RESEARCH ARTICLE Open Access Gut microbiota in Immunoglobulin A Nephropathy: a Malaysian Perspective Sugurmar Agni Nhirmal Kumar 1* , Rozita Mohd 1 , Shamsul Azhar Shah 2 , Hui-min Neoh 3 and Rizna Abdul Cader 1,4 Abstract Introduction: The alteration of the gut microbiome in the gut-kidney axis has been associated with a pro- inflammatory state and chronic kidney disease (CKD). A small-scaled Italian study has shown an association between the gut microbiome and Immunoglobulin A Nephropathy (IgAN). However, there is no data on gut microbiota in IgAN in the Asian population. This study compares the gut microbial abundance and diversity between healthy volunteers and Malaysian IgAN cohort. Methods: A comparative cross-sectional study was conducted involving biopsy-proven IgAN patients in clinical remission with matched controls in a Malaysian tertiary centre. Demographic data, routine blood and urine results were recorded. Stool samples were collected and their DNA was extracted by 16S rRNA gene sequencing to profile their gut microbiota. Results: Thirty-six IgAN patients (13 male; 23 female) with the mean age of 45.5 ± 13.4 years and median estimated glomerular filtration rate (eGFR) of 79.0 (62.1–92.2) mls/min/1.73m 2 with median remission of 7 years were analysed and compared with 12 healthy controls (4 male; 8 female) with the mean age of 46.5 ± 13.5 years and eGFR of 86.5 (74.2–93.7) mls/min/1.73m 2 . Other demographic and laboratory parameters such as gender, ethnicity, body mass index (BMI), haemoglobin, serum urea and serum albumin were comparable between the two groups. There were no significant differences seen in the Operational Taxonomic Unit (OTU) and alpha diversity (Shannon index) between IgAN and healthy controls. Alpha diversity increased with increasing CKD stage (p = 0.025). Firmicutes/ Bacteroidetes (F/B) ratio was low in both IgAN and healthy cohort. Fusobacteria phylum was significantly increased (p = 0.005) whereas Euryarchaoeota phylum was reduced (p = 0.016) in the IgAN group as compared to the control cohort. Conclusion: Although we found no differences in OTU and alpha diversity between IgAN in remission and control cohort, there were some differences between the two groups at phylum level. Keywords: Gut microbiota, IgA nephropathy, Alpha diversity, Chronic kidney disease, Microbiome, Dysbiosis, Firmicutes/Bacteroidetes ratio © The Author(s). 2021 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data. * Correspondence: agnishevchenko@gmail.com 1 Department of Medicine, Universiti Kebangsaan Malaysia Medical Centre, Jalan Yaacob Latif, Bandar Tun Razak, 56000 Kuala Lumpur, Malaysia Full list of author information is available at the end of the article Sugurmar et al. BMC Nephrology (2021) 22:145 https://doi.org/10.1186/s12882-021-02315-z