Probiotics are microorganisms, including both bacteria and yeast, that live in the small and large intestines (also referred to as the gut). Collectively, all organisms in the gut are referred to as flora.
There are more than 400 different types of bacteria species living in the gut, accounting for a whopping 3-5 pounds of body weight. Your gut is also home to a network of lymphoid tissue that makes up 60-70 percent of your immune system. That’s why keeping a healthy balance is critical to your ability to fight infection and optimally digest and metabolize food.
Two genuses of bacteria—Lactobacillus (L.) and Bifidobacterium (B.)—are the most beneficial strains commonly used in probiotics, and a complete probiotic should contain strains of both in order to provide protection for both the small and large intestine. Here are a few examples of specific strains of these genuses that have unique capabilities:
L. acidophilus strains predominantly live in the mouth, small intestine and vagina. They greatly benefit digestion by producing enzymes that break down food (e.g. lactase, which breaks down dairy), assisting in absorption of vitamins K and B, calcium and fatty acids, and protecting against infection and disease by lowering the pH of the gut to make it uninhabitable by bad bacteria.
B. bifidum predominantly live in the large intestine and vagina, and adhere themselves to the walls of each, thus preventing bad bacteria from colonizing. B. Bifidum also produces substances that lower the pH of their environment so bad bacteria cannot thrive, and enhances assimilation of minerals.
Many more strains exist that have shown specific beneficial properties. Consult with a qualified health practitioner for strains that are specific to helping certain health conditions (e.g. L. Rhamnosus, called the “travelers’ probiotic,” because it has shown protection against diarrhea while traveling).
Beneficial yeast can also serve as probiotics. Here are a few examples of yeasts commonly found in probiotic formulas:
Saccharomyces boulardii is a yeast that can sustain flora in the gut and help prevent and treat diarrhea from various causes (e.g. traveling or antibiotics).
Saccharomyces cerevisiae, also known as brewer’s yeast or nutritional yeast, has been used for thousands of years to make dough rise and create alcohol (due to the yeast’s special ability to ferment certain sugars). S. cerevisiae has many beneficial effects, and is high in protein, fiber, B vitamins and folic acid.
Different types of probiotics can be helpful for a variety of health conditions—they aid nutrient absorption, produce key vitamins, improve digestion and immunity, balance intestinal and vaginal flora, protect us from antibiotic use damage and improve overall wellbeing.
Now that we know a bit about types of probiotics, the next step is in figuring out how to choose which one is right for you.