Probiotics: How Microbes Help Us Stay Healthy

Over 100 years ago, Élie Metchnikoff, often called the “Father of Natural Immunity,” received the Nobel Prize for his work on how our immune system works naturally. He believed that we could improve our health by changing the bacteria in our gut, replacing harmful microbes with helpful ones. Though he didn’t use the term “probiotic,” his ideas laid the foundation for how we understand them today.

What Are Probiotics?

Probiotics are live microorganisms (usually bacteria or yeast) that provide health benefits when consumed, mainly by supporting or restoring the natural balance of gut bacteria. The study of probiotics began with their use in treating infectious diarrhea. Today, research shows that they may help with a wide range of health issues, such as:

  • Digestive problems (like IBS, constipation, and diarrhea)
  • Inflammatory diseases (like ulcerative colitis)
  • Infections (urinary tract, respiratory, hospital-related)
  • Liver and brain disorders (like NAFLD and encephalopathy)
  • Mental health issues (like depression)
  • Oral and vaginal health
  • Even improving outcomes for premature babies and trauma patients

Probiotics and the Immune System

One of the most powerful effects of probiotics is how they influence the immune system. Some strains help activate macrophages, a type of immune cell that protects the body from invaders. For example, certain bacteria in kefir and yogurt can help convert a protein found in milk into GcMAF, a substance that boosts immune function.

However, most probiotic capsules don’t work well unless they’re taken with the right substrate—which is the food source for these microbes. For instance, colostrum (the first milk from cows after giving birth) increases probiotic colonization in the gut by 52 times. Other helpful substrates include lactose and milk oligosaccharides, which support gut health and help good bacteria grow.

Natural Probiotic Sources vs. Capsules

Originally, people got probiotics from natural fermented foods like cheese, kefir, and yogurt. These foods provide both the bacteria and the environment they need to thrive. Today, capsules are popular, but many don’t work well on their own unless taken with milk or a sugar source. Also, many strains found in capsules don’t colonize the gut long-term, meaning you need to take them regularly.

In contrast, kefir contains multiple strains that can colonize and stay in the gut. Combining kefir, yogurt, milk, and colostrum gives the best chance for lasting benefits. You can even add your favorite probiotic capsules to this mix for extra support.

How Probiotics Help

Here are just a few of the health benefits linked to probiotics:

  1. Type II Diabetes – May reduce blood sugar and A1C levels.
  2. Cholesterol – Helps lower total and LDL (“bad”) cholesterol.
  3. High Blood Pressure – May help lower it, especially if it’s already high.
  4. Stomach Infections – Improves treatment of H. pylori.
  5. IBD (like Ulcerative Colitis) – Can help during flare-ups and for long-term care.
  6. Constipation – Improves stool consistency and regularity.
  7. Allergies and Eczema – May reduce symptoms in children and infants.
  8. Respiratory Infections – Can reduce symptoms and duration.
  9. Fatty Liver (NAFLD) – Improves liver function and insulin sensitivity.
  10. Brain Function (Encephalopathy) – Helps reduce confusion and related symptoms in liver disease.
  11. Gum Disease (Periodontitis) – Helps when used with dental treatments.
  12. Depression – Can lower scores on depression scales.
  13. Premature Birth – Reduces the risk of dangerous infections like sepsis.
  14. After Trauma or Surgery – Lowers infection rates and shortens hospital stays.

Tips for Using Probiotics

  • Start slowly, especially if you have gut issues—think of it like feeding a baby’s digestive system.
  • Use bifidobacteria first, as it’s well-tolerated and reduces inflammation.
  • Always pair probiotics with a sugar source, like milk or lactose, to help them grow.
  • Colostrum, kefir, yogurt, and milk are ideal for mixing with capsules or powders.
  • Know your strains—different probiotics support different parts of your health.
  • Environment matters—probiotics work best when supported by the right foods and gut conditions.

Final Thought

Probiotics are living organisms that work best when we give them the right environment and nutrients to thrive. Natural sources like fermented foods, milk, and colostrum provide both the microbes and the fuel they need. With the right combination, probiotics can do much more than support digestion—they can influence the immune system, mental health, and even serious medical conditions.