When I was growing up, we usually thought of all bacteria as the bad guys; microscopic organisms that cause disease and symptoms and therefore should be avoided. Times have changed as experts have uncovered the worlds of beneficial and harmful (bad) bacteria, intestinal flora, and the impact they have on our overall health.
Probiotics are live bacteria that have been shown to be beneficial for our health. These good bacteria can be consumed through various foods (generally fermented) and supplements. Fermented foods are foods transformed by microbial means or acted on by beneficial bacteria. Fermented foods may have probiotics. Whereas probiotics are very specific bacteria known to have a benefit to human health. Prebiotics are healthy plant fibers that feed the beneficial bacteria. Prebiotics and fermented foods are part of a healthy diet but supplements are a more concentrated form of probiotics.
The most common types of bacteria classified as probiotics belong to one of two groups: Lactobacillus or Bifidobacterium. Species in the former genus are more common and found in fermented foods and can help with management of diarrhea and lactose intolerance. Those in the latter group also can be found in some dairy foods and can ease the symptoms of irritable bowel syndrome and other conditions.
Intestinal flora and probiotics
When there is an imbalance between beneficial and bad bacteria in the intestinal tract, the harmful bacteria dominate and can result in infections, digestive problems, depression, fatigue, and a wide variety of other symptoms and illnesses.
Intestines, including intestinal flora has been referred to as our second brain, and that’s because the bacteria-good and bad-in our gut are constantly exchanging messages with the body’s cells. Therefore, bacteria are involved with our health in all areas of the body. For example, bacteria play a significant role in immune system functioning, digestion, and the production of new molecules such as enzymes and vitamins.
Our intestinal flora is not a static environment; it is changing constantly and is influenced heavily by factors over which we have some control as well as those we don’t. This range of influences include diet, stress, use of medications (especially antimicrobials), health conditions, and environmental contaminants, as well as age and heredity. When negative factors take the upper hand, bad bacteria dominate and health problems can occur.
What probiotics can do
Probiotics can perform several critical functions in the body. For example, probiotics can:
- Help restore levels of beneficial bacteria in the intestinal tract after use of antimicrobials including antibiotics, but also antivirals and antimycotics which are drugs that destroy both bad and good bacteria
- Help restore balance of good and bad bacteria in the body to ensure it functions optimally
- Help in the management of certain health challenges associated with an imbalance of good and bad bacteria, such as diarrhea, irritable bowel syndrome, depression, inflammatory bowel disease, allergies, and eczema, among others. Probiotics may also enhance immune system functioning and help keep your heart healthy by reducing blood cholesterol levels..
Let’s expand on this latter bullet point to illustrate the far-reaching effects probiotics can have on our health.
- Allergies and eczema. Probiotics have been shown to significantly reduce the risk of infants developing eczema among breast-feeding mothers who took the beneficial bacteria supplements. In a recent study, investigators reported that probiotics showed an ability to help prevent allergic diseases beginning during adolescence and later years rather than in childhood.
- Diarrhea. Probiotics can be helpful in relieving various types of diarrhea, including antibiotic-associated diarrhea, infectious diarrhea, travelers’ diarrhea, and that of other causes.
- Diabetes. Probiotics may help with blood glucose management and insulin sensitivity in people with type 2 diabetes.
- Heart health. Research shows that probiotics may lower your levels of bad (LDL) cholesterol and total cholesterol as well as blood pressure.
- Indigestion. Probiotics have been shown to ease the symptoms of indigestion and heartburn. These beneficial bacteria enhance enzymes that promote better digestion as well as team up with prebiotics (which nourish good bacteria) to help keep things moving.
- Mental health. Both animal and human studies have shown that use of probiotic supplements can assist in managing various mental health disorders, such as anxiety, autism, depression, memory, and obsessive-compulsive disorder.
Read about probiotics: fighting with good
How to choose and use probiotics
When using probiotic supplements, follow the instructions provided by the manufacturer or your physician. Typically, probiotic supplements should be taken on an empty stomach about 30 minutes before a meal. However, your doctor may recommend a different approach.
The presence of food in the stomach prompts the production of stomach acids and other fluids that can kill the beneficial bacteria, therefore you can maximize the benefit of your probiotics when your stomach is empty. It’s also recommended you take probiotics with purified water, since chlorine and other chemicals in public water sources can kill beneficial microorganisms.
Probiotic supplements are dosed in values called CFUs or colony forming units. This refers to the number of viable bacterial cells in a given sample that can divide and form colonies. Good bacteria that can form colonies are alive and thus able to benefit your intestinal flora.
CFU values are given in millions or billions, and a typical probiotic dose for health maintenance may be 10 to 15 billion CFUs daily for adults, with higher dosing if you are addressing a specific health condition or symptom. If you are dealing with diarrhea, for example, you may need to take 50 billion CFUs daily. Your individual dosing needs should be discussed with a knowledgeable health professional.
Probiotic supplements are available in several forms. It's important that whichever formulation you choose, you want to ensure the concentration of bacteria is guaranteed until the date of expiration. A capsule or tablet will be enteric coated to protect the bacteria through the stomach and ensure they arrive in the intestinal tract ready to go to work. Keep the capsule intact even if it contains a powder by consuming it as directed. A liquid probiotic can be added to smoothies or taken on its own. Heating a probiotic is never recommended.
Choose probiotic supplements that provide at least two to three different species of beneficial bacteria with research behind finished product highlighting the synergy between the strains.
In the majority of cases, use of probiotics supplements is not associated with side effects. However, some people may experience mild cases of diarrhea, gas, bloating, or upset stomach when you first start taking them. In rare cases, individuals experience allergic reactions, in which case you should stop the supplements and contact your physician.
Always ask your healthcare professional about the clinical efficacy / clinical studies of the specific probiotic you’re looking for.
[Editor's Note: Our partner Bio-K+ has been recognized by Health Canada (similar to the FDA in the US) to reduce the risk of antibiotic associated diarrhea and C. difficile associated diarrhea. They have a wide range of products for your needs including fermented drinkable products for adults and children as well as capsules.]
Agerholm-Larsen L et al. The effect of a probiotic milk product on plasma cholesterol: a meta-analysis of short-term intervention studies. European Journal of Clinical Nutrition 2000 Nov; 54(11): 856-60
Allen SJ et al. Probiotics for treating acute infectious diarrhea. Cochane Database of Systematic Reviews 2010 Nov 10; (11):CD003048
Bousvaros A. Can probiotics help treat depression and anxiety? Harvard Medical School 2017 Jul 26
Hempel S et al. Probiotics for the prevention and treatment of antibiotic-associated diarrhea: a systematic review and meta-analysis. JAMA 2012 May; 307(18): 1959-69
Kim YA et al. Probiotics, prebiotics, synbiotics and insulin sensitivity. Nutrition Research Review 2017 Oct 17: 1-17
Krzych-Falta E et al. Probiotics: Myths or facts about their role in allergy prevention. Advances in Clinical and Experimental Medicine 2018 Jan; 27(1): 119-24
Ouwehand AC et al. The mucus binding of Bifidobacterium lactis Bb12 is enhanced in the presence of lactobacillus GG and Lact. Delbrueckii subsp. bulgaricus. Letters in Applied Microbiology 2000 Jan; 30(1): 10-13
Wang H et al. Effect of probiotics on central nervous system functions in animals and humans: a systematic review. Journal of Neurogastroenterology and Motility 2016 Oct 30; 22(4): 589-605