Fig. 4

Microbial diversity contributes to the relatively stable functional distribution. a Functional profile of Kyoto Encyclopedia of Genes and Genomes (KEGG) standard categories. For each functional pathway, the relative abundance was calculated as the sum of marker KOs’ coverage normalized by the number of KOs. Relative abundance of a given functional pathway was normalized by the sums of all studied pathways’ abundance. Details of amino acid, carbohydrate, and lipid metabolisms are expanded. b Ridge plot shows the most abundant bacteria that were affiliated with the phyla Actinobacteriota and Proteobacteria. The numbers in the ridge plot are the maximum relative abundance of bacteria