The Microbiome: The Role of Gut Microbiota

Did you know that there is 10 times the amount of microbial cells in your digestive tract than cells in your entire body? Sometimes referred to as a “newly discovered organ”, the bacteria in your intestines weigh about 1.5-2kg. These bacteria take up residence from the day we are born and remain with us all our lives. They are essential to overall health.

When discussing this incredible topic, please note the following terminology:

1) Microbiota (formerly known as flora): the collection of microorganisms that reside in a previously established environment. For us, this means we have microbiota in and on our skin, lungs, digestive tract, urinary & vaginal tracks. Similarly, the term microbiome is used interchangeably with microbiota, but refers to the combined genetic material of microorganisms in a particular environment (this “second genome” actually makes up 99% of our genetic information).

2) Probiotics: Live microorganisms which, when administered in adequate amounts, give health benefit to the host. Probiotics are simply live food or supplements you take to support your microbiota.

Gut bacteria are not just our friends; we are partners with them in a mutually beneficial relationship. Our microbiota performs many physiological functions and directly impacts our health in the following ways:

• It helps us digest our foods properly so that we can comfortably absorb our nutrients. It ensures proper digestive function and even assists in the production of some vitamins (B and K).
• It acts as a barrier to infectious microorganisms and also combats pathogenic toxins (like those from Clostridium difficile).
• It balances and drives correct development of the immune system, influencing the formation of white blood cells & cytokines in the gut to prevent allergies and autoimmunity.As we age, our microbiota is constantly in flux and is reduced or becomes imbalanced (a term called dysbiosis) by a variety of factors, such as:

• Antibiotic or medication use (including antibiotic soaps)
• Lifestyle and poor diet (specifically a diet high in sugar and simple carbohydrates)
• Stress
• Digestive disorders
• Infection or illness
• TravellingSince these factors relate to all of us daily, it is imperative to introduce probiotics to maintain health. Probiotics are naturally occurring in fermented foods such as yogurt, miso, kimchi, sauerkraut, and kefir. For maintaining health, including fermented foods in your daily diet may be sufficient. However, to therapeutically treat a condition a probiotic supplement is often required. When looking for a good quality probiotic it should:

• Be potent. Look for colony forming units on the bottle, or CFUs. Therapeutic doses typically begin around 10 billion CFUs and increase from there.
• Be scientifically proven to work. There are many probiotics on the market so it’s important to use strains that have been studied for safety as well as specific populations and conditions. Brand does matter and affects quality of the product.
• Be human. Human strains of probiotics will naturally adhere to your digestive tract more readily than animal strains. They also tend to survive stomach acid better.
• Be free of allergens. Many people are sensitive to dairy and, therefore, yogurt wouldn’t work for them. High quality supplements are a great way to take your probiotics without dairy.

  Probiotics may be indicated for digestive complaints, food sensitivities, antibiotic use, atopic conditions (eczema, allergies, Asthma), infections (from cold and flu to urinary tract and digestive infections including yeast), IBS, Crohn’s and Ulcerative colitis, and cancer1. There is also growing evidence in probiotics supporting healthy mood2, cardiovascular disease, obesity, and metabolic syndrome3.

  We’ve only just scratched the surface on how important these beneficial bacteria are to our overall health. As research into microbiota continues to evolve we will undoubtedly learn more about specific bacterial strains and their impact on health and disease.

  References:

  1) Goldin, B. R., and S. L. Gorbach. “Clinical indications for probiotics: an overview.“ Clinical Infectious Diseases 46.Supplement 2 (2008): S96-S100.
  2) Foster, Jane A., and Karen-Anne McVey Neufeld. “Gut–brain axis: how the microbiome influences anxiety and depression.“ Trends in neurosciences36.5 (2013): 305-312.

  3) Kumar, Manoj, et al. “Cholesterol-lowering probiotics as potential biotherapeutics for metabolic diseases.“ Experimental diabetes research 2012 (2012).