Data collection description.

Sequence collections representing five control groups from previously published studies used for this meta-analysis were stored in the Sequence Read Archive (SRA, http://www.ncbi.nlm.nih.gov/sra), National Center for Biotechnology Information (NCBI). The pool of human samples (SRA058021) composed of the control and the placebo group. Samples from these two categories were sequenced in four independent runs resulting in 16 human GM profiles sequenced in 4 replicates for each sample collected at time zero (the control group) and 4 replicates for samples collected after 6 weeks from the time zero (the placebo group). The B6. V-Lep ob/J mice (SRA057283) composed of the two sampled at 8 and 16 weeks of age. The GM profile of BALB/c mice was verified for caecal and fecal samples (studies SRA051317 and SRA059019 respectively).