Gut microbiota-based prediction for the transition from normal glucose tolerance (NGT) to impaired glucose tolerance (IGT) in a remote island cohort study

Aim

The present cohort study explored whether specific gut microbiota (GM) profile would predict the development of impaired glucose tolerance (IGT) in individuals with normal glucose tolerance (NGT).

Methods

A total of 114 study subjects with NGT in Kumejima island, Japan participated in the present study and underwent 75 g oral glucose tolerance tests at baseline and one year later. We compared the profile of GM at baseline between individuals who consistently maintained NGT (NRN, n = 108) and those who transitioned from NGT to IGT (NTI, n = 6).

Results

Within-individual bacterial richness and evenness as well as inter-individual bacterial composition showed no significant differences between NRN and NTI. Of note, however, partial least squares discriminant analyses revealed distinct compositions of GM between groups, with no overlap in their 95 % confidence interval ellipses. Multi-factor analyses at the genus level demonstrated that the proportions of CF231, Corynebacterium, Succinivibrio, and Geobacillus were significantly elevated in NTI compared to NRN (p < 0.005, FDR < 0.1, respectively) after adjusting for age, sex, HbA1c level, and BMI.

Conclusions

Our data suggest that increased proportion of specific GM is linked to the future deterioration of glucose tolerance, thereby serving as a promising predictive marker for type 2 diabetes mellitus.