Jafarnejad 2016.

Study characteristics
Methods	Parallel randomised control trial (Block randomisation)
Participants	Pregnant women with GDM (n = 82) Setting: Tuba Endocrine clinic (Sari, Iran) Dates of study May 2014 to October 2015 Inclusion criteria Pregnant women diagnosed with GDM diagnosed by 2‐hour, 75 g OGTT: fasting venous plasma glucose level, 5.5mmol⋅L−1 or higher or 75‐g OGTT 2‐hour venous plasma glucose level, 8.0 mmol⋅L−1 or higher Exclusion criteria Unwillingness to follow a prescribed diet, pre‐GDM (either type 1 or type 2 DM), the need for insulin treatment, and pregnancy co‐morbidities other than obesity, hypertension, and/or dyslipidaemia
Interventions	Probiotics: VSL#3 is a freeze‐dried pharmaceutical probiotic preparation containing 112.5 × 109 CFU/capsule of 8 strains of lactic acid bacteria (Streptococcus thermophilus, Bifidobacterium breve, Bifidobacterium longum, Bifidobacterium infantis, Lactobacillus acidophilus, Lactobacillus plantarum, Lactobacillus paracasei, and Lactobacillus delbrueckii subsp. Bulgaricus), microcrystalline cellulose, stearic acid, magnesium stearate, and vegetable capsule (hydroxypropyl methylcellulose), silicon dioxide (n = 41). Placebo: capsules containing 40mg microcrystalline cellulose; placebo boxes had identical appearances (n = 41)
Outcomes	FPG, HbA1c, HOMA‐IR, insulin levels, IL‐6, IL‐10, TNF‐α, hs‐CRP, IFN‐ɣ
Notes	Funding: no detail Conflicts of interest: authors declare that they have no competing interests.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computer‐generated randomisation performed by trained personnel at the endocrine clinic.
Allocation concealment (selection bias)	Unclear risk	Allocation of the intervention or control group was concealed from the researchers.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Neither the participants nor the investigators were aware of the treatment assignments.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Allocation blinded from the researchers.
Incomplete outcome data (attrition bias) All outcomes	Low risk	82 women randomised. 4 women excluded from probiotic group (2 women needed insulin and 2 birthed prematurely < 35 weeks); 6 women in the placebo group were excluded (5 needed insulin treatment and 1 birthed prematurely).
Selective reporting (reporting bias)	Unclear risk	No retrospective trial registration. Insufficient information to judge if pre‐specified outcomes are reported in full.
Other bias	Low risk	Groups were balanced at the baseline