Spss v22.0 statistical software for windows

All data were expressed as the mean ± standard deviation. Statistical analyses were performed with SPSS V22.0 statistical software for Windows (SPSS Inc., Chicago, IL, USA). Comparisons between groups were performed using an independent-sample t-test. The differences among more than two groups were analyzed using one-way analysis of variance (ANOVA) followed by Duncan’s test. Significance was set at p < 0.05.

Statistical analyses were performed with SPSS V22.0 statistical software for Windows (SPSS Inc., Chicago, IL, USA) to determine the statistical differences among groups using Mann-Whitney U-test (two groups) and Kruskal-Wallis test (more than two groups). A Spearman’s rank correlation was used to evaluate trends between the relative abundance of gut microbiota at family and genus level and predicted metabolic pathways. Correlations between age and the relative abundance of gut microbiota at family and genus level were determined by Pearson’s analysis with adjustment for gender and BMI. The Venn plots in OTUs were plotted with the R package “VennDiagram”version 3.1.1. Principal component analysis (PCA) in OTUs was plotted with the R package “ade4”. Other graphs were drawn by GraphPad Prism 8 (GraphPad Software, La Jolla, CA, USA).

All data were expressed as means ± standard deviations. Statistical analyses were performed with SPSS V22.0 statistical software for Windows (SPSS Inc., Chicago, IL, USA) to determine the statistical differences among groups using parametric methods (analysis of variance, ANOVA) and nonparametric statistical methods (Mann–Whitney U-test and Kruskal–Wallis test). The differences among more than two groups were analyzed using a one-way ANOVA followed by a LSD test. Significance was set at p < 0.05.