Gut Microbiota Changes in response to Medical Nutrition Therapy for Different Subtypes of Gestational Diabetes Mellitus

Abstract

Abstract Background Our research aimed to analyze differences in gut microbiota composition among pregnant women with different GDM subtypes and evaluated the impact of medical nutrition therapy. Methods 124 pregnant women, including 33 non-GDM and 91 GDM were enrolled. The GDM group was divided into 2 subgroups according to their 75 g oral glucose tolerance test (OGTT) results: abnormal glucose tolerance (GDM1, n=66) and elevated fasting blood glucose + abnormal glucose tolerance (GDM2, n=25). Fecal samples were collected from groups GDM1 and GDM2 after the confirmation of GDM diagnosis by OGTT at 24-28 weeks of pregnancy prior to medical nutrition therapy and again 8 weeks after commencement of medical nutrition therapy (32-36 weeks of pregnancy). Fecal samples were collected from non-GDM group at the corresponding gestational weeks. The compositions and changes of gut microbiota from different groups were analyzed and compared. Results Compared to GDM with fasting blood glucose combined with glucose tolerance abnormalities, the gut microbiota Alpha diversity of GDM with isolated glucose tolerance abnormalities is closer to the normal group. Beta diversity between three groups were significant different. The 8-week medical nutrition therapy did not cause significant changes in the gut microbiota composition of GDM patients, the Alpha diversity and Beta diversity had no statistical differences. LEfSe differential analysis showed that the abundance of Bifidobacterium, Anaerostipes, Streptococcus and Streptococcaceaesignificantly increased, while the abundance of Klebsiella, Enterobacteriaceae, Raoultella, and Acidaminococcaceae significantly decreased in group GDM1 after medical nutrition therapy. While the abundance of unclassified.Clostridiales, Turicibacter significantly increased, and the abundance of Phascolarctobacterium significantly decreased in group GDM2. Conclusions The gut microbiotacomposition of different subtypes of GDM had different characteristics. The medical nutrition therapy did not cause significant changes to gut microbiota composition of GDM patients but promoted increased abundance of beneficial Bifidobacterium.