SummaryMetagenomic surveys of human microbiota are becoming increasingly widespread in academic research as well as in food and pharmaceutical industries and clinical context. Intuitive tools for exploration of experimental data are of high interest to researchers. Knomics-Biota is a Web-based resource for exploratory analysis of human gut metagenomes. Users can generate analytical reports that correspond to common experimental schemes (like case-control study or paired comparison). Statistical analysis and visualizations of microbiota composition are provided in association with the external factors and in the context of thousands of publicly available datasets.\n\nAvailability and ImplementationThe Web-service is available at https://biota.knomics.ru.\n\nContactanna.popenko@knomics.ru or a.tyakht@gmail.com.\n\nSupplementary informationSupplementary figures are available at Bioinformatics online.