Probiotic Building Blocks

The basics of probiotics
By Shekhar Challa, MD

Our bodies are full of bacteria. Before you shudder and reach for the hand sanitizer, you need to know that much of this bacteria is beneficial. We have over 1,000 strains of bacteria on our skin alone, and even more in our gastrointestinal system, called the gut flora.

These beneficial bacteria are known as probiotics, and in the US, the study of probiotic health benefits is an emerging science. In other parts of the world, probiotics are well studied and are regularly incorporated into health regimens, both through the diet and as supplements.

Good bacteria work in three ways in the body:

• They adhere to the intestinal wall, crowding out the bad bacteria that cause disease or illness.

• They produce enzymes or proteins that inhibit or kill bad bacteria.

• They boost immunity through an increased production of mucin, a protein that helps protect against friction and erosion, creating an unfavorable environment for bad bacteria.

Your body’s bacteria impact many health-related functions. Initial studies in mice are finding connections between bacteria and brain development, mood and anxiety issues, obesity, allergies and aging issues. Exploring aging was actually what led Russian scientist Eli Metchnikoff to discover probiotics in the early 20th century.

Metchnikoff was trying to figure out what caused Bulgarian peasants to live longer-than-normal lives. As he researched, he hypothesized that the fermented milk they drank (fermented foods contain probiotics) helped to “seed” their intestines with good bacteria, which in turn fought off harmful bacteria. He was the first scientist to suggest it would be possible to modify the gut flora by replacing bad bacteria with good bacteria, thus earning a Nobel Prize for his work.

Today, new research studies constantly update our knowledge of probiotics. Scientists are focusing heavily on the body’s microbiome—or the bacterial world in and on our bodies—because early research evidence points to widespread health effects when bacteria in the body changes.

Keeping in mind that this is a relatively new science, the potential in probiotics is fascinating and exciting. For instance:

• The gut bacteria in a thin person is different than that of an obese person. And when the obese person loses weight, his or her gut bacteria changes to match that of a thin person.

• The gut bacteria in children with autistic symptoms is different than that in children without autistic symptoms.

• A study published in American Journal of Clinical Nutrition found that foods fortified with probiotics and prebiotics reduced certain markers of colon cancer in patients who already had colon cancer.

While much of that research is in the initial stages, probiotics are well-studied with regard to gut health. Patients with chronic diarrhea, irritable bowel syndrome, and inflammatory bowel disease are finding help by taking probiotics. Many people get antibiotic-associated diarrhea when they take antibiotics, because the drugs kill bad bacteria but also manage to wipe out good bacteria. (Many women also report getting yeast infections when they take antibiotics.) Probiotics help fight that type of diarrhea, and in England and other countries, many pediatricians automatically prescribe a probiotic supplement as they also prescribe antibiotics. We’re starting to see that trend develop in the US.

Another well-studied area is that of urogenital infections, such as yeast infections and urinary tract infections (UTIs). One recent US study found that women who used a probiotic vaginal suppository had markedly reduced UTIs. Lactobacillus acidophilus, Lactobacillus rhamnosus, and Lactobacillus fermentum have been shown to prevent and treat yeast infections.

Probiotics are showing up in all kinds of oral health products, from toothpastes to mints and gum. Your mouth contains numerous bacteria, and studies have found that oral products with probiotics can fight plaque formation, bleeding from the gums, and may even affect chronic periodontitis, the most common form of gum disease.

Probiotics are found naturally in fermented foods, which used to be a much more important part of our diets because fermentation was a prime way of preserving foods. Today, you can find probiotic-enhanced foods and that’s a trend expected to continue as people understand the benefits of taking probiotics. Yogurt, chocolate, and even gum boast probiotic labels. Other foods that contain probiotics are kefir, kimchi, pickles, miso, sauerkraut, and buttermilk. Remember that heat kills probiotics, so manufacturers must add live probiotics after the product is heated. In other words, pasteurization kills probiotics.

However, particularly if you’re trying to treat a specific medical condition, most people can’t get enough probiotics in their diet to make a difference in their health and will need to take a supplement.

When you’re buying a probiotic supplement, look for one that contains numerous strains of bacteria (the names on the label typically will be various strains of lactobacillus and bifidobacteria, which are the most studied types of bacteria). A good probiotic supplement will include a variety of elements beneficial to your system:

• A prebiotic, such as chicory root Inulin.

• The more strains of probiotics included the better, particularly Lactobacillus acidophilus DDS-1.

• Find one that uses an acidprotection technology so the good bacteria is able to pass through the harsh stomach acid and reach the small intestine.

I mention several probiotic supplement products in my book Probiotics For Dummies, but one of the new generations of probiotics is Probulin, which includes all of the elements I’ve listed above. Ask your doctor or research online if you have a specific condition you want to treat, as particular probiotic strains may be more effective in treating your health concerns.

You’ll also want to take at least three to five billion colony forming units (CFUs) each day. Read the label to see if the company uses technology to help the live bacteria get through the stomach acid, which can destroy the bacteria. Those bacteria need to travel safely to the gut to do the most good. And as noted above, heat kills bacteria, so don’t drink coffee or hot tea right after taking your supplement.

Talk to your doctor before you begin taking any over-the-counter medications. Probiotics have occasionally caused issues for individuals with compromised immune systems, but are considered safe for most people.

As scientific, evidence-based research continues to pinpoint the impact of bacteria on health, it is believed that people will take probiotic supplements on a regular basis, just as they do vitamins. When vitamins first came into use, they were often prescribed to treat conditions, and now many of us take them as a regular part of our health regimen.

Always consult your physician before adding a supplement—including probiotics—to your diet.


Shekhar Challa, MD, is a board-certified gastroenterologist, co-producer of probiotic video game Microwarriors: The Battle Within, and author of the new book Probiotics for Dummies.