Beat The Cold Bug With Bacteria

Have you ever wondered why some people tend to catch every bug that goes around, while others manage to never catch anything? It all comes down to immunity. There are many simple things you can do to keep your immune system healthy such as getting plenty of sleep, washing your hands regularly,  taking a multivitamin, and reducing stress. What you may not be aware of, is that the microbes in your intestines play a huge role in boosting the immune system. These beneficial bacteria are your first line of defence in the fight against colds and the flu.

Girl with flue

Our intestines are home to millions of resident microbes also called the ‘gut microbiota’. These microbiota are considered to be symbiotic to humans; they use our intestines as a home, but also contribute to our health by helping to break down our foods, thereby providing access to nutrients that would normally be inaccessible to us. Not only do these microbes help with our metabolism, but more and more research is showing that the gut is an important immune organ, as it contains the largest lymphoid tissue mass in the body. (Greer et al, 2013)

Approximately 70% of the immune system is found in GALT (gut-associated lymphoid tissue) within the intestinal tract. A relationship between the intestinal microbiota and immunity has been well researched in the last few years. These gut bacteria have been shown to help immunity through the activation of our immune response during periods of stress, as well as during pathogenic threats. However, if our bodies are in a constant state of stress (not uncommon for most people) or other threats to these ‘good’ mictobiotas occur (such as taking broad spectrum antibiotics), they can die off and ‘bad’ bacteria can take over. When the balance of ‘good’ to ‘bad’ microbes changes, it is called ‘dysbiosis’. When dysbiosis occurs it can lead to compromised immune responses and has been shown to be a contributing factor to many different conditions including diabetes and autoimmune disorders. (Howarth & Wang, 2013).

If your immunity isn’t enough of a reason to be concerned about having the proper levels of intestinal microbiota, they also have many other functions including:

  • Synthesizing vitamins such as thiamine (B1), folic acid (B9), pyridoxine (B6) and vitamin K
  • Producing digestive enzymes and aid in the absorption of calcium, magnesium and iron
  • Improving the strength and function of the lining of our colon. This mucosal barrier helps to prevent harmful organisms and toxins in the intestinal tract from passing into the bloodstream
  • Helping to control inflammation in the body
  • Helping to maintain regularity and health of the bowel

Since stress is often unavoidable and sometimes antibiotics are required, what can be done to ensure a healthy balance is restored to our intestinal microbes? You may have heard of the term ‘probiotics’; these are the ‘good’ microbes we need, many of which are found in yogurt. But is eating yogurt really enough? Yogurt is naturally  very healthy for us (before the  sugar, artificial sweeteners and food colouring is added).  However most commercial yogurts do not even contain the ‘live’ microbes we need. When choosing a yogurt brand ensure that the label says “live bacterial cultures”. Even if it does include live cultures, you would have to eat a ridiculous amount of it to replace the microbes lost during a course of antibiotic treatments.  In fact,  you would need to consume 50 small containers of yogurt to equal what is in one capsule of a 50 billion strength probiotic supplement. This is why taking a probiotic supplement can be in your best interest.

There are many different probiotic supplements available, but not all are created equal. In order to choose a quality probiotic supplement you should look at the following:

Culture Count

This refers to the total amount of bacteria per serving and can vary widely from product to product. If you are taking a probiotic for general health, you can take a lower potency probiotic with 2-6 Billion bacteria per serving. If you are treating a health condition, choose a therapeutic strength probiotic with a high culture count between 50 and 100 billion bacteria per capsule.

Number and Type of Strains

Because we all have a different microbial make-up in our body, it is important to choose a probiotic supplement with multiple strains. Your probiotic supplement should include many different strains of bacteria including both bifidobacteria (large intestine) and lactobacilli (small intestine). It is also important to look for a formula that delivers both resident (human strain) and transient bacteria. Transient bacteria do not populate the gut but exert a positive benefit, such as protecting against harmful bacteria or reducing inflammation, while travelling through the digestive tract.

Targeted Formulas

Most people would benefit from a high potency, multiple strain formula. If needed, you can also choose formulas that are specific to certain areas of concern such as colon health or vaginal support. While you should choose a child-specific formula for kids, adults do not need age specific formulas. Instead, if you are an older adult, choose a multi-strain formula with at least 30 billon bifidobacteria. After the age of 50, the levels of probiotics (specifically bifidobacteria) begin to decline in number so probiotics are an important supplement to take daily.

Delivery System

Most bacteria cannot survive the high acid environment of the stomach. For this reason, make sure that the probiotic you are buying has a delivery system. This could be an enteric coated capsule or bio-tract tablet. Both of these protect the probiotics from harsh stomach acid and deliver them directly to the intestines where they are needed and utilized by the body.

Guaranteed Potency

Always ensure that the product packaging states that the potency is guaranteed at expiry, not at the date of manufacture. Guaranteeing potency at expiry means that the amount of probiotic listed on the label is actually in the capsule when you consume it. This ensures you are getting what you paid for and more importantly, the health benefits of the probiotic itself.


Balch, P.A. and Balch, J.F. (2000). Prescription for Nutritional Healing 3rd Edition. New York, NY: Avery.

Greer, RL, Morgun, A., Shulzhenko, N. (2013). Bridging immunity and lipid metabolism by gut microbiota. The Journal of Allergy and Clinical Immunology Volume 132, Issue 2 P. 253-262.

Howarth, G.S. & Wang, H. (2013). Role of Endogenous Microbiota, Probiotics and Their Biological Products in Human Health. Nutrients.  January; 5(1): 58–81.

Reuter, Gerhard (2001) The Lactobacillus and Bifidobacterium Microflora of the Human Intestine: Composition and Succession. Curr. Issues Intest.Microbiol. 2(2): 43-53.

Salminen, Seppo.(2001) Human Studies on probiotics: Aspects of scientific documentation. Scandinavian Journal of Nutrition Vol 45. 8-12

Whelan K, Quigley EM (2013) Probiotics in the management of irritable bowel syndrome and inflammatory bowel disease. Curr Opin Gastroenterol. Mar;29(2):184-9.

About the Author

Cheryl Wright, RHN, BA hons.

Cheryl Wright, RHN, BA hons.

Registered Holistic Nutritionist
Over the past 15 years Cheryl has taught thousands of Canadians how to better their health using natural methods. She has provided individual nutrition consultations, as well as creating and facilitating corporate nutrition seminars including for the Toronto Police Dept. Currently an instructor at the Canadian School of Natural Nutrition, she has also taught nutrition courses at Centennial College. An expert in digestive health, Cheryl has educated audiences through seminars and talk radio across the country, as well as writing articles for health magazines and websites. Enthralled by the new research in the natural health field, Cheryl enjoys breaking it down and sharing her findings with the general public in easy to understand terms.
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