Probiotics 101: The Good Bacteria Revolution

Written by BAE Nutrients

5 minutes

4 Citations

Last updated February 7, 2025

You’ve heard the buzz about probiotics—but what are they really?

Probiotics are live microorganisms, often referred to as "good" or "friendly" bacteria, that offer health benefits when consumed in adequate amounts. These beneficial microbes help keep your gut healthy, balance your microbiome, and play a surprising role in immunity, mood, and even skin health.

What Are Probiotics?

Probiotics are mostly bacteria (though some are yeasts) that naturally live in your body, especially in your gastrointestinal tract. The most common probiotic strains come from two main groups:

  • Lactobacillus: Known to help with digestion, diarrhea, and supporting vaginal health.
  • Bifidobacterium: Helps ease symptoms of IBS and improve immunity.


Other beneficial strains include Saccharomyces boulardii (a probiotic yeast) and Streptococcus thermophilus.

How Do Probiotics Work?

Probiotics contribute to your well-being in multiple ways:

  • Balancing your gut flora by crowding out harmful bacteria
  • Strengthening the gut barrier to prevent pathogens from entering your bloodstream
  • Producing enzymes and vitamins, especially B vitamins and vitamin K
  • Modulating immune response, helping your body recognize friend vs. foe


They even interact with the gut-brain axis—your gut’s communication highway with your brain—impacting mood, stress, and cognition.

Types of Probiotic Strains & Their Benefits
  • L. acidophilus – Aids digestion and nutrient absorption
  • B. lactis – Enhances immune response
  • L. rhamnosus – Helps reduce diarrhea and supports skin health
  • S. boulardii – Useful during antibiotic therapy


Each strain serves a unique purpose, which is why multi-strain probiotics are often more effective.

Probiotics and Women’s Health

Probiotics play a key role in balancing vaginal flora, preventing infections like bacterial vaginosis and yeast overgrowth. They also support urinary tract health and can ease bloating or hormonal-related digestive issues.

Do All Probiotics Work the Same?

No. Different strains have different effects, and not all probiotics survive the harsh environment of your stomach. That's why it's important to choose:

  • Clinically studied strains
  • Adequate CFUs (colony-forming units)
  • A delivery system that ensures survivability

Choosing the Right Probiotic

Look for probiotics with:

  • 5+ strains for diversity
  • At least 1–10 billion CFUs
  • No added sugars, fillers, or artificial ingredients

    Bonus if it includes prebiotics, which we'll get into next!

Final Thoughts

Probiotics aren’t just a wellness trend—they’re essential allies in supporting your digestive system, immunity, and overall vitality. Adding them to your daily routine, whether through food or supplementation, can be a game-changer for long-term health.

Citations
  1. Hill, C. et al. (2014). Expert consensus document: The International Scientific Association for Probiotics and Prebiotics consensus statement on the scope and appropriate use of the term probiotic. Nature Reviews Gastroenterology & Hepatology, 11(8), 506–514.

  2. Azad, M. B. et al. (2013). Infant gut microbiota and the hygiene hypothesis of allergic disease: impact of household pets and siblings on microbiota composition and diversity. Allergy, Asthma & Clinical Immunology, 9(1).

  3. Martin, C. R., Osadchiy, V., Kalani, A., & Mayer, E. A. (2018). The Brain-Gut-Microbiome Axis. Cellular and Molecular Gastroenterology and Hepatology, 6(2), 133–148.

  4. Plaza-Díaz, J., Ruiz-Ojeda, F. J., Vilchez-Padial, L. M., & Gil, A. (2019). Evidence of the anti-inflammatory effects of probiotics and synbiotics in intestinal chronic diseases. Nutrients,