Viral illness: Can probiotics help in prevention?

• Are probiotics useful for preventing and treating Respiratory Tract Infections such as COVID-19?
• What dosage of Probiotics should I use?
• What is the scientific basis for using probiotics?

The short answer to the above questions is ‘Yes’, ‘20bcfu’ and ‘considerable’

There are more bacterial cells (the microbiome) in a human body than human cells¹, so it is hardly surprising that altering the composition of the microbiome has an impact on well-being. In addition more than half the body’s immune cells are located near the gut². Modern life with exposure to antibiotics, herbicides, sweeteners and a highly refined diet has a significant impact on the composition of the microbiome³.

The beneficial effect of probiotics to humans has been known for thousands of years with consumption of foods such as kefir and yoghurt for nutrition and therapeutic purposes⁴. More recently, in 1917 Prof Nissle in Germany isolated a strain of bacteria from soldiers that were resistant to dysentery and used this strain to treat bacterial gastroenteritis⁵. This product is still available today.

This century there has been an explosion of research in to the use of probiotics to prevent and treat illness including respiratory tract infections. The positive effects of probiotics are generalizable across respiratory tract infections as their effect is due to improved immune response to infections and resilience. Meta-analysis is a powerful statistical tool that pools data from scientific studies that increases the power to detect effects. A Cochrane Database meta-analysis found that probiotics were better than placebo (a treatment with no active ingredient) in reducing the number of people who had episodes of acute infection of the upper respiratory tract, in reducing the average episode length of acute infection of the upper respiratory tract, and in reducing the use of antibiotics and the number off days school or work. Probiotics significantly reduce the number of subjects with at least 1 episode of respiratory tract infections; furthermore, children supplemented with probiotics showed the number of days with fever and number of days of absence from the school lower than in children who were given a placebo⁶.

There are many probiotic formulas available locally. A moderate strength product with around 20 bcfu (billion colony forming units) should be suficient to produce these effects.

In addition to respiratory tract infections meta-analyses⁷ of the effect of probiotics has found them to be effective for:

• Reducing Cholesterol and High Blood pressure,
• Irritable Bowel Syndrome andConstipation
• Preventing allergy
• Treating Depression and Anxiety
• Reducing Oxidative Stress and Inflammation, two of the causes of aging

References

1. Sender, R., Fuchs, S., & Milo, R. (2016, August 19). Revised Estimates for the Number of Human and Bacteria Cells in the Body. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4991899/

2. Vighi, G., Marcucci, F., Sensi, L., Di Cara, G., & Frati, F. (2008, September). Allergy and the gastrointestinal system. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2515351/

3. Cully, M. (2019, June 17). Antibiotics alter the gut microbiome and host health. Retrieved from https://www.nature.com/articles/d42859-019-00019-x

4. Ozen, M., & Dinleyici, E. C. (2015). The history of probiotics: the untold story. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/25576593

5. Artur, Oswald, Sibylle, Sonnenborn, Ulrich, Corinne, … A., T. (2004, April 1). probiotic Escherichia coli strain Nissle 1917 interferes with invasion of human intestinal epithelial cells by different enteroinvasive bacterial pathogens. Retrieved from https://academic.oup.com/femspd/article/40/3/223/539109

6. Hao, Q., Dong, B. R., & Wu, T. (2015, February 3). Probiotics for preventing acute upper respiratory tract infections - Hao, Q - 2015: Cochrane Library. Retrieved from https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD006895.pub3/abstract

7. Rondanelli, M., Faliva, M. A., Perna, S., Giacosa, A., Peroni, G., & Castellazzi, A. M. (2017, November 2). Using probiotics in clinical practice: Where are we now? A review of existing meta-analyses. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/28640662