A study on the association between gut microbiota, inflammation, and type 2 diabetes

Area of Science:

• Microbiome research
• Immunology
• Metabolic disease research

Background:

• Type 2 diabetes mellitus (T2DM) is linked to immune dysfunction and gut microbiome changes.
• The precise mechanisms connecting gut microbes, inflammation, and T2DM progression are not fully understood.

Purpose of the Study:

• To investigate the association between retinoic acid-inducible gene-I-like receptors (RLRs) signaling, gut microbiome, microbial metabolites, inflammation, and T2DM duration.
• To elucidate the role of microbial tryptophan metabolites in T2DM pathogenesis.

Main Methods:

• 16S rRNA amplicon sequencing and untargeted metabolomics on stool samples from T2DM patients and controls.
• RNA sequencing (RNA-seq) on peripheral blood samples.
• Animal models (C57BL/6J SPF mice) were used to validate findings.

Main Results:

• Prolonged T2DM correlated with decreased probiotic abundance (e.g., Bacteroides, Faecalibacterium) and reduced skatole production.
• Low probiotic abundance and skatole levels were associated with increased inflammation via RLRs and NF-κB signaling activation.
• Hyperglycemia may suppress tryptophanase activity, impacting skatole production and potentially GLP-1 expression.

Conclusions:

• Reduced gut probiotics and skatole production in T2DM activate RLRs and NF-κB signaling, contributing to inflammation.
• This study reveals a significant link between gut microbial alterations, inflammation, and the progression of T2DM.
• Targeting the gut microbiome may offer therapeutic strategies for managing T2DM-associated inflammation.