Table 1.

Changes in gut microbiota after administration of metformin therapy.

Research object	Increased gut bacteria	Decreased gut bacteria	References
HFD C57BL/6 mice	Bacteroides, Akkermansia, Parabacteroides	Ruminococcus, Desulfovibrio, Dorea, Lachnoclostridium	Ryan et al. (2020)
HFD C57BL/6 mice	Akkermansia, Bacteroides, Butyricimonas, Verrucomicrobia, Parabacteroides	Firmicutes/Bacteroidetes ratio	Lee et al. (2018)
db/db mice	Akkermansia, Butyricimonas, Lactobacillus, Coprococcus, Ruminococcus	Prevotella, Proteus	Zhang et al. (2019)
db/db mice	Akkermansia, Bacteroides, Bacteroidales, Lactobacillus, Allobaculum	Enterococcus, Staphylococcus, Corynebacterium, Jeotgalicoccus, Aerococcus, Facklamia	Chen et al. (2018)
KKAy mice	Bacteroides, Akkermansia, Enterococcus, Proteus, Parasutterella, Escherichia/Shigella	Lactobacillus, Lachnoclostridium, Pseudomonas, Staphylococcus	Gao et al. (2018)
HFD SD rats	Roseburia, Akkermansia, Lactobacillus	Desulfovibrio, Lachnospiraceae NK4A136	Cui et al. (2019)
HFD Wistar rats	Akkermensia, Bacteroides, Butyricicoccus, Lactobacillus, Parasutterella, Klebsiella, Prevotella, Allobaculum	Clostridium XIVa, Clostridium XI, Flavonifractor, Roseburia, Lachnospiracea	Zhang et al. (2015)
T2DM patients	Akkermansia muciniphila, Pectobacterium, Pantoea, Serratia, Bacillus, Pseudomonas, Klebsiella, Enterobacter, Escherichia	Dethiosulfovibrio, Deferribacter, Pseudogulbenkiania, Pseudoflavonifractor, Subdoligranulum, Intestinibacter	Wu et al. (2017)
T2DM patients	Akkermansia muciniphila, Prevotella, Butyrivibrio, Bifidobacterium bifidum, Megasphaera	Clostridiaceae 02d06, Oscillospira, Barnesiellaceae	de la Cuesta-Zuluaga et al. (2017)
T2DM patients			Forslund et al., 2015
Obesity patients	Akkermansia, Klebsiella Clostridium XIVa, Clostridium XIVb, Escherichia/Shigella	Clostridium XI, Clostridium XVIII, Roseburia	Hiel et al. (2020)
Healthy individuals	Escherichia/Shigella	Intestinibacter	Bryrup et al. (2019)