Gut Microbiome Changes in Gestational Diabetes

Abstract

Gestational diabetes mellitus (GDM), one of the most common endocrine pathologies during pregnancy, is defined as any degree of glucose intolerance with onset or first discovery in the perinatal period. Physiological changes that occur in pregnant women can lead to inflammation, which promotes insulin resistance. In the general context of worldwide increasing obesity in young females of reproductive age, GDM follows the same ascending trend. Changes in the intestinal microbiome play a decisive role in obesity and the development of insulin resistance and chronic inflammation, especially in patients with type 2 diabetes mellitus (T2D). To date, various studies have also associated intestinal dysbiosis with metabolic changes in women with GDM. Although host metabolism in women with GDM has not been fully elucidated, it is of particular importance to analyze the available data and to discuss the actual knowledge regarding microbiome changes with potential impact on the health of pregnant women and newborns. We analyzed peer-reviewed journal articles available in online databases in order to summarize the most recent findings regarding how variations in diet and metabolic status of GDM patients can contribute to alteration of the gut microbiome, in the same way that changes of the gut microbiota can lead to GDM. The most frequently observed alteration in the microbiome of patients with GDM was either an increase of the Firmicutes phylum, respectively, or a decrease of the Bacteroidetes and Actinobacteria phyla. Gut dysbiosis was still present postpartum and can impact the development of the newborn, as shown in several studies. In the evolution of GDM, probiotic supplementation and regular physical activity have the strongest evidence of proper blood glucose control, favoring fetal development and a healthy outcome for the postpartum period. The current review aims to summarize and discuss the most recent findings regarding the correlation between GDM and dysbiosis, and current and future methods for prevention and treatment (lifestyle changes, pre- and probiotics administration). To conclude, by highlighting the role of the gut microbiota, one can change perspectives about the development and progression of GDM and open up new avenues for the development of innovative therapeutic targets in this disease.

Keywords: Firmicutes/Bacteroidetes ratio; dysbiosis; gestational diabetes; gut microbiome; microbiota; prebiotics; probiotics.

Figure 1

Glycemic status in normal pregnancy versus GDM. (A) In a normal pregnancy, the euglycemic status from the pre-gestational period will be preserved by the compensatory mechanisms (increasing blood glucose, hyperplasia and hypertrophy of β-cells, decreasing insulin sensitivity) which will return to normal after birth. (B) In a GDM pregnancy, these mechanisms fail to adapt, resulting in hyperglycemic status. After pregnancy, glycemic status can either return to normal or it can be a risk of T2D and of GDM in future pregnancy [17]. Created with BioRender.com (accessed on 8 October 2022).

Figure 2

Evolution of the microbiota during pregnancy and its consequences.