Using the Gut Microbiome Genome to Predict Type 2 Diabetes

Ali A. Torkamani, PhD


July 31, 2013

Gut Metagenome in European Women With Normal, Impaired and Diabetic Glucose Control

Karlsson FH, Tremaroli V, Nookaew I, et al
Nature. 2013;498:99-103


Type 2 diabetes (T2D) is a result of a complex interplay between genetic and environmental factors. The heritability of T2D is estimated at 26%, meaning that the bulk of the risk for T2D is thought to be determined by environmental factors.[1] However, the estimate for the heritability of impaired glucose tolerance is much higher (61%), and concordance rates for T2D incidence in monozygotic twins increase dramatically with prolonged follow-up (33% concordance vs 76% concordance at 5 vs 15 years of follow-up),[2] suggesting that the genetic contribution to T2D may be substantially higher than estimated.

Nevertheless, risk prediction models incorporating genetic markers do not appear to perform significantly better than do risk prediction models incorporating more traditional demographic and clinical characteristics.[3] Although it has been suggested that statistical models incorporating gene/environment interactions may improve prediction performance, initial models have not supported this notion.[4]

The current study by Karlsson and colleagues investigating the role of another environmental, albeit pseudoinherited, factor -- the gut microbiome -- demonstrated that the abundance of particular bacterial species in the gut could differentiate diabetic vs normal glucose-tolerant individuals with a degree of accuracy similar to that of traditional predictive models. Although the bacterial species most predictive of T2D were not consistent across different ethnic groups, this study suggests that additional environmental factors may be useful for predicting T2D.