What Are Probiotics?

Tiny Helpers for Your Health

The word "probiotic" comes from Greek, meaning "for life" — and that's exactly what these microorganisms are about. According to the World Health Organization, probiotics are live microorganisms that, when administered in adequate amounts, confer a health benefit on the host.

In simpler terms: they're the "good" bacteria (and sometimes yeasts) that can help keep your body healthy, especially your digestive system.

Where Do Probiotics Come From?

You can get probiotics from two main sources:

• Fermented foods: Yogurt, kefir, sauerkraut, kimchi, kombucha, miso, tempeh, and some cheeses contain live beneficial bacteria
• Supplements: Capsules, tablets, or powders containing concentrated doses of specific probiotic strains

The Most Common Probiotic Species

Not all bacteria are created equal when it comes to probiotic benefits. The most well-studied probiotics include:

• Lactobacillus species:
  • L. acidophilus — helps digest lactose, supports immune function
  • L. rhamnosus GG — one of the most researched strains, helps prevent diarrhea
  • L. plantarum — found in fermented vegetables, supports gut barrier
• Bifidobacterium species:
  • B. longum — helps break down carbohydrates
  • B. breve — supports infant gut health
  • B. lactis — boosts immunity and helps with constipation
• Saccharomyces boulardii: A beneficial yeast that helps prevent and treat diarrhea, especially antibiotic-associated diarrhea

What Can Probiotics Do?

Research supports several potential benefits of probiotics:

• Digestive health: Help prevent and treat diarrhea (including antibiotic-associated and traveler's diarrhea)
• Lactose digestion: Some strains help people who are lactose intolerant digest dairy better
• Immune support: May help reduce the frequency and duration of common respiratory infections
• Mental health: Emerging research links certain probiotics to reduced anxiety and depression symptoms (the "psychobiotics")
• Skin health: Some evidence suggests probiotics may help with conditions like eczema

Probiotics vs. Prebiotics

Don't confuse probiotics with prebiotics! They work together but are different:

• Probiotics: The beneficial bacteria themselves
• Prebiotics: The food that feeds probiotics — typically certain types of fiber (like inulin) found in foods like garlic, onions, bananas, and asparagus
• Synbiotics: Products that contain both probiotics and prebiotics

How to Choose a Probiotic

If you're considering a probiotic supplement, keep these factors in mind:

• Strain specificity: Different strains do different things. Look for strains studied for your specific health goal
• CFU count: CFU (Colony Forming Units) indicates the number of viable bacteria. Most effective probiotics contain 1-10 billion CFUs
• Survival: The bacteria need to survive stomach acid to reach your intestines. Look for strains with good survival rates or special coatings
• Quality: Choose products from reputable manufacturers with third-party testing

Are Probiotics Safe?

For most healthy people, probiotics are safe. However:

• Side effects like gas and bloating may occur initially but usually resolve
• People with weakened immune systems or serious illnesses should consult a doctor before taking probiotics
• Probiotics are not regulated as strictly as medications, so quality can vary

The Bottom Line

Probiotics represent an exciting frontier in health science. While they're not a cure-all, the evidence supports their use for specific conditions. The best approach might be combining probiotic supplements with a diet rich in fermented foods and fiber — giving your gut the diverse community of beneficial microbes it needs to keep you healthy.