Are There Differences in Gut Microbiome in Patients with Type 2 Diabetes Treated by Metformin or Metformin and Insulin?

Abstract

Introduction

Recently, gut microbiota has been described as being involved in the health and diseases of the host, and together with diet and drugs may influence metabolic health. Yet, there is still no answer which type of treatment plays the most important role in the interplay of gut microbiota and type of treatment for type 2 diabetes (T2DM). An attempt was made to answer the question of which factors have the most significant impact on the intestinal microbiome in the context of metformin or metformin+insulin use in treatment of the patients with T2DM. Thus the aim of the study was to compare the gut microbiome profiles of patients with T2DM and two of the most traditional treatment methods.

Methods

T2DM patients treated by metformin (Met) and metformin+insulin (Met+Ins), with the treatment duration of 5–10 years were enrolled. Biochemically blood glucose and glycated hemoglobin (HbA1c), lipids and kidney function were investigated and the quantitative and qualitative examination of the fecal intestinal flora were performed through the next-generation sequencing.

Results

There were no significant differences in the study of the gut microbiome: the dominant bacterial phyla were Firmicutes and Verrucomicrobia, while Bacteroidetes and Proteobacteria shared smaller proportions in both groups. However, the group Met+Ins had worse metabolic control in terms of blood glucose and HbA1c in comparison with the Met group.

Conclusion

As there are no differences in gut microbiome in T2DM patients treated with metformin only or metformin plus insulin, adding insulin in the treatment of T2DM may delay late diabetic complications development.

Keywords:

• gut microbiome
• type 2 diabetes
• metformin
• metformin+insulin

Acknowledgements

The authors would like to thank to doctor Jan Paweł Jastrzębski, who assisted in all aspects of bioinformatics in the field of NGS.

Ethics Approval and Consent to Participate

The current study protocol was registered with the Bioethical Committee of the Medical University of Silesia in Katowice. The Committee wrote that the project does not meet the criteria of a medical experiment in the context of law and does not require assessment by the bioethical committee; However, failure to obtain the consent requirement does not release the applicant from compliance with generally applicable laws and standards. (Letter KNW/0022/KB1/39/19). The decision of the Committee was final. Based on this decision, written informed consent was not required of our study nor was separate patient consent required for our statistical analysis or research. Still, according the Declaration of Helsinki 2013 the participation in the study was voluntary and informed. Moreover, participants were informed in detail about the study. Thus, patients data has been encoded in accordance with the pseudo-anonymization procedure, which means that personal data is processed in such a way that it cannot be assigned to a specific data subject, without the use of an additional “key.”

Disclosure

The authors report no conflicts of interest in this work.