2Probiotics: definition, scope and mechanisms of action
Introduction
Definitions for many, are necessary evils, which describe the meaning of a term, and in some cases every object the term describes. But, with differences of opinion of the definition of definition itself, one can appreciate why readers will have already tuned out.
In defining probiotics as “Live microorganisms which when administered in adequate amounts confer a health benefit on the host”, the Expert Panel commissioned in 2001 by the Food and Agriculture Organization of the United Nations, at Argentina's request, and supported by the World Health Organization, provided clarity and distinctiveness to the term probiotic [1]. While initially this was in relation to food, the Panel was cognisant of the potential for probiotics to be used under many regulatory categories. The wording was carefully chosen to encompass all real or envisaged ways of delivering various types of microbes to a host. Therefore, words like consumption and ingested were too restrictive, and ‘administered’ was chosen. The Panel was clear that there is no such entity as a dead probiotic. If dead organisms convey a benefit, they should be referred to by a different term. Yet to this day, authors continue to misunderstand the term, even when they include the actual reference to the FAO/WHO definition [2]. In this particular example, the author states “Probiotic applications can be either mono or multiple strains, or even in combination with prebiotic, immunostimulants such as synbiotics and synbiotism, and in live or dead forms.” It behoves editors and journals to enforce the proper use of the definition, but this is rarely done.
The conferring of a health benefit has been criticized as being too vague or requiring further clarification. In fact, a Working Group of FAO/WHO was convened in 2002 to provide such clarification [3]. More recently, the FAO/WHO definition has been re-evaluated and supported [4]. Clearly, a benefit to the host must be realized and shown to be above and beyond that placebo, yet the majority of products on the market have not undergone such appropriate testing and verification.
In this review, reasons for misunderstanding probiotic will be explored, as well as mechanisms whereby their effects are conveyed.
Section snippets
Why the confusion?
It is clear from the literature and conference presentations around the world, that either people want to define probiotics themselves, or they misunderstand what probiotics are. Examples of the former include the FDA which still uses the term biotherapeutics, ostensibly because no one has taken the time to update the field. Terms such as biotherapeutics and pharmacobiotics appear to emerge as a means of specifying an activity rather than being an alternative to the term probiotic and its
What can consumers and patients look for?
The failure or most medical schools to adequately teach future physicians about the human microbiome and applications of probiotics and prebiotics, has left a void that has serious implications for patient care. While continuing medical education courses and conferences have started to offer lectures on these topics, widespread ignorance or misunderstanding prevails. Admittedly, this is a perception that is not easy to prove. But, 19% of Irish doctors surveyed recommended probiotics for autism
Mechanisms of action
A common question is how do probiotics work? Given that different strains and product formulations exist, there is no single answer. The perception is that mechanisms of action of drugs are all known, and thus the same should apply for probiotics. Certainly, pharmaceutical agents like Warfarin prescribed to reduce the risk of cardiac arrest decrease the body's ability to form blood clots by blocking the formation of vitamin K–dependent clotting factors. Such knowledge was acquired by animal and
Summary
In summary, with microbes being such a large physical part of the gastrointestinal tract, as well as other sites, it is vitally important that specialists appreciate their existence, and consider what role they might have in health and disease. It will not be long before rapid diagnostic tools become available to inform about the contents of the microbiome, and while guidance will accompany results, it will make life much easier for interpreters of the findings, if they have some knowledge of
Conflict of interest
The author has no conflict of interest with respect to the content of this review.
Acknowledgements
Our work is supported by a grant from NSERC, but it played no part in the preparation of this paper.
References (58)
- et al.
Novel probiotics and prebiotics: road to the market
Curr Opin Biotechnol
(2015) - et al.
Psychobiotics: a novel class of psychotropic
Biol Psychiatry
(2013) - et al.
The gastrointestinal microbiome - functional interference between stomach and intestine
Best Pract Res Clin Gastroenterol
(2014) - et al.
In vitro evaluation of single- and multi-strain probiotics: Inter-species inhibition between probiotic strains, and inhibition of pathogens
Anaerobe
(2012) - et al.
Aspirin therapy in primary cardiovascular disease prevention: a position paper of the European society of cardiology working group on thrombosis
J Am Coll Cardiol
(2014) - et al.
Combined antimicrobial activity of reuterin and diacetyl against foodborne pathogens
J Dairy Sci
(2014) - et al.
Probiotic Lactobacillus rhamnosus GR-1 supernatant prevents lipopolysaccharide-induced preterm birth and reduces inflammation in pregnant CD-1 mice
Am J Obstet Gynecol
(2014) - et al.
Impact of maternal probiotic-supplemented dietary counseling during pregnancy on colostrum adiponectin concentration: a prospective, randomized, placebo-controlled study
Early Hum Dev
(2012) - et al.
Screening for cholesterol-lowering probiotic based on deoxycholic acid removal pathway and studying its functional mechanisms in vitro
Anaerobe
(2012) Evaluation of health and nutritional properties of powder milk and live lactic acid bacteria
(2001)
The use of probiotics in aquaculture
J Appl Microbiol
Guidelines for the evaluation of probiotics in food
Expert consensus document. The international scientific association for probiotics and prebiotics consensus statement on the scope and appropriate use of the term probiotic
Nat Rev Gastroenterol Hepatol
Actual concept of “probiotics”: is it more functional to science or business?
World J Gastroenterol
Clinical guide to probiotic supplements
Opinion paper: Quo vadis - EFSA?
Benef Microbes
Use of probiotic Lactobacillus preparation to prevent diarrhoea associated with antibiotics: randomised double blind placebo controlled trial
BMJ
Complementary alternative medicine for children with autism: a physician survey
J Autism Dev Disord
Consumer demographics and expectations of probiotic therapy in New Zealand: results of a large telephone survey
N. Z Med J
Practices and attitudes toward complementary and alternative medicine in inflammatory bowel disease: a survey of gastroenterologists
J Complement Integr Med
Patient experience and use of probiotics in community-based health care settings
Patient Prefer Adherence
Correspondence of treatment of acute diarrhea to WHO recommendations in Georgia
Georgian Med News
[Use of bifidumbacterin for the correction of intestinal dysbacteriosis]
Kosm Biol Aviakosm Med
Probiotics as therapy in gastroenterology: a study of physician opinions and recommendations
J Clin Gastroenterol
The role of gut microbiota in drug response
Curr Pharm Des
A multi-platform metabolomics approach identifies highly specific biomarkers of bacterial diversity in the human vagina of pregnant and non-pregnant women
Scientific Reports
Patients receiving prebiotics and probiotics before liver transplantation develop fewer infections than controls: a systematic review and meta-analysis
Clin Gastroenterol Hepatol
A four-probiotics regimen reduces postoperative complications after colorectal surgery: a randomized, double-blind, placebo-controlled study
World J Surg
Improved cure of bacterial vaginosis with single dose of tinidazole (2 g), Lactobacillus rhamnosus GR-1, and Lactobacillus reuteri RC-14: a randomized, double-blind, placebo-controlled trial
Can J Microbiol
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