Appendix A. Supplementary data for Exploring the universal healthy human gut microbiota around the world

Supplementary data to this article: Supplementary Document 1. Detailed description of the databases construction. Supplementary Figure 1. Processing and construction workflow of reference databases. The final databases used in the comparison are highlighted in red. Supplementary Figure 2. Determination of the optimal number of clusters for average abundance clustering analysis. The Elbow method was used to set the optimal number of clusters for the k-means algorithm at genus (A) and species (B) level. Supplementary Figure 3. Determination of the optimal number of clusters for z-scored average abundance patterns analysis. The Elbow method was used to set the optimal number of clusters for the k-means algorithm at genus (A) and species (B) level. Supplementary Figure 4. Bracken results comparison between the enriched filtered-MAG and original NT databases. From top to bottom, the performance of the databases was examined in terms of classification capacity for all samples as a whole, by host lifestyles and geographic origin at genus (A) and species (B) level. In the box plots, the black line within the box marks the median and the red triangle the mean, outliers are presented as red dots. Supplementary Figure 5. Relative abundances of top gut microbiota at the genus level. Only the 25 most abundant taxa in all samples were represented. Taxa are sorted by average relative abundances and their NCBI’s taxID is indicated in parentheses. In the box plots, the black line within the box marks the median and the red triangle the mean. Supplementary Figure 6. Universal core species. (A) Intersections between cores of interest. (B) Taxonomic relationships between universal core species. The number of core taxa assigned to a particular level is indicated inside the square brackets. (C) Prevalence-Abundance Heatmap. Taxa are sorted by average relative abundances and their NCBI’s taxID is indicated in parentheses. Supplementary Figure 7. Taxonomic relationships between different i