BACKGROUND Children with primary nephrotic syndrome (PNS) who relapse after glucocorticoid therapy are shown to have a decreased total proportion of butyrate-producing bacteria in the gut at onset. Glucocorticoid treatment changes the gut microbiota composition. It is unclear whether gut microbiota at remission right after therapy and gut bacteria other than butyrate-producing bacteria are associated with PNS relapse. METHODS PNS relapse of paediatric patients within 1 year after glucocorticoid therapy was recorded. The gut microbiota composition, profiled with 16S rRNA gene V3-V4 region sequencing, was compared between relapsing and non-relapsing PNS children at onset before glucocorticoid treatment (preT group) and in PNS children at remission right after treatment (postT group), respectively. RESULTS The gut microbiota composition of postT children significantly differed from that of preT children by having lower levels of Bacteroides, Lachnoclostridium, Flavonifractor, Ruminococcaceae UBA1819, Oscillibacter, Hungatella and Coprobacillus and higher levels of Ruminococcaceae UCG-013 and Clostridium sensu stricto 1 group. In the preT group, compared with non-relapsing patients, relapsing patients showed decreased Blautia, Dialister and total proportion of butyrate-producing bacteria and increased Oscillibacter, Anaerotruncus and Ruminococcaceae UBA1819. However, relapsing and non-relapsing postT children showed no difference in gut microbiota composition. CONCLUSIONS PNS relapse-associated gut microbiota dysbiosis at onset, which includes alterations of both butyrate-producing and non-butyrate-producing bacteria, disappeared right after glucocorticoid therapy. It is necessary to study the association of the longitudinal changes in the complete profiles of gut microbiota after glucocorticoid treatment with later PNS relapse.

Objective: To analyze the clinical characteristics, molecular biological characteristics and therapeutic effect of children with coenzyme Q (CoQ) nephropathy induced by different gene mutations, and review relevant literature. Methods: The medical history, laboratory examination, treatment and prognosis of 4 cases clin-ically diagnosed with CoQ deficiency induced by different gene mutations admitted to the Department of Renal Rheumatology of our hospital from January 2017 to January 2020 were collected and analyzed, including 3 cases of CoQ8 mutation and 1 case of CoQ6 mutation. Results: All of the 4 children with CoQ10 deficiency had a family history, and through renal biopsy, the pathology type was identified as FSGS, mostly associated with steroid resistance. Among them, homozygous mutation occurred at a young age and had obvious symptoms. While CoQ8 heterozygous mutation caused severe renal tubular lesions and early renal failure. All of the 4 mutations belonged to locus mutations. Conclusion: Different gene mutations can lead to nephrotic syndrome, mostly manifested as steroid-resistant FSGS, but the clinical phenotypes and progression of CoQ deficiency induced by different gene mutations vary with symptoms. Early CoQ10 supplement therapy has a good curative effect on children with CoQ nephropathy, but in the event of severe renal injury, the progression of the disease should be controlled with conventional drugs, such as cyclosporine and tacrolimus.

Background Primary nephrotic syndrome (PNS) is a common glomerular disease in children. T cell dysfunction plays a crucial role in the pathogenesis of PNS. Moreover, dysbiosis of gut microbiota contributes to immunological disorders. Whether the initial therapy of PNS affects gut microbiota remains an important question. Our study investigated compositional changes of gut microbiota after initial therapy. Methods Fecal samples of 20 children with PNS were collected before and after 4-week initial therapy. Total bacteria DNA were extracted and the V3-V4 regions of bacteria 16S ribosomal RNA gene were sequenced. The composition of gut microbiota before and after initial therapy was analyzed by bioinformatics methods. The function of altered gut microbiota was predicted with PICRUSt method. Results The richness and diversity of gut microbiota were similar before and after 4-week initial therapy. Gut microbiota at the phylum level was dominated by four phyla including Firmicutes, Proteobacteria, Bacteroidetes and Actinobacteria, but the increased relative abundance after initial therapy was found in Deinococcus-Thermus and Acidobacteria. At the genus level, the increased abundance of gut microbiota after initial therapy was observed in short chain fat acids (SCFA)-producing bacteria including Romboutsia, Stomatobaculum and Cloacibacillus (p < 0.05). Moreover, the predicted functional profile of gut microbiota showed that selenocompound metabolism, isoflavonoid biosynthesis and phosphatidylinositol signaling system weakened after initial therapy of PNS. Conclusions Initial therapy of PNS increased SCFA-producing gut microbiota, but might diminish selenocompound metabolism, isoflavonoid biosynthesis and phosphatidylinositol signaling system in children.

Additional file 3: The profile of all identified phyla before and after initial therapy. Totally 13 phyla were identified by using Metastats method. Two phyla (Deinococcus-Thermus and Acidobacteria) increased significantly. “A_mean” and “B_mean” represented the relative abundance of gut microbiota in Group A and Group B respectively. p