Fewer individuals with a high microbiome diversity coupled with an increased proportion of butyrate-producing bacteria presented with type 2 diabetes (T2D), according to results of a cross-sectional study published in JAMA Network Open.

Data were sourced from the Rotterdam Study (RS) and LifeLines-DEEP (LLD) study, which both recruited residents of the Netherlands. A total of 2166 individuals were assessed between 2012 and 2013 for gut microbiome composition via stool samples, insulin resistance, and incidence of T2D.

Participants in the RS (n=1418) and LLD (n=748) cohorts were aged mean 62.4±5.9 and 44.7±13.4 years, 57.5% and 57.6% were men, and body mass index (BMI) was 27.5±4.5 and 25.2±4.1 kg/m2, respectively. A total of 193 individuals were diagnosed with T2D during the study.

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Stratified by diabetes status, those with T2D had lower microbial richness than those without T2D (odds ratio [OR], 0.93; 95% CI, 0.88-0.99).

In the fully adjusted model, insulin resistance associated with Shannon index (b, -0.06; 95% CI, -0.10 to -0.02; P =.02), richness (b, -0.07; 95% CI, -0.11 to -0.03; P =.03), and inverse Simpson index (b, -0.04; 95% CI, -0.08 to 0.002; P =.05) and T2D with richness (b, 0.93; 95% CI, 0.88-0.99; P =.04).

The most highly significant taxa for insulin resistance included Ruminococcaceae NK4A214, UCG005, UCG008, and UCG010, Christensenellaceae, and Marvinbryantia (b range, -0.09 to -0.07; all P <.001).

The most highly significant taxa for T2D were Clostridiaceae 1, Peptostreptococcaceae, Clostridium sensu stricto 1, Intestinibacter, and Romboutsia (b range, 0.51-0.60; all P <.001).

Similar results were observed when the investigators stratified participants by their use of metformin. However, these analyses had low statistical power.

This was a cross-sectional study and therefore, no causal relationships could be assessed between microbiome diversity and insulin resistance or T2D.

These data indicated that the composition of an individual’s gastrointestinal microbiome may influence the development of T2D. Additional research is needed to ascertain the biological relationship between gut microbial diversity with insulin resistance.


Chen Z, Radjabzadeh D, Chen L, et al. Association of insulin resistance and type 2 diabetes with gut microbial diversity: a microbiome-wide analysis from population studies. JAMA Netw Open. 2021;4(7):e2118811. doi:10.1001/jamanetworkopen.2021.18811