Fig. 2

A: Interclass correlation coefficients (ICC) for stability using RNAlater frozen after 4 days at room temperature (day-4) compared to immediately frozen (day-0) for alpha diversity, beta diversity metrics, and the three most dominant phyla (i.e., Firmicutes, Bacteroidetes, Proteobacteria) in fecal samples from Yazd and Gonbad, Iran, (N participants = 84, n samples = 269). Phylum relative abundances were square root transformed prior to calculating ICCs. P-values for testing statistical heterogeneity between Gonbad and Yazd are shown in Additional files 2 Table S1 and S3. B: ICCs for evaluating stability using fecal occult blood test (FOBT) card cards frozen after 4 days at room temperature (day-4) compared to immediately frozen (day-0). C: ICCs for evaluating comparability between RNAlater and FOBT card for immediately frozen samples (day-0)