Seasonal Allergy “Off Switch” Discovered in the GUT

By Dr. Scott Olson, ND Posted June 26, 2025

“Doc, why am I suddenly suffering from seasonal allergies when I’ve never had them before?”

It’s a question I get all the time—and my answer might surprise you.

Stop looking up at the trees—and start looking down at your gut…

Your sneezing fits, itchy eyes, and runny nose might have more to do with what’s happening in your gut than what’s floating in the air.

We’ve known for quite some time that the gut microbiome—the collection of trillions of bacteria, fungi, and other microorganisms that live in your digestive tract—affects our health in a variety of ways.

But now, scientists say your gut health could also influence your chances of developing seasonal allergies.

Here’s what the research revealed…

People with seasonal allergies, especially to pollen, have significantly lower diversity in their gut microbiota. Recent research suggests they typically have higher levels of Bacteroidales and lower levels of Clostridiales bacteria.

But why would your gut bacteria affect your reaction to pollen? The answer lies in how your immune system develops and functions.

The bacteria in your gut help control how your immune system works. These helpful microbes influence your body’s defenses from the time you’re born and continue to communicate with your immune system throughout your life.

When your gut bacteria fall out of balance, your immune system may overreact to harmless substances like pollen—triggering allergy symptoms.

Various things can cause this gut imbalance in the first place:

• Antibiotics: These powerful drugs are sometimes necessary, but they kill good gut bacteria along with the bad and should be used sparingly.
• Processed foods: High-sugar, low-fiber, ultra-processed foods deprive your beneficial bacteria of nutrients while feeding the problematic ones.
• Stress: Chronic stress changes your gut environment, reducing diversity and promoting inflammation.
• Environmental toxins: Pesticides, food additives, and chemicals can all disrupt your microbiome.

So, what can you do about it? Rather than masking symptoms with medication, the real solution to your seasonal allergies is to focus on fixing your gut:

• Feed the good bugs: Eat more foods that are rich in prebiotic fiber—including fruits, vegetables, nuts, and seeds—to nourish your beneficial bacteria.
• Eat fermented foods: Eating foods like yogurt, kefir, sauerkraut, and kimchi boosts beneficial bacteria.
• Ditch the junk foods: Reduce the amount of sugar and processed foods in your diet, which feed harmful bacteria and promote inflammation.
• Take a probiotic: Research shows that probiotics—including Lactobacillus casei, Lactobacillus paracasei, and Bifidobacterium longum—can significantly improve seasonal allergies by restoring gut health.
• Identify food sensitivities: A simple elimination diet (removing one food category at a time) can pinpoint allergy-triggering foods, reducing overall inflammation and improving seasonal allergies.

The next time your eyes start itching, and your nose starts running, remember that popping an antihistamine is just putting a Band-Aid on the problem.

The real solution is to heal your gut.

P.S. Avoid these common mistakes that make seasonal allergies WORSE.

Written By Dr. Scott Olson, ND

Nearly 25 years ago, failed mainstream medical treatments left Dr. Olson in constant pain – and his health in ruins. And that’s when he did something REVOLUTIONARY. He began his career in medicine – and dedicated his life to uncovering the true, underlying causes of disease.
Through his innovative medical practices in Tennessee and Colorado, Dr. Olson has helped cure countless seniors from across America of arthritis… heart disease… diabetes… and even cancer. All without risky prescription drugs or painful surgeries.

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