CLINICAL AND PATHOGENETIC SIGNIFICANCE OF THE MICROBIOTA OF A FEMALE BODY IN THE DEVELOPMENT OF GESTATIONAL DIABETES MELLITUS IN PREGNANT WOMEN WITH OBESITY

Abstract

Introduction. Obesity is a significant risk factor for gestational diabetes mellitus (GDM), which is diagnosed in 12-18% of the obstetric population worldwide. In recent years, the potential role of the gut microbiome in women during pregnancy has become a subject of considerable interest among researchers.

The purpose of the study is to determine the clinical and pathogenetic role of metabolic indicators and a comprehensive study of the nasal, oral, vaginal, colonic microbiota to further improve the effectiveness of treatment and prevention of gestational diabetes mellitus in obese pregnant women.

Materials and methods. 91 pregnant women at 28-34 weeks of pregnancy were divided into clinical groups: group 1 consisted of 20 (21.9%) pregnant women with obesity; group 2 included 22 (24.2%) pregnant women with GDM; group 3 – 26 (28.6%) pregnant women with GDM against the background of obesity; group 4 (control) – 23 (25.3%) practically healthy pregnant women. The composition and differences of the main phylotypes of the nasal, oral, vaginal and colonic microbiota in women with GDM were assessed, depending on the presence and degree of obesity. To study the microbial composition, a bacteriological research method using bacteriological analyzers BD BACTEC FX40 №442296, BD Phoenix M50 №443625, VITEK® 2 Compact, №VK2C24329 was used. Statistical analysis of the obtained results was carried out with the generally accepted statistical methods using Microsoft Exel, and Statistica licensed programs.

Results. When comparing the colonic microbiota in women of groups 1, 2, and 3 and the indicators of the control group, a decrease in the content of Bifidobacterium bifidum was revealed from billions (10⁹) CFU/g in the control group to 10 million (10⁷) CFU/g in GDM and to 100 thousand (10⁵) CFU/g in obesity and GDM against the background of obesity (Р<0.05). There was also a decrease in Lactobacillus spp. from 10⁷ CFU/g in the control to 10⁵ CFU/g in the comparison groups (Р<0.05). Attention was drawn to the decrease in the number of E. coli with normal enzymatic activity from 10⁸ CFU/g in healthy pregnant women to 10⁴ CFU/g in pregnant women with GDM and 10⁶ CFU/g in obesity and, accordingly, a combination of GDM and obesity (Р<0.05). The lactose-negative activity of E. coli increased significantly from 10⁵ CFU/g in the control group to 10⁹ CFU/g in GDM and 10⁷ CFU/g in GDM against the background of obesity (Р<0.05). There was an increase of Enterococcus faecalis from 10⁶ CFU/g in the control group by 30-60 times in GDM, by 200-250 times in obesity, and a combination of GDM and obesity (Р<0.05). Also, the content of Staphylococcus epidermidis and Staphylococcus aureus increased 20-30 times when combined in pregnant women with GDM and obesity.

When comparing the results of a microbiological examination of the throat of the group of women with GDM against the background of obesity compared to the control group, attention should be paid to a significant increase in the number of Staphylococcus epidermidis – from 10³ to 10⁴-10⁸ CFU/mL (Р<0.05) and the detection of Staphylococcus aureus in the amount of 10⁶ CFU/mL. Also, in pregnant women of group 3, the number of Staphylococcus epidermidis in nasal secretions was significantly increased – up to 10⁵-10⁶ CFU/mL, compared to the control group – 10³ CFU/mL (Р<0.05) and the appearance of Klebsiella pneumoniae in the amount of 10⁵ CFU/mL during the examination of vaginal microflora.

Conclusions. In pregnant women with gestational diabetes, significant deviations in the species composition of the nasal, oral, vaginal, colonic microbiota were found, to a greater extent against the background of obesity, which emphasizes the need to take measures to prevent and correct pro-inflammatory shifts in the microbiome of this population. Determining the clinical and pathogenetic role of metabolic indicators and a comprehensive study of the nasal, oral, vaginal, colonic microbiota is necessary to further increase in the effectiveness of treatment and prevention of gestational diabetes mellitus in pregnant women with obesity. The use of bifidobacteria in the complex therapy of pregnant women with metabolic disorders can be considered as an alternative way of correcting the species composition of the gut microbiota.