Plant-based diets for prevention and management of chronic kidney disease:

Feeling gutted in chronic kidney disease (CKD): Gastrointestinal disorders and therapies to improve gastrointestinal health in individuals CKD, including those undergoing dialysis

Chronic kidney disease (CKD) affects 9.1% of the population worldwide. CKD may lead to structural and functional gastrointestinal alterations, including impairment in the intestinal barrier, digestion and absorption of nutrients, motility, and changes to the gut microbiome. These changes can lead to increased gastrointestinal symptoms in people with CKD, even in early grades of kidney dysfunction. Gastrointestinal symptoms have been associated with lower quality of life and reduced nutritional status. Therefore, there has been considerable interest in improving gastrointestinal health in this clinical population. Gastrointestinal health can be influenced by lifestyle and medications, particularly in advanced grades of kidney dysfunction. Therapies focused on gastrointestinal health have been studied, including the use of probiotics, prebiotics, and synbiotics, yielding limited and conflicting results. This review summarizes the alterations in the gastrointestinal tract structure and function and provides an overview of potential nutritional interventions that kidney disease professionals can provide to improve gastrointestinal health in individuals with CKD.

Analysis of the Nutritional Composition of Ready-to-Use Meat Alternatives in Belgium

BACKGROUND

The interest in meat alternatives has increased over the years as people embrace more varied food choices because of different reasons. This study aims to analyse the nutritional composition of ready-to-use meat alternatives and compare them with meat (products).

METHODS

Nutritional composition values were collected in 2022 of all ready-to-use meat alternatives in Belgian supermarkets, as well as their animal-based counterparts. A one-sample t-test was performed to test the nutritional composition of ready-to-use meat alternatives against norm values, while an independent samples t-test was used to make the comparison with meat.

RESULTS

Minced meat and pieces/strips/cubes scored favourably on all norm values. Cheeseburgers/schnitzels, nut/seed burgers and sausages contained more than 10 g/100 g total fat. The saturated fat and salt content was lower than the norm value in each category. Legume burgers/falafel contained less than 10 g/100 g protein. Vegetarian/vegan minced meat and bacon contained fewer calories, total and saturated fat, and more fibre compared to their animal-based counterparts.

CONCLUSIONS

Minced meat and pieces/strips/cubes came out as the most favourable categories regarding nutritional composition norm values. Vegetarian/vegan steak came out the least favourable compared to steak, while vegetarian/vegan minced meat and vegetarian/vegan bacon came out the most favourable compared to their animal-based counterparts.

Diet and Physical Activity in Fabry Disease: A Narrative Review

Fabry disease (FD) is caused by mutations in the galactosidase alpha (GLA) gene which lead to the accumulation of globotriaosylceramide (Gb-3). Enzyme replacement therapy (ERT) and oral chaperone therapy are the current pharmacological treatments for this condition. However, in the literature, there is a growing emphasis on exploring non-pharmacological therapeutic strategies to improve the quality of life of patients with FD. In particular, the nutritional approach to FD has been marginally addressed in the scientific literature, although specific dietary interventions may be useful for the management of nephropathy and gastrointestinal complications, which are often present in patients with FD. Especially in cases of confirmed diagnosis of irritable bowel syndrome (IBS), a low-FODMAP diet can represent an effective approach to improving intestinal manifestations. Furthermore, it is known that some food components, such as polyphenols, may be able to modulate some pathogenetic mechanisms underlying the disease, such as inflammation and oxidative stress. Therefore, the use of healthy dietary patterns should be encouraged in this patient group. Sports practice can be useful for patients with multi-organ involvement, particularly in cardiovascular, renal, and neurological aspects. Therefore, the aim of this review is to summarize current knowledge on the role of nutrition and physical activity in FD patients.

Safety and efficacy of sodium zirconium cyclosilicate for the management of acute and chronic hyperkalemia in children with chronic kidney disease 4-5 and on dialysis

BACKGROUND

Sodium zirconium cyclosilicate (SZC), an ion-exchange resin, is effective in the control of hyperkalemia in adults with chronic kidney disease (CKD); reports of use in children are limited. Prolonged therapy with SZC to relax dietary potassium restriction in CKD has not been examined.

METHODS

We conducted a retrospective chart review of patients 6 months to 18 years of age with CKD stage 4-5 or on dialysis (5D) administered SZC for sustained hyperkalemia (potassium ≥ 5.5 mEq/L, three consecutive values). Patients received SZC (0.5-10 g per dose; age-based) either short-term (< 30 days) or long-term (> 30 days).

RESULTS

Twenty patients with median age 10.8 (inter-quartile range 3.9, 13.4) years were treated with SZC. Short-term SZC, for 5 (3, 19) days, was associated with safe management of dialysis catheter insertions (n = 5) and access dysfunction (n = 4), and was useful during palliative care (n = 1). Serum potassium levels decreased from 6.7 (6.1, 6.9) to 4.4 (3.7, 5.2) mEq/L (P < 0.001). Long-term SZC for 5.3 (4.2, 10.1) months achieved decline in serum potassium from 6.1 (5.8, 6.4) to 4.8 (4.2, 5.4) mEq/L (P < 0.001). SZC use was associated with liberalization of diet (n = 6) and was useful in patients with poor adherence to dietary restriction (n = 3). Adverse events or edema were not observed; serum sodium and blood pressure remained stable.

CONCLUSIONS

SZC was safe and effective for the management of acute and chronic hyperkalemia in children with CKD4-5/5D. Its use was associated with relaxation of dietary potassium restriction. Studies to examine its routine use to improve diet and nutritional status in children with CKD are required.

Assessment of Knowledge on Dietary Management of Chronic Kidney Disease Among Patients Undergoing Hemodialysis at a Tertiary Care Hospital in South India: A Cross-Sectional Analytical Study

Background This cross-sectional analytical study aimed to assess the level of knowledge on dietary management of chronic kidney disease (CKD) among patients undergoing hemodialysis in a tertiary care hospital in Puducherry, South India. Methodology The study was conducted among 86 inpatients diagnosed with CKD and undergoing hemodialysis in the dialysis unit. They were selected by simple random sampling. The self-administered, validated, self-structured questionnaire was used to collect the data. The study was conducted from May to September 2019. Descriptive statistics (frequency, percentage, mean, and standard deviation) and inferential statistics (chi-square) were used to find out the relationship between the level of knowledge and background variables using IBM SPSS Statistics for Windows, Version 25.0 (Released 2017; IBM Corp., Armonk, New York, United States). Results The findings indicated that the majority of patients were in the 20-30 age range (36, 41.9%), male (58, 67.4%), from nuclear families (58, 66.3%), with mixed dietary habits (60, 69.8%), and undergoing thrice-weekly hemodialysis (34, 53.5%). Additionally, 59 (68.6%) were hypertensive and 14 (16.3%) were diabetic. Most patients exhibited a moderate level of knowledge (74, 86%), while a small percentage had inadequate (6, 7%) and adequate (6, 7%) knowledge, with a mean (SD) value of 2.00 (0.376). The study identified statistically significant associations between knowledge levels and age, occupation, food habits, duration of dialysis, pre-existing co-morbid illnesses, and treatment of hemodialysis with a p-value <0.05. Conclusions In conclusion, this study highlights that the majority of the CKD patients undergoing hemodialysis exhibit moderately adequate knowledge of dietary management. However, a notable need remains for further education and support in this area. Addressing these knowledge gaps is crucial, as it can empower nursing students and healthcare professionals to educate these patients on their dietary needs effectively. By providing comprehensive education and support, we can enhance the quality of care and improve outcomes for hemodialysis patients.

Effects of Plant-Based Protein Consumption on Kidney Function and Mineral Bone Disorder Outcomes in Adults With Stage 3-5 Chronic Kidney Disease: A Systematic Review

INTRODUCTION

Plant-based protein is of growing interest for dietary management of chronic kidney disease (CKD) and is hypothesized to preserve kidney function and reduce CKD-mineral bone disorder (MBD) complications, among other benefits. This systematic review aimed to summarize the available clinical trial evidence for the effect of plant-based protein on kidney function and CKD-MBD outcomes in adults with stage 3-5 CKD not on dialysis.

METHODS

Searches of Medline, Embase, Agricola, CAB abstracts, Web of Science, Scopus, and hand searching were performed. Clinical trials with ≥8 participants ≥18 years of age with an estimated glomerular filtration rate <60 mL/min/1.73 m2 but not on dialysis were included. Additionally, only clinical trials with ≥1-week interventions with ≥50% dietary protein from plant-based sources and reported at least one outcome for both kidney function and CKD-MBD outcomes were included. Of the 10,962 identified abstracts, 32 met inclusion criteria and were assessed for risk of bias.

RESULTS

Results for kidney function and CKD-MBD outcomes were heterogenous, with most studies having suboptimal methodological quality. In most of the studies (27/32), protein source was altered only secondarily to low-protein diet interventions. Thus, data synthesis and interpretation were focused on a subset of five studies that investigated a change in protein source only (i.e., animal vs. plant). Of this subset, four studies reported no change in kidney function, while one study reported a decrease. Three studies reported no change in serum phosphorus, and one study reported lower serum phosphorus following a vegetarian diet. Further, limited data and inconclusive results were observed for phosphaturic hormones, parathyroid hormone, and fibroblast growth factor-23.

CONCLUSION

Current clinical trial evidence on plant-based protein interventions for preserving kidney function and preventing CKD-MBD is limited to inform clinical guidelines at this time. This systematic review emphasizes the ongoing need to research the effects of plant-based protein on kidney function and CKD-MBD outcomes.

Targeting the Gut Microbiota in Kidney Disease: The Future in Renal Nutrition and Metabolism

There is increasing interest in the therapeutic potential of manipulating the gut microbiome of patients with chronic kidney disease (CKD). This is because there is a substantial deviation from a balanced gut microbiota profile in CKD, with many deleterious downstream effects. Nutritional interventions such as plant-based diets with reduced animal protein intake and the use of probiotics, prebiotics, and synbiotics may alter the microbiome. This article aims to briefly describe what is known about the gut microbiome in patients with CKD, factors contributing to gut dysbiosis, and outline important evidence gaps. Future potential therapies, including restoring the microbiota with food and microbiota-based and metabolomic-based therapies, are also discussed.

Nutritional and Dietary Management of Chronic Kidney Disease Under Conservative and Preservative Kidney Care Without Dialysis

While dialysis has been the prevailing treatment paradigm for patients with advanced chronic kidney disease (CKD), emphasis on conservative and preservative management in which dietary interventions are a major cornerstone have emerged. Based on high-quality evidence, international guidelines support the utilization of low-protein diets as an intervention to reduce CKD progression and mortality risk, although the precise thresholds (if any) for dietary protein intake vary across recommendations. There is also increasing evidence demonstrating that plant-dominant low-protein diets reduce the risk of developing incident CKD, CKD progression, and its related complications including cardiometabolic disease, metabolic acidosis, mineral and bone disorders, and uremic toxin generation. In this review, we discuss the premise for conservative and preservative dietary interventions, specific dietary approaches used in conservative and preservative care, potential benefits of a plant-dominant low-protein diet, and practical implementation of these nutritional strategies without dialysis.

Novel Therapeutic Approaches in the Management of Chronic Kidney Disease

Chronic kidney disease (CKD) is a progressive and incurable disease that impairs kidney function. Its prevalence is estimated to affect up to 800 million individuals within the general population, and patients with diabetes and hypertension are particularly at risk. This disorder disrupts the physiological mechanisms of the body, including water and electrolyte balance, blood pressure regulation, the excretion of toxins, and vitamin D metabolism. Consequently, patients are exposed to risks such as hyperkalemia, hyperphosphatemia, metabolic acidosis, and blood pressure abnormalities. These risks can be reduced by implementing appropriate diagnostic methods, followed by non-pharmacological (such as physical activity, dietary, and lifestyle adjustment) and pharmacological strategies after diagnosis. Selecting the appropriate diet and suitable pharmacological treatment is imperative in maintaining kidney function as long as possible. Drugs such as finerenone, canakinumab, and pentoxifylline hold promise for improved outcomes among CKD patients. When these interventions prove insufficient, renal replacement therapy becomes essential. This is particularly critical in preserving residual renal function while awaiting renal transplantation or for patients deemed ineligible for such a procedure. The aim of this study is to present the current state of knowledge and recent advances, providing novel insights into the treatment of chronic kidney disease.

Chronic kidney disease in children: an update

Chronic kidney disease (CKD) is a major healthcare issue worldwide. However, the prevalence of pediatric CKD has never been systematically assessed and consistent information is lacking in this population. The current definition of CKD is based on glomerular filtration rate (GFR) and the extent of albuminuria. Given the physiological age-related modification of GFR in the first years of life, the definition of CKD is challenging per se in the pediatric population, resulting in high risk of underdiagnosis in this population, treatment delays and untailored clinical management. The advent and spreading of massive-parallel sequencing technology has prompted a profound revision of the epidemiology and the causes of CKD in children, supporting the hypothesis that CKD is much more frequent than currently reported in children and adolescents. This acquired knowledge will eventually converge in the identification of the molecular pathways and cellular response to damage, with new specific therapeutic targets to control disease progression and clinical features of children with CKD. In this review, we will focus on recent innovations in the field of pediatric CKD and in particular those where advances in knowledge have become available in the last years, with the aim of providing a new perspective on CKD in children and adolescents.

Anti-inflammatory and antioxidant actions of extracts from Rheum rhaponticum and Rheum rhabarbarum in human blood plasma and cells in vitro

Rheum rhaponticum L. (rhapontic rhubarb) and Rheum rhabarbarum L. (garden rhubarb) are edible and medicinal rhubarb species used for many centuries in traditional medicine. This work is focused on the biological activity of extracts from petioles and roots of R. rhaponticum and R. rhabarbarum as well as rhapontigenin and rhaponticin, typical stilbenes present in these rhubarbs, in a context of their effects on blood physiology and cardiovascular health. Anti-inflammatory properties of the examined substances were evaluated in human peripheral blood mononuclear cells (PBMCs) and THP1-ASC-GFP inflammasome reporter cells. Due to the coexistence of inflammation and oxidative stress in cardiovascular diseases, the study design included also antioxidant assays. This part of the work involved the assessment of the protective efficiency of the examined substances against the peroxynitrite-triggered damage to human blood plasma components, including fibrinogen, a protein of critical importance for blood clotting and maintaining the haemostatic balance. Pre-incubation of PBMCs with the examined substances (1-50 μg/mL) considerably decreased the synthesis of prostaglandin E2 as well as the release of pro-inflammatory cytokines (IL-2 and TNF-α) and metalloproteinase-9. A reduced level of secreted apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) specks in the THP-1-ASC-GFP cells was also observed. The examined substances significantly diminished the extent of ONOO‾induced oxidative modifications of blood plasma proteins and lipids and normalized, or even strengthened blood plasma antioxidant capacity. Furthermore, a reduction of oxidative damage to fibrinogen, including modifications of tyrosine and tryptophan residues along with the formation of protein aggregates was found.

Nutritional Strategies to Prevent Muscle Loss and Sarcopenia in Chronic Kidney Disease: What Do We Currently Know?

Loss of muscle mass is an extremely frequent complication in patients with chronic kidney disease (CKD). The etiology of muscle loss in CKD is multifactorial and may depend on kidney disease itself, dialysis, the typical chronic low-grade inflammation present in patients with chronic kidney disease, but also metabolic acidosis, insulin resistance, vitamin D deficiency, hormonal imbalances, amino acid loss during dialysis, and reduced dietary intake. All these conditions together increase protein degradation, decrease protein synthesis, and lead to negative protein balance. Aging further exacerbates sarcopenia in CKD patients. Nutritional therapy, such as protein restriction, aims to manage uremic toxins and slow down the progression of CKD. Low-protein diets (LPDs) and very low-protein diets (VLPDs) supplemented with amino acids or ketoacids are commonly prescribed. Energy intake is crucial, with a higher intake associated with maintaining a neutral or positive nitrogen balance. Adequate nutritional and dietary support are fundamental in preventing nutritional inadequacies and, consequently, muscle wasting, which can occur in CKD patients. This review explores the causes of muscle loss in CKD and how it can be influenced by nutritional strategies aimed at improving muscle mass and muscle strength.

Gut Microbiota-Targeted Interventions in the Management of Chronic Kidney Disease

Recent advances in microbiome research have informed the potential role of the gut microbiota in the regulation of metabolic, cardiovascular, and renal systems, and, when altered, in the pathogenesis of various cardiometabolic disorders, including chronic kidney disease (CKD). The improved understanding of gut dysbiosis in cardiometabolic pathologies in turn has led to a vigorous quest for developing therapeutic strategies. These therapeutic strategies aim to investigate whether interventions targeting gut dysbiosis can shift the microbiota toward eubiosis and if these shifts, in turn, translate into improvements in (or prevention of) CKD and its related complications, such as premature cardiovascular disease. Existing evidence suggests that multiple interventions (eg, plant-based diets; prebiotic, probiotic, and synbiotic supplementation; constipation treatment; fecal microbiota transplantation; and intestinal dialysis) might result in favorable modulation of the gut microbiota in patients with CKD, and thereby potentially contribute to improving clinical outcomes in these patients. In this review, we summarize the current understanding of the characteristics and roles of the gut microbiota in CKD and discuss the potential of emerging gut microbiota-targeted interventions in the management of CKD.

Patient Perception of Plant Based Diets for Kidney Disease

OBJECTIVE

Plant-based diets can delay the progression of chronic kidney disease (CKD) and help manage complications and comorbid conditions such as hypertension, acidosis, diabetes, and cardiovascular disease. The objective of this study was to understand nephrology patients' familiarity, perception, and use of plant-based diets.

DESIGN & METHODS

A survey was shared via the National Kidney Foundation's social media channels. Analysis included 844 responses. Survey items were evaluated with descriptive statistics. Differences across items were determined using chi-square tests.

RESULTS

Most respondents were 61-70 years of age (26.7%, n = 225), female (56.5%, n = 477) and achieved a Bachelor's or advanced degree (49.9%, n = 421). The majority of respondents suffered from nondialysis-dependent CKD (34%) or received a kidney transplant (34%). About half (45%) of respondents were familiar with plant-based diets and most (58%) were aware that plant-based diets can improve CKD. Twenty-two percent reported following some version of a vegetarian diet, and 29% reported "eating less meat". Respondents were not confident (Mdn = 2, IQR = 2, on a scale of 1-5) in their ability to plan a balanced plant-based meal, and were moderately confident that a plant-based diet could help blood pressure (Mdn = 3, IQR = 2) and slow progression of CKD (Mdn = 3, IGR = 2). Family eating preference, meal planning skills, preference for meat, figuring out what is healthy to eat, food cost, time constraints, and ease of cooking were rated as equal barriers to following a plant-based diet (Mdn = 3). A sample meal plan, individual counseling session with a Registered Dietitian Nutritionist (RDN), handouts, and cooking classes were resources rated most helpful to transition to a plant-based diet (Mdn = 4).

CONCLUSION

Approximately half of respondents were aware that plant-based diets can be beneficial for CKD. Many patients are following a vegetarian or plant-based eating pattern. More research should be done to see how effective RDNs are in educating and moving patients toward a plant-based eating pattern, as they are an underutilized resource in the CKD population.

Influence of the vegan, vegetarian and omnivore diet on the oral health status in adults: a systematic review and meta-analysis

OBJECTIVE

This systematic review aimed to evaluate the influence of the nature of diet (vegan, vegetarian, and omnivore) on the oral health status in adults.

METHODS

This systematic review and meta-analysis was performed using the PRISMA guidelines. Electronic databases [PubMed, Embase, CENTRAL], online search engines (Google Scholar), research portals, and hand searches were performed systematically to identify studies. The last literature search was performed February 1st, 2021. Studies were included if they reported on the influence of the nature of diet on the oral health status (oral hygiene, periodontal health, dental status, and salivary function) in adults, by two investigators. Inter-investigator reliability was evaluated using Kappa (κ) statistics. PROSPERO registration number: CRD42020211567.

RESULTS

Twenty-two studies were included for data extraction and final analysis. The meta-analysis revealed that the bleeding on probing measure was higher in omnivores (Z = -4.057, p < 0.0001; 95% CI: -0.684, -0.238; I² = 0.0%) and the overall periodontal health was significantly better in vegan/vegetarians than omnivores (Z = -2.632, p = 0.008; 95% CI: -0.274, -0.073; I² = 29.7%). Vegan/vegetarians demonstrated more dental erosion (Z = 3.325, p = 0.001; 95% CI: 0.170, 0.659; I² = 0.0%). In adults over 60 years old, the prevalence of caries was higher in omnivores (Z = 3.244, p = 0.001; 95% CI: 0.092, 0.371; I² = 0.0%), while complete edentulism was more prevalent in vegetarians (Z = -4.147, p < 0.0001; 95% CI: -0.550, -0.197; I² = 0.0%).

CONCLUSIONS

This review reveals that adults on an omnivore diet may be associated with a higher risk for periodontal problems and dental caries, while vegetarians/vegans may be associated with a higher risk for dental erosion.

Are We What We Eat? The Moral Imperative of the Medical Profession to Promote Plant-Based Nutrition

The typical Western diet, high in processed and animal-based foods, is nutritionally and ethically problematic. Beyond the well-documented cruelty to animals that characterizes the practices of the factory-farming industry, current patterns of meat consumption contribute to medical and moral harm in humans on both an individual level and a public health scale. We aim to deconstruct, by highlighting their fallacies, the common positive and normative arguments that are used to defend current nutritional patterns. Animal-based foods promote the mechanisms that underlie chronic cardiometabolic disease, whereas whole-food plant-based nutrition can reverse them. Factory farming of animals also contributes to climate change, antibiotic resistance, and the spread of infectious diseases. Finally, the current allocation of nutritional resources in the United States is unjust. A societal shift toward more whole-food plant-based patterns of eating stands to provide significant health benefits and ethical advantages, and the medical profession has a duty to advocate accordingly. Although it remains important for individuals to make better food choices to promote their own health, personal responsibility is predicated on sound advice and on resource equity, including the availability of healthy options. Nutrition equity is a moral imperative and should be a top priority in the promotion of public health.

Nutritional Assessment and Support in Children with Chronic Kidney Disease: The Benefits of Working with a Registered Dietitian

BACKGROUND

An unbalanced dietary pattern, characterized by high animal protein content: may worsen metabolic control, accelerate renal deterioration and consequently aggravate the stage of the chronic kidney disease (CKD) in pediatric patients with this condition.

AIM

to assess the effect of a registered dietitian (RD) intervention on the CKD children's eating habits.

METHODS

Anthropometric and dietetic parameters, obtained at baseline and 12 months after implementing healthy eating and nutrition education sessions, were compared in 16 patients (50% girls) of 8.1 (1-15) years. On each occasion, anthropometry, 3-day food records and a food consumption frequency questionnaire were carried out. The corresponding relative intake of macro- and micronutrients was contrasted with the current advice by the European Food Safety Authority (EFSA) and with consumption data obtained using the Spanish dietary guidelines. Student's paired t-test, Wilcoxon test and Mc Nemar test were used.

RESULTS

At Baseline 6% were overweight, 69% were of normal weight and 25% were underweight. Their diets were imbalanced in macronutrient composition. Following nutritional education and dietary intervention 63%, 75% and 56% met the Dietary Reference Values requirements for fats, carbohydrates and fiber, respectively, but not significantly. CKD children decreased protein intake (p < 0.001), increased dietary fiber intake at the expense of plant-based foods consumption (p < 0.001) and a corresponding reduction in meat, dairy and processed food intake was noticed. There were no changes in the medical treatment followed or in the progression of the stages.

CONCLUSIONS

RD-led nutrition intervention focused on good dieting is a compelling helpful therapeutic tool to improve diet quality in pediatric CKD patients.

Dietary Acid Load and Predialysis Serum Bicarbonate Levels in Patients With End-Stage Renal Disease

OBJECTIVES

Maintaining the predialysis serum bicarbonate at a recommended level is critical in patients undergoing hemodialysis. Therefore, the present study investigated the association between dietary acid load (DAL) and serum predialysis bicarbonate levels in patients with end-stage renal disease.

METHODS

Adult patients undergoing hemodialysis were enrolled in this cross-sectional study. Diet was assessed using a semiquantitative food frequency questionnaire. DAL was calculated with 2 validated indices: potential renal acid load (PRAL) and net endogenous acid production (NEAP). Values regarding predialysis serum bicarbonate level and serum electrolytes were obtained from the participant's medical records. The multiple linear regression analysis was used to determine the association between DAL indices and predialysis serum bicarbonate level.

RESULTS

The number of hemodialysis patients eligible for this study was 122. The participants' mean age and body mass index was 57.14 ± 3.8 years and 25.2 ± 4.9 kg/m², respectively. About 65.6% of participants were male. The mean serum levels of predialysis bicarbonate were 21.59 ± 3.1 mEq/L. Also, 47.5% of patients had predialysis serum bicarbonate levels below the recommended value. The mean values of PRAL and NEAP were -2.8 ± 7.48 and 42.7 ± 10.1 mEq/day, respectively. PRAL significantly and inversely predicted predialysis serum bicarbonate level independent of covariates (standardized β = -0.38; P < .001). Also, NEAP was independently and inversely associated with predialysis bicarbonate level (standardized β = -0.40; P < .001). Consuming vegetables such as lettuce, tomato, cucumber, spinach, and dried fruits as well as low-fat milk, plain yogurt, and cream cheese were positively correlated to predialysis serum bicarbonate level. However, the canned tuna had a negative correlation with the predialysis serum bicarbonate.

CONCLUSIONS

The study's findings showed that the lower DAL was associated with higher predialysis serum bicarbonate levels in patients with end-stage renal disease. Due to the cross-sectional nature of the present study, prospective cohorts or well-controlled clinical trials are needed to confirm our result.

Low dietary sodium potentially mediates COVID-19 prevention associated with whole-food plant-based diets

Compared with an omnivorous Western diet, plant-based diets containing mostly fruits, vegetables, grains, legumes, nuts and seeds, with restricted amounts of foods of animal origin, are associated with reduced risk and severity of COVID-19. Additionally, inflammatory immune responses and severe acute respiratory symptoms of COVID-19, including pulmonary oedema, shortness of breath, fever and nasopharyngeal infections, are associated with Na toxicity from excessive dietary Na. High dietary Na is also associated with increased risks of diseases and conditions that are co-morbid with COVID-19, including chronic kidney disease, hypertension, stroke, diabetes and obesity. This article presents evidence that low dietary Na potentially mediates the association of plant-based diets with COVID-19 prevention. Processed meats and poultry injected with sodium chloride contribute considerable amounts of dietary Na in the Western diet, and the avoidance or reduction of these and other processed foods in whole-food plant-based (WFPB) diets could help lower overall dietary Na intake. Moreover, high amounts of K in plant-based diets increase urinary Na excretion, and preagricultural diets high in plant-based foods were estimated to contain much lower ratios of dietary Na to K compared with modern diets. Further research should investigate low Na in WFPB diets for protection against COVID-19 and co-morbid conditions.

Cannabis sativa L. protects against oxidative injury in kidney (vero) cells by mitigating perturbed metabolic activities linked to chronic kidney diseases

ETHNOPHARMACOLOGICAL RELEVANCE

Cannabis sativa L. is among numerous medicinal plants widely used in traditional medicine in treating various ailments including kidney diseases.

AIMS

The protective effect of C. sativa on oxidative stress, cholinergic and purinergic dysfunctions, and dysregulated glucogenic activities were investigated in oxidative injured kidney (Vero) cell lines.

METHODS

Fixed Vero cells were treated with sequential extracts (hexane, dichloromethane [DCM] and ethanol) of C. sativa leaves for 48 h before subjecting to MTT assay. Vero cells were further incubated with FeSO₄ for 30 min, following pretreatment with C. sativa extracts for 25 min. Normal control consisted of Vero cells not treated with the extracts and/or FeSO₄, while untreated (negative) control consisted of cells treated with only FeSO₄.

RESULTS

MTT assay revealed the extracts were slightly cytotoxic at the highest concentrations (250 μg/mL). There was a significant depletion in glutathione level and catalase activity on induction of oxidative stress, with significant elevation in malondialdehyde level, acetylcholinesterase, ATPase, ENTPDase, fructose-1,6-biphosphatase, glucose 6-phosphatase and glycogen phosphorylase activities. These activities and levels were significantly reversed following pretreatment with C. sativa extracts.

CONCLUSION

These results portray the protective potentials of C. sativa against iron-mediated oxidative renal injury as depicted by the ability of its extracts to mitigate redox imbalance and suppress acetylcholinestererase activity, while concomitantly modulating purinergic and glucogenic enzymes activities in Vero cells.

Potassium and fiber: a controversial couple in the nutritional management of children with chronic kidney disease

BACKGROUND

Fruit and vegetable intake is commonly discouraged in children with chronic kidney disease (CKD) to avoid hyperkalemia. However, direct evidence in support of this widespread practice is lacking. Furthermore, the resultant restricted fiber exposure may deprive CKD patients from potential health benefits associated with the latter. Therefore, we investigated associations between dietary potassium intake, fiber intake, and serum potassium levels in pediatric CKD.

METHODS

This study is a longitudinal analysis of a 2-year, prospective, multi-institutional study, following children with CKD at 3-month intervals. At each visit, dietary potassium and fiber intake were assessed, using 24-h recalls and 3-day food records. On the same occasion, serum potassium concentrations were determined. Associations between dietary potassium intake, dietary fiber intake, and serum potassium concentrations were determined using linear mixed models.

RESULTS

Fifty-two CKD patients (7 transplant recipients, none on dialysis) aged 9 [4;14] years with an estimated glomerular filtration rate (eGFR) of 49 [25;68] mL/min/1.73 m² were included. For every g/day decrease in dietary potassium intake, the estimated mean daily fiber intake was 5.1 g lower (95% confidence interval (CI), 4.3-5.9 g/day; p < 0.001). Neither dietary potassium intake (p = 0.40) nor dietary fiber intake (p = 0.43) was associated with circulating potassium in a model adjusted for time point, eGFR, treatment with a renin-angiotensin-aldosterone system blocker, serum bicarbonate concentration, and body surface area.

CONCLUSIONS

Dietary potassium and fiber intake are closely related but were not associated with circulating potassium levels in pediatric CKD. A higher-resolution version of the graphical abstract is available as Supplementary information.

Vitamin B12 sources in non-animal foods: a systematic review

Interest in plant-based diets and vegetarianism is increasing worldwide, however, a concern for total vegetarians is vitamin B12 (B12) deficiency. We conducted a systematic review to investigate non-animal food sources of B12. Databases were PubMed, LILACS, Cochrane, Embase and Google Scholar, up to September 9, 2020. Quality of the eligible studies were assessed. We identified 25 studies which assessed B12 content in seaweeds, mushrooms, plants and fermented foods. Initial studies were microbiological bioassay, ELISA and HPLC. In the last decade, more sensitive method for real B12 determination was used, the liquid chromatography-electrospray ionization tandem mass spectrometry chromatograms. Real B12 content varied from mean (SD) mcg/portion size of seaweed hijiki 3 × 10-3/7 g to nori 1.03 - 2.68/sheet; mushroom white button cap 2 × 10-3(7 × 10-4)/20 g dry weight (dw) to shiitake 0.79(0.67)-1.12 (0.78)/20 g dw; and fermented foods from soy yogurt 20/cup. It is possible that daily recommendations for B12 can be met by a varied diet containing non-animal B12 food sources. Future research should consider different methods of storage, preparation, fermented foods and standardization of the production of certain foods.Supplemental data for this article is available online at https://doi.org/10.1080/10408398.2022.2053057.

Plant-Based Diets and Peritoneal Dialysis: A Review

Whole food plant-based diets are gaining popularity as a preventative and therapeutic modality for numerous chronic health conditions, including chronic kidney disease, but their role and safety in end-stage kidney disease patients on peritoneal dialysis (PD) is unclear. Given the general public's increased interest in this dietary pattern, it is likely that clinicians will encounter individuals on PD who are either consuming, considering, or interested in learning more about a diet with more plants. This review explores how increasing plant consumption might affect those on PD, encompassing potential benefits, including some specific to the PD population, and potential concerns.

Benefits of a plant-based diet and considerations for the athlete

Individuals may opt to follow a plant-based diet for a variety of reasons, such as religious practices, health benefits or concerns for animal or environmental welfare. Such diets offer a broad spectrum of health benefits including aiding in the prevention and management of chronic diseases. In addition to health benefits, a plant-based diet may provide performance-enhancing effects for various types of exercise due to high carbohydrate levels and the high concentration of antioxidants and phytochemicals found in a plant-based diet. However, some plant-based foods also contain anti-nutrional factors, such as phytate and tannins, which decrease the bioavailability of key nutrients, such as iron, zinc, and protein. Thus, plant-based diets must be carefully planned to ensure adequate intake and absorption of energy and all essential nutrients. The current narrative review summarizes the current state of the research concerning the implications of a plant-based diet for health and exercise performance. It also outlines strategies to enhance the bioavailability of nutrients, sources of hard-to-get nutrients, and sport supplements that could interest plant-based athletes.

Glomerular Biomechanical Stress and Lipid Mediators during Cellular Changes Leading to Chronic Kidney Disease

Hyperfiltration is an important underlying cause of glomerular dysfunction associated with several systemic and intrinsic glomerular conditions leading to chronic kidney disease (CKD). These include obesity, diabetes, hypertension, focal segmental glomerulosclerosis (FSGS), congenital abnormalities and reduced renal mass (low nephron number). Hyperfiltration-associated biomechanical forces directly impact the cell membrane, generating tensile and fluid flow shear stresses in multiple segments of the nephron. Ongoing research suggests these biomechanical forces as the initial mediators of hyperfiltration-induced deterioration of podocyte structure and function leading to their detachment and irreplaceable loss from the glomerular filtration barrier. Membrane lipid-derived polyunsaturated fatty acids (PUFA) and their metabolites are potent transducers of biomechanical stress from the cell surface to intracellular compartments. Omega-6 and ω-3 long-chain PUFA from membrane phospholipids generate many versatile and autacoid oxylipins that modulate pro-inflammatory as well as anti-inflammatory autocrine and paracrine signaling. We advance the idea that lipid signaling molecules, related enzymes, metabolites and receptors are not just mediators of cellular stress but also potential targets for developing novel interventions. With the growing emphasis on lifestyle changes for wellness, dietary fatty acids are potential adjunct-therapeutics to minimize/treat hyperfiltration-induced progressive glomerular damage and CKD.

Medical nutrition therapy using plant-focused low-protein meal plans for management of chronic kidney disease in diabetes

PURPOSE OF REVIEW

Nearly half of all Americans with chronic kidney disease (CKD) also have type-2-diabetes (T2D). Whereas traditional and emerging pharmacotherapies are increasingly frequently used for the management of CKD in diabetes (CKD/DM), the role of integrated or multimodal interventions including the potentially synergistic and additive effect of diet and lifestyle modifications in addition to pharmacotherapy has not been well examined, in sharp contrast to the well-known integrated approaches to heart disease.

RECENT FINDINGS

Low-carbohydrate low-fat diets are often recommended in T2D, whereas low-protein diets (LPD) are recommended by guidelines for nondiabetic CKD with increasing emphasis on plant-based protein sources. High-protein diets with greater animal protein lead to glomerular hyperfiltration, especially in patients with T2D, and faster decline in renal function. Guidelines provide differing recommendations regarding the amount (low vs high) and source (plant vs animal) of dietary protein intake (DPI) in CKD/DM. Some such as KDIGO recommend 0.8 g/kg/day based on insufficient evidence for DPI restriction in CKD/DM, whereas KDOQI and ISRNM recommend a DPI of 0.6 to <0.8 g/kg/day. A patient-centered plant-focused LPD for the nutritional management of CKD/DM (PLAFOND), a type of PLADO diet comprising DPI of 0.6 to <0.8 g/kg/day with >50% plant-based sources, high dietary fiber, low glycemic index, and 25-35 Cal/kg/day energy, can be implemented by renal dietitians under Medical Nutrition Therapy.

SUMMARY

Potential risks vs benefits of high vs low protein intake in CKD/DM is unknown, for which expert recommendations remain opinion based. Randomized controlled studies are needed to examine safety, acceptability and efficacy of PLAFOND.

Treatment of Lupus Nephritis from Iranian Traditional Medicine and Modern Medicine Points of View: A Comparative Study

Objective

Nephritis or kidney inflammation is characterized as one of the most common renal disorders leading to serious damage to the kidneys. Nephritis, especially lupus nephritis (LN), has remained as the main cause of chronic renal failure which needs serious therapeutic approaches such as dialysis and kidney transplant. Heredity, infection, high blood pressure, inflammatory diseases such as lupus erythematosus and inflammatory bowel disease, and drug-related side effects are known as the main causes of the disease. According to Iranian traditional medicine (ITM), infectious diseases and fever are the main reasons of nephritis, which is called “Varam-e-Kolye” (VK).

Results

There are various plant-based remedies recommended by ITM for the treatment of nephritis, as discussed herein, comparing with those available in the modern medicine. There is no definite cure for the treatment of nephritis, and immunosuppressive drugs such as corticosteroids and nonsteroidal anti-inflammatory drugs, antibiotics, diuretics, analgesics, and finally dialysis and kidney transplantation are usually used. Based on the efficacy of medicinal plants, jujube (Ziziphus jujuba), almond (Prunus amygdalus), pumpkin seeds (Cucurbita pepo), purslane (Portulaca oleracea), and fig (Ficus carica) were found to be effective for the treatment of kidney inflammation in ITM.

Conclusion

Considering the fact that there is no efficient strategy for the treatment of nephritis, use of herbal medicine, particularly based on the fruits or nuts that have been safely used for several years can be considered as a versatile supplement along with other therapeutic methods.

Chronic Kidney Disease: Role of Diet for a Reduction in the Severity of the Disease

Chronic kidney disease affects ~37 million adults in the US, and it is often undiagnosed due to a lack of apparent symptoms in early stages. Chronic kidney disease (CKD) interferes with the body's physiological and biological mechanisms, such as fluid electrolyte and pH balance, blood pressure regulation, excretion of toxins and waste, vitamin D metabolism, and hormonal regulation. Many CKD patients are at risk of hyperkalemia, hyperphosphatemia, chronic metabolic acidosis, bone deterioration, blood pressure abnormalities, and edema. These risks may be minimized, and the disease's progression may be slowed through careful monitoring of protein, phosphorus, potassium, sodium, and calcium, relieving symptoms experienced by CKD patients. In this review, the current Kidney Disease Outcomes Quality Initiative (KDOQI) recommendations are highlighted, reflecting the 2020 update, including explanations for the pathophysiology behind the recommendations. The Dietary Approaches to Stop Hypertension, the Mediterranean diet, and the whole foods plant-based diet are currently being examined for their potential role in delaying CKD progression. Biological explanations for why the whole foods plant-based diet may benefit CKD patients compared to diets that include animal products are examined. Strong evidence continues to support the importance of diet meeting the daily requirement in the prevention and progression of kidney disease, and medical nutrition therapy with a registered dietitian is a critical aspect in medical intervention for CKD.

Effects of vegetarian versus Mediterranean diet on kidney function: Findings from the CARDIVEG study

BACKGROUND

The aim of the present study was to assess the effects of a lacto-ovo-vegetarian diet (VD), compared to a Mediterranean diet (MD), on kidney function in a group of subjects with medium-to-low cardiovascular risk profile.

METHODS

We analysed 107 subjects (82 women, 25 men; median age 52) who followed a VD (n = 54) and a MD (n = 53) for 3 months in the CARDIVEG study, a randomized, open, crossover trial that compared the effects of these 2 diets on cardiovascular disease risk.

RESULTS

The effect of the two diets on kidney function markers was evaluated by conducting a general linear model for repeated measurements adjusted for possible confounding factors such as age, sex, physical activity, alcohol, smoking, hypertension, LDL cholesterol, glucose and body weight change. A significant reduction in creatinine (-5.3%; P < .001), urea nitrogen levels (-9%; P = .001), blood urea nitrogen (BUN) (-8.7%; P = .001) and BUN/creatinine ratio (-5.8%; P < .001), and an increase in estimated glomerular filtration rate (eGFR) (+3.5%; P = .001) was observed during the VD period. On the contrary, no significant changes were noted in the MD group. Variations obtained in the two dietary interventions were significantly different (P < .0001) for creatinine levels, BUN/creatinine and eGFR, for which opposite trends were observed in the VD and MD groups.

CONCLUSIONS

In a selected group of subjects with medium-to-low cardiovascular risk profile, a 3 month VD period determined significant improvements in kidney function markers. Further trials are needed to confirm these results.

The dietary management of potassium in children with CKD stages 2-5 and on dialysis-clinical practice recommendations from the Pediatric Renal Nutrition Taskforce

Dyskalemias are often seen in children with chronic kidney disease (CKD). While hyperkalemia is common, with an increasing prevalence as glomerular filtration rate declines, hypokalemia may also occur, particularly in children with renal tubular disorders and those on intensive dialysis regimens. Dietary assessment and adjustment of potassium intake is critically important in children with CKD as hyperkalemia can be life-threatening. Manipulation of dietary potassium can be challenging as it may affect the intake of other nutrients and reduce palatability. The Pediatric Renal Nutrition Taskforce (PRNT), an international team of pediatric renal dietitians and pediatric nephrologists, has developed clinical practice recommendations (CPRs) for the dietary management of potassium in children with CKD stages 2-5 and on dialysis (CKD2-5D). We describe the assessment of dietary potassium intake, requirements for potassium in healthy children, and the dietary management of hypo- and hyperkalemia in children with CKD2-5D. Common potassium containing foods are described and approaches to adjusting potassium intake that can be incorporated into everyday practice discussed. Given the poor quality of evidence available, a Delphi survey was conducted to seek consensus from international experts. Statements with a low grade or those that are opinion-based must be carefully considered and adapted to individual patient needs, based on the clinical judgment of the treating physician and dietitian. These CPRs will be regularly audited and updated by the PRNT.

Gastrointestinal symptom burden and dietary intake in patients with chronic kidney disease

BACKGROUND

Gastrointestinal (GI) symptoms can present a significant burden to patients with chronic kidney disease (CKD) but the reported prevalence is inconsistent.

OBJECTIVE

To examine the GI burden and dietary intake in patients with CKD with or without dialysis.

METHODS

This was a cross-sectional study of 216 adults, recruited from outpatient and dialysis clinics, with CKD stage 4 or 5 not receiving dialysis (CKD-ND), or receiving haemodialysis (HD) or peritoneal dialysis (PD). Three questionnaires were administered: the Bristol Stool Form Scale (BSFS); a modified Gastrointestinal Symptom Rating Scale and a short Food Frequency Questionnaire. Outcomes were stool frequency and consistency, GI symptoms and dietary intake.

RESULTS

Data were collected from 216 patients (mean age, 63 years [95% CI: 61, 65]; 63% males; CKD-ND: n = 134; HD: n = 67; PD: n = 15). Mean stool frequency for all groups was one bowel action per day (p = .45) and consistency was normal (BSFS type 4, p = .95). Overall GI symptom burden was low but several symptoms occurred at least "most of the time" including "tiredness/lethargy" (54% of participants), "reduced appetite" (29%), "early satiety" (25%) and "change in taste" (15%). Low intakes of fresh fruit, vegetables, whole-grains and legumes were found. No associations were observed between diet and GI symptoms.

CONCLUSION

The overall GI symptom burden was low, but >15% of participants reported several symptoms as occurring most to all of the time. Low intakes of fresh fruit, vegetables, whole-grains and legumes were observed in all CKD patients.

Dietary protein intake, kidney function, and survival in a nationally representative cohort

BACKGROUND

High-protein diets (e.g., Paleo, Atkins, South Beach, ketogenic) have gained popularity as a means to promote weight loss and avoid excess carbohydrate consumption. Yet in chronic kidney disease (CKD) patients, evidence suggests low dietary protein intake (DPI) leads to attenuation of kidney function decline, although concerns remain for risk of protein-energy wasting.

OBJECTIVES

To examine associations of DPI with mortality in a nationally representative cohort of US adults, stratified by kidney function.

METHODS

We examined the association between daily DPI scaled to actual body weight (ABW), ascertained by 24-h dietary recall, with all-cause mortality among 27,604 continuous NHANES adult participants (1999-2010), stratified according to impaired versus normal kidney function (estimated glomerular filtration rates <60 compared with ≥60 ml/min/1.72 m2, respectively), using multivariable Cox models. We also examined the relation between high biological value (HBV) protein consumption with mortality.

RESULTS

In participants with impaired kidney function, a high DPI of ≥1.4 g/kg ABW/day was associated with higher mortality, while lower DPI levels were not associated with mortality (reference, 0.6 to <1.0 g/kg ABW/day): the adjusted HRs (aHRs) were 1.09 (95% CI: 0.90, 1.32), 1.03 (95% CI: 0.82, 1.29), and 1.37 (95% CI: 1.02, 1.85) for DPI <0.6, 1.0 to <1.4, and ≥1.4 g/kg ABW/day, respectively. Yet in participants with normal kidney function, a low DPI of <0.6 g/kg ABW/day was associated with higher mortality, whereas higher DPI levels were not associated with death: the aHRs were 1.18 (95% CI: 1.04, 1.34), 0.92 (95% CI: 0.81, 1.04), and 0.99 (95% CI: 0.85, 1.16) for DPI <0.6, 1.0 to <1.4, and ≥1.4 g/kg ABW/day, respectively. The highest 2 tertiles of HBV consumption were associated with higher mortality in participants with impaired kidney function.

CONCLUSIONS

Among participants with impaired kidney function, a higher DPI and greater HBV consumption were associated with higher mortality, whereas a lower DPI was associated with higher mortality in those with normal kidney function. Further studies are needed to elucidate the specific pathways between higher DPI and mortality in CKD.

The International Society of Renal Nutrition and Metabolism Commentary on the National Kidney Foundation and Academy of Nutrition and Dietetics KDOQI Clinical Practice Guideline for Nutrition in Chronic Kidney Disease

The Academy of Nutrition and Dietetics and the National Kidney Foundation collaborated to provide an update to the Clinical Practice Guidelines (CPG) for nutrition in chronic kidney disease (CKD). These guidelines provide a valuable update to many aspects of the nutrition care process. They include changes in the recommendations for nutrition screening and assessment, macronutrients, and targets for electrolytes and minerals. The International Society of Renal Nutrition and Metabolism assembled a special review panel of experts and evaluated these recommendations prior to public review. As one of the highlights of the CPG, the recommended dietary protein intake range for patients with diabetic kidney disease is 0.6-0.8 g/kg/day, whereas for CKD patients without diabetes it is 0.55-0.6 g/kg/day. The International Society of Renal Nutrition and Metabolism endorses the CPG with the suggestion that clinicians may consider a more streamlined target of 0.6-0.8 g/kg/day, regardless of CKD etiology, while striving to achieve intakes closer to 0.6 g/kg/day. For implementation of these guidelines, it will be important that all stakeholders work to detect kidney disease early to ensure effective primary and secondary prevention. Once identified, patients should be referred to registered dietitians or the region-specific equivalent, for individualized medical nutrition therapy to slow the progression of CKD. As we turn our attention to the new CPG, we as the renal nutrition community should come together to strengthen the evidence base by standardizing outcomes, increasing collaboration, and funding well-designed observational studies and randomized controlled trials with nutritional and dietary interventions in patients with CKD.

Characterization of Maize Near-Isogenic Lines With Enhanced Flavonoid Expression to Be Used as Tools in Diet-Health Complexity

Increasing incidence of chronic diseases in the 21st century has emphasized the importance of developing crops with enhanced nutritional value. Plant-based diets are associated with reduced incidence of many chronic diseases. The growing population and increased food demand have prioritized the development of high-yielding commercial crop varieties at the expense of natural flavors as well as health-benefiting compounds including polyphenols. Flavonoids are a large subfamily of polyphenols abundant in the plant kingdom with known health-promoting effects, making them a promising trait to be re-introduced into elite lines. Given the vast array of flavonoids and the complexity of plant food metabolome interactions, it is difficult to identify with certainty the specific class(es) of flavonoids in the food matrix that are anti-inflammatory. To address this, we have developed four maize near-isogenic lines (NILs); a line that lacked both anthocyanins and phlobaphenes, a second NIL containing phlobaphenes, a third line had anthocyanins, and a fourth line that contained both anthocyanins and phlobaphenes. The phytochemical profiles and the antioxidant potential of the NILs were characterized. The accumulation of anthocyanins and phlobaphenes contributed significantly to antioxidant capacity compared to maize lines that lacked one or both of the compounds (p < 0.05). Pilot study showed that intake of flavonoid-rich maize diets were able to alleviate experimental colitis in mice. These NILs offer novel materials combining anthocyanins and phlobaphenes and can be used as powerful tools to investigate the disease-preventive effects of specific flavonoid compound in diet/feeding experiments.

Microbiome modulation as a novel therapeutic approach in chronic kidney disease

PURPOSE OF REVIEW

Gut dysbiosis has been implicated in the pathogenesis of chronic kidney disease (CKD). Interventions aimed at restoring gut microbiota have emerged as a potential therapeutic option in CKD. This review summarizes the current evidence on gut microbiota-targeted strategies in patients with CKD.

RECENT FINDINGS

A growing number of studies have shown that plant-based diets, low-protein diets, prebiotic, probiotic, and synbiotic supplementation, and constipation treatment may lead to favorable alterations in the gut microbiota. Current evidence suggests that the implementation of both plant-based and low-protein diets has potential benefits for the primary prevention of CKD, and for slowing CKD progression, with minimal risk of hyperkalemia and/or cachexia. The use of prebiotics, probiotics, and synbiotics and laxatives may have beneficial effects on uremic toxin generation, but their evidence is limited for the prevention and treatment of CKD. Recent advances in diagnostic technologies (e.g., high-throughput sequencing and nanotechnology) could enhance rapid diagnosis, monitoring, and design of effective therapeutic strategies for mitigating gut dysbiosis in CKD.

SUMMARY

Plant-based and low-protein diets, prebiotic, probiotic, and synbiotic supplementation, and constipation treatment represent novel gut microbiota-targeted strategies in the conservative management of CKD, which could improve clinical outcomes in CKD.

Novel conservative management of chronic kidney disease via dialysis-free interventions

PURPOSE OF REVIEW

In advanced chronic kidney disease (CKD) patients with progressive uremia, dialysis has traditionally been the dominant treatment paradigm. However, there is increasing interest in conservative and preservative management of kidney function as alternative patient-centered treatment approaches in this population.

RECENT FINDINGS

The primary objectives of conservative nondialytic management include optimization of quality of life and treating symptoms of end-stage renal disease (ESRD). Dietetic-nutritional therapy can be a cornerstone in the conservative management of CKD by reducing glomerular hyperfiltration, uremic toxin generation, metabolic acidosis, and phosphorus burden. Given the high symptom burden of advanced CKD patients, routine symptom assessment using validated tools should be an integral component of their treatment. As dialysis has variable effects in ameliorating symptoms, palliative care may be needed to manage symptoms such as pain, fatigue/lethargy, anorexia, and anxiety/depression. There are also emerging treatments that utilize intestinal (e.g., diarrhea induction, colonic dialysis, oral sorbents, gut microbiota modulation) and dermatologic pathways (e.g., perspiration reduction) to reduce uremic toxin burden.

SUMMARY

As dialysis may not confer better survival nor improved patient-centered outcomes in certain patients, conservative management is a viable treatment option in the advanced CKD population.

Dietary protein interventions to improve nutritional status in end-stage renal disease patients undergoing hemodialysis

PURPOSE OF REVIEW

Poor nutritional status is prevalent among end-stage renal disease patients undergoing hemodialysis. Chronic hemodialysis patients show an accelerated decline in skeletal muscle mass and strength, which is associated with higher mortality rates and a reduced quality of life. The current review aims to summarize recent advances regarding underlying causes of muscle loss and interventions that support muscle mass maintenance in patients with chronic hemodialysis.

RECENT FINDINGS

Muscle maintenance in chronic hemodialysis patients is compromised by low dietary protein intake levels, anabolic resistance of skeletal muscle tissue, sedentary behavior, and amino acid removal during hemodialysis. Studies assessing the effect of increased protein intake on nutritional status generally show beneficial results, especially in hypoalbuminemic chronic hemodialysis patients. The muscle protein synthetic response following protein ingestion in chronic hemodialysis patients may be enhanced through incorporation of structured physical activity and/or concurrent ketoacid ingestion.

SUMMARY

A coordinated program that combines nutritional and physical activity interventions is likely required to attenuate the decline in muscle mass and strength of chronic hemodialysis patients. Nephrologists, dieticians, and exercise specialists should collaborate closely to establish guidelines regarding the appropriate quantity and timing of protein ingestion. In addition, they should provide tailored nutritional and physical activity interventions for chronic hemodialysis patients (see video, Supplemental Digital Content 1, Video abstract, http://links.lww.com/COCN/A14).

Protein intake and renal function in older patients

PURPOSE OF REVIEW

Chronic kidney disease (CKD) is highly prevalent in elderly patients. There is growing recognition of the importance of attention to dietary protein intake (DPI) in this population given their predisposition to age-related changes in kidney function and coexisting comorbidities (i.e., hypertension). We reviewed the impact of DPI on kidney health and survival and the role of dietary protein management in older CKD patients.

RECENT FINDINGS

While kidney function parameters including glomerular filtration rate (GFR) and renal plasma flow are slightly lower in elderly patients irrespective of CKD status, the kidneys' ability to compensate for increased DPI by augmentation of GFR is preserved until 80 years of age or less. However, long-term consumption of high DPI in individuals of older age and/or with CKD may contribute to kidney function deterioration over time. Prescription of a plant-dominant low-protein diet of 0.6-0.8 g/kg/day with more than 50% from plant sources or very low protein diets less than 0.45 g/kg/day supplemented with essential amino acids or their keto-analogues may be effective in preserving kidney function in older patients and their younger counterparts, while also monitoring for development of protein-energy wasting (PEW).

SUMMARY

Using tailored precision nutrition approaches in prescribing plant-dominant low DPI that also maintains adequate energy and nitrogen balance may ameliorate kidney function decline while also preventing development of PEW in elderly patients with CKD.

Source and Composition in Amino Acid of Dietary Proteins in the Primary Prevention and Treatment of CKD

Nutrition is a cornerstone in the management of chronic kidney disease (CKD). To limit urea generation and accumulation, a global reduction in protein intake is routinely proposed. However, recent evidence has accumulated on the benefits of plant-based diets and plant-derived proteins without a clear understanding of underlying mechanisms. Particularly the roles of some amino acids (AAs) appear to be either deleterious or beneficial on the progression of CKD and its complications. This review outlines recent data on the role of a low protein intake, the plant nature of proteins, and some specific AAs actions on kidney function and metabolic disorders. We will focus on renal hemodynamics, intestinal microbiota, and the production of uremic toxins. Overall, these mechanistic effects are still poorly understood but deserve special attention to understand why low-protein diets provide clinical benefits and to find potential new therapeutic targets in CKD.

Nutritional management in patients with chronic kidney disease

The global prevalence of chronic kidney disease (CKD) is increasing with the aging of populations worldwide. As kidney function declines, the accumulation of metabolic waste products and excessive electrolytes can significantly impair the health of patients with CKD. As nutritional management of patients with CKD is thought to control uremic symptoms and provide beneficial effects on the progression of kidney dysfunction, the diet of patients with CKD should be an important consideration in their care. Many guidelines recommend limiting protein intake in these patients, as high-protein diets aggravate kidney dysfunction. Excess sodium may be associated with CKD progression and all-cause mortality and, therefore, limiting salt intake is generally recommended. Low potassium is associated with muscle weakness and hypertension, whereas high potassium is associated with cardiac arrhythmia. Therefore, recent guidelines recommend adjusting dietary potassium intake on an individual basis to maintain serum potassium levels within the normal range. Appropriate dietary calcium intake is recommended to maintain calcium balance in patients with CKD G3, G4. Given the many dietary considerations for patients with CKD, effective nutritional management is challenging. Individualized strategies are needed to ensure the best outcome for patients with CKD.

Dietary potassium and the kidney: lifesaving physiology

Potassium often has a negative connotation in Nephrology as patients with chronic kidney disease (CKD) are prone to develop hyperkalaemia. Approaches to the management of chronic hyperkalaemia include a low potassium diet or potassium binders. Yet, emerging data indicate that dietary potassium may be beneficial for patients with CKD. Epidemiological studies have shown that a higher urinary potassium excretion (as proxy for higher dietary potassium intake) is associated with lower blood pressure (BP) and lower cardiovascular risk, as well as better kidney outcomes. Considering that the composition of our current diet is characterized by a high sodium and low potassium content, increasing dietary potassium may be equally important as reducing sodium. Recent studies have revealed that dietary potassium modulates the activity of the thiazide-sensitive sodium-chloride cotransporter in the distal convoluted tubule (DCT). The DCT acts as a potassium sensor to control the delivery of sodium to the collecting duct, the potassium-secreting portion of the kidney. Physiologically, this allows immediate kaliuresis after a potassium load, and conservation of potassium during potassium deficiency. Clinically, it provides a novel explanation for the inverse relationship between dietary potassium and BP. Moreover, increasing dietary potassium intake can exert BP-independent effects on the kidney by relieving the deleterious effects of a low potassium diet (inflammation, oxidative stress and fibrosis). The aim of this comprehensive review is to link physiology with clinical medicine by proposing that the same mechanisms that allow us to excrete an acute potassium load also protect us from hypertension, cardiovascular disease and CKD.

Plant-Dominant Low-Protein Diet for Conservative Management of Chronic Kidney Disease

Chronic kidney disease (CKD) affects >10% of the adult population. Each year, approximately 120,000 Americans develop end-stage kidney disease and initiate dialysis, which is costly and associated with functional impairments, worse health-related quality of life, and high early-mortality rates, exceeding 20% in the first year. Recent declarations by the World Kidney Day and the U.S. Government Executive Order seek to implement strategies that reduce the burden of kidney failure by slowing CKD progression and controlling uremia without dialysis. Pragmatic dietary interventions may have a role in improving CKD outcomes and preventing or delaying dialysis initiation. Evidence suggests that a patient-centered plant-dominant low-protein diet (PLADO) of 0.6–0.8 g/kg/day composed of >50% plant-based sources, administered by dietitians trained in non-dialysis CKD care, is promising and consistent with the precision nutrition. The scientific premise of the PLADO stems from the observations that high protein diets with high meat intake not only result in higher cardiovascular disease risk but also higher CKD incidence and faster CKD progression due to increased intraglomerular pressure and glomerular hyperfiltration. Meat intake increases production of nitrogenous end-products, worsens uremia, and may increase the risk of constipation with resulting hyperkalemia from the typical low fiber intake. A plant-dominant, fiber-rich, low-protein diet may lead to favorable alterations in the gut microbiome, which can modulate uremic toxin generation and slow CKD progression, along with reducing cardiovascular risk. PLADO is a heart-healthy, safe, flexible, and feasible diet that could be the centerpiece of a conservative and preservative CKD-management strategy that challenges the prevailing dialysis-centered paradigm.