Fig. 4

Microbiota profiles in fresh samples frozen directly and frozen after 48 h in room temperature. a Boxplot of Inverse Simpson alpha-diversity index in samples frozen directly and frozen after 48 h. b Bray-Curtis dissimilarities between samples from the same individuals with different storage conditions, and between different individuals regardless of room temperature storage. c Heatmap of the log transformed OTU table from paired fecal samples from 8 presumably healthy individuals (serial number 01 to 10). One part of the samples was directly frozen (0 h, marked with green text) and the other part of the samples was frozen after 48 h in room temperature (48 h, marked with blue text). Hierarchical clustering and Euclidean distance produced the clustering showing higher inter-person variability than intra-person variability. Only OTUs with a log sum > 2 were illustrated