Dr. Gregor Reid
Chair of the Centre for Human Microbiome and and Probiotics, Lawson Health Research Institute

Studies have shown that along with a healthy diet and a well-balanced lifestyle, ingesting probiotics appears to improve the body’s immune response, which can play a role in decreasing the duration and severity of the common cold.

The human body contains vast amounts of bacteria. When the bacterial balance is disrupted by stress,  poor nutrition, or through antibiotics, which kill off a wide range of bacteria, your immune system activity is challenged. Ingesting probiotics, live microorganisms sold in some foods and capsules, can help the body fight off infection.

Dr. Gregor Reid, Chair of the Centre for Human Microbiome and Probiotics at the Lawson Health Research Institute, points out that humans evolved eating fermented foods and those such as sauerkraut and yogurt contain beneficial bacteria. Nowadays, we eat a lot of refined and preserved food, and “the modern diet is bereft of fermented foods,” he says. Unless you eat fermented foods daily, he advises taking clinically documented probiotics, which typically contain billions of beneficial bacteria, such as Lactobacillus and Bifidobacterium. Dr. Reid strongly recommends only those probiotics tested in human studies.

Although ingesting probiotics ultimately enhances the immune system, the way probiotics work is actually rather complex, according to Dr. Reid. “Studies show that if you take probiotics, the effect might benefit the heart, the breast in lactating women, the respiratory tract, or the bladder. In large part via modulating your immune response,” he says. “But the probiotic strains produce and stimulate small molecules to benefit the host, and we’re only now trying to identify what these are.”

Reduces duration of colds

Dr. Reid points out that a number of studies show that ingesting probiotics can reduce the length of colds by 20 percent. Studies have revealed that although a particular probiotic had no effect on the incidence of common cold infections, it shortened the duration by almost two days and reduced the severity of symptoms. Probiotics can particularly benefit children who attend day cares as well as elderly people, groups in which the impact of colds can be more detrimental, says Dr. Reid.

"Probiotics can particularly benefit children who attend day cares as well as elderly people, groups in which the impact of colds can be more detrimental, says Dr. Reid."

According to the Canadian Centre for Occupational Health & Safety, adults suffer 2–5 colds per year and they are one of the leading causes of missed days at work. Most children average between 6–10 colds per year. Based on a recent study, taking probiotics has shown to have a significant economic impact.

Aiding in the fight against antibiotic resistance

From a public health perspective, the recent alarming news that we are running out of antibiotics raises the questions of what else can we use? While only in rare cases can probiotics actually be considered to treat infection, probiotics might replace the use of low dose antibiotics to prevent infection.

“We have to think outside the box and utilize beneficial microbes to manage disease. Given that humans are mostly microbes — lots more of them than our human cells — it’s time to nurture them rather than carpet bomb them with broad spectrum antimicrobials” says Dr. Reid.