Probiotics As a Tx Resource in Primary Care
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ONLINE EXCLUSIVE Daniel J. Merenstein, MD; Probiotics as a Tx resource Mary Ellen Sanders, PhD; Daniel J. Tancredi, PhD Georgetown University Medical in primary care Center, Washington, DC (Dr. Merenstein); International Scientific Association for While probiotics have not been marketed as drugs, Probiotics and Prebiotics, Centennial, CO (Dr. Sanders); clinicians can still recommend them in an evidence- University of California Davis School of Medicine and Center based manner. for Healthcare Policy and Research, Sacramento (Dr. Tancredi) [email protected] Dr. Merenstein reported no potential e are in the age of the microbiome. Both lay and scien- conflict of interest relevant to this PRACTICE tific press proliferate messages about the importance article. RECOMMENDATIONS of the microbiome to our health even while they often Dr. Sanders consults with companies ❯ Consider specific probiotics W engaged in probiotic business, remain unclear on how to correct microbiota patterns associated to prevent antibiotic- but has no financial stake in any with different diseases or suboptimal health states. Probiotics are company. She serves on scientific associated diarrhea, reduce advisory boards for Danone, Yakult crying time in colicky infants, defined as “live microorganisms that, when administered in ad- Honsha Co., Ltd, Danone North 1 America, and Winclove. and improve therapeutic equate amounts, confer a health benefit on the host.” effectiveness of antibiotics Certain probiotics have been shown to prevent and treat Dr. Tancredi has received statistics educational consulting fees from for bacterial vaginosis. A specific diseases or conditions, inside or outside the gut. But Pfizer Consumer Health. ❯ Consider specific the level and quality of evidence varies greatly. In addition, the probiotics to reduce the health claims allowed by government regulators depend on risk for Clostridioides making discrete distinctions (food vs drug, maintaining health ( formerly Clostridium) vs treating disease, and emerging evidence vs significant sci- difficile infections, to treat entific agreement) along dimensions that are increasingly rec- acute pediatric diarrhea, ognized as continuous and complex.2 This leads to confusion and to manage symptoms among doctors and patients about whether to trust claims on of constipation. B product labels and what to make of the absence of such claims. ❯ Check a product’s label to ❚ Find out which probiotic is effective for a patient’s condi- ensure that it includes the tion. Simply recommending that a patient “take probiotics” is not probiotic’s genus, species, and particularly helpful when the individual wants a product that will strains; the dose delivered aid a specific condition. While probiotics, to date, have not been in colony-forming units marketed as drugs in the United States, clinicians can still ap- through the end of shelf life; proach recommending them in an evidence-based manner. and expected benefits. C In this article, we review diseases/conditions for which pro- Strength of recommendation (SOR) biotic products have good efficacy data. We discuss probiotic A Good-quality patient-oriented efficacy and safety, offer relevant information on regulatory -cat evidence egories of probiotics, and give direction for proper usage based B Inconsistent or limited-quality patient-oriented evidence on the current evidence base. Although this review is meant to C Consensus, usual practice, be an easy-to-use resource for clinicians, it is not a comprehen- opinion, disease-oriented evidence, case series sive or detailed review of the numerous probiotic products and studies currently available. Regulatory and commercial variances with probiotics In the United States, probiotics have been marketed as dietary MDEDGE.COM/FAMILYMEDICINE VOL 69, NO 3 | APRIL 2020 | THE JOURNAL OF FAMILY PRACTICE E1 supplements, medical foods, or conventional end of shelf life, and expected benefits. (For foods, all of which require different levels of help in deciphering these labels, see the evidence and types of oversight than drugs. label schematic developed by the Interna- The efficacy of some probiotics in treating tional Scientific Association for Probiotics or preventing certain diseases and condi- and Prebiotics40 at https://isappscience.org/ tions is similar to, if not better than, effects infographics/probiotic-labelling/.) observed with traditional drug interventions Per guidelines from the Food and Ag- (TABLE 13-32). However, unlike drugs, which are ricultural Organization of the United Na- subject to premarket oversight, the probiotic tions and the World Health Organization, all marketplace contains products with uneven probiotic products should have this type of levels of evidence, from well substantiated to information clearly displayed on the prod- greatly limited. Currently, no probiotics are uct packaging.41 However, some probiotic sold in the United States as over-the-counter foods display less information; for example, or prescription drugs, although probiotic drugs they may not specify the product’s strains or will likely enter the US market eventually. recommended dosage levels. Product Web ❚ What to consider when recommend- sites may or may not disclose details miss- ing a product. When considering probiotics, ing from the food label. The absence of such remember that strain, dosage, and indication information makes it impossible to make are all important. Just as we know that not all evidence-based recommendations about Some probiotics antibiotics are equally effective for all infec- those products. are as effective tions, so, too, effectiveness among probiot- as, if not better ics can—and often does—vary for any given than, drugs condition. Effectiveness also may vary from Probiotics are generally safe, traditionally patient to patient. Most recommendations with caveats used to treat or made in this review are tied to specific pro- The overall safety of typical probiotics (Lac- prevent certain biotic strains and doses. In some cases, more tobacillus species, Bifidobacterium species, diseases and than one probiotic may be efficacious, likely and Saccharomyces cerevisiae var. boulardii) conditions. due to the same or similar underlying mecha- has been well documented.42,43 Many probi- nism of action. For example, most probiotics otic strains have been granted Generally Rec- produce short-chain fatty acids in the colon, ognized as Safe status for use in foods in the providing a common mechanism supporting United States.44,45 Many traditional probiotic digestive health.33-35 species have been evaluated by the European Contrary to the blanket recommenda- Food Safety Authority (similar to FDA, except tion preferring higher dosages or a greater jurisdiction is only over foods, not drugs) and number of strains,36 our recommendations are considered safe for use in food in the Eu- are based on levels shown to be effective in ropean Union. clinical trials, which in some contexts can be Be aware that probiotics delivered in di- as low as 100 million colony-forming units etary supplements and foods are intended (CFU) per day.37,38 Indeed, a survey we con- for the general population and not for patient ducted previously of retail dietary supple- populations. Manufacturers therefore are not ment products indicated that products with required to assure safety in vulnerable popu- lower CFUs or fewer strains could more read- lations. Nevertheless, probiotics are often ily be linked to evidence of efficacy than mul- stocked in hospital formularies.46,47 Probiotic tistrain, high-CFU products.39 usage in vulnerable patient groups has been ❚ Understanding probiotic product la- considered by an expert working group from bels is a good start. Information shown on the standpoint of quality assurance for micro- the label of a probiotic dietary supplement biologic products used to treat and prevent in the United States should include the ge- disease, with the experts recommending that nus, species, and strains contained in the health care professionals (including pharma- product, the dose delivered in CFU (the most cists and physicians) seek quality information common measure of the number of live mi- from manufacturers and that manufacturers crobes in a probiotic product) through the participate in programs providing third-party E2 THE JOURNAL OF FAMILY PRACTICE | APRIL 2020 | VOL 69, NO 3 PROBIOTICS 9 questions patients frequently ask about probiotics Q. Is a higher dose and greater number are regulated. The FDA does not conduct premarket of strains better? review of data on safety or health benefits. However, A. Not necessarily. The best approach is to recommend the FDA requires that these products are manufactured products that have been tested in human studies with under current Good Manufacturing Procedures. Further, positive outcomes. Sometimes these products are single products are required to be labeled in a truthful (and strain and have doses lower than other commercial not misleading) fashion. Enforcement of these standards products. If your patient’s goal is to simply add live, requires action by the FDA, and limited resources within potentially beneficial microbes to a diet, and he or she is the agency result in products on the market that may not presenting with any specific health complaints, then not comply with standards. fermented foods or any probiotic supplement should be sufficient. Q. Are refrigerated products better than nonrefrigerated? Q. Is yogurt a good choice for managing A. The stability of the live