The effects of selenium and probiotics co-supplementation on on pregnancy outcomes, inflammatory factors, oxidative stress biomarkers and gene expression related to inflammation in women with gestational diabetes

Objective: The aim of this study is to determine the effects of zinc and vitamin E supplementation on pregnancy outcomes, inflammatory factors, oxidative stress biomarkers and gene expression related to inflammation in patients with gestational diabetes mellitus.

Study design: Randomized double-blind placebo-controlled trial. Randomization will be done by the use of computer-generated random numbers. Patients will be assigned into two groups to receive combined probiotics and selenium supplement (n=30) or placebo (n=30).

Among patients with GDM referred to Kosar Clinic affiliated to Arak University of Medical Sciences, 60 patients will be selected according to inclusion and exclusion criteria. Participants, investigators or the assessors of the outcomes will be unaware of the study groups. Supplements and placebos are similar in shape and size. Fasting blood samples will be taken at baseline and 6 weeks after the intervention. At the beginning and the end of the intervention: 6 weeks.

Inclusion criteria: Patients with gestational diabetes mellitus aged 18 to 40 years. Exclusion criteria: Taking any supplements before the intervention.

Intervention group: Combined probiotic, including 2×109 Lactobacillus acidophilus, 2×109 Bifidobacterium bifidum, 2×109 Bifidobacterium langum, 2×109 Bifidobacterium lactis daily, and selenium supplements (Webber Naturals, Canada), 200 µg, daily, for 6 weeks orally. Control group: Probiotic and selenium placebo capsules (Barij essence, Kashan, Iran), daily, for 6 weeks orally.

Outcomes: Markers of insulin metabolism (primary outcomes) and lipid profiles, and gene expression related to insulin and lipid (secondary outcomes) will be quantified at study baseline and end-of-trial.

To decrease potential confounding effects, all participants will have stratified randomization according to BMI (<25 and ≥25 kg/m2) and age (<30 and ≥30 y). Then, participants in each block will be randomly allocated into two treatment groups to take either supplements or placebo. Randomization will be done by the use of computer software.

Randomization and allocation will be concealed from the researchers and participants until the final analyses are completed. Another person at the Kosar clinic, who is not involved in the trial and not aware of random sequences, will be assigned the participants to the numbered bottles of capsules