Do I Need Probiotics?
Updated: Jul 21
The answer might surprise you...
Welcome to the Gut Honest Truth blog where a Certified Functional Medicine Practitioner gives you digestible information to tackle your chronic health concerns.
That's me, Katie Morra; and in this blog I'm going to break down what probiotics actually are, the different types, how to know if you're taking a quality product, and what the research actually says about who needs them.
If you want to learn more about supporting your gut conditions, I highly recommend checking out my How to Get Rid of Your IBS e-book.
And as always, working one-on-one for your specific needs is always our top recommendation, check out our appointment options to get started with one of our licensed health care professionals today.
What Are Probiotics?
Probiotics are living microorganisms found naturally in fermented foods — yogurt, kefir, kimchi, kombucha, sauerkraut — and widely available in supplement form. They're the good guys in the gut, and we want them to be both robust and diverse.
When present in adequate amounts, probiotics help:
Support a diverse gut microbiome
Prevent pathogenic bacterial overgrowth
Clear certain parasitic infections
Strengthen immune resilience
Support mood and mental health
Maintain gut lining integrity and reduce intestinal permeability
Don't confuse probiotics with prebiotics. Both matter. Prebiotics are the digestible fibers that feed probiotics and allow them to actually thrive in the gut — without them, you may quite literally have expensive stool. Prebiotic-rich foods include asparagus, onions, leeks, garlic, legumes, bananas, dandelion greens, oats, chicory, endive, honey, jicama, and Jerusalem artichokes. Prebiotic supplements are also available if consistent food sources aren't realistic right now.
One important nuance: probiotics are generally transient in nature. They don't always permanently colonize in the gut, which is why consistent and ongoing consumption — through food or supplements — is often necessary to maintain their benefit.
The 3 Main Types of Probiotics
1. Lactobacillus and Bifidobacterium Blends
The most familiar and most researched category. These are the strains you'll find in most over-the-counter products. Well-studied for supporting gut diversity, immune function, mood, and skin health. Different strains within this family have different specific applications — which is why generic "probiotic" blends are hit or miss, and strain-specific selection matters.
2. Saccharomyces Boulardii
Technically not a bacteria but a yeast — I like to call it "yeast-fighting yeast." S. boulardii is particularly helpful for supporting clearance or prevention of C. difficile infection, candida overgrowth, certain parasitic infections including B. hominis, and H. pylori. It's a tool I use frequently in gut infection protocols.
3. Bacillus (Soil-Based Organisms / SBOs)
These help replace bacteria that have become rare in modern gut profiles due to reduced contact with soil and the natural environment. Key strains include Bacillus coagulans, subtilis, and clausii. Often well-tolerated even by people who are sensitive to Lactobacillus and Bifidobacterium blends.
Triple probiotic therapy — using all three simultaneously — can provide the most comprehensive support since each type works differently. That said, if you're sensitive or new to probiotics, I recommend introducing one at a time, monitoring for tolerance, and building from there. Most people notice improvements within a few weeks.
How Do You Know If a Probiotic Is Good Quality?
The FDA doesn't regulate supplements, which means quality varies enormously. Here's what to look for:
Free of artificial colors, flavors, and preservatives
Guarantees living units (CFUs) through the expiration date — not just at time of manufacture. Note: more CFUs is not always better. A quality, potent product doesn't need hundreds of billions of CFUs per dose.
GMP (Good Manufacturing Practices) or USP certification on the label
Third-party tested for quality and potency
Purchased from a reputable source — avoid ordering from Amazon, where products may sit in unregulated temperature conditions (hot trucks, warehouses) that kill live organisms
We recommend purchasing through Fullscript — a professional-grade supplement dispensary with verified quality standards.
Can You Test Whether You Need Probiotics?
Yes and no — and I know that's a frustrating answer.
Comprehensive stool testing like the GI-MAP can detect certain probiotic strains and species, and identify pathogenic overgrowths where specific strains may be therapeutically indicated. However, most stool tests require you to discontinue probiotics 2-4 weeks before testing — making it difficult to assess what you're currently working with. And since probiotics are transient, what shows up on a test may not reflect long-term gut composition.
In practice, a thoughtful trial-and-error approach — introducing one strain at a time and monitoring your response — often tells you as much or more than testing alone. Your gut is like a fingerprint: no two microbiomes are the same, and what works brilliantly for one person may not work for another.
Final Thoughts
Every gut microbiome is unique — we can't assume everyone needs the same strains or species
Focus on quality over quantity — CFU count isn't the measure of a good probiotic
Don't neglect prebiotic foods and fiber — they're what allow probiotics to thrive
Comprehensive stool testing can identify specific strains that may help address pathogenic overgrowths or deficiencies
Buy from a reputable source like Fullscript
If you've been taking a probiotic and not noticing results, or if bloating, IBS symptoms, or digestive issues persist despite supplementation, there's likely something else going on that needs to be identified and addressed before the probiotic can do its job.
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