Gut microbiota affect the formation of calcium oxalate renal calculi caused by high daily tea consumption

Potassium sodium hydrogen citrate intervention on gut microbiota and clinical features in uric acid stone patients

The high recurrence rate of renal uric acid stone (UAS) poses a significant challenge for urologists, and potassium sodium hydrogen citrate (PSHC) has been proven to be an effective oral dissolution drug. However, no studies have investigated the impact of PSHC on gut microbiota and its metabolites during stone dissolution therapy. We prospectively recruited 37 UAS patients and 40 healthy subjects, of which 12 patients completed a 3-month pharmacological intervention. Fasting vein blood was extracted and mid-stream urine was retained for biochemical testing. Fecal samples were collected for 16S ribosomal RNA (rRNA) gene sequencing and short chain fatty acids (SCFAs) content determination. UAS patients exhibited comorbidities such as obesity, hypertension, gout, and dyslipidemia. The richness and diversity of the gut microbiota were significantly decreased in UAS patients, Bacteroides and Fusobacterium were dominant genera while Subdoligranulum and Bifidobacterium were poorly enriched. After PSHC intervention, there was a significant reduction in stone size accompanied by decreased serum uric acid and increased urinary pH levels. The abundance of pathogenic bacterium Fusobacterium was significantly downregulated following the intervention, whereas there was an upregulation observed in SCFA-producing bacteria Lachnoclostridium and Parasutterella, leading to a significant elevation in butyric acid content. Functions related to fatty acid synthesis and amino acid metabolism within the microbiota showed upregulation following PSHC intervention. The correlation analysis revealed a positive association between stone pathogenic bacteria abundance and clinical factors for stone formation, while a negative correlation with SCFAs contents. Our preliminary study revealed that alterations in gut microbiota and metabolites were the crucial physiological adaptation to PSHC intervention. Targeted regulation of microbiota and SCFA holds promise for enhancing drug therapy efficacy and preventing stone recurrence. KEY POINTS: • Bacteroides and Fusobacterium were identified as dominant genera for UAS patients • After PSHC intervention, Fusobacterium decreased and butyric acid content increased • The microbiota increased capacity for fatty acid synthesis after PSHC intervention.

Xylanase Supplement Enhances the Growth Performance of Broiler by Modulating Serum Metabolism, Intestinal Health, Short-Chain Fatty Acid Composition, and Microbiota

This study aimed to investigate the effects of different levels of xylanase supplementation in a wheat-based diet on growth performance, short-chain fatty acids, intestinal health, microbial composition, and serum metabolism. A total of 1200 male chicks were randomly assigned to four wheat-based diet treatments: Group C (adding 0 mg/kg of xylanase), Group L (adding 50 mg/kg of xylanase), Group M (adding 100 mg/kg of xylanase), and Group H (adding 150 mg/kg of xylanase). The experiment lasted for 56 days. The results indicated that Group H broilers experienced a decreased feed-to-gain ratio throughout the study period. Additionally, dietary supplementation with xylanase led to an increase in the physical barrier, as indicated by increased VH and VH/CD in the gut (p < 0.05). Furthermore, levels of D-lactic acid and endotoxin were reduced. Xylanase supplementation also increased the abundance of Muc-2, ZO-1, and Occludin (p < 0.05). Moreover, xylanase supplementation enhanced the activity of sucrase and maltase in the duodenum (p < 0.05), which may be attributable to the upregulation of the abundance of SI and MGA (p < 0.05). Furthermore, xylanase addition promoted propionic acid produced by specific bacteria, such as Phascolarctobacterium, and influenced the microbial composition to some extent, promoting intestinal health. Additionally, 150 mg/kg of xylanase supplementation increased the amino acid, peptide, and carbohydrate content and upregulated the metabolism of amino acids related to histidine, cysteine, methionine, and other pathways (p < 0.05). These findings suggest adequate xylanase supplementation can enhance nutritional digestibility and absorption, improve growth performance, stimulate endogenous enzyme activity, optimize intestinal morphology and barrier function, and positively influence acid-producing bacteria and amino acid metabolic pathways.

Deficient butyrate metabolism in the intestinal microbiome is a potential risk factor for recurrent kidney stone disease

Intestinal microbiome dysbiosis is a known risk factor for recurrent kidney stone disease (KSD) with prior data suggesting a role for dysfunctional metabolic pathways other than those directly utilizing oxalate. To identify alternative mechanisms, the current study analyzed differences in the metabolic potential of intestinal microbiomes of patients (n = 17) and live-in controls (n = 17) and determined their relevance to increased risk for KSD using shotgun metagenomic sequencing. We found no differences in the abundance of genes associated with known oxalate degradation pathways, supporting the notion that dysfunction in other metabolic pathways plays a role in KSD. Further analysis showed decreased abundance of key enzymes involved in butyrate biosynthesis in patient intestinal microbiomes. Furthermore, de novo construction of microbial genomes showed that the majority of genes significantly enriched in non-stone formers are affiliated with Faecalibacterium prausnitzii, a major butyrate producer. Specifically pertaining to butyrate metabolism, the majority of abundant genes mapped back to F. prausnitzii, Alistipes spp., and Akkermansia muciniphila. No differences were observed in ascorbate or glyoxylate metabolic pathways. Collectively, these data suggest that impaired bacterial-associated butyrate metabolism may be an oxalate-independent mechanism that contributes to an increased risk for recurrent KSD. This indicates that the role of the intestinal microbiome in recurrent KSD is multi-factorial, which is representative of the highly intertwined metabolic nature of this complex environment. Future bacteria-based treatments must not be restricted to targeting only oxalate metabolism.

Chaihu Shugan prevents cholesterol gallstone formation by ameliorating the microbiota dysbiosis and metabolic disturbance in mice

Introduction: Cholesterol gallstone (CGS) is a biliary tract disorder requiring treatment in approximately 20% of patients. The efficacy of Chaihu Shugan in preventing CGS recurrence after successful treatment remains uncertain. Methods: We examined the in vivo preventive efficacy of Chaihu Shugan using a CGS mouse model and used multi-omics to study the interplay between gut microbiota, metabolism, and gene expression. Results: The intestinal microbiota was severely dysregulated during the formation of CGS, showing a marked decrease in the abundance of beneficial microbiota, especially Lactobacillus and Akkermansia. Chaihu Shugan prevented CGS formation by restoring the composition of the gut microbiota and reversing the metabolic disturbances caused by dysbiosis. This preventive effect of Chaihu Shugan was paralleled by changes in the expression of metabolism-related genes in the liver. A network pharmacology analysis of Chaihu Shugan revealed that obacunone may be the key active metabolite in regulating bile acid metabolism. Multi-omics and correlation analyses elucidated the interplay between gut microbiota, metabolism, and gene alterations in the dose-dependent effect of Chaihu Shugan. Conclusion: Our data show that Chaihu Shugan can prevent CGS and indicate its mechanisms of action.

Multi-site microbiota alteration is a hallmark of kidney stone formation

BACKGROUND

Inquiry of microbiota involvement in kidney stone disease (KSD) has largely focussed on potential oxalate handling abilities by gut bacteria and the increased association with antibiotic exposure. By systematically comparing the gut, urinary, and oral microbiota of 83 stone formers (SF) and 30 healthy controls (HC), we provide a unified assessment of the bacterial contribution to KSD.

RESULTS

Amplicon and shotgun metagenomic sequencing approaches were consistent in identifying multi-site microbiota disturbances in SF relative to HC. Biomarker taxa, reduced taxonomic and functional diversity, functional replacement of core bioenergetic pathways with virulence-associated gene markers, and community network collapse defined SF, but differences between cohorts did not extend to oxalate metabolism.

CONCLUSIONS

We conclude that multi-site microbiota alteration is a hallmark of SF, and KSD treatment should consider microbial functional restoration and the avoidance of aberrant modulators such as poor diet and antibiotics where applicable to prevent stone recurrence. Video Abstract.

The emerging role of the urinary microbiome in benign noninfectious urological conditions: an up-to-date systematic review

PURPOSE

The goal of this systematic review was to examine the current literature on the urinary microbiome and its associations with noninfectious, nonmalignant, urologic diseases. Secondarily, we aimed to describe the most common bioinformatics used to analyze the urinary microbiome.

METHODS

A comprehensive literature search of Ovid MEDLINE using the keywords "microbiota" AND "prostatic hyperplasia," "microbiota" AND "urinary bladder, overactive," "microbiota" AND "pelvic pain," and "microbiota" AND "urolithiasis" OR "nephrolithiasis" OR "urinary calculi" AND "calcium oxalate" was performed to identify relevant clinical microbiome studies associated with noninfectious benign urological conditions published from 2010 to 2022. We included human studies that evaluated the urinary, stone, or semen microbiota, or any combination of the above-mentioned locations.

RESULTS

A total of 25 human studies met the inclusion criteria: 4 on benign prostatic hyperplasia (BPH), 9 on overactive bladder (OAB), 8 on calcium oxalate stones, and 4 on chronic pelvic pain syndrome (CPPS). Specific taxonomic profiles in the urine microbiome were associated with each pathology, and evaluation of alpha- and beta-diversity and relative abundance was accounted for most of the studies. Symptom prevalence and severity were also analyzed and showed associations with specific microbes.

CONCLUSION

The study of the urogenital microbiome is rapidly expanding in urology. Noninfectious benign urogenital diseases, such as BPH, calcium oxalate stones, CPPS, and OAB were found to be associated with specific microbial taxonomies. Further research with larger study populations is necessary to solidify the knowledge of the urine microbiome in these conditions and to facilitate the creation of microbiome-based diagnostic and therapeutic approaches.

The altered composition of gut microbiota and biochemical features as well as dietary patterns in a southern Chinese population with recurrent renal calcium oxalate stones

The correlation among gut microbiota, biochemical features, and dietary patterns in recurrent stone formers has been inadequately investigated in the Chinese population. Forty-two patients with calcium oxalate stones (CaOxS group), including 34 recurrent stone formers (RS group), and 40 nonstone healthy subjects (NS group) from Changshu Hospital Affiliated with Soochow University, were prospectively recruited. Food frequency questionnaires were completed by participants, fasting vein blood was extracted, 24-h urine was collected for biochemical detection, and fecal samples were gathered for 16S ribosomal RNA (rRNA) gene sequencing. BMI; serum levels of triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), magnesium, and creatinine; and urine levels of magnesium in stone formers were significantly different from those of controls, and RS patients showed significantly low serum phosphate and high urine phosphate levels. Celery, bamboo shoots, and pickled food were the favored foods of local stone formers. Patients with recurrent stones had altered microbiota composition, with Escherichia, Fusobacterium, and Epulopiscium being the predominant pathogenic genera. The gut microbiota in RS patients had stronger functions in fatty acid and amino acid degradation but weaker functions in their biosynthesis. The pathogenic genera were positively correlated with BMI; serum levels of TGs and creatinine; urine levels of calcium, phosphate, and uric acid (UA); and celery, bamboo shoots, and pickled food intake. The abundance of Escherichia and Fusobacterium and the levels of serum magnesium and creatinine were the most relevant factors associated with stone recurrence and could be validated as biomarkers of recurrence. Our research provides a novel prevention strategy for the recurrence of renal calcium oxalate stones in the Han Chinese population of southern China.

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. 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 (35.11% vs 21.25%, Z = 3.56, P = 0.0004) and Escherichia_Shigella (4.39% vs 1.78%, Z = 3.23, P = 0.001), and a lower abundance of Prevotella_9 (8.41% vs 10.65%, Z = 4.49, P < 0.00001). Qualitative analysis revealed that beta-diversity was different between the two groups (P < 0.05); Ten taxa (Bacteroides, Phascolarctobacterium, Faecalibacterium, Flavobacterium, Akkermansia, Lactobacillus, Escherichia coli, Rhodobacter and Gordonia) helped the detection of kidney stones (P < 0.05); 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.

The role of microbiome: a novel insight into urolithiasis

Urolithiasis, referred to as the formation of stones in the urinary tract, is a common disease with growing prevalence and high recurrence rate worldwide. Although researchers have endeavoured to explore the mechanism of urinary stone formation for novel effective therapeutic and preventative measures, the exact aetiology and pathogenesis remain unclear. Propelled by sequencing technologies and culturomics, great advances have been made in understanding the pivotal contribution of the human microbiome to urolithiasis. Indeed, there are diverse and abundant microbes interacting with the host in the urinary tract, overturning the dogma that urinary system, and urine are sterile. The urinary microbiome of stone formers was clearly distinct from healthy individuals. Besides, dysbiosis of the intestinal microbiome appears to be involved in stone formation through the gut-kidney axis. Thus, the human microbiome has potential significant implications for the aetiology of urolithiasis, providing a novel insight into diagnostic, therapeutic, and prognostic strategies. Herein, we review and summarize the landmark microbiome studies in urolithiasis and identify therapeutic implications, challenges, and future perspectives in this rapidly evolving field. To conclude, a new front has opened with the evidence for a microbial role in stone formation, offering potential applications in the prevention, and treatment of urolithiasis.

Role of microbiome in kidney stone disease

PURPOSE OF REVIEW

The process of renal stone formation is complex, multifactorial, and variable depending on the type of stone. The microbiome, whether by direct or indirect action, is a factor that both promotes the formation and protects from developing of renal stones. It is a highly variable factor due to the great interindividual and intraindividual variability that it presents. In recent years, with the incorporation of nonculture-based techniques such as the high-throughput sequencing of 16S rRNA bacterian gene, both intestinal and urinary microbiota have been deeply studied in various diseases such as the kidney stone disease.

RECENT FINDINGS

This review has examined the new insights on the influence of the intestinal and urinary microbiome in nephrolithiasis disease and its usefulness as a diagnostic and prognostic tool, highlighting its contribution to the pathogenesis, its ability to modulate it and to influence disease development.

SUMMARY

The incidence of urolithiasis has been increasing considerably. These patients represent a significant expense for national health systems. With the knowledge of the influence of the urobiome and intestinal microbiota on the urolithiasis, it could be possible to modulate it to interrupt its development.

Association between body fat distribution and kidney stones: Evidence from a US population

OBJECTIVES

We aimed to evaluate the relationship between the proportion of Android to Gynoid ratio and the incidence of kidney stones among US adults.

METHODS

Participants aged 20-59 years from the 2011-2018 National Health and Nutrition Examination Survey (NHANES) database were selected to assess the association between Android to Gynoid ratio and kidney stone prevalence using logistic regression analysis, subgroup analysis and calculation of dose-response curves.

RESULTS

This study ultimately included 10858 participants, of whom 859 self-reported a history of kidney stones. And after adjusting for all confounders, an increased Android to Gynoid ratio was associated with an increased prevalence of kidney stones (OR=2.75, 95% CI:1.62-4.88). And subgroup analysis showed an increased prevalence of kidney stones in women (OR=3.55, 95% CI: 1.54-8.22), non-diabetic (OR=2.59, 95% CI: 1.45-4.60), 60 > age ≥ 40 years (OR=3.51, 95% CI: 1.83-6.71), Mexican-American (OR=4.35, 95% CI: 1.40- 13.53) and white (OR=3.86, 95% CI: 1.82-8.18) groups, there was a significant positive association between A/G ratio and kidney stones. In contrast, in the hypertensive subgroup, the A/G ratio was associated with kidney stones in all groups.

CONCLUSIONS

Higher Android to Gynoid ratio is associated with a high prevalence of kidney stone disease.