family taking probiotics

Our immune system is made up of various organs, cells and proteins. It has several roles within our body, including the ability to fight disease causing pathogens including bacteria, viruses, parasites or fungi and remove them from our body.


70% of our immune system lays along our digestive tract. This means that our gut microbiota plays a significant role in the function of our immune system.


In order to support immunity, a well-functioning and an optimum gut microbiota can be considered vital. This may be achieved through supplementing with friendly bacteria. Several beneficial effects of probiotics on the host immune system have been identified. Probiotics are able to enhance our immune response as well as interacting indirectly and directly with pathogens to help fight infection.


A systemic review* was carried out the evaluate the use of friendly bacteria, specifically Bifidobacterium and Lactobacillus strains on the duration of acute respiratory infections in otherwise healthy children and adults.


The results showed that the mean duration of illness episodes decreased by between half and 1 day in participants who received a friendly bacteria supplement compared with those who did not. They also found significantly fewer numbers of days of illness per person and significantly fewer numbers of days absent from day care/school/work in participants who had taken a friendly bacteria supplement than in those who had taken a placebo.


The authors concluded that... “this systematic review provides evidence from a number of good-quality RCT that the average duration of respiratory illness episodes, the number of days of illness per person and the number of days absent from day care/work/school are significantly reduced with probiotic treatment compared with placebo.”


This trial compared included different types of friendly bacteria, in different forms and amounts. Whilst the authors were unable to conclude what species of friendly bacteria are most effective for reducing the symptoms and duration of an acute respiratory infection, it may suggest you should look out for friendly bacteria supplements containing species of Lactobacillus and Bifibacterium.


* A systematic review summarises the results of available carefully designed healthcare studies (controlled trials) and provides a high level of evidence on the effectiveness of healthcare interventions. Judgments may be made about the evidence and inform recommendations for healthcare.

 If you'd like to learn more about supporting your gut and immune health, why not book a free 1:1 consultation with our nutrition team? We can recommend diet and lifestyle changes that can make a big difference. To book, simply click here.



King S, Glanville J, Sanders ME, Fitzgerald A, Varley D (2014) Effectiveness of probiotics on the duration of illness in healthy children and adults who develop common acute respiratory infectious conditions: a systematic review and meta-analysis. British Journal of Nutrition Jul 14;112(1):41-54