Digestive problems? Try probiotics

The Bottom Line

  • Probiotics are “good” bacteria that promote gut health and keep harmful bacteria in check.
  • When given to people taking antibiotics, probiotics help prevent diarrhea associated with C. difficile.
  • There is evidence that probiotics improve symptoms of other gastrointestinal problems such as irritable bowel syndrome and chronic constipation.

Probiotics: They’re being added to more food items and touted as solving a wide range of health problems, boosting body functions from your brain to your breathing to your bowels. But is this just another fad? What are probiotics anyway? And do they live up to all the hype?

Probiotics are actually bacteria – the “good” kind. Our bodies have trillions of these microorganisms, some harmful but the majority of them beneficial. “Good” bacteria help break down food and keep the “bad” bacteria at bay. Probiotic bacteria are found in cultured dairy foods like yogurt, fermented vegetables like kimchi and sauerkraut, and foods fortified with probiotic bacterial cultures. They’re also available in capsules.

So they’re easy to find and consume… but are they really the “miracle cure” many claim them to be?

What the research tells us

Although there is some indication from the research evidence that probiotics may help to treat many common health issues (including respiratory infections (1) and pneumonia (2)), so far, we can only say with confidence that probiotics are beneficial for improved digestive health.

Medications (especially antibiotics), stress, diet and other factors can alter the ratio of good to bad bacteria in your gut, causing infection and disease. This happens more often than you might think: antibiotics are one of the most prescribed medications in Canada and the US (and often prescribed unnecessarily… but that’s another story) (3;4). They’re important and effective in killing infection-causing bacteria, but they often end up killing a lot of good bacteria, upsetting that important balance and giving dangerous Clostridium difficile bacteria a chance to cause severe diarrhea and other bowel diseases, sometimes with fatal results (5).

That’s where probiotics – like Lactobacillus rhamnosus, Lactobacillus casei and Bifidobacterium lactis – come in. Research evidence shows that probiotics given to children and adults taking antibiotics successfully lowers the risk of C. difficile-associated diarrhea (6;7). Thanks to results from these and other studies, probiotics are now recommended and commonly prescribed for people who are taking antibiotics, particularly as they are relatively inexpensive and safe for most people (6). 

There is also promising evidence that probiotics may also help in the treatment of other common gastrointestinal problems, including irritable bowel syndrome and chronic constipation (8), conditions that affect more than 10% of the adult population (9;10).

As we continue to learn more about the role probiotics play in promoting health, go ahead and enjoy your yogurt, especially if you are prescribed antibiotics. Consuming more probiotic-rich food isn't likely to cause harm, and very well may help keep your gut balanced and happy!

As for the other health benefits of probiotics? Time – and evidence from ongoing research – will tell.

Featured Resources

  1. Web Resource Rating: What are probiotics?
  2. Web Resource Rating: Do I need to include probiotics and prebiotics in my diet?
  3. Web Resource Rating: Irritable bowel syndrome: What helps and what doesn’t?

  4. Web Resource Rating: Infectious diarrhea

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  1. Hao Q, Dong BR, Wu T. Probiotics for preventing acute upper repiratoy tract infections. Cochrane Database Syst Rev. 2015; (2):CD006895. doi: 10.1002/14651858.CD006895.pub3.
  2. Bo L, Li J, Tao T, et al. Probiotics for preventing ventilator-associated pneumonia. Cochrane Database Syst Rev. 2014; (10):CD009066. doi: 10.1002/14651858.CD009066.pub2.
  3. Government of Canada. Canadian antimicrobial resistance surveillance system report 2016. [Internet] 2016. [cited March 2017]. Available from:https://www.canada.ca/en/public-health/services/publications/drugs-health-products/canadian-antimicrobial-resistance-surveillance-system-report-2016.html#a3-2-2
  4. Centers for Disease Control and Prevention. Get smart: Know when antibiotic work in doctor’s offices. [Internet] 2017. Available from https://www.cdc.gov/getsmart/community/programs-measurement/measuring-antibiotic-prescribing.html
  5. Oake N, Taljaard M, van Walraven C et al. The effect of hospital-acquired Clostridium difficile infection on in-hospital mortality. Arch Intern Med. 2010; 170(2):1804-1810. doi: 10.1001/archinternmed.2010.405.
  6. Johnston BC, Ma S, Goldenberg JZ et al. Probiotics for the prevention of Clostridium difficile-associated diarrhea: A systematic review and meta-analysis. Ann Intern Med. 2012; 157(2):878–888.
  7. Hempel S, Newberry SJ, Maher AR et al. Probiotics for the prevention and treatment of antibiotic-associated diarrhea: A systematic review and meta-analysis. JAMA. 2012; 307(18):1959-1969. doi: 10.1001/jama.2012.3507.
  8. Ford AC, Quigley EM, Lacy BE et al. Efficacy of prebiotics, probiotics, and synbiotics in irritable bowel syndrome and chronic idiopathic constipation: Systematic review and meta-analysis. Am J Gastroenterol. 2014; 109(10):1547-1561. doi: 10.1038/ajg.2014.202.
  9. Lovell RM, Ford AC. Global prevalence of, and risk factors for, irritable bowel syndrome: A meta-analysis. Clin Gastroenterol Hepatol. 2012; 10(7):712-721. doi: 10.1016/j.cgh.2012.02.029.
  10. Suares NC, Ford AC. Prevalence of, and risk factors for, chronic idiopathic constipation in the community: Systematic review and meta-analysis. Am J Gastroenterol. 2011; 106(9):1582-1591. doi: 10.1038/ajg.2011.164.

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