Inthout J, Ioannidis JP, Borm GF. The Hartung-Knapp-Sidik-Jonkman method for random effects meta-analysis is straightforward and considerably outperforms the standard DerSimonian-Laird method. BMC Med Res Methodol. 2014;14:1–12. Kakiuchi T, Mizoe A, Yamamoto K, Imamura I, Hashiguchi K, Kawakubo H, et al. Effect of probiotics during vonoprazan-containing triple therapy on gut microbiota in Helicobacter pylori infection: a randomized controlled trial. Helicobacter. 2020;25:1–8. Lozupone CA, Hamady M, Kelley ST, Knight R. Quantitative and qualitative β diversity measures lead to different insights into factors that structure microbial communities. Appl Environ Microbiol. 2007;73:1576–85. Madden JAJ, Plummer SF, Tang J, Garaiova I, Plummer NT, Herbison M, et al. Effect of probiotics on preventing disruption of the intestinal microflora following antibiotic therapy: a double-blind, placebo-controlled pilot study. Int Immunopharmacol. 2005;5:1091–7.

Nesnášenlivost potravin (netolerance laktózy může být způsobena nízkou kvalitou bakterií ve střevech)The selection was performed with the reference management program EndNote X9 (Clarivate Analytics, Philadelphia, PA, USA). After automatic and manual duplicate removal, two independent investigators manually selected the articles stepwise, first by title and abstract and subsequently by full-text contents adhering to the predefined eligibility criteria. Cohen’s kappa coefficient was calculated at each selection step to quantify the agreement between assessors. Disagreements were solved by consensus. Data collection Lance GN, Williams WT. Computer programs for hierarchical polythetic classification (“similarity analyses”). Comput J. 1966;9:60–4.

MacPherson CW, Mathieu O, Tremblay J, Champagne J, Nantel A, Girard SA, et al. Gut bacterial microbiota and its resistome rapidly recover to basal state levels after short-term amoxicillin-clavulanic acid treatment in healthy adults. Sci Rep. 2018;8:1–14. Allocati N, Masulli M, Alexeyev MF, Di Ilio C. Escherichia coli in Europe: an overview. Int J Environ Res Public Health. 2013;10:6235–54.This study is the first systematic review and meta-analysis that summarizes the results of the currently available randomized controlled trials investigating the effect of probiotic supplementation during antibiotic treatment on the gut microbiome. Probiotic supplementation to prevent antibiotic-induced dysbiosis is not supported by our results. Luo D, Wan X, Liu J, Tong T. Optimally estimating the sample mean from the sample size, median, mid-range, and/or mid-quartile range. Stat Methods Med Res. 2018;27:1785–805.

Although all the included studies were RCTs, the baseline values in the article by De Wolfe et al. [ 53] showed a marked difference between the probiotic and control groups (MD = 0.64 [(0.05 –1.22]). As a sensitivity analysis, we performed a separate calculation for data before the treatment and for the “before-after” values change in each study (Additional File 3: Fig. S1-2). We did not find any significant difference in the change values between the experimental and control groups regarding the Shannon diversity index (MD = 0.07 [(−)0.19 –0.32]). The impact of probiotic supplementation during antibiotic therapy on the Chao1 index Oh B, Kim BS, Kim JW, Kim JS, Koh SJ, Kim BG, et al. The effect of probiotics on gut microbiota during the Helicobacter pylori eradication: Randomized Controlled Trial. Helicobacter. 2016;21:165–74. Probiotics are preparations containing live micro-organisms, typically composed of microbes that are also found in the natural gut flora. Probiotics may contain bacteria, yeasts, or a mixture of them [ 11]. These products are used to prevent dysbiosis; however, the effects of concurrent probiotic supplementation on fecal microbiota diversity and taxonomical composition during antibiotic therapy are not fully understood. The effects of these products on clinical outcomes during antibiotic therapy have been intensely researched; however, most research did not focus on investigating the composition of the gut microbiome. This aspect is also missing from the current guidelines on the use of probiotics of the American Gastroenterological Association (AGA) and World Gastroenterology Organization (WGO) [ 11, 12]. The minimum recommended effective daily dose is between 100 million and 1 billion cells per day. Most probiotics contain at least 1 billion CFUs.

The additional sensitivity analysis for the baseline and the change values revealed no significant difference between groups either (Additional File 3: Fig. S5-6) (change: MD = 8.09 [(−)3.87–20.05]). Qualitative synthesis The impact of simultaneous probiotic supplementation during antibiotic treatment on α-diversity indices Other ingredients: Acid-resistant vegetable capsule (HPMC, pectin), magnesium stearate (vegetable source) Ginger root PE 4:1 (Zingiber officinale) Fennel seed extract 4:1 (Foeniculum vulgare) Artichoke leaf extract 4:1 (Cynara scolymus) Peppermint leaf powder (Mentha piperita) Prebiotic fiber provides food for probiotic organisms, creating a more effective “synbiotic” product once it reaches the small intestine. Very few probiotic products on the market contain prebiotic ingredients, reducing the efficacy and benefits that are sought from a probiotic supplement 4*. Gupta VK, Kim M, Bakshi U, Cunningham KY, Davis JM, Lazaridis KN, et al. A predictive index for health status using species-level gut microbiome profiling. Nat Commun. 2020;11:4635.