Rationale of the study. The authors should better clarify their working hypothesis. Gut microbiota. It is clear that the authors are not experts of the theme. The presentation of the data and their discussion, as well as the introductory and final sections are inadequate, gross and denote a very poor knowledge of the topic. The authors should tone down speculations related to the use of yogurt as a tool to modulate the gut microbiota, indicate the amount of bacteria contained and the amount of yogurt consumed by athletes. What about the “other beneficial bacteria”? The authors should provide experimental details related to library preparation, bioinformatics (e.g. did they use QIIME? Which software did they use for chimera filtering? What metrics did they use for alpha diversity? What about beta diversity?) and statistics (did they correct p values for multiple comparisons? Did they use paired tests when appropriate? They cannot have used Kruskal-Wallis for pairwise comparisons. Mann-Whitney U test and Wilcoxon rank sum test are the same test). Some significant differences are questionable, e.g. figures 3 and 6, left panel. How is it possible that those values are significantly different? Please do not comment on taxa that are not significantly different (e.g. Akkermansia), do not make irrelevant comparisons (like that with Parkinson’s disease), and tone down inappropriate speculations on bifidobacteria and the gut-brain axis. Accession number. The authors should deposit their microbiota data in a public repository, e.g. MG-RAST, NCBI SRA, etc., and provide the accession number in the main text.