Looking for a review that covers all the bases of probiotic health effects? A new, open access paper may serve that purpose. “Probiotics for human use” is a peer-reviewed paper published by the Nutrition Bulletin. This was a collaborative effort by experts in clinical effects (Prof. Dan Merenstein MD from Georgetown University, Claire Merrifield PhD from Imperial College London), fermented foods (Prof. Bob Hutkins PhD, University of Nebraska) and probiotic microbiology and regulatory matters (Mary Ellen Sanders PhD from ISAPP). Although many modern reviews of probiotics provide in-depth coverage of a specific health benefit, this paper covers all benefits with robust evidence.
The paper opens with a general overview of probiotics, detailing the importance of adhering to the accepted definition (see ISAPP consensus paper, Hill et al. 2014), strain-specificity of effects and the need to identify probiotics using current nomenclature. This last point is especially relevant today, considering that many probiotic lactobacilli are being renamed and no longer will be considered part of the Lactobacillus genus. The paper also discusses the concept that core benefits may be expressed by many strains of a probiotic species and, as such, some general effect may be considered to be associated with a given, well-studied species, and not be limited to specific strains. The importance of high quality probiotics that are safe for their intended use—in some cases in vulnerable populations—was also emphasized.
The paper reviews the strength of evidence for probiotic health effects in humans, focusing on infantile colic, eczema, inflammatory bowel diseases, antibiotic-associated diarrhea, C. difficile infections, and necrotizing enterocolitis. Probiotic applications for healthy people are also discussed, with Table 1 providing a list of benefits and effect sizes as determined from meta-analyses.
A section on fermented foods provides clarity about the difference between probiotics and fermented foods. Fermented foods are made by live microbes, but live microbes might not survive in the final food product due to heat treatments or other processing steps. Furthermore, fermented foods may not have been tested for benefits beyond the basic nutritional value of the food, which means fermented foods are not necessarily probiotic foods. However, it should also be remembered that some fermented foods—primarily yogurts and cultured milks—are sources of probiotics and have been subjected to controlled human studies documenting health effects.
Finally, the paper explores marketplace issues, including how to read a probiotic product label and understanding the complexities of regulatory issues regarding making health benefit claims for probiotics. The article also features the ISAPP infographic on Deciphering a Probiotic Label from an EU perspective.
The paper includes a box of frequently asked questions about probiotics.
Sanders ME, Merenstein D, Merrifield CA, Hutkins R. Probiotics for human use. Nutr Bull. 2018; 43(3):212-25. doi: 10.1111/nbu.12334.