Written by Evita Basilio BSc Nutrition
Reviewed by Andrea Miller MHSc, RD
The Science of Our Gut
Humans are hosts to huge numbers of bacteria ~100 trillion all through our body. The gut flora is our largest organ of immunity. The composition of each person’s microflora is as unique as your fingerprint and what we feed our flora determines which bacteria are found in our gut.
Consumption of foods high in sugar, fat and calories can reduce the diversity of our gut flora, whereas a varied diet with more vegetables, fruits and fiber supports a healthy microflora.
What are probiotics?
Probiotics are live microorganisms, which when administered in adequate amounts, confer a health benefit on the host. Derived from the Greek word ‘for life.’ A probiotic must be of human origin, have a demonstrated safety profile (cannot be invasive, carcinogenic), must be able to survive the acidity of our stomachs, must be able to colonize our gastrointestinal (GI) tract, and must have a demonstrated beneficial health effect through research. Probiotics cannot be used interchangeably with “live active cultures” – there must be a health benefit.
Probiotics are referred to be their genus, species and strain. Strain is extremely important, as it creates a different performance. Health benefits can only be attributed to the strain tested.
What’s the difference between probiotics and prebiotics?
A prebiotic is referred to as a selectively fermented ingredient that results in specific changes in the composition and/or activity of the GI microflora, thus conferring benefits to host health. They are food substances found in the diet that can nurture the good bacteria. Prebiotics are mostly found in food. Inulin is a common prebiotic found in onion, leek, garlic, artichoke, banana, chicory root. Another type of prebiotic is galacto-oligosaccharides found in human milk.
What are the health benefits?
Combining prebiotics and probiotics can be beneficial to gut health. Prebiotics help promote the growth of the probiotics. Emerging research links several diseases to the microflora of the colon. If your GI tract is working well, you may be more resistant to certain infections and intestinal disorders.
How to get probiotics in your diet?
Probiotics are regulated in Canada. When choosing a probiotic supplement – consider the following – does the product list the genus, species and strain, provide the number of organisms/serving, serving size/capsule and dose, guaranteed potency until consumption, storage information, and contact information? You can talk to your Registered Dietitian about which probiotic would be best suited for you.
Probiotics often do not colonize the gut after 1-4 weeks so we have to continually replenish it. The product needs to kept out of heat and light, after opening it should be kept away from moisture, keep refrigerated to prolong shelf life and check expiration dates.
Can You Get Probiotics from Foods?
There are lots of food products with “live culture bacteria,” or a probiotic in them. Products such as Activia, Yoptimal, Yakult, Bio-K and DanActive are probiotics. When choosing a probiotic food, review the ingredient list to determine which microorganism is present in the product, determine how many live microorganisms per serving size are indicated on the food package, and does the product list the health benefits.
Fermented foods including Kimchi, natto, sauerkraut, kefir, tempeh, miso, kombucha contain “live active cultures” but many of these have not been evaluated, but could be recommended based on emerging evidence that consuming these may confer health benefits.
In general, probiotic foods and supplements are thought to be safe for most people. As always, talk to your Doctor or Registered Dietitian determine if they are safe for you. In some cases, mild side effects might include upset stomach, diarrhea, gas, and bloating for the first couple of days after you start them.
Reference: Adapted from A Gut Feeling: An Inside Look at Pre and Probiotics by Natasha Haskey, Msc RD