a-Glucosidase Inhibitors Affect the Gut Microbiome in Japanese Patients with Type 2 Diabetes

The aim of this study was to reveal the characteristics of the gut microbiome altered by acarbose intervention in Japanese patients with type 2 diabetes (T2D). Eighteen patients with T2D were administered acarbose for four weeks. We obtained fecal samples before and four weeks after the start of acarbose administration and analyzed the gut microbiome using 16S-rRNA data. Habitat diet intake was evaluated by a brief-type self-administered diet history questionnaire.Alpha and beta diversity metrics did not show major compositional alterations in the gut microbiome before and after the intervention of acarbose. At the phylum level, the abundance of Actinobacteria was higher (p=0.0104) and that of Bacteroidetes was lower (p=0.0019) in the group after the intervention than in the group before the intervention. At the genus level, there were significant changes in the abundance of ten genera including the greater abundance of Bifidobacterium, Eubacterium, and Lactobacillus (p=0.0132, 0.0477, and 0.0455, respectively) and the lower abundance of Bacteroides (p=0.0112) in the group after the intervention than in the group before the intervention. Regarding the habitual dietary intake, 12 dietary nutrient items were used for hierarchical clustering based on the pattern of the major microbial data delta and, classified into three clusters. Cluster I consisted of sucrose, cluster II mainly included fat intake items, and cluster III mainly included carbohydrate intake items.Acarbose significantly affected the composition of the gut microbiome in Japanese patients with T2D, which was possibly associated with their habitual dietary intake.