Longitudinal profiling of non-disease individuals. Microbiota data.. S3WP_microbiome

In order to use the microbiota as potential biomarker the definition of a normal microbiota with measurable characteristics needs to be established. Here we longitudinally profiled the fecal microbiota of a normal Swedish population with no clinical evidence of disease using both shotgun metagenomics and 16S rRNA gene sequencing to determine compositional and functional variation over the course of one year. Our analyses confirmed that inter-individual differences are larger than intra-individual variation for the composition of gut microbiota, and we identified gene richness and abundance of Faecalibacteriusm prausnitzii, and Bifidobacterium species as stabilizing factors of the gut microbiota in this population. However, the abundance of different microbial species exhibited different levels of intra-individual variability, which was largest for facultative anaerobes and oxygen tolerant bacteria. These bacteria varied extensively in abundance also in individuals with high compositional stability. Therefore, we conclude that repeated sampling is required to account for the normal intra-individual variation of the gut microbiota and allow a more reliable quantification of microbial biomarkers and suggest that the concept of gut microbiota dysbiosis based on the expansion of rare taxa needs to be updated as these may bloom in normal individuals as well.