Spatial variation of the gut microbiome in response to long-term metformin treatment in high-fat diet-induced type 2 diabetes mouse model of both sexes

ABSTRACT

Antidiabetic drug metformin alters the gut microbiome composition in the context of type 2 diabetes and other diseases; however, its effects have been mainly studied using fecal samples, which offer limited information about the intestinal site-specific effects of this drug. Our study aimed to characterize the spatial variation of the gut microbiome in response to metformin treatment by using a high-fat diet-induced type 2 diabetes mouse model of both sexes. Four intestinal parts, each at the luminal and mucosal layer level, were analyzed in this study by performing 16S rRNA sequencing covering six variable regions (V1-V6) of the gene and thus allowing to obtain in-depth information about the microbiome composition. We identified significant differences in gut microbiome diversity in each of the intestinal parts regarding the alpha and beta diversities. Metformin treatment altered the abundance of different genera in all studied intestinal sites, with the most pronounced effect in the small intestine, where Lactococcus increased remarkably. The abundance of Lactobacillus was substantially lower in male mice compared to female mice in all locations, in addition to an enrichment of opportunistic pathogens. Diet type and intestinal layer had significant effects on microbiome composition at each of the sites studied. We observed a different effect of metformin treatment on the analyzed subsets, indicating the multiple dimensions of metformin’s effect on the gut microbiome.

KEYWORDS:

• Metformin
• gut microbiome
• intestinal parts
• lumen and mucosa
• C57BL/6N
• high-fat diet
• 16S rRNA sequencing

Acknowledgments

We thank Justine W Debelius for helping with feature table construction and the use of the q2-Sidle plugin.

Disclosure statement

No potential conflict of interest was reported by the authors.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/19490976.2023.2188663

Additional information

Funding

This work was supported by European Regional Development Fund (ERDF), Measure 1.1.1.1 “Support for applied research” „Role of miRNAs in the host-gut microbiome communication during metformin treatment in the context of metabolic disorders” and “Strengthening of the capacity of doctoral studies at the University of Latvia within the framework of the new doctoral model,” identification No. 8.2.2.0/20/I/006.