Longitudinal changes in the gut microbiota with the progression of obesity-associated type 2 diabetes in KK-Ay mice

KK-Ay mice spontaneously develop obesity-associated type 2 diabetes. We compared the gut microbiota structure between 4-week-old (4W) and 11-week-old (11W) female KK-Ay mice. Amplicon sequencing of the 16S rRNA gene revealed a different β-diversity of gut microbiota between the 4W and 11W mice and a higher Bacillota/Bacteroidota ratio in the 11W mice than in the 4W mice. The relative abundance of genus Blautia positively correlated with body weight, gonadal white adipose tissue weight, inguinal adipose tissue weight, and urine glucose level. We propose that genus Blautia represents the most consistent microbial signature associated with metabolic deterioration in KK-Ay mice.