Fig. 2

Microbiota impact of the consumption of fermented products. PDB could be detected in the samples obtained during the corresponding intervention period. L. rhamnosus and S. thermophilus constituted 8.5%, and 5.2% of the total microbiota on average, but displayed extreme variation in intra- and inter-individual comparison (A–F). Subject corrected RDA analysis separated samples obtained during the different intervention periods at species (G, p = 0.001, explained variation 2.7%) and genus (H, p = 0.001, explained variation 2.03%) level. Samples are coloured by intervention period (yogurt [red], placebo [green] and L. rhamnosus [yellow]), and the microbial species or genera with the strongest contribution to the separation are indicated, with the PDB underlined. Subject corrected RDA analysis of the microbial composition of the intervention period samples after removal of the OTUs corresponding to PDB indicated that samples could still be significantly separated on basis of the intervention period in which they were taken, albeit with much less variation explained (species level, I; genus level, J; explained variation 0.44% and 0.48%, p = 0.024 and 0.036 respectively)