How to Support Your Immune System as Fall Approaches

The transition to fall brings with it more than cooler days and shifting light. Our immune systems, microbiomes, and even our circadian rhythms begin to respond to seasonal cues that are hard-wired into our biology.

In the fall, the focus of our immune system and gut microbiome shifts: fall allergies and pollens rise, carbohydrate-rich fruits and vegetables reach their peak, kids go back to school, the sunlight begins to wane, and we spend more time indoors. Each of these changes brings new inputs—both microbial and environmental—that challenge the balance of our internal ecosystem.

The Gut and Your Immune System: A Two-Way Street

Approximately 70% of the immune system resides in the gut. The gut is a primary interface of mucosal immunity, along with the nasal passages and lungs. These mucosal surfaces are constantly interacting with the outside world, and their ability to respond appropriately depends on the signals they receive from our microbial community and how this immunity has been “trained” over our lifetime.  

A healthy gut lining—supported by beneficial bacteria—helps determine whether an immune response is triggered or tempered. In babies this training occurs in the first three years of life.   When functioning well, this interface acts as both a physical barrier and an intelligent communicator deciding self from non-self and what an appropriate response is. When it's compromised, the immune system can become overactive or under-responsive, increasing susceptibility to illness and chronic immune stress.

Butyrate: A Fatty Acid That Supports A Healthy Gut

Butyrate is one of the most important compounds produced by gut microbes. It supports the regeneration and strength of the intestinal lining, regulates immune signaling, and reduces oxidative stress. It also influences how immune cells differentiate and how inflammatory responses are expressed.

Butyrate-producing bacteria tend to be the ones most impacted by antibiotic use, dietary changes, and modern environmental exposures. Rebuilding that population is key to regaining balanced immune responses and healthy gut barrier. 

Why We Designed Ideal Immunity®

Ideal Immunity® was developed to strengthen the mucosal immune barrier by reintroducing microbial allies that perform specific functions. It’s a six-strain formula that includes:

• Lactobacillus ruminis (TBC0073™) – a keystone strain with strong pathogen control and immune-modulating properties.
• Bacillus subtilis (DE111®) – supports immune regulation and produces compounds that reduce unwanted microbes.
• Lactobacillus plantarum (TBC0036™) – improves microbial stability and helps buffer the system under stress.
• Pediococcus acidilactici (TBC0068™) – regulates nutrient transport and supports the mucosal lining.

Ideal Immunity is more than  a general-purpose probiotic. It’s a targeted reintroduction of a frontline microbial defense force—designed to reestablish microbial communities that can produce butyrate, adjust gut pH, and directly counteract foodborne pathogens like Listeria, Salmonella, and E. coli.  If you have been struggling and are looking for something that really works, look no further.  

REAL RESULTS

“Having lived with an intestinal infection that I believed had caused permanent damage to the lining of my intestinal tract since 1974, and after having tried over 50 different probiotics without seeing any improvement, I am presently in my second year of taking Ideal Immunity and I'm seeing slow but steady improvement that I had not believed possible after 40 years... No other probiotic has done this. I believe the team at BiotiQuest is really on to something with this probiotic for treatment of chronic post infectious irritable bowel syndrome with diarrhea.”
— Jeff M. ★★★★★

Fall, the Microbiome, and Seasonal Eating

Fall is a season of abundance—and traditionally, a time to prepare for scarcity. While modern life has disrupted those cycles, our biology still remembers. My garden is ripe with tomatoes and winter squash and the farmer’s markets are filling up with fall fruits.  

It’s the season to explore these local sources of nutrient-dense foods, including pasture-raised beef, pork, lamb, and wild game. These foods support immune function by providing fat-soluble vitamins, complete proteins, and minerals necessary for gut repair and resilience. Finding a local source for your meats is a great way to support your local farming community, as well as, providing you the opportunity to ask specific questions about how they raise their animals.  

While a fiber-rich diet is often encouraged for gut health, it’s important to be cautious if you're dealing with SIBO or other unresolved gut issues. Many of our customers are working to resolve sensitivity to fermentable fibers.  In these cases, focusing first on calming microbial overgrowth and repairing the terrain can help move you in a positive direction—eventually allowing for a gradual reintroduction of fiber to support microbial diversity over time.

REAL RESULTS

“My hayfever allergy symptoms were intense this year and not relieved by any over-the-counter antihistamines. In desperation I tried Ideal Immunity Probiotics. To my surprise, this product reduced my symptoms to the point that my allergies are finally well managed. Also, I've recovered more quickly from minor cold symptoms than I did before taking this product.”
— Brenda M. ★★★★★

Immune Resilience Isn’t Seasonal—But It Is Shaped by the Seasons

We don’t “boost” the immune system in a single moment. We support and shape it over time through our inputs, exposures, and the microbial conversations happening beneath the surface.

Fall is an opportunity to align with that shaping process. Whether you’re managing allergies, navigating the shift into cooler months, or recovering from gut imbalance, supporting your mucosal immunity through the gut is one of the most effective steps you can take.

Ideal Immunity is a tool, one informed by science and shaped by the philosophy that healing starts with restoring terrain, not overriding it.

Learn more about Ideal Immunity® and the science behind our targeted probiotic guilds here.