Probiotics can protect the intestinal microbiome during a course of antibiotics, thereby reducing the risk of antibiotics-associated diarrhoea. Nevertheless, in the Netherlands probiotics are seldom prescribed alongside a course of antibiotics. One reason for this is that there are so many different probiotics on the market that healthcare professionals can’t see the wood for the trees. Therefore, the National guide to clinically proven probiotics in antibiotic therapy (Nationale gids van klinisch bewezen probiotica bij antibioticagebruik), has been developed to help healthcare professionals make a choice.
Antibiotics are used to combat pathogenic bacteria. Unfortunately, antibiotics also have a disruptive effect on the gut microbiome, and antibiotics-associated diarrhoea (AAD) is the best-known symptom of this problem. When taking a broad-spectrum antibiotic such as amoxicillin, no fewer than 1 in 4 adults will suffer from AAD. It is important to realize that even if there is no diarrhoea the gut microbiome is disrupted, with potentially harmful long-term consequences.
Probiotics in antibiotic therapy
In late 2016, the development of the National guide to clinically proven probiotics in antibiotic therapy was initiated by Professor Remco Kort. The guide, which was recently published in BMC Gastroenterology gives a practical overview of those probiotics for which scientific research studies have demonstrated that they can be used in combination with antibiotic therapy in order to prevent antibiotics-associated diarrhoea. In earlier publications, the European Society for Pediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) and the World Gastroenterology Organisation also gave guidelines for the use of probiotics to prevent AAD during antibiotic therapy.
In order to select probiotics with proven efficacy, this review devised a general methodology with three separate steps. These were: (1) a systematic review of relevant clinical studies into probiotics that proved to be efficacious against AAD. This review included only those studies that met the strictest methodological demands: randomized, double-blind, placebo-controlled RCTs that employed a clear definition of antibiotics-related diarrhoea and which administered a probiotic regime for at least the duration of the antibiotic therapy. Next, (2) a list was drawn up of the probiotic products available in the Netherlands. Lastly, (3) recommendations were made for those probiotic products on this list that had been demonstrably efficacious.
Only 32 of the 128 RCTs found by this review met its strict criteria and were therefore included in the systematic review. The results of these studies were then pooled for each probiotic product available in the Netherlands (both dairy products and food supplements). Lastly, all products were excluded from the review for which the label did not clearly indicate which probiotic strains were included in the product and how many colony forming units (CFU) it contained. Products were given three stars if an effect was observed in at least three of the selected studies; two stars for an observed effect in two studies; and one star for an observed effect in a single study. The result was that eight products remained whose efficacy in preventing AAD had been scientifically proven.
What do the stars actually mean?
More stars do not mean that a product is more effective, and therefore better. It simply means that more randomized, double-blind, placebo-controlled RCTs were carried out on it. Nor does the number of stars say anything about the size of the effect observed; a product that was tested in three studies may have been less effective in preventing AAD than a product whose efficacy was examined in only a single study.
How can probiotics be best deployed to prevent AAD?
There is as yet no scientific evidence on how best to administer probiotic therapy, but on the basis of clinical studies it may be concluded that as a general rule probiotics should be taken for the entire duration of the antibiotics therapy (taken 2 hours after taking the antibiotic) and for 1 to 2 weeks thereafter.
Why is the guide useful?
The guide offers healthcare professionals and consumers alike clear, scientifically-supported recommendations as to which specific probiotic products can be used to prevent AAD. The manual will be reviewed annually, and modified to accommodate the results of any new research that meets the review inclusion criteria. The manual has been published in the scientific journal BMC Gastroenterology.