Antibiotic treatment often leads to a violation of the resistance of the microflora of the gastrointestinal tract to colonization. This can cause complications, the most serious of which is the development of diarrhea associated with Clostridium difficile or diarrhea associated with antibiotics (AAD).

The purpose of the systematic review and meta-analysis, the results of which were published in the November issue of the journal Annals of Internal Medicine, was to assess the efficacy and safety of probiotics in preventing the occurrence of ADA in children and adult patients receiving antibiotics.

Searches were performed in the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, CINAHL, the Allied and Complementary Medicine Database, the Web of Science and 12 "gray" literary sources, ie. publications that cannot be found freely through traditional search channels.

A meta-analysis and systematic review included randomized controlled trials in adult patients or children receiving antibiotics that compared the use of any probiotic strain or different doses of a specific probiotic with placebo or no treatment and evaluated the incidence of Clostridium difficile associated diarrhea.

Two experts independently reviewed each other potentially eligible for meta-analysis of the publications, extracted the necessary data on the study population, interventions and results, and also assessed the risk of 'fault.

A total of 20 studies with a total number of 3,818 participants were found to be suitable for inclusion in the meta-analysis. Probiotics have been shown to reduce the incidence of AMA by 66% (combined relative risk of 0.34, 95% confidence interval 0.24-0.49). In a population with an AAA frequency of 5% (average risk in the control group), the prophylactic use of probiotics will prevent 33 episodes (confidence interval 25 to 38 episodes) per 1000 people. In the probiotic group, adverse events were observed in 9.3% of patients compared to 12.6% in the control group (relative risk 0.82, 95% confidence interval 0.65-1.05).

The limits of this meta-analysis are the fact that in 13 studies, information on the development of AMA was lost in 5 to 45% of patients. Nevertheless, the results obtained indicate that at present there is moderate evidence that the prophylactic use of probiotics results in a significant decrease in the rate of development of AMA without increasing the incidence of clinically significant adverse events.