Every spring it creeps in—the congestion, sneezing, itchy eyes, and relentless sniffles. You may think you know the cause and the cure. But what if your hay fever has less to do with the air around you and more to do with what’s living deep in your gut? New research reveals a surprising connection between your immune response to pollen and the trillions of microbes that line your intestines, offering an unexpected, natural path to lasting allergy relief.
Key Takeaways
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Gut health plays a crucial role in regulating immune responses, including allergic reactions such as hay fever.
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A specific probiotic blend (Lactobacillus gasseri, Bifidobacterium bifidum, and Bifidobacterium longum) significantly reduced hay fever symptoms in a clinical trial.
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Supporting gut microbiota through diet and probiotics may provide long-term relief from allergies without the side effects of conventional medications.
The Shocking Link Between Your Gut and Seasonal Allergies
Runny nose, swollen nasal passages, sinus headaches, itchy, puffy eyes, and sneezing. Yes, you guessed it, the hay fever season is upon us.
Many still think of it as a childhood affliction, but you can get your first attack of hay fever at any age. Its occurrence in older adults is rising each year.
Most of the 40 million Americans affected will be reaching for decongestants and antihistamines in the hope of some relief.
But these medications are often not only of minimal value, they can cause dizziness, drowsiness, blurred vision, dry mouth, and even nausea, vomiting, and restlessness. I used to take them myself, from time to time, but I can hardly tolerate them anymore.
Now a new study suggests a natural alternative may be better than pharmaceuticals, with none of the unpleasant side effects. . .
It all relates to the bacteria in your intestines – the gut microbiota.
Three-quarters of our immune system resides in the microbiota. Immune cells throughout the whole body receive signals and are in constant communication with the gut bacteria.
Considering that hay fever is an autoimmune problem in which our immune system attacks harmless substances like dust and pollen, we shouldn’t be surprised to learn there’s a colon connection.
The cocktail of different strains of bacteria in our colon can determine how our immune system responds to challenges. If the colon becomes unbalanced with too many ‘bad’ varieties of microbes and not enough ‘good’ ones, the result can be allergies and many other health problems.
Putting The Idea to The Test
To test the impact of gut bacteria on hay fever, researchers from the University of Florida recruited 173 healthy men and women, average age 27, who suffered from mild to moderate seasonal allergic rhinitis (inflammation of the nasal membrane.)
The participants were randomly assigned to take either a placebo or two Kyo-Dophilus supplements a day, containing a total of three billion colony-forming units of three strains of bacteria – Lactobacillus gasseri (formerly called L. acidophilus), Bifidobacterium bifidum, and Bifidobacterium longum. The trial lasted for eight weeks.
The strains chosen were the only ones shown from previous studies to improve immunity in people.
The study was conducted during the allergy season, and the participants were asked not to consume any bacteria-containing fermented foods during the study to avoid distorting the results.
The findings were published in the American Journal of Clinical Nutrition.
Probiotics Reduce Hay Fever Symptoms
Those taking the probiotics reported fewer allergy-related symptoms, were less troubled during their daily activities, didn’t suffer as much with constipation, and saw improvements in their quality of life compared to the placebo group.
Remember, they didn’t know whether they were taking the placebo or the probiotic.
An analysis of participants’ stool samples found a shift in the overall profile of intestinal microorganisms in the probiotics group, toward the types of bacteria that should benefit the immune system.
Although the precise mechanism is still being researched, the probiotic strains are believed to work by raising the number of regulatory T cells (T-regs).
A lack of T-regs can lead to an over-aggressive immune response, making people more prone not just to allergies but to autoimmune and inflammatory bowel diseases. On the other hand, an abundance of T-regs can dampen inflammatory responses.
Certain species of bacteria can recruit these T-regs to the gut, while molecules produced by these bacterial strains, such as short-chain fatty acids, also help the intestine accumulate T-regs to increase tolerance to hay fever symptoms.
How to Improve Gut Immunity
Kenya Honda, M.D., Ph.D., is a leading researcher in immunology and microbiology. He maintains that people’s microbiota has deteriorated because of the use of antibiotics and poor-quality food, which renders the host more prone to autoimmunity and allergy.”
If you do have to take a course of antibiotics, it would be wise to follow this with a course of probiotics to help repopulate the bowel with good bacteria.
Your gut will also thank you if you eat fewer refined and processed foods and more fruits, vegetables, and whole grains. These contain dietary fibers (prebiotics) that feed friendly gut bacteria.
Another way to boost friendly bacteria is to eat fermented foods. These contain a diverse collection of microorganisms. Examples include non-pasteurized yogurt and cultured varieties of sour cream, butter, and cream cheese. Kefir is a probiotic dairy beverage that contains billions of microbes per serving. Nondairy versions are also available.
Vegetable-based probiotics include fermented sauerkraut, kimchi, and pickles. Make sure you buy those with live cultures, widely available in health food stores. Pasteurized sauerkraut contains no live microorganisms.
Of course, probiotics are also available as supplements.
Summary
A groundbreaking study from the University of Florida found that probiotics containing specific bacterial strains significantly reduced hay fever symptoms. This natural approach works by restoring balance to the gut microbiota, which plays a key role in regulating immune function. Participants experienced fewer allergy symptoms, better digestion, and improved quality of life. Unlike medications, probiotics carry no harsh side effects and may help prevent overactive immune responses linked to both allergies and autoimmune disorders. Researchers suggest improving gut health through probiotics, fiber-rich foods, and fermented products to support long-term immune balance.
Frequently Asked Questions
Can gut bacteria affect allergies?
Yes. The gut microbiota influences the immune system, and an imbalance can contribute to allergies like hay fever.
Which probiotic strains were tested in the study?
Lactobacillus gasseri, Bifidobacterium bifidum, and Bifidobacterium longum were used and shown to improve immune function.
Are probiotics safer than traditional allergy medications?
Probiotics do not cause side effects like drowsiness or nausea, making them a safer long-term alternative for many people.
How long did the participants take probiotics before seeing results?
The study lasted 8 weeks, and those on probiotics reported reduced symptoms and improved daily functioning by the end.
What else can help improve gut health naturally?
Eating fiber-rich foods, fermented products, and minimizing antibiotics and processed foods can help support a balanced microbiome.
Susan D. Clark
Susan Clark is an award-winning, Emmy-nominated journalist and author who has written about nutrition, health, and wellness for 27 years. She has developed content for articles, reports, books, videos, and television news segments featuring some of today’s top alternative and integrative doctors. She earned a bachelor of science in broadcast journalism from Texas Christian University. She lives in Los Angeles with her husband, two sons, and numerous pets.