Table 1 Characteristics of the studies reviewed
Study | Participant characteristics | Intervention | Design | Microbiomics | Sample size calculation | Probiotic effects on fecal microbiota compared to placebo |
|---|---|---|---|---|---|---|
Lahti et al. 2013 [22] | 25/25 (72 %) 23–55 years Finland | L. rhamnosus GG ATCC53103 (1.55 × 1010 CFU) in 250 mL milk-based fruit drink | Double-blinded, parallel, two-armed, placebo (drink) controlled (21 days) | 16S rRNA (regions V1 and V6); HITchip based characterization of >1000 microbial species-like phylotypes | Post hoc | ↔ Composition of the fecal microbiota ↔ Stability of the fecal microbiota quantified by inter-individual and intra-individual correlations within and between time points |
Rampelli et al. 2013 [23] | 32/32 (59 %) 71–88 years Italy | B. longum Bar33 and L. helveticus Bar13 (109 CFU) in biscuit | Double-blinded, parallel, two-armed, placebo (biscuit) controlled (30 days) | 16S rRNA (region unknown); HTF-Microbi.Array based characterization of 31 phylogenetically related groups | No | ↔ Relative abundance of 31 phylogenetically related groups |
Ferrario et al. 2014 [27] | 22/34* (56 %) 23–55 years Italy | L. paracasei DG (>2.4 × 1010 CFU) in capsules | Double-blinded, cross-over, placebo (capsules) controlled (two 28-day intervention periods with a 28-day wash-out) | 16S rRNA (region V3) sequencing on Ion Torrent platform | No | ↔ α-diversity Modified β diversity (with absolute distances higher for the probiotic than for the placebo treatments) |
Bjerg et al. 2015 [19] | 20/64* (50 %) 20–45 years Denmark | L. casei W8® (1010 CFU) in capsules | Double-blinded, parallel, two-armed, placebo (capsules) controlled (28 days) | 16S rRNA (regions V3 and V4) sequencing on Roche 454 pyrosequencing platform | No | ↔ α- and β-diversity |
Brahe et al. 2015 [20] | 34/58* (100 %) 40–70 years Denmark | L. paracasei F19 (9.4 × 1010 CFU) or flaxseed mucilage (10 g) in sachets | Single-blinded, parallel, three-armed, placebo (sachets) controlled (42 days) | Quantitative metagenomics on a SOLiD 5500×l platform | Yes | ↔ Bacterial gene count (richness) and abundance of specific bacterial genes compared to placebo |
Hanifi et al. 2015 [21] | 37/81* (52 %) 19–49 years United States | Bacillus subtilis R0179 (0.1 × 109, 1.0 × 109, and 10 × 109 CFU, respectively) in capsules | Double-blinded, parallel, four-armed, placebo (capsules) controlled (28 days) | 16S rRNA (regions V1 to V3) pyrosequencing | No | ↔ β-diversity and OTU based richness |
Simon et al. 2015 [24] | 21/21 (52 %) 40–65 years Germany | L. reuteri SD5865 (2 × 1010 viable cells) in capsules | Double-blinded, parallel, two-armed, placebo (capsules) controlled (28 days) | 16S rRNA (regions V5 and V6) sequencing on Illumina MiSeq platform | Yes | ↔ α- and β-diversity |