Distinct gut metagenomics and metaproteomics signatures in prediabetics and treatment-naive type 2 diabetics

Background: The gut microbiota plays important roles in modulating host metabolism. Previous studies have demonstrated differences in the gut microbiome ofT2D and prediabetic individuals compared to healthy individuals, with distinct disease-related microbial profiles being reported in groups of different age and ethnicity. However, confounding factors such as anti-diabetic medication hamper identification of the gut microbial changes in disease development. Method: We used a combination of in-depth metagenomics and metaproteomics analyses of faecal samples from treatment-naive type 2 diabetic (TN-12D, n = 77), pre-diabetic (Pre-DM, it 80), and normal glucose tolerant (NGT, n = 97) individuals to investigate compositional and functional changes of the gut microbiota and the faecal content of microbial and host proteins in Pre-DM and treatment-naive 72D individuals to elucidate possible host-microbial interplays characterizing different disease stages. Findings: We observed distinct differences characterizing the gut microbiota of these three groups and validated several key features in an independent TN-72D cohort. We also demonstrated that the content of several human antimicrobial peptides and pancreatic enzymes differed in faecal samples between three groups. Interpretation: Our findings suggest a complex, disease stage-dependent interplay between the gut microbiota and the host and point to the value of metaproteomics to gain further insight into interplays between the gut microbiota and the host. (C) 2019 Published by Elsevier B.V.