Microbiota-friendly diet ameliorates hypoalbuminemia in chronic kidney disease: evidence from NHANES

Abstract

Chronic kidney disease (CKD) is a global health issue, affecting approximately 10% of the population. Hypoalbuminemia, a common complication in advanced CKD, is associated with poor prognosis. This study aimed to investigate the association between a microbiota-friendly dietary scoring system (Dietary Index for Gut Microbiota, DI-GM) and serum albumin levels in patients with CKD. We utilized a cross-sectional cohort from the NHANES 2007-2018, which included 2,947 CKD patients. Multivariable logistic regression and restricted cubic spline models were applied to analyze the relationship between DI-GM scores and serum albumin. Higher DI-GM scores were significantly associated with increased serum albumin levels (β = 0.18 g/L, 95% CI: 0.07-0.28, p = 0.002). Furthermore, each 1-point increase in DI-GM score was linked to a 15% reduction in the odds of hypoalbuminemia (OR: 0.85, 95% CI: 0.74-0.97, p = 0.014). The findings suggest that a high DI-GM diet may have beneficial effects in managing hypoalbuminemia in CKD patients by modulating gut microbiota composition and reducing inflammation. This diet pattern could be a promising dietary intervention for improving clinical outcomes in CKD patients, especially those at risk for malnutrition and inflammation.

Keywords: CKD; dietary index for gut microbiota; dietary pattern; hypoalbuminemia; serum albumin.

Figure 1

Study Population and flowchart. #: Diagnosis of chronic kidney disease (CKD): estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m² or urinary albumin-to-creatinine ratio (UACR) ≥30 mg/g. Complete and reliable dietary intake data for calculating DI-GM. *Abnormal dietary records: <800 kcal/day or >4000 kcal/day for men; <500 kcal/day or >3500 kcal/day for women.

Figure 2

The Relationship Between Dietary Index for Gut Microbiota (DI-GM) and Refined Grains Intake with Serum Albumin Levels in CKD Patients Using Restricted Cubic Splines (RCS). DI-GM and Serum Albumin Levels: An RCS analysis revealed a nonlinear relationship (p = 0.004). Serum albumin levels significantly increase as the DI-GM score exceeds 5. Refined Grain Intake and Serum Albumin Levels: An RCS analysis showed a nonlinear relationship (p = 0.013). At approximately 5.28 oz. eq. of refined grains per day, albumin levels remain stable. However, intake beyond this point is associated with a decrease in serum albumin levels.

Figure 3

Subgroup Analysis of the relationship Between Dietary Index for Gut Microbiota (DI-GM), daily refined grain intake (oz.eq.) and Serum Albumin Levels in CKD Patients (A, B). The positive association between DI-GM and serum albumin levels was consistent across most subgroups, with stronger effects observed in males, smokers, individuals with lower BMI, and those with diabetes. The significant interaction by smoking status suggests that smoking may modify the relationship between DI-GM and serum albumin (A). Additionally, refined grain intake is consistently associated with lower serum albumin levels across most subgroups (B).