Learn how probiotics aid the body in maintaining health, regulating the immune system and managing disease.

With the influx of hand sanitizers and anti-bacterial products on the market, it’s easy to think of bacteria as a bad thing. However, for the last 20 years or so, the positive impacts probiotics have on gut health have become well-known and highly accessible in our current culture.

In the beginning

There have been references to sour milk or fermented cultures throughout written history. But it wasn’t until Ukrainian-born scientist Elie Metchnikoff became deputy director of the Pasteur Institute laboratory in 1904 that the true benefits of this phenomenon were understood.

Through his research, Metchnikoff found that regular consumption of lactic acid bacteria in fermented dairy products, like yogurt or sour milk, was associated with enhanced health and longevity. His study of a certain segment of the Bulgarian population, along with research by Dr. Stamen Grigorov, lead to the publication of their findings in 1907 and an eventual Nobel Peace Prize for Metchnikoff.

Between 1908 and 1964, very little was done in the field of microbial therapy. The discovery and use of antibiotics lead to a shift in medicine that more or less forgot about Metchnikoff’s discovery. The term probiotic was first used by researchers D.M. Lilly and R.H. Stillwell in 1965. Some 35 years later, many credit the 2001 consultation by United Nations Food and Agriculture Organization and the World Health Organization for the now widely accepted uses of probiotics in everyday health.

What are they, exactly?

Most probiotics are bacteria, single-celled microorganisms that live within all of us. Many of these microorganisms keep our bodies properly functioning. The bacteria present in our intestines help with digestion, fight bad bacteria that can cause illness and help produce vitamins.

Bacteria are categorized with genus, species and strain names – like the probiotic bacterium Lactobacillus rhamnosus GG. The common name for this strain of probiotics that appears on product labels is LGG. Other commonly used probiotic strains include Bifldobacterium, Escherichia, Enterococcus, Bacillus, Propionibacterium and Saccharomyces.

The bacteria added to foods or used in supplements are grown in large numbers, purified, concentrated in high doses, and then preserved. They can be added to milk-based foods like yogurt, fermented foods like sauerkraut or concentrated and dried for supplements.

How they work

It’s estimated that the human body has billions of microbes in and on our bodies and over 1,000 different types of bacteria. These microbes help with the functions of our immune system, cell development, digestion, metabolism and many other activities critical to human health.

Both lactobacilli and bifidobacteria live in our intestinal tract and aid in breaking down our food.

All the uses and impact of probiotics are still being studied and researched. Probiotics sold as supplements and fortified in foods are regulated through the Food and Drug Administration (FDA), just like other dietary-and health-related supplements. However, many of the claims made by commercial sellers are not backed by the FDA.

There are numerous studies and claims that probiotics can aid in everything from allergic disorders (eczema, hay fever), tooth decay, colic, liver disease and even the common cold. Studies have shown probiotics may have an impact on many conditions, such as:


Research published in the U.S. Library of Medicine showed that probiotics can provide relief for this condition. A steady intake of fluids along with food containing probiotics were shown to help fight the germs causing diarrhea.


The American Heart Association says regular consumption of probiotics can “modestly improve” blood pressure. Their research suggests that probiotics may help lower blood pressure by “having other positive effects on health, including improved total cholesterol; reduced blood glucose; and helping to regulate the hormone system that regulates blood pressure and fluid balance.”

Irritable Bowel Syndrome

The International Foundation for Functional Gastrointestinal Disorders cites studies that show daily supplementation or consumption of probiotics “may be effective in improving intestinal function and some symptoms, such as bloating, gas and discomfort.” They also stress that more research is needed to support those claims.

Lactose intolerance

Most dairy products are off limits for people with this condition. Through numerous studies and research, yogurt has been found to be the single-most effective way to help lactose-intolerant people with the digestion of lactose.

Take a healthy bite

One of the most impactful ways for probiotics to work in your body is consuming them through food sources.


There is an incredible amount of bacteria in a single serving of yogurt. Yogurt producers add cultures of bacteria after milk has been pasteurized to ensure the bacteria survives. The National Yogurt Association’s Live & Active Cultures seal certifies that the product contains at least 100 million cultures per gram, or 20 billion per eight-ounce serving.

Dill pickles

These snack favorites also deliver a healthy dose of probiotics. Look for varieties that are brined in water and sea salt. The vinegar brine in some mixes prevents the beneficial bacteria from growing.

Sourdough bread

These chewy loaves made with fermented wheat contain lactobacillus (L.acidophilus), one of the most commonly used probiotics.