Study populations
Researchers have not yet established which probiotic works best, who is most likely to benefit, or whether any improvements last after supplementation stops.
There is currently no evidence that probiotics cure hay fever or replace established treatments, such as antihistamines, nasal corticosteroids or allergen immunotherapy.
What Does ZOE Say?
ZOE’s nutrition research and educational material highlights the relationship between dietary diversity, the gut microbiome and immune health.
Their discussions around allergies also acknowledge an important uncertainty: researchers do not yet know whether microbiome differences contribute to allergies, whether allergic disease changes the microbiome, or whether both processes occur.
The practical dietary advice is sensible.
Eating a broad range of plant foods and fibre can support microbial diversity and fermentation. However, the stronger claim that a personalised microbiome diet will significantly improve hay fever remains unproven.
How Can You Support Your Gut Health?
You do not need an expensive microbiome test or a cupboard full of supplements to support your gut health.
Instead, focus on the basics.
Aim to eat a wide variety of:
Vegetables and fruit
Legumes such as beans and lentils
Whole grains
Nuts and seeds
Other fibre-rich foods
You can also include sources of resistant starch, such as cooled potatoes, rice or legumes.
If you enjoy them and tolerate them well, fermented foods such as natural yoghurt, kefir, kimchi and sauerkraut can be useful additions to a varied diet.
These habits support general health and provide fuel for beneficial microbial activity.
Any improvement in hay fever should be considered a possible additional benefit, rather than a guaranteed outcome.
Don't Forget Evidence-Based Hay Fever Treatment
While supporting your gut health can be part of a healthy lifestyle, it shouldn't mean ignoring treatments that are known to help hay fever.
If hay fever is affecting your sleep, work, exercise or quality of life, speak with your GP or pharmacist about evidence-based treatment options.
Persistent or severe symptoms may warrant assessment by an allergy specialist.
The Bottom Line
Your gut microbiome is involved in regulating your immune system, and research suggests it may play a role in the development of allergic disease.
Probiotics show some promise for reducing hay fever symptoms, but the evidence remains inconsistent.
A healthy, fibre-rich diet is a worthwhile foundation for overall health — but it is not a proven allergy cure.
The most useful approach is to support your gut health while continuing to manage hay fever with treatments supported by clinical evidence.
At Lane Cove Chiropractic Centre, we encourage a whole-person approach to health, including movement, sleep, nutrition and appropriate medical care.
If you have questions about how your health habits fit together, speak with your chiropractor at your next visit.
Research References
Cait A, et al. Reduced genetic potential for butyrate fermentation in the gut microbiome of infants who develop allergic sensitization. Journal of Allergy and Clinical Immunology. 2019;144:1638–1647. PMID: 31279007.
Roduit C, et al. High levels of butyrate and propionate in early life are associated with protection against atopy. Allergy. 2019. PMID: 30390309.
Depner M, et al. Maturation of the gut microbiome during the first year of life contributes to the protective farm effect on childhood asthma. Nature Medicine. 2020. PMID: 33139948.
Zajac AE, Adams AS, Turner JH. A systematic review and meta-analysis of probiotics for allergic rhinitis. International Forum of Allergy & Rhinology. 2015;5:524–532. PMID: 25899251.
Farahmandi K, Mohr AE, McFarland LV. Effects of probiotics on allergic rhinitis. American Journal of Rhinology & Allergy. 2022;36:440–450. PMID: 35099301.
Liu D, Wang X, Zhang H. Efficacy and safety of gastrointestinal microbiome supplementation for allergic rhinitis. Phytomedicine. 2023. PMID: 37418839.
Dr Mark has a special interest in helping recreational athletes of all ages perform better and prevent injury. Correct breathing and postural alignment are critical for top performance and injury prevention and is an integral part of “The Over 40 Athlete System” that Mark has developed.
Dr Julie has a special interest in helping mothers and “mothers to be”. Her Post Graduate qualifications in Paediatric Chiropractic and as an ex-midwife give her a unique ability to help pregnant women, new mums and their young children.
Yours in Health,
Dr's Mark & Julie
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