Association between Dietary Fiber Intake and Hyperuricemia among Chinese Adults: Analysis of the China Adult Chronic Disease and Nutrition Surveillance (2015)

Gut microbiota as a new target for hyperuricemia: A perspective from natural plant products

BACKGROUND

Hyperuricemia, a prevalent chronic metabolic disorder caused by purine metabolism disturbances, is characterized by elevated serum uric acid (UA) levels. Prolonged hyperuricemia can cause severe complications such as gout or kidney damage. However, the toxic side effects of and adverse reactions to UA-lowering drugs are becoming increasingly prominent. Therefore, new targets and drugs for hyperuricemia are needed.

PURPOSE

This review aims to summarize recent research progress on the prevention and treatment mechanisms for gut microbiota-hyperuricemia from the perspective of plant-derived natural products.

METHODS

Data from PubMed, Web of Science, ScienceDirect, and the CNKI databases spanning from January 2020 to December 2024 were reviewed. The aim of this study is to categorize and summarize the relevant mechanisms through which natural products improve hyperuricemia via the gut microbiota. The retrieved data followed PRISMA criteria (Preferred Reporting Items for Systematic reviews and Meta-Analyses).

RESULTS

Regulating gut microbiota as a treatment for hyperuricemia. Targeting the gut microbiota could reduce host UA levels by promoting purine degradation, reducing UA production, and increasing UA excretion. Moreover, the gut microbiota also exerts anti-inflammatory and antioxidant effects that alleviate complications such as renal damage caused by hyperuricemia. Due to their diverse sources, multicomponent synergy, multitarget effects, and minimal side effects, plant-derived natural products have been extensively utilized in the management of hyperuricemia. Especially, utilizing natural products from plants to regulate the gut microbiota has become a new strategy for reducing UA levels.

CONCLUSION

This review comprehensively summarizes recent advances in understanding the preventive and therapeutic mechanisms of plant-derived natural products in ameliorating hyperuricemia and its comorbidities through gut microbiota modulation. This review contributes a novel perspective for the development of safer and more efficacious UA-lowering products.

METTL14 downregulates GLUT9 through m6A methylation and attenuates hyperuricemia-induced fibrosis in mouse renal tubular epithelial cells

Hyperuricemia is a known risk factor for chronic kidney disease (CKD) and subsequent renal fibrosis. N6-methyladenosine (m6A) is the most prevalent chemical modification in eukaryotic mRNAs and has been implicated in various diseases. However, its role in hyperuricemic nephropathy (HN) remains unclear. This study investigated the involvement of the methylase METTL14 in HN pathogenesis. Our in vitro and in vivo function experiments demonstrated that METTL14 plays a crucial role in HN. In mouse models of uric acid (UA)-induced renal injury, we detected impaired kidney function, increased renal interstitial fibrosis, and significantly decreased m6A methylation levels in renal tissues. Treatment with benzbromarone, a UA-lowering drug, alleviated renal injury, restored m6A methylation levels, and upregulated METTL14 expression. Cellular experiments showed that METTL14 overexpression attenuated high UA-induced fibrosis in renal tubular epithelial cells. This overexpression significantly decreases the expression of GLUT9, a key protein involved in UA transport, leading to reduced UA reabsorption. Additionally, MeRIP-qPCR and dual-luciferase reporter gene experiments further demonstrated that METTL14 overexpression enhanced Glut9 mRNA m6A methylation modification, accelerating its degradation and decreasing expression levels. Thus, METTL14-mediated RNA m6A modification plays a role in the renal tubular epithelial cell damage induced by high UA, by regulating Glut9 mRNA post-transcriptionally. These findings provide valuable insights for the diagnosis and development of therapeutic drugs for HN.

Dietary Carbohydrates, Genetic Susceptibility, and Gout Risk: A Prospective Cohort Study in the UK

This study aimed to investigate the associations between carbohydrate intake and gout risk, along with interactions between genetic susceptibility and carbohydrates, and the mediating roles of biomarkers. We included 187,387 participants who were free of gout at baseline and completed at least one dietary assessment in the UK Biobank. Cox proportional hazard models were used to estimate the associations between carbohydrate intake and gout risk. Over a median follow-up of 11.69 years, 2548 incident cases of gout were recorded. Total carbohydrate intake was associated with a reduced gout risk (Q4 vs. Q1: HR 0.67, 95% CI 0.60-0.74), as were total sugars (0.89, 0.80-0.99), non-free sugars (0.70, 0.63-0.78), total starch (0.70, 0.63-0.78), refined grain starch (0.85, 0.76-0.95), wholegrain starch (0.73, 0.65-0.82), and fiber (0.72, 0.64-0.80), whereas free sugars (1.15, 1.04-1.28) were associated with an increased risk. Significant additive interactions were found between total carbohydrates and genetic risk, as well as between total starch and genetic risk. Serum urate was identified as a significant mediator in all associations between carbohydrate intake (total, different types, and sources) and gout risk. In conclusion, total carbohydrate and different types and sources of carbohydrate (excluding free sugars) intake were associated with a reduced risk of gout.

Disease burden of stroke and its subtypes attributable to low dietary fiber in China, 1990-2019

This study aimed to assess the current status and changing trends of the disease burden of stroke and its subtypes due to low dietary fiber intake in China from 1990 to 2019. In cases of stroke and its subtypes attributable to low dietary fiber, deaths, disability-adjusted life-years (DALYs), age-standardized mortality rates (ASMR), age-standardized DALYs rates (ASDR), and percentage change were used to assess disease burden. Data were obtained from the 2019 global burden of disease study. Trends were assessed using Joinpoint regression and age-period-cohort analysis. Between 1990 and 2019, there was a declining trend in stroke and its subtypes, ASDR and ASMR, as well as the corresponding number of deaths and DALYs, due to low dietary fiber intake in China. Subarachnoid hemorrhage (SH) showed the greatest decrease, followed by intracerebral hemorrhage (IH) and ischemic stroke (IS). Local drift curves showed a U-shaped distribution of stroke, IS, and IH DALYs across the whole group and sex-based groups. For mortality, the overall and male trends were similar to those for DALYs, whereas female stroke, IH, and IS showed an upward trend. The DALYs for stroke and IH showed a clear bimodal distribution, IS showed an increasing risk with age. For mortality, the SH subtype showed a decreasing trend, whereas other subtypes showed an increasing risk with age. Both the period and cohort rates of stroke DALYs and motality due to low dietary fiber have declined. Males had a higher risk of DALYs and mortality associated with low fiber levels. The burden of stroke and its subtypes associated with a low-fiber diet in China has been declining over the past 30 years, with different patterns of change for different stroke subtypes and a higher burden for males, highlighting the differential impact of fiber intake on stroke and its subtypes.

Association between serum uric acid levels and dietary fiber intake in adults: the Korea national health and nutrition examination survey (KNHANES VII, 2016-2018)

BACKGROUND

Hyperuricemia could be a risk for various chronic diseases, and it could be largely corrected by diet control. This study was a nationwide cross-sectional study to investigate the association between serum uric acid level and dietary fiber intake.

METHODS

This study analyzed data based on the Korean National Health and Nutrition Examination Survey conducted from 2016 to 2018. Adults over 20 years of age with normal renal function, defined as an estimated glomerular filtration rate (eGFR) over 30mL/min/1.73m2, were included. The criteria for hyperuricemia were ≥ 7 mg/dL in men and ≥ 6 mg/dL in women. Data regarding dietary intake were obtained using the 24-hour recall method.

RESULTS

A total of 15,278 subjects (6,455 males/8,823 females) were analyzed. The prevalence of hyperuricemia was 19.3% in men and 6.8% in women. There were significant, negative associations between serum uric acid and total fiber intake in both men and women. Consuming more than 27.9 g of dietary fiber in men and 20.7 g in women reduced the risk of hyperuricemia by approximately 30% with odds ratios of 0.72 (0.62-0.83) and 0.71 (0.56-0.88) in men and women, respectively. With regard to the risk reduction by the type of dietary fiber, cereal fiber was significantly identified in both men and women, while fruit fiber was only significant in men. In the subgroup analysis, this association remained significantly in young and metabolically healthy populations with normal weight.

CONCLUSIONS

Dietary fiber intake was inversely associated with serum uric acid levels. This relationship was particularly significant in metabolically healthy young adults.

Relationship between dietary fiber and all-cause mortality, cardiovascular mortality, and cardiovascular disease in patients with chronic kidney disease: a systematic review and meta-analysis

BACKGROUND

The potential protective effects of dietary fiber against all-cause mortality, cardiovascular mortality, and cardiovascular disease in patients with chronic kidney disease have not been definitively established. To verify this relationship, a systematic review and a meta-analysis were undertaken.

METHODS

PubMed, The Cochrane Library, Web of Science, Embase, ProQuest, and CINAHL were used to systematically search for prospective cohort studies that investigate the association between dietary fiber and all-cause mortality, cardiovascular mortality, and cardiovascular disease in individuals with chronic kidney disease (CKD). This search was conducted up to and including March 2023.

RESULTS

The analysis included 10 cohort studies, with a total of 19,843 patients who were followed up for 1.5-10.1 y. The results indicated a significant negative correlation between dietary fiber and all-cause mortality among patients with CKD (HR 0.80, 95% CI 0.58-0.97, P < 0.001). Subgroup analysis further revealed that the study population and exposure factors were significantly associated with all-cause mortality (P < 0.001). Increased dietary fiber intake was associated with a reduced risk of cardiovascular mortality (HR 0.78; 95% CI 0.67-0.90) and a reduced incidence of cardiovascular disease (HR 0.87; 95% CI 0.80-0.95) among patients with CKD.

CONCLUSIONS

The pooled results of our meta-analysis indicated an inverse association between dietary fiber intake and all-cause mortality, cardiovascular mortality, and cardiovascular disease.

Assessment of the temporal trend and daily profiles of the dietary purine intake among Chinese residents during 2014 to 2021

The incidence of hyperuricemia is on the rise in China, primarily due to dietary habits. However, limited data exists regarding dietary purine intake in the country. This study aimed to estimate the daily dietary purine intake among Chinese residents from 2014 to 2021 and evaluate the temporal trend using joinpoint regression analysis. The analysis revealed an annual percentage change (APC) of 0.8% (95% CI: 0.1-1.5%) in dietary purine intake prior to the joinpoint (2014-2019). Following the joinpoint (2019-2021), the APC significantly increased to 6.5% (95% CI: 3.3-9.8%), indicating a noteworthy upward trend (p = 0.045). Furthermore, the average daily purine intake varied significantly among different regions of China, with the southern region showing the highest dietary intake of purines. Considering the diverse contributions of various food sources to dietary purine intake, it was observed that meat consumption had the greatest impact, accounting for 36.2% of purine intake, followed by cereals consumption (25.3%) and vegetables and edible fungi (24.2%). These findings hold significance for dietary intervention and management strategies aimed at reducing purine intake among the population.

Association Between Dietary Fiber Intake and Cardiometabolic Risk Factors in Adolescents in the United States

OBJECTIVE

To determine the association between dietary fiber intake and markers of cardiometabolic risk in adolescents, with blood pressure (BP) as the primary outcome of interest and secondary outcome measures including other established markers of childhood cardiometabolic risk, such as obesity, lipids, albuminuria, estimated glomerular filtration rate (eGFR), and uric acid.

STUDY DESIGN

Dietary fiber intake was assessed by two 24-hour dietary recall interviews, which were averaged and corrected for body weight. Logistic and linear regression models were used to analyze the cross-sectional association between dietary fiber and cardiometabolic markers. Participants aged 13-17 years in the National Health and Nutritional Examination Survey 2009-2018 who completed a 24-hour dietary recall survey were included. Exclusion criteria included pregnancy, small for gestational age status, and history of major health comorbidities.

RESULTS

In fully adjusted regression models, low dietary fiber intake was significantly associated with greater diastolic blood pressure (β = -13.29; 95% CI, -20.66 to -5.93), body mass index z-score (β = -0.91; 95% CI, -1.47 to -0.34), and uric acid (β = -0.80; 95% CI, -1.44 to -0.16).

CONCLUSIONS

The association found between low dietary fiber intake and poor childhood cardiometabolic risk markers indicate a need for prospective studies using fiber intake as a dietary intervention in childhood and as a tool for prevention of many chronic conditions.

Dietary patterns, uric acid levels, and hyperuricemia: a systematic review and meta-analysis

Background: Studies investigating the effects of dietary intake on serum uric acid (SUA) and hyperuricemia have yielded inconsistent results. Therefore, we conducted a meta-analysis to assess the associations between various dietary patterns and SUA levels as well as hyperuricemia. Methods: We searched PubMed, Web of Science, and EMBASE databases for relevant articles examining the association between dietary intake and SUA levels and/or hyperuricemia published until March 2023. Dietary intake patterns were classified into plant-based, animal-based, and mixed dietary patterns based on predominant foods. The pooled effect sizes of eligible studies and their corresponding 95% confidence intervals (CIs) were estimated using random-effects models. Publication bias was assessed using Egger's test. Results: We included 41 studies, comprising 359 317 participants, that investigated the effects of dietary patterns on SUA levels (n = 25) and hyperuricemia (n = 19). Our findings suggested that a plant-based dietary pattern was associated with decreased SUA levels in both interventional (standard mean difference: -0.24 mg dL-1, 95% CI: -0.42, -0.06; I2 = 61.4%) and observational studies (odds ratio (OR): 0.92, 95% CI: 0.89, 0.95, I2 = 91.1%); this association was stronger in men (OR: 0.45, 95% CI: 0.35, 0.58; I2 = 0). We observed that plant- and animal-based dietary patterns were associated with a reduced risk (OR: 0.75; 95% CI: 0.67, 0.83, I2 = 93.3%) and an increased risk (OR: 1.38; 95% CI: 1.20, 1.59, I2 = 88.4%) of hyperuricemia, respectively. Conclusions: Collectively, a plant-based dietary pattern is negatively associated with SUA levels and hyperuricemia. Therefore, a plant-based dietary pattern should be recommended for the management of SUA levels and the prevention of hyperuricemia.

Association between dietary approaches to stop hypertension (DASH) diet and hyperuricemia among Chinese adults: findings from a nationwide representative study

Background

Certain foods and food groups could positively or negatively impact serum uric acid (SUA) levels. However, evidence on the holistic dietary strategy to prevent and control hyperuricemia (HUA) development remains limited.

Objective

The aim of this research work was to explore the association of dietary approaches to stop hypertension (DASH) diet with SUA levels and odds of HUA among Chinese adults.

Methods

This research premise included 66,427 Chinese adults aged 18 and above who were part of the China Adult Chronic Disease and Nutrition Surveillance in 2015. Dietary consumptions were assessed via the household condiment weighing approach and a three-day, 24-hour dietary recall. Total fat, saturated fat, calcium, protein, potassium, cholesterol, magnesium, fiber, and sodium were all adopted to calculate the DASH score (score range, 0–9). The associations of DASH score with SUA levels and odds of HUA were evaluated using multiple linear and logistic regression models, respectively.

Results

We established that a higher DASH score was linked with a lower SUA levels (β = − 0.11; 95% CI: − 0.12, − 0.1; p < 0.001) and odds of HUA (OR = 0.85; 95% CI: 0.83, 0.87; p < 0.001) after adjustment for age, sex, ethnicity, education status, marital status, health behaviours and health factors. The association of the DASH diet with odds of HUA was stronger among men (p-interaction = 0.009), non-Han Chinese (p-interaction< 0.001) as well as rural residents (p-interaction< 0.001).

Conclusions

Our results illustrate that the DASH diet was remarkably negatively with SUA levels and odds of HUA in the Chinese adult population.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12937-023-00845-w.

Determination of purines in prepackaged food using optimum acid hydrolysis followed by high performance liquid chromatography

A high performance liquid chromatography was established to determine purine content of prepackaged food. Chromatographic separation was performed on Agilent5 TC-C18 column. Ammonium formate (10 mmol/L, pH = 3.385) and methanol (99:1) were used as mobile phase. Purine concentration and peak area showed good linear relationships in the range from 1 to 40 mg/L (guanine, hypoxanthine, adenine) and xanthine exhibited a good linear relationship ranged from 0.1 to 4.0 mg/L. Recoveries of four purines ranged from 93.03% to 107.42%. Purine content in prepackaged food was following: animal derived prepackaged food: 16.13-90.18 mg/100 g; beans and bean products: 66.36-157.11 mg/100 g; fruits and fruit products: 5.64-21.79 mg/100 g; instant rice and flour products: 5.68-30.83 mg/100 g; fungi, algae, fungi and algae products: 32.57-70.59 mg/100 g. This proposed method had good precision and accuracy with a wide linear range for detection of purine. Animal derived prepackaged food was purine-rich food, purine content of plant derived prepackaged food varied greatly.

Insoluble Fiber in Barley Leaf Attenuates Hyperuricemic Nephropathy by Modulating Gut Microbiota and Short-Chain Fatty Acids

Hyperuricemia (HUA), characterized by abnormal serum uric acid (UA) levels, is recognized as an important risk factor for hyperuricemic nephropathy (HN), which is strongly linked to gut microbiota. This study investigated the protective effects and regulatory mechanisms of insoluble fiber from barley leaves (BL) against HN, induced by adenine (Ad) and potassium oxonate (PO). The results showed that BL dramatically reduced the levels of serum UA and creatinine (CR) and alleviated renal injury and fibrosis. Moreover, BL modulated oxidative stress and downregulated the expression of urate transporter 1 (URAT1) and glucose transporter 9 (GLUT9) in the kidneys of mice with HN. In addition, the 16S rRNA sequence data showed that BL also increased the relative abundance of short-chain fatty acids (SCFAs)-producing bacteria, including Bacteroides, Alloprevotella, and Eisenbergiella. Besides, BL treatment also increased SCFAs levels. Of interest, the application of SCFAs in hyperuricemic mice effectively reduced their serum UA. Furthermore, SCFAs dose-dependently inhibited URAT1 and GLUT9 in vitro and potently interacted with URAT1 and GLUT9 in the docking analysis. When taken together, our results indicate that BL and its metabolite SCFAs may be potential candidates for relieving HUA or HN.

Dietary Patterns in Association With Hypertension: A Community-Based Study in Eastern China

Objective

This study aimed to explore the association between dietary patterns and hypertension based on a community–based survey in Suzhou, Eastern China.

Methods

This cross–sectional analysis was undertaken from the subset of the Suzhou Food Consumption and Health State Survey in 2018–2019. Adults aged ≥ 18 years were invited to participate in this survey. Dietary intake was collected by a 24–h dietary recall and a weighing method over three consecutive days (including two weekdays and one weekend day). Dietary patterns were defined using factor analysis. Association between the dietary patterns and hypertension was examined by multivariable logistic regression models with adjustment for covariates. Moreover, sensitivity analysis was used to reinforce our findings.

Results

A total of 2,718 participants were included in the final analysis. Rice-vegetable pattern, fast food pattern, fruit-dairy pattern, and wheat-meat pattern were identified. We observed that the fruit-dairy pattern was inversely associated with hypertension after adjustment for all the covariates (OR = 0.55; 95% CI: 0.40, 0.75; P = 0.002). The association between the wheat-meat pattern and hypertension was attenuated and became statistically nonsignificant in sensitivity analyses. The other two patterns were not significantly associated with hypertension (P &gt; 0.05).

Conclusion

The fruit-dairy pattern was inversely associated with the risk of hypertension among Chinese adults. Our findings further emphasize the important role of optimal diet combination in the prevention of hypertension.

The Burden of Colorectal Cancer Attributable to Diet Low in Fiber from 1990 to 2019: A Global, Regional and National Analysis

OBJECTIVES

The colorectal cancer (CRC) burden is increasingly high. The aim of this study was to investigate temporal and geographical trends in CRC deaths and disability-adjusted life-years (DALYs) attributable to diet low in fiber globally from 1990 to 2019.

DESIGN

Cross-sectional study.

SETTING

The study based on the Global Burden of Disease Study (GBD) 2019.

PARTICIPANTS

The population comprised individuals from 204 countries and territories who were diagnosed with CRC attributable to diet low in fiber from 1990 to 2019.

MEASUREMENTS

Deaths, DALYs, age-standardized mortality rates (ASMR), and age-standardized DALY rates (ASDR) for CRC attributable to diet low in fiber were described, and estimated annual percentage change (EAPC) was further calculated to assess the burden in different regions, countries, sexes, and age groups. Additionally, we explored the association between EAPC and ASMR/ASDR (in 1990) and Human Development Index (HDI, in 2019).

RESULTS

From 1990 to 2019, global ASMR and ASDR for CRC attributable to diet low in fiber decreased slightly, but the corresponding deaths and DALYs increased by 63.37% and 51.36%, respectively. Those burden varied considerably between regions and countries. The burden was higher in high, high-middle and middle SDI regions, especially in Asia and Western Europe, but when HDI > 0.7, an increasingly rapid decline in ASMR and ASDR was revealed. Unexpectedly, many less well-developed countries within the traditionally low deaths and DALYs regions of Africa, Central Latin America, and Middle East showed gradual increases in ASMR and ASDR.

CONCLUSION

The global burden of CRC attributable to diet low in fiber has decreased over the last 30 years, but remains at a high level. It is essential for decision-makers to take targeted measures for improving population awareness and intake of dietary fiber.