Aim of the study:
The analysis of the effect of immunosuppressive therapy on gut microbiota in pediatric patients with stable idiopathic nephrotic syndrome (INS) treated with different protocols of immunosuppressive therapy and examined the changes in their gut microbiota components along with accompanying clinical symptoms.

Material and methods:
The study consisted of 44 children with INS divided into 3 groups according to treatment protocols (group A: 18 children on cyclosporine A [CsA], 9 of which receiving additional glucocorticosteroids [GCS]; group B: 17 children on GCS; and group C: 9 children on cyclophosphamide [CYC] and GCS), along with 20 healthy children serving as controls. Intestinal microflora was analysed with microbiological diagnostics based on KyberStatus and KyberMyk tests. Additional laboratory blood and urine tests were performed along with history data and clinical symptoms analysis. Study was approved by local Ethical Committee. All caregivers gave an informed consent for participation.

Results:
Total number of bacterial colonies was significantly lower in group A (p < 0.001) and group B children (p = 0.04) when compared to the healthy controls. Group C children had a significantly lower number of Bifidobacterium colonies than the controls (p = 0.01), while number of Candida colonies were significantly higher in group A subjects than in controls (p = 0.01). No significant correlation between clinical symptoms reported by patients and the therapy used was found. Degree of disbiosis did was not related to the patients’ complaints either.

Conclusions:
Immunosuppressed INS paediatric patients who are in remission had significantly unfavourable changes in their intestinal microbiota. Patient on chronic CsA therapy showed higher degree of dysbiosis.