Table 2.
The Effects of Metformin on Composition of Gut Microbiota in T2DM or Obese Rats
| Animal Model | Control Group (Number) | Metformin Treatment Group (Number) | Effect of Metformin on Gut Microbiota | Country | Method for Detection | Author, Year and References | |
|---|---|---|---|---|---|---|---|
| 1 | Wistar rats (8–10 weeks old) | HFD for 10 weeks + HFD for 8 weeks (n=10) | HFD for 10 weeks + HFD with metformin treatment (200mg/kg/d) for 8 weeks (n=10) | Phylum: Proteobacteria↑, Verrucomicrobia↑Genus: Allobaculum↑, Bacteroides↑, Blautia↑, Butyricicoccus↑, Lactobacillus↑, Phascolarctobacterium↑, Parasutterella↑, Klebsiella↑, Prevotella↑, Akkermensia↑, Clostridium XIVa↓, Flavonifractor↓, Lachnospiracea_incertae_sedis↓, Roseburia↓, Clostridium XI↓ | China | 16S rRNA | Zhang et al 201541 |
| 2 | OLETF rats (4 weeks old) | Distilled water for 12 weeks (n=7) | Metformin treatment (100mg/kg/d) for 12 weeks (n=7) | Species: Akkermansia spp.↑, Prevotella spp.↓ | Korea | DGGE,qPCR | Wang et al 201748 |
| 3 | Wistar rats (200g) | HFD for 4 weeks+ STZ + HFD for 2 weeks +HFD for 4 weeks (n=8) | HFD for 4 weeks + STZ + HFD for 2 weeks + HFD with metformin treatment (200mg/kg/d) for 4 weeks (n=9) | Phylum: Bacteroidetes↑ Verrucomicrobia↓, Proteobacteria↓ Genus: 02d06, rc4_4↑ Sutterella, Prevotella changed | China | 16S rRNA,qPCR | Liu et al 201843 |
| 4 | Wistar rats (200g) | HFD for 4 weeks + STZ + HFD for 2 weeks +HDF for 4 weeks (n=6) | HFD for 4 weeks + STZ + HFD for 2 weeks +HFD wit metformin treatment (200mg/kg/d) for 4 weeks (n=7) | Phylum: Bacteroidetes changed | China | 16S rRNA | Liu et al 201844 |
| 5 | Zucker diabetic fatty fa/fa (ZDF) rats (7 weeks old) | HFD for 4 weeks + HFD with saline for 4 weeks (n=8) | HFD for 4 weeks + HFD with metformin treatment (215.15mg/kg/d) for 4 weeks (n=8) | Phylum: Firmicutes↑ Genus: Lactobacillus↑ Species: Lactobacillus intestinalis↑, Lactobacillus johnsonii↑ | China | 16S rRNA | Zhang et al 201949 |
| 6 | Wistar rats | HFD for 4 months + HFD with saline for 6weeks (n=8) | HFD for 4 months +HFD with metformin treatment (150 mg/kg/d) for 6 weeks (n=8) | Species: Bifidobacteria↑, Akkermansia↑, Shewanella↑, Allobaculum↑, Peptostreptococcaceae↑, Intestinibacter↑, Prevotella↓, Deferribacteres↓ | China | 16S rRNA | Li et al 201942 |
| 7 | Sprague-Dawley rats (100–120g) | HFD for 12 weeks + STZ + HFD for 2 days + HFD with distilled water for 6weeks (n=6) | HFD for 12 weeks + STZ + HFD for 2days + HFD with metformin treatment (100 mg/kg/d) for 6 weeks (n=6) | Order: Clostridiales↑, Lactobacillales↑, Enterobacteriales↓ Genus: Lactobacillus↑, Roseburia↑, Akkermansia↑, Desulfovibrio↓, Lachnospiraceae NK4A136↓ | China | 16S rRNA | Cui et al 201945 |
| 8 | Sprague-Dawley rats (170–190g) | HFD for 6 weeks + STZ + HFD for 1 week + HFD with saline for 8weeks (n=6) | HFD for 6 weeks + STZ + HFD for 1 week + HFD with metformin treatment (120 mg/kg/d) for 8 weeks (n=6) | Genus: Eubacterium_xylanophilum↑, Oscillibacter↑, Anaerotruncus↑, Bacteroidales_S24-7_group↓ | China | 16s rRNA | Liu et al 202046 |
| 9 | Wistar rats (180–200g) | HFD for 2 weeks + STZ + HFD for 2 weeks +HFD for 12weeks (n=5) | HFD for 2 weeks + STZ + HFD for 2 weeks + HFD with metformin treatment (30mg/kg/d) for 12 weeks (n=5) | Species: Lactobacillus spp.↑, Bifidobacterium spp.↑, Escherichia spp.↓, Clostridium perfringens↓ | Thailand | qPCR | Khat-udomkii et al 202047 |
Notes: ↑, Increase; ↓, decrease.
Abbreviations: N/A, not available; STZ, streptozotozin; DGGE, denaturing gradient gel electrophoresis.