Human intestinal flora is a complicated micro-ecology system, and its relationship with human health has been given more attention. Multiple studies overseas indicated that the changes of intestinal flora are closely associated with the occurrence and development of type 2 diabetes and other diseases. The amount, diversity and composition of intestinal bacteria during pregnancy have shown significant changes, and the relation between the characteristics of these changes and the development of GDM deserves to be studied. The prevention and treatment of related chronic diseases via adjustment of intestinal flora may become an effective way for prevention and treatment.

Gestational Diabetes Mellitus

GDM is a commonly seen complications during pregnancy, and is a special type of diabetes. The patients do not show diabetes and abnormal sugar tolerance before pregnancy, and the disease usually occurs during middle to late term of pregnancy, with the characteristics of lower fasting blood sugar and higher blood sugar after dinner, which have considerable harms to pregnant women and infants and may lead to multiple negative pregnancy outcomes, including macrosomia, stillbirth and ketoacidosis^[1]. Currently, it is thought that the pathogenesis of GDM includes multiple factors of genetics and environment. In addition to the diet, weight and living habits, the relation between the changes of intestinal flora and the occurrence of GDM has been paid more attention. There have been existing studies demonstrating that the intestinal flora during pregnancy do have significant changes. However, how the influencing factors of the changes of diet and hormone levels induce the changes of intestinal flora, and whether the changes of intestinal flora in normal pregnant women or pregnant women with GDM have differences are still yet to be discussed.

Relation between Intestinal Flora and Diabetes

The relation between intestinal flora and diabetes is close.The majority of intestinal bacteria in human body are mainly bacteroidetes, firmicutes, actinobacteria, and proteobacteria. Studies have shown that the content of clostridia among intestinal flora in the patients with diabetes was significantly lower than that in the healthy control group, and the composition of beta proteobacteria is significantly higher than that in the healthy control group, and is positively correlated to the concentration of blood sugar^[2]. The changes of human intestinal flora are closely related to the occurrence and development of type 2 diabetes and other diseases, so the prevention and treatment of related chronic diseases via adjustment of intestinal flora may become an effective way for prevention and treatment.

Factors Influencing Intestinal Flora

Factors influencing intestinal flora include ages and diseases (including obesity, type 2 diabetes, etc.) which may have influences on intestinal flora, the status of intestinal flora in the special period of pregnancy will also have significant changes. According to the analysis of intestinal bacteria in pregnancy women, excessive weight gain during pregnancy is related to the increased concentration of bacteroid. The amount of bacteroid and staphylococcus in the intestinal tracts of obses and overweight pregnant women is significantly higher than that in the healthy control with normal weight^[3]. Bacterial diversity in healthy pregnancy women during the third trimester significantly reduces compared to the first trimester, and the amount of clostridia reduces, but the amount of enterobacteriaceae in proteobacteria dramatically increases. The bacterial diversity in the intestinal tract for the pregnant women with GDM during the first trimester is lower than that in healthy pregnant women^[4].

In order to understand the effects of adaptive changes of metabolism during pregnancy and changes of hormone on intestinal flora changes, and to explore the relation between the intestinal flora and the occurrence and development of GDM, this project aims to explore the changing pattern and differences of intestinal flora in different stages for healthy pregnant women and GDM pregnant women; to clarify the effects of diet and weight gain on the changes of intestinal flora during pregnancy and its relation with GDM occurrence and development, providing scientific basis for the prevention of GDM; and to show the economic and social benefits induced by the promotion of maternal and child’s health by effective prevention of GDM.

References:

[1]Viana, L.V., J.L. Gross, and M.J. Azevedo, Dietary intervention in patients with gestational diabetes mellitus: a systematic review and meta-analysis of randomized clinical trials on maternal and newborn outcomes. Diabetes Care, 2014. 37(12): p. 3345-55.

[2]Larsen, N., et al., Gut microbiota in human adults with type 2 diabetes differs from non-diabetic adults. PLoS One, 2010. 5(2): p. e9085.

[3] Collado, M.C., et al., Distinct composition of gut microbiota during pregnancy in overweight and normal-weight women. Am J Clin Nutr, 2008. 88(4): p. 894-9.

[4] Koren, O., et al., Host remodeling of the gut microbiome and metabolic changes during pregnancy. Cell, 2012. 150(3): p. 470-80.