Effect of SGLT2 Inhibitors + DPP-4 Inhibitors on Urine Microbiota in Type 2 Diabetes

Aims: A reduced compliance, due to urogenital minor infections, frequently compromises the clinical efficacy of SGLT2 inhibitors in subjects with type 2 diabetes (T2D). The combined use of SGLT2 inhibitors and dipeptidyl-peptidase four inhibitors seems to reduce the incidence of such side effects. We evaluated how these drugs, alone or in combination, might influence resident urinary microbiota. Materials and Methods: An open label, randomised clinical study was conducted on 30 T2D individuals for 12 weeks to compare the impact of Empagliflozin and Empagliflozin/Linagliptin on clinical parameters and urinary microbiota. Fifteen healthy individuals served as baseline controls. The composition of urinary bacterial populations was evaluated by Real-Time quantitative PCR and 16S rRNA gene sequencing. Results: BMI was reduced by both treatments, while fasting glucose and HbA1c significantly improved only with the combination. At baseline, T2D showed a higher total bacterial load and abundance of Bacillota than controls. The prevalence and proportion of bacterial species profoundly differed between the groups, revealing a urinary dysbiosis in T2D. A different effect of Empagliflozin alone or combined with Linagliptin on microbial populations was observed: Empagliflozin increased the total bacterial load of Bacillota and Aerococcus, while the combination therapy restored a microbial community similar to that of controls, further reducing the prevalence of potential urinary pathogens. Conclusions: In T2D subjects, the combination of Empagliflozin and Ligandliptin might help in restoring a normal composition of the urinary microbiota, likely improving compliance and persistence in therapy with SGLT2 inhibitors.