# Gut microbiome disparities reflect type 2 diabetes progression and medication status

## TL;DR

This study explores how gut microbes differ in people with prediabetes and type 2 diabetes in India, and how diabetes medications like metformin affect the gut microbiome.

## Contribution

The study identifies gut microbiome changes linked to diabetes progression and metformin use in an Indian cohort.

## Key findings

- Gut microbial diversity was significantly reduced in treated T2D patients compared to untreated ones.
- Lactobacillus abundance increased with disease progression, while Clostridium_sensu_stricto_1 was linked to glucose homeostasis.
- β diversity differed only between controls and prediabetics, not between other groups.

## Abstract

Type 2 diabetes mellitus (T2D) prevalence is rapidly increasing in India, yet microbiome signatures linked to disease progression and oral antidiabetic therapy remain underexplored. We performed full-length 16S rRNA sequencing of fecal samples from prediabetics (PDs), untreated newly diagnosed T2D (UKT2D), and clinically diagnosed T2D patients (KT2D), alongside biochemical, anthropometric, and medication data. Despite comparable glycemic control and insulin resistance between UKT2D and KT2D groups, gut microbial diversity was significantly reduced in KT2D, coinciding with antidiabetic drug use, primarily metformin. Lactobacillus abundance increased with disease progression, while Clostridium_sensu_stricto_1 was associated with glucose homeostasis and insulin sensitivity. β diversity differed only between controls and PD, with no other pairwise differences. Collectively, these results indicate that T2D progression and oral antidiabetic medications remodel the gut microbiome in this south Asian cohort and highlight the need to reassess antidiabetic treatment efficacy using larger longitudinal studies.

•Gut microbiome signatures of T2D progression and treatment remain underexplored in India•Full-length 16S rRNA sequencing profiled gut microbiomes across glycemic stages toward T2D•Gut microbiome composition differs across disease stages and medication use•Key glycemic markers remain comparable between untreated and treated T2D patients

Gut microbiome signatures of T2D progression and treatment remain underexplored in India

Full-length 16S rRNA sequencing profiled gut microbiomes across glycemic stages toward T2D

Gut microbiome composition differs across disease stages and medication use

Key glycemic markers remain comparable between untreated and treated T2D patients

Endocrinology; Microbiome; Public health