Note to Reporters: The following column was written by Melissa Wdowik, an assistant professor at Colorado State University in the Department of Food Science and Human Nutrition, and director of the Kendall Anderson Nutrition Center.
Probiotics are live microorganisms that are similar to, or even the same as, beneficial bacteria found naturally in the human body. A wide variety of these “good” bacteria live in the gut — trillions of microorganisms from over 500 different species — where they promote digestive health. The most well-known groups of probiotics include Lactobacillus and Bifidobacterium, and within each group are diverse species that have different strains with unique benefits. These regulate digestion and immune function, but can be disrupted by medications or illness, making it helpful to get probiotics in our diet. It still needs to be confirmed which probiotics (alone or in combination) work to treat which disorders or diseases, but here is what we know so far.
Uses of Probiotics
• Irritable Bowel Syndrome (IBS). People with IBS may have diarrhea, constipation or both. Probiotics help regulate these as well as relieve bloating from gas.
• Inflammatory Bowel Diseases. Studies and patient reports indicate probiotics help reduce inflammation and delay future flare-ups, especially in patients with ulcerative colitis.
• Antibiotic Use. Antibiotics kill beneficial bacteria in addition to the harmful bacteria they target, often leading to stomach aches and digestive problems. Although research is inconclusive, probiotics seem to help reduce these symptoms by replacing the good bacteria.
• Infectious Diarrhea. This disorder, caused by bacteria, viruses, or parasites, responds well to probiotics that shorten the severity and course of the discomfort.
• Digestion. Probiotics aid the digestion of carbohydrates such as lactose, thus providing relief for people with lactose intolerance.
• Reduction of Digestive Tract Infections. Probiotics inhibit the growth of harmful bacteria, preventing damage to the gut lining.
• Eczema and Allergies. Preliminary research indicates probiotics may improve eczema and help prevent allergies in children.
• Obesity and other chronic diseases. Research is ongoing to identify strains to prevent these.
• While you may think of probiotics as a pill to swallow, your first stop should be the probiotics found in food. They occur naturally in fermented food products such as yogurt, kefir, kimchi, kombucha, sauerkraut, tempeh, miso, and soy beverages. Probiotics are also added to some food products during processing. Use by the date recommended and make sure the label says “live” or “active” cultures since heat and food processing can destroy probiotics.
• Probiotics are also available as dietary supplements, but buyer beware: They are not regulated by the Food and Drug Administration, so the supplement may contain more or less bacteria than the label states. The beneficial effects of probiotics are specific to particular probiotic strains, and the health effects of one strain may not apply to other strains. Thus, it is generally recommended to take 10 billion units per day of a variety of species.
While the long-term effects of probiotic supplementation are unknown, most people who consume probiotics in food or take supplements do not have side effects. Some people do have minor intestinal discomfort, so start with a small amount. Also start with food sources to improve your chances of getting a variety, and remember that some strains of probiotics that work for specific symptoms may not be widely available in supplement form. The National Center for Complementary and Alternative Medicine has made probiotic research a priority, and the future holds exciting possibilities. Stay tuned!
Melissa Wdowik is an assistant professor at Colorado State University in the Department of Food Science and Human Nutrition, and director of the Kendall Anderson Nutrition Center.