Probiotic supplements may be considered as an adjunct treatment for glycemic control in women who are pregnant and have gestational diabetes.
There is increasing evidence regarding the use of probiotics in the prevention of gestational diabetes. Theories by which probiotic intake may improve markers of insulin resistance and lipid profiles in patients with gestational diabetes include its anti-inflammatory effects, both locally in the gut and systemically, increased production of bacteriocins and short-chain fatty acids such as butyric acid, and by downregulating inflammation and blocking suppression of glucose transporter type 4. Still the effects of probiotic supplementation on markers of insulin resistance and lipid concentrations in patients with gestational diabetes are scarce.
A new randomized, double-blind, placebo-controlled trial published January 2019 aimed to evaluate the effect of probiotic supplements on insulin resistance in pregnant women with diet-controlled gestational diabetes mellitus.
The study was carried out between June 2016 and February 2017. Pregnant women with diet-controlled gestational diabetes mellitus were enrolled in the study at 24–28 weeks of gestation and randomized to receive either probiotic supplements containing Bifidobacterium and Lactobacillus or a placebo daily for four consecutive weeks. Primary outcomes were mean differences in insulin resistance (homeostatic model assessment for insulin resistance), fasting insulin and fasting plasma glucose between the two groups. Secondary outcomes were changes in maternal weight after the intervention.
Probiotic supplementation for four weeks during the late second to early third trimester resulted in favorable metabolic changes on fasting plasma glucose, fasting plasma insulin and Homeostatic model assessment for insulin resistance, compared with placebo. These effects occurred without significant differences in caloric intake, dietary macronutrient composition, fiber intake or weight gain between the placebo and probiotic groups. In addition, probiotic supplementation was shown to be well-tolerated and safe in the participants.
The study concluded that four weeks of probiotic supplements in women with diet-controlled gestational diabetes in the late second and early third trimester lowered fasting glucose and increased insulin sensitivity. Probiotic supplements may be considered an adjunct treatment for glycemic control in these patients.
In another study, N. Dolatkhah et al, aimed to assess the effect of a probiotic supplement capsule containing four bacterial strains on glucose metabolism indices and weight changes in women with newly diagnosed gestational diabetes. Sixty-four pregnant women with gestational diabetes were enrolled into a double-blind placebo-controlled randomized clinical trial. They were randomly assigned to receive either a probiotic or placebo capsule along with dietary advice for eight consecutive weeks. The trend of weight gain along with glucose metabolism indices was assayed.
During the first six weeks of the study, the weight gain trend was similar between the groups. However, in the last two weeks of the study, the weight gain in the probiotic group was significantly lower than in the placebo group. Fasting blood glucose decreased in both intervention and control groups significantly, and the decrease in the probiotic group was significantly higher than in the placebo group.
While these studies support the favorable effect of probiotics on fasting glucose levels, there is still conflicting data as seen in a large study conducted by K.L. Lindsay et al, in which 149 pregnant women with gestational diabetes who were randomized to either a daily probiotic (Lactobacillus salivarius) or placebo capsule for 4–6 weeks. There were no significant differences in fasting glucose levels between the two groups after the intervention. According to A. Kijanawat et al, this could be due to the lack of positive effects in fasting glucose levels seen in some studies could be due to a relatively mild degree of hyperglycemia in these women with diet-controlled gestational diabetes, and probiotics could not further lower glucose levels, as some of them might have been in the normal range at baseline.
This still shows that further research is needed to strengthen these results before recommendations can be made.
- Probiotic supplements have been shown to lower fasting glucose and decrease insulin resistance in patients with gestational diabetes.
- There is still conflicting data from large trials showing no significant difference seen with the use of probiotics, therefore further research is warranted.
Kijmanawat A, Panburana P, Reutrakul S, Tangshewinsirikul C. Effects of probiotic supplements on insulin resistance in gestational diabetes mellitus: A double-blind randomized controlled trial. J Diabetes Investig. 2019 Jan;10(1):163-170.
Dolatkhah N, Hajifaraji M, Abbasalizadeh F, et al. Is there a value for probiotic supplements in gestational diabetes mellitus? A randomized clinical trial. J Health Popul Nutr 2015; 33: 25
Lindsay KL, Brennan L, Kennelly MA, et al. Impact of probiotics in women with gestational diabetes mellitus on metabolic health: a randomized controlled trial. Am J Obstet Gynecol 2015; 212: 496.e1–496.e11.
Dahlia Elimairi, Pharm D Student UC Denver Skaggs School of Pharmacy