Does Your Probiotic Actually Work to Build Immune Resilience?
Here’s What Your Gut Has to Say.
Fall gets busy fast. The kids are back in school, weekends are filled with birthday parties and football games, and before you know it someone is asking who’s hosting Thanksgiving this year.
Almost all of it happens indoors. Cooler weather pulls everyone inside, which means more time in close-quarters sharing the same air, the same snack table and, let’s be honest, the same doorknobs. Add holiday travel and a to-do list that keeps getting longer, and it’s no wonder so many of us feel run down by December.
So if a probiotic is part of your routine, it’s fair to ask whether it’s pulling its weight this time of year. Here’s what the research says about your gut, your immune system and the two L. reuteri strains at the heart of ZOGURI that go beyond the immunity tips in our Back-to-School, Back-to-Balance article from last fall.
This question is personal for our founder, Dan.
“A few years ago, I watched my son go through what felt like a never-ending cycle of health issues, missed school days and doctor visits,” he says. “That’s when I started digging into gut health and immunity, and that research is what ultimately led me to create ZOGURI.”
Most of Your Immune System Lives in Your Gut
Here’s a number that surprises a lot of people. An estimated 70 to 80 percent of your immune cells are found in your gut. They work alongside the trillions of microbes that live there, and researchers increasingly recognize that this partnership affects immunity throughout the body, well beyond your digestive tract. Food plays a role here too, since what you eat helps shape both the makeup of your gut bacteria and your immune system itself.1
That balance can also slip. Overusing antibiotics and an unhealthy lifestyle can both throw your gut’s microbial community off balance, and diet can shift it too. Antibiotics in particular reduce the amount and variety of gut bacteria, which can make the immune response less effective.2
The Stress Factor
If fall hands out one thing generously, it seems to be stress. A rough afternoon here and there is one thing. Weeks of juggling work, family, and holiday plans is another.
A major review that pooled more than 300 studies found that chronic stress was associated with suppression of key parts of the immune system. Researchers have also linked long-term stress to higher levels of inflammation in the body.3,4
You can’t cancel the holidays (and who would want to?). It’s just worth knowing that the busiest weeks of the year are the worst time to let your gut-friendly habits slide. Having a solid plan to support your gut throughout the season could be your secret weapon for boosting your immunity and staying well.
Why ZOGURI Is Fermented
In September, a Washington Post column made a point that there’s little evidence that probiotic supplements in the form of capsules, gummies, powders and pills can improve or benefit gut health in healthy people. Rather, it argued the benefits of feeding your gut instead with real food such as fruits, vegetables, beans, nuts, and fermented foods like yogurt, kimchi, and kefir. The column also pointed out that typical probiotic supplements contain concentrated doses of a limited number of bacterial strains.
This is a big part of why ZOGURI was created as a real food, fermented, yogurt-based supplement. We hand-craft it in small batches with real dairy, natural ingredients, and long fermentation that makes every spoonful creamy, delicious, and packed with live, beneficial, science-backed strains to help support your gut and immunity.
ZOGURI is not a singular probiotic supplement. It is fermented with seven strains of beneficial bacteria: two different keystone strains of L. reuteri (ATCC PTA 6475 and DSM 17938), plus S. thermophilus, L. bulgaricus, L. acidophilus, Bifidus and L. casei. Each spoonful delivers prebiotics and postbiotics right along with the probiotics for complete, comprehensive support for your gut that doesn’t come in a pill. To learn more about the benefits of a fermented food vs. capsule delivery, check out our article, Does How You Take Your Probiotics Actually Matter?
Meet the Two L. reuteri Strains
L. reuteri has been researched so thoroughly that entire scientific reviews are devoted to it, including a 2025 review on how it interacts with the immune system. One point that review makes clear is that results can differ quite a bit from one strain to the next.5 That’s why we always name ours.
L. reuteri ATCC PTA 6475. In lab studies, this strain has shown that it produces reuterin, a natural antimicrobial compound. It also cut the amount of TNF-α (tumor necrosis factor-alpha), an inflammatory signal, released by lab-grown human immune cells by up to 76 percent.6 (We took a deeper look at this research in our immunity research highlights article.)
L. reuteri DSM 17938. This strain has drawn interest for its effect on regulatory T-cells, the immune cells that help keep the body’s immune response in balance. In lab and animal research, DSM 17938 helped increase these cells.5
Both strains, studied together. A small 2024 trial followed adults with IBS-D (irritable bowel syndrome with diarrhea) who took L. reuteri ATCC PTA 6475 alone, both strains together, or a placebo for six weeks. At the end, the group taking both strains had lower levels of hsCRP, a common blood marker of inflammation, than the placebo group. The researchers were careful to call this an early finding that needs larger studies to confirm, and the strains did not appear to change gut barrier function in that trial.7
We’d rather give you the full picture than oversell it. The research on these two strains is still growing, and we’re following it closely. But don’t just take our word for it, look at the reviews on our website to see what real people are experiencing with ZOGURI.
Making It Through the Season
You can’t control every germ that walks through the door between now and New Year’s, but you can control a few daily habits.
Stick with your ZOGURI. The suggested use is two tablespoons a day, and it’s easiest to remember when you pair it with something you already do, like your morning coffee. Consistency is key, so once you find a routine that works for you, stay the course in order to experience the most possible benefits.
Feed your gut. Fruits, vegetables, beans and whole grains give your gut bacteria fiber to work with, and good nutrition supports both your microbiome and your immune system. Don’t forget to add those wonderful fermented foods too!
Make room to decompress. Since chronic stress can weigh on immune function, a walk outside or a quiet night in between gatherings is time well spent. Think of taking that little bit of time for yourself every day and how it will help you get through the holiday season with better health.
Take care of your gut, then go enjoy the party. Your gut buddies will be right there with you.