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The Benefits of Fiber in Chronic Kidney Disease

  • Heather Lochmann
    Correspondence
    Address correspondence to Heather Lochmann, MS, RD, LD, Renal Dietitian at Strive Health, 1600 Stout St, Denver, Colorado 80202.
    Affiliations
    Renal Dietitian at Strive Health, Academy of Nutrition and Dietetics Renal Practice Group's committee for Patient Education, Denver, Colorado
    Search for articles by this author
      Patients who have chronic kidney disease (CKD) represent 1 in 7 adults living in the United States. The incidence is growing as 1 in 3 adults are at risk for developing CKD.
      Kidney disease: the Basics. Natl Kidney Found.
      Nutrition can impact the leading risk factors, diabetes and hypertension, and slow the progression of CKD and improve metabolic markers of health.
      Kidney disease: the Basics. Natl Kidney Found.
      ,
      • Ranganathan N.
      • Anteyi E.
      The Role of dietary fiber and gut Microbiome Modulation in progression of chronic kidney disease.
      Medical nutrition therapy previously focused on limiting fruits, vegetables, legumes, nuts, seeds, and whole grains because they are high in potassium and phosphorus. Research has shown these foods have a lower bioavailability for absorption and offer more nutritional benefits than the items people may use in place of them.
      The 2020 Clinical Practice Guidelines for Nutrition in CKD recommend consuming these natural sources of fiber to aid in satiety, reduce acid load, and help control blood pressure.
      • Ranganathan N.
      • Anteyi E.
      The Role of dietary fiber and gut Microbiome Modulation in progression of chronic kidney disease.
      The National Kidney Foundation recommends the Dietary Approaches to Stop Hypertension (DASH) diet to improve blood pressure, heart disease, and slow the progression of kidney disease. The DASH diet incorporates at least 4 to 5 servings of fruits and vegetables daily; use of whole grains; lean proteins like poultry, fish, and beans; and nuts, seeds, and low-fat dairy.
      The DASH diet
      National kidney Foundation.
      An increase in foods naturally containing fiber has numerous benefits for patients with CKD.
      • Ikee R.
      • Yano K.
      • Tsuru T.
      Constipation in chronic kidney disease: it is time to reconsider.
      These advantages range from reducing progression of CKD, improving gut microbiota, blood pressure, lipid panel, glucose control, satiety for weight reduction, bowel regularity, and reducing risk of colon cancer.
      The DASH diet
      National kidney Foundation.
      ,
      • Ikee R.
      • Yano K.
      • Tsuru T.
      Constipation in chronic kidney disease: it is time to reconsider.
      The recommended daily intake of fiber is 14 g per 1,000 kilocalories which equates to at least 20-25 g for women and 30-38 g for men.
      • Ikee R.
      • Yano K.
      • Tsuru T.
      Constipation in chronic kidney disease: it is time to reconsider.
      Patients with CKD have been noted to only consume up to 12 g of fiber per day and there is a high prevalence of constipation which may be due to a lack of fiber, use of iron supplements, lack of physical activity, decreased intestinal motility, and polypharmacy.
      • Ikee R.
      • Yano K.
      • Tsuru T.
      Constipation in chronic kidney disease: it is time to reconsider.
      ,
      • Lohia S.
      • Vlahou A.
      • Zoidakis J.
      Microbiome in chronic kidney disease (CKD): an Omics Perspective.
      Fiber contains components that the body is unable to digest in the small intestine which are used by the gut bacteria to perform either saccharolytic or proteolytic fermentation.
      • Ikee R.
      • Yano K.
      • Tsuru T.
      Constipation in chronic kidney disease: it is time to reconsider.
      ,
      • Lohia S.
      • Vlahou A.
      • Zoidakis J.
      Microbiome in chronic kidney disease (CKD): an Omics Perspective.
      The saccharolytic process results in beneficial short-chain fatty acids, while the proteolytic produces ammonia, amines, and other products that can become uremic toxins.
      • Ranganathan N.
      • Anteyi E.
      The Role of dietary fiber and gut Microbiome Modulation in progression of chronic kidney disease.
      ,
      • Ikee R.
      • Yano K.
      • Tsuru T.
      Constipation in chronic kidney disease: it is time to reconsider.
      ,
      • Lohia S.
      • Vlahou A.
      • Zoidakis J.
      Microbiome in chronic kidney disease (CKD): an Omics Perspective.
      In gut dysbiosis, there are less bacteria that can produce the healthier end products and higher concentration of the bacteria whose fermentation results in toxin precursors. The latter of these yields end products that can promote proinflammatory processes, oxidative stress, and reduced epithelial layer which leads to transit of endotoxins and fibrosis in the kidney.
      • Ikee R.
      • Yano K.
      • Tsuru T.
      Constipation in chronic kidney disease: it is time to reconsider.
      • Lohia S.
      • Vlahou A.
      • Zoidakis J.
      Microbiome in chronic kidney disease (CKD): an Omics Perspective.
      • Ikee R.
      • Saski N.
      • Yasuda T.
      • Fukazawa S.
      Chronic kidney disease, gut dysbiosis, and constipation: a burdensome Triplet.
      Animal research has suggested that proteolytic-derived uremic toxins may promote vascular calcification and insulin resistance.
      • Lohia S.
      • Vlahou A.
      • Zoidakis J.
      Microbiome in chronic kidney disease (CKD): an Omics Perspective.
      Patients with CKD have increased urea within their systemic fluids which results in a large flow into the intestine. The urea is converted to ammonia and then to ammonium hydroxide producing an increase in pH resulting in lumen that is less inhabitable for beneficial bacteria and impair the intestinal barrier.
      • Ikee R.
      • Saski N.
      • Yasuda T.
      • Fukazawa S.
      Chronic kidney disease, gut dysbiosis, and constipation: a burdensome Triplet.
      Research has found that CKD-associated gut dysbiosis can decrease intestinal transit likely due to inflammation in the gastrointestinal tract, the increased production of uremic toxins within the gut, and compromised integrity of the intestinal barrier.
      • Ikee R.
      • Yano K.
      • Tsuru T.
      Constipation in chronic kidney disease: it is time to reconsider.
      • Lohia S.
      • Vlahou A.
      • Zoidakis J.
      Microbiome in chronic kidney disease (CKD): an Omics Perspective.
      • Ikee R.
      • Saski N.
      • Yasuda T.
      • Fukazawa S.
      Chronic kidney disease, gut dysbiosis, and constipation: a burdensome Triplet.
      • Ramos C.I.
      • Nerbass F.B.
      • Cuppari L.
      Constipation in chronic kidney disease: it is time to Bridge the Gap.
      • Su G.
      • Qin X.
      • Yang C.
      • et al.
      Fiber intake and health in people with chronic kidney disease.
      One study transplanted fresh fecal microbes from a patient living with end-stage renal disease to mice with CKD and found it resulted in an increased production of uremic toxins, oxidative stress, and fibrosis of the kidney compared to the control group who did not receive fecal transplantation.
      • Lohia S.
      • Vlahou A.
      • Zoidakis J.
      Microbiome in chronic kidney disease (CKD): an Omics Perspective.
      Increasing fiber intake provides indigestible starch which can improve growth of helpful bacteria and stimulate motility, maintain integrity of intestinal barrier, increase renal function as noted in histopathology of the kidney, and reduce inflammation and oxidation.
      • Ranganathan N.
      • Anteyi E.
      The Role of dietary fiber and gut Microbiome Modulation in progression of chronic kidney disease.
      ,
      • Lohia S.
      • Vlahou A.
      • Zoidakis J.
      Microbiome in chronic kidney disease (CKD): an Omics Perspective.
      ,
      • Ikee R.
      • Saski N.
      • Yasuda T.
      • Fukazawa S.
      Chronic kidney disease, gut dysbiosis, and constipation: a burdensome Triplet.
      ,
      • Su G.
      • Qin X.
      • Yang C.
      • et al.
      Fiber intake and health in people with chronic kidney disease.
      The National Health and Nutrition Examination Survey III observed that participants with CKD who increased their total daily fiber consumption, by 10 g/day, experienced a 38% reduction in the likelihood of C-reactive protein being elevated.
      • Su G.
      • Qin X.
      • Yang C.
      • et al.
      Fiber intake and health in people with chronic kidney disease.
      Dietary consumption of complex carbohydrates may also improve fermentation, which can increase acid creation and reduce the intestinal pH, therefore creating an environment more conducive to beneficial bacteria.
      • Ikee R.
      • Saski N.
      • Yasuda T.
      • Fukazawa S.
      Chronic kidney disease, gut dysbiosis, and constipation: a burdensome Triplet.
      Large observational studies have also shown participants with the highest fiber intakes had a 40%-50% reduction in occurrence of CKD. Other research conducted in a population of more than 1,600 subjects noted that for each 5 g/day increase in fiber there was 11% less risk of CKD.
      • Su G.
      • Qin X.
      • Yang C.
      • et al.
      Fiber intake and health in people with chronic kidney disease.
      A meta-analysis of several studies including more than 15,000 patients with CKD noted healthy eating consisting of fruits, vegetables, and whole grains was regularly associated with a less risk of all-cause mortality.
      • Su G.
      • Qin X.
      • Yang C.
      • et al.
      Fiber intake and health in people with chronic kidney disease.

      Acknowledgments

      Thank you to Jennifer Martin, RD, LD.

      References

      1. Kidney disease: the Basics. Natl Kidney Found.
        https://www.kidney.org/news/newsroom/fsindex
        Date: 2021
        Date accessed: May 14, 2022
        • Ranganathan N.
        • Anteyi E.
        The Role of dietary fiber and gut Microbiome Modulation in progression of chronic kidney disease.
        Toxins. 2022; 14: 183-194
        • The DASH diet
        National kidney Foundation.
        • Ikee R.
        • Yano K.
        • Tsuru T.
        Constipation in chronic kidney disease: it is time to reconsider.
        Ren Replace Ther. 2019; 5
        • Lohia S.
        • Vlahou A.
        • Zoidakis J.
        Microbiome in chronic kidney disease (CKD): an Omics Perspective.
        Toxins. 2022; 14: 176-196
        • Ikee R.
        • Saski N.
        • Yasuda T.
        • Fukazawa S.
        Chronic kidney disease, gut dysbiosis, and constipation: a burdensome Triplet.
        Microorganisms. 2020; 8: 1862-1880
        • Ramos C.I.
        • Nerbass F.B.
        • Cuppari L.
        Constipation in chronic kidney disease: it is time to Bridge the Gap.
        Kidney Dial. 2022; 2: 221-233
        • Su G.
        • Qin X.
        • Yang C.
        • et al.
        Fiber intake and health in people with chronic kidney disease.
        Clin Kidney J. 2021; 15: 213-225