By Purna Kashyap, MBBS, scientific advisory board member for the AGA Center for Gut Microbiome Research and Education
Along with the growing interest in the connection between the gut microbiome and human health, probiotic products have become increasingly popular. The World Health Organization defines probiotics as “live microorganisms, which when consumed in adequate amounts confer health and benefit to the host.” Data from the 2012 National Health Interview Survey showed that 3.9 million U.S. adults reported using probiotics or prebiotics, which was a four-fold increase from the previous survey in 2007. I’m sure, like me, most of you frequently receive questions from patients about utility of probiotics and prebiotics.
There is a lot of research ongoing about the safety and efficacy of probiotics, especially in patients with GI disorders such as irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD). While probiotics are generally regarded as safe, studies up-to-date have failed to show a consistent, reproducible, clinically meaningful effect in majority of conditions tested. In a recent analysis of 14 Cochrane reviews on probiotics for GI disorders, the authors reported that the majority of the reviews reported insufficient evidence to determine if probiotics conferred a benefit. This analysis also highlighted inconsistencies in how probiotics studies are described in the literature. For example, while most of the studies reported dosage, many did not specify the strain(s) contained in the probiotic and most did not specify any follow-up beyond the initial intervention.
Beyond study design, there are other key questions that are still being investigated such as the best way to deliver probiotics to the gut (as a pill, in food, other approaches?), the stability and efficacy of probiotics at room temperature vs. refrigeration, and of course what combination of strains are effective in which subset of patients.
However, the outlook is optimistic with some of the recent studies in children showing a significant health benefit suggesting that probiotics have the potential to make a tremendous impact on the care of patients with digestive disorders, but there is more that we need to learn as scientists and clinicians. As we march into the era of personalized medicine, we are seeing an emergence of precision approaches using probiotics, so stay tuned.
To help address patient questions on the topic, I worked with my AGA microbiome center colleague Geoffrey Preidis, MD, PhD, to develop a new resource for patients in the AGA GI Patient Center on probiotics (available in English and Spanish). We summarize, in patient-friendly language, what we do and do not know about probiotics, who might consider taking a probiotic, and how to approach choosing a probiotic product. This resource is freely available to the public at www.gastro.org/probiotics and I encourage you to share it with your patients who are considering probiotics.
Recommended reading
1. Clarke T.C., Black L.I., Stussman B.J., Barnes P.M., Nahin R.L. Trends in the use of complementary health approaches among adults: United States, 2002–2012. Natl Health Stat Report. 2015; 79:1-16. https://www.cdc.gov/nchs/data/nhsr/nhsr079.pdf.
2. Parker E.A., Roy T., D’Adamo C.R., Wieland L.S. Probiotics and gastrointestinal conditions: An overview of evidence from the Cochrane Collaboration. Nutrition. 2018; 45:125-134.e11. https://www.ncbi.nlm.nih.gov/pubmed/28870406.
3. Hanage W.P. Microbiology: Microbiome science needs a healthy dose of skepticism. Nature. 2014; 512(7514):247-248. https://www.nature.com/news/microbiology-microbiome-science-needs-a-healthy-dose-of-scepticism-1.15730.
