Why taking PROBIOTICS could ease your hay fever symptoms

For millions of Britons, this time of year heralds the start of the hay fever season, meaning months of misery as their lives are blighted by constant sneezing, runny noses and itchy, watery eyes.

Whether you become one of those unlucky enough to be afflicted — and to what extent — has always been thought to be down to a mixture of genetics and the environment, with those living in urban areas, for instance, suffering worse than people in the countryside.

And while for many sufferers pollen is seen as public enemy number one, it may not be entirely to blame.

Groundbreaking new research is now suggesting another element is at work — the bugs in your nose.

Thanks to advances in science, many of us are now aware that our gut microbiome — the intestinal ‘soup’ made up of trillions of bacteria, viruses and even fungi — plays a hugely significant part in our health.

This microbial mixture is now thought by scientists to be crucial for supporting the immune system and keeping a whole host of conditions at bay — including inflammatory bowel disease, obesity, heart disease, food allergies and dementia.

Having a diverse range of bugs and a healthy balance between good and bad bacteria is essential.

Now scientists have discovered that the mix of bacteria in the tissues lining our nasal passages may be similarly important when it comes to hay fever.

Hay fever is triggered in the spring and summer (although some people get it all year round), when pollen from grass and trees comes into contact with the immune cells that line the mouth, nose, eyes and throat.

In those affected, the body mistakes the pollen particles for an infection and reacts by flooding the area with histamine, a chemical released into the bloodstream to try to flush out the invading organism. It is this rush of histamine that causes the symptoms.

Over-the-counter remedies provide relief in about 60 per cent of cases. These include antihistamine tablets (such as cetirizine and loratadine), which lock on to histamine receptors in the nose and throat, blocking the effects of the histamine rush.

Corticosteroid nasal sprays such as beclometasone (brand name Beconase) and fluticasone (Flixonase) also help, by suppressing the immune system response. If these don’t work, patients may be prescribed Grazax — a tablet made with grass pollen that melts under the tongue, gradually teaching the immune system not to overreact. But the drug is available only from a small number of specialist NHS allergy clinics.

However, could changing the bacterial make-up of the nasal cavity offer an alternative?

This relatively new area of research gained wider attention in January, when a paper published in the journal Nature Microbiology revealed that the type of bacterial cocktail you have in your nose can determine whether or not you get hay fever.

Researchers at the U.S. National Institute of Allergy and Infectious Diseases in Maryland and the Shanghai Jiao Tong University in China compared the nasal microbiomes of 55 adults with hay fever with those of 105 healthy volunteers.

They found the hay fever recruits had a much narrower range of bacteria and 17 times as much of one particular type of bacteria: Streptococcus salivarius.

One of the first bugs to colonise the mouth and nose in all of us from birth, it is thought to play an important role in building the immune system in the early years of life. But in hay fever patients, levels seem to be excessive — and further tests revealed why. When researchers took cells from the mucus membrane lining of volunteers’ noses, exposed them to pollen and then put them in a dish alongside S. salivarius and other nasal bacteria, the S. salivarius instantly bonded to the cells ahead of rival bacteria.

This was due to proteins on the bug’s surface that for some reason make it home in on pollen-carrying cells.

Once the bacterium had latched on to nasal cavity cells, it proceeded to boost the cells’ production of proteins that promote inflammation, while also stimulating the immune system to trigger the histamine release that leads to sneezing, watery eyes and runny nose.

In short, this specific bacterium seems to turbocharge the immune system’s response to the presence of pollen — making hay fever symptoms much worse.

The researchers now plan to investigate ways to reduce levels of the rogue bacterium without wiping out healthy nasal bacteria at the same time.

And some studies already suggest there is a way to do this — by taking probiotic supplements, just as many people already do for a healthy gut.

One such study in 2022, led by scientists at the National Institute of Integrative Medicine in Melbourne, Australia, recruited 40 severe hay fever sufferers during the peak hay fever season; half took a daily probiotic powder that they either sprinkled on food or dissolved in water, while the others were given a placebo powder mainly containing corn starch. The powder, a commercially available product in Australia, contained a wide range of probiotics also commonly found in over-the-counter supplements available in the UK.

The key ones were Lactobacillus reuteri GL104, Lactobacillus plantarum LPl28, Lactobacillus rhamnosus MP108 and Bifidobacterium lactis Bl-04.

The results, published in May 2022 in the journal Frontiers in Nutrition, showed a significant decline in symptoms in the probiotic group compared with those taking the placebo.

They also reported better sleep and reduced daytime fatigue (a common symptom of hay fever), while blood tests showed the group had more anti-inflammatory cytokines (proteins released by the immune system) compared with pro-inflammatory ones.

Dr Karin Ried, director of research at the National Institute of Integrative Medicine and a scientist involved in the study, said although consuming the probiotics as a powder acts upon the bacterial mix in the gut, this would also affect the nasal region. ‘Probiotics taken orally will work primarily on the gut,’ she told Good Health.

‘But metabolites [by-products produced when probiotics are broken down in the gut] will travel to other parts of the body via the bloodstream and so also indirectly influence the nose.’

The key to success, she added, is to start taking probiotics roughly three weeks before the start of the hay fever season to give the gut microbiome enough time to respond properly.

The findings partly echo those of a small UK study carried out in 2013, where 60 hay fever sufferers were split into two groups — for 16 weeks one group had a daily drink containing a probiotic, while the others were given a placebo.

The study, at the University of East Anglia and published in the journal PLOS One, showed significant reductions in nasal tissue inflammation (a key part of hay fever) in the probiotic group due to bacterial changes.

But the patients reported little significant change in their hay fever symptoms. Nevertheless, the researchers concluded in their report: ‘This is strong evidence of how the gut microbiome can influence distant cells, such as those lining our nasal passages.’

Some studies even suggest that our nasal bacterial profile is set in the first few years of life and determines whether we suffer hay fever from childhood.

A 2018 investigation by the National University of Singapore, published in the Journal of Allergy and Clinical Immunology, studied nasal swabs from 122 babies in the first 18 months of life and found that those free of hay fever symptoms had a much broader variety of bacteria in their noses.

British allergy experts acknowledge that nasal microbiome research is shedding new light on how hay fever develops but warn that it’s too early to say if it will transform treatment.

‘It has caught the attention of the allergy community,’ says Professor Adam Fox, a consultant in paediatric allergy at Guy’s and St Thomas’ Hospital in London.

‘But the truth is we still know very little about it. We can’t say for certain, for instance, if people with hay fever’s nasal microbiome is like that because they have hay fever, or whether it’s the cause of the hay fever.’

One unusual example of this new interest in nasal bugs is mucus transplants from the noses of healthy donors into those of patients with chronic rhinosinusitis. This condition, which affects nearly one adult in ten in the UK, often arises from severe hay fever: it occurs when the nasal passages become inflamed and blocked, allowing bacteria to grow, causing painful infection in the sinuses.

Treatment often involves antibiotics and sometimes surgery to clear the clogged sinuses.

But researchers at the University of Queensland in Australia are currently running a trial involving 60 volunteers using nasal mucus transplanted from healthy strangers as an alternative to drugs and surgery. The idea borrows from faecal transplants, used on the NHS to combat C. difficile infections.

Researchers say the trial, due to finish in 2025, could pave the way for a whole new approach to treating a condition that affects an estimated ten million Britons.