Dietary Fiber Intake (Supplemental or Dietary Pattern Rich in Fiber) and Diabetic Kidney Disease: A Systematic Review of Clinical Trials

Abstract

Fiber intake is associated with better glycemic control being an important nonpharmacologicaltreatment for diabetes (DM). We hypothesize that a dietary fiber intake can bringbenefits to diabetic kidney disease (DKD), improving renal outcomes. This systematic review aimedto evaluate the effect of dietary fiber (supplemental or dietary pattern rich in fiber) on DKD. Wesearched six databases to identify clinical trials that reported fiber intake and renal outcomes(albuminuria, proteinuria, estimated glomerular filtration rate (eGFR) dialysis) in patients with DM.From 1814 studies, 48 papers were fully evaluated. In the end, seven trials (161 patients, aged 58.3years, 49% females) were included. The studies were organized into three categories (vegetarian,Dietary Approaches to Stop Hypertension (DASH) diet, and fiber supplement), two evaluatedsupplements and five dietary patterns. Vegetarian diet reduced albuminuria in three trials, two inpatients with type 1 DM and one in patients with type 2 DM; and one study demonstrated a change inthe eGFR in type 1 DM. The individual quality of the studies was low/uncertain. A vegetarian dietarypattern may have a beneficial effect on these renal outcomes. However, the individual effect of theintake of fiber on DKD not was possible to be evaluated.

Dietary Fiber and Gut Microbiota in Renal Diets

“…A recent review analyzed the role of dietary fiber in diabetic kidney disease [45]. Starting from 1814 studies, 48 articles were evaluated, and due to lack of dietary or renal outcome information, only seven clinical trials were included.…”

“…A vegetarian diet showed a beneficial effect on renal outcomes, but the individual effect of fiber intake could not be evaluated. Limitation for the small numbers of studies, for the short term follow-up, and for the amount of fiber, which was lower than recommended by most guidelines, led to the conclusion that further investigation is needed to deliver evidence that is currently still limited [45].…”

Empfehlungen zur Ernährung von Personen mit Typ-1-Diabetes mellitus

“…Es sind Glukoseanstiege nach fett-und eiweißreichen Lebensmitteln festzustellen, allerdings muss die Menge der Insulindosierung individuell ermittelt und geschult werden. [38]. Als positives Outcome einer höheren Ballaststoffzufuhr werden bei T1Dm ein verminderter Blutdruck [39] und eine geringere inflammatorische Last genannt [40].…”

Nutritional Recommendations for People with Type 1 Diabetes Mellitus

“…Although many studies have been designed for type 2 diabetes, there is often no explicit differentiation between diabetes types, although there are certain aspects that require separate consideration [37]. In later life, for example, the study situation for high-fiber diets (DASH diet, vegetarian, vegan) is inconsistent regarding, e. g., renal endpoints, but there is a small indication to the benefits of vegetarian diets in a systematic review [38]. Lower blood pressure [39] and a lower inflammatory load are positive outcomes of higher dietary fiber intake in T1Dm [40].…”