Table 1 Comparison of the microbiome of women with and without GDM

[2]

Finland

Stool samples

15 GDM and 76 non-GDM

(1st trimester, 3rd trimester, 1 month postpartum)

16S rRNA gene sequencing (V1–V2 region)

Depleted microbial richness at T1(Trimester 1)

[59]

Italy

Stool samples

41 GDM (within patient comparison at enrolment (24–28 weeks) and at 38 weeks of gestation

16S rRNA gene sequencing ( V3–V4 region)

At study end compared to enrollment:

Bacteroides, Collinsella and Rikenellaceae

Blautia, Butyricicoccus, Clostridium, Coprococcus, Dorea, Faecalibacterium, L − Ruminococcus (Ruminococcus genus assigned to Lachnospiraceae family), and Lachnospiraceae

[62]

Denmark

Stool samples

50 GDM and 157 non-GDM (3rd trimester, 8 months postpartum)

16S rRNA gene sequencing ( V1–V2 region)

Differentially abundant OTUs in Third trimester of pregnancy:

Actinobacteria, Collinsella, Rothia, Desulfovibrio, Blautia, Faecalibacterium

Postpartum:

Actinobacteria, Collinsella, Olsenella, Clostridium, Faecalibacterium, Bacteroides, Veillonella, Bavariicoccus, Clostridium sensu stricto, Clostridiaceae_1, Hafnia, Howardella, Dehalobacter

[86]

Germany

Stool samples

42 post-GDM and 35 control (3–16 months post-partum)

16S rRNA gene sequencing (V4 region)

Prevotellaceae

Firmicutes

[63]

China

Stool samples

Pregnant women with GDM (n = 30) and normal controls(n = 31) in third trimester

16S rRNA gene sequencing (V3–V4)

Gammaproteobacteria, Hemophilus

[87]

Denmark

Saliva samples

Pregnant women with GDM (n = 50) and normal glucose regulation (n = 160) in third trimester and 9 months postpartum

16S rRNA gene sequencing (V3-V4)

Third trimester of pregnancy

Actinobacillus paraheamolyticus (OTU_196)Neisseria (OTU_387)

Nine months after pregnancy

Bacteriodales (OTU_142), Treponema (OTU_242)

Leptotrichia (OTU_37), Streptococcus (OTU_183), Neisseria (OTU_387), unclassified Bacteria (OTU_76), Weeksellaceae (OTU_29) and Atopobium (OTU_382)

[63]

China

Saliva samples

Pregnant women with GDM (n = 30) and normal controls(n = 31) in third trimester

16S rRNA gene sequencing (V3–V4)

alpha-diversity, Fusobacteria, Leptotrichia

Selenomonas, Bifidobacterium

[14]

China

Saliva samples

346 pregnant women (42.98% GDM +), 175 oral samples collected

16S rRNA gene sequencing (V3–V4)

Proteobacteria

Firmicutes

[88]

China

Vaginal samples

25 pregnant women with GDM (n = 15) and normal controls (n = 10) in second and third trimester

16S rRNA gene sequencing (V4–V5)

Lactobacillus jensenii, Lactobacillus listeri, Lactobacillus amylovorus, Lactobacillus fructivorans

Lactobacillus salivarius

[75]

Brazil

Vaginal samples

68 pregnant women with GDM (n = 26) and normal controls (n = 42) in third trimester

16S rRNA gene sequencing (V4)

Bacteroides, Veillonella, Klebsiella, Escherichia-Shigella, Enterococcus, and Enterobacter