Gut microbiota in patients with kidney stones: a systematic review and meta-analysis

Background: Mounting evidence indicates that the gut microbiome (GMB) plays an essential role in kidney stone (KS) formation. In this study, we conducted a systematic review and meta-analysis to compare the composition of gut microbiota in kidney stone patients and healthy individuals, and further understand the role of gut microbiota in nephrolithiasis; Results Six databases were searched to find taxonomy-based comparison studies on the GMB until September 2022. Meta-analyses were performed using RevMan 5.3 to estimate the overall relative abundance of gut microbiota in KS patients and healthy subjects. Qualitatively summarized the altered diversity, genetic functions and detection capability of gut microbiota in stone patients; Eight studies were included with 356 nephrolithiasis patients and 347 healthy subjects. The meta-analysis suggested that KS patients had a higher abundance of Bacteroides (34.95% vs 21.18%) and Escherichia (4.39% vs 1.78%, P < 0.05), and a lower abundance of Prevotella (8.51% vs 10.4%); Beta-diversity was different between the two groups in four out of the eight studies (P < 0.05). Three studies reported that ten taxa ( Bacteroides, Phascolarctobacterium, Faecalibacterium, Flavobacterium, Akkermansia, Lactobacillus, P. aeruginosa, Escherichia coli, Rhodobacter and Gordonia ) helped the detection of kidney stones P < 0.05). Four studies reported genes or protein families of the GMB involved in oxalate degradation, glycan synthesis, and energy metabolism were altered in patients (P < 0.05). Conclusions There is a characteristic gut microbiota dysbiosis in kidney stone patients. Individualized therapies like microbial supplementation, probiotic or synbiotic preparations and adjusted diet patterns based on individual gut microbial characteristics of patients may be more effective in preventing stone formation and recurrence.