Fig. 3

Effects of multiple factors on relative abundance of BSHs. a Relative abundance (RA) of BSHs in different genders among nine populations. b Correlation between BSHs RA and age in eight populations. c Correlation between BSHs RA and BMI in seven populations. d The cumulative RA and genera distribution of BSHs in different populations. e The multivariable-adjusted analysis of cumulative RA of BSHs against individual conditions including four factors. p^a values were calculated by nonparametric univariate method (Mann-Whitney U test) corrected for false discovery rate. p^b values were calculated by multivariable-adjusted analyses using linear regression model for target factor with remaining three factors. Here, the 11 populations form six continents include Africa: HZ; Asia: CN, JP, and KR; Europe: DK, SE, AT, and FR; Oceania: AU; North America (N-America): US; South America (S-America): PE. Note that the datasets of KR and AU have no individual information of gender, age, and BMI, and the dataset of HZ has no individual information of BMI, while the dataset of US has no individual information of age and BMI. Thus, the above datasets were excluded in related analysis. Details are shown in Additional file 2: Table S3, S4