J STANFORD1,2, K CHARLTON1,2, A STEFOSKA-NEEDHAM1,2, H ZHENG3, L BIRD4, A BORST1, A FULLER1, K LAMBERT1,2
1 School of Medicine, Faculty of Science, Medicine and Health, University of Wollongong, Wollongong, Australia, 2Illawarra Health & Medical Research Institute, Wollongong, Australia, 3Microbiome Medicine Center, Division of Laboratory Medicine, Zhujiang Hospital, Southern Medical University, Guangzhou, China, 4Wollongong Hospital, Illawarra Shoalhaven Local Health District., Wollongong, Australia
Aim: To investigate associations between diet quality, serum uremic toxin concentrations and the gut microbiota profile in adults undertaking hemodialysis therapy.
Background: Diet plays a major role in modulating the composition and metabolic activity of the human gut microbiota. Plant-based diets have received increased attention for individuals with chronic kidney disease. However, not all plant foods are necessarily beneficial for health.
Methods: This is a cross-sectional analysis of baseline data from a clinical trial involving adults receiving hemodialysis therapy. Two methods were used for diet quality assessment: (i) using three plant-based diet indices—an overall plant-based diet index (PDI), a healthy PDI, and an unhealthy PDI— and (ii) classification of food group intake. Gut microbiota composition was established through sequencing the 16S rRNA gene in stool samples. Ultra-performance liquid chromatography was performed to determine serum uremic toxins (p-cresyl sulfate (pCS) and indoxyl sulfate (IS); free and total) levels.
Results: Data from twenty-two subjects were included in the final analysis. Higher adherence to the unhealthy PDI was associated with increases in both free and total IS levels, independent of dialysis adequacy, urinary output and blood albumin levels. Higher adherence to the PDI was negatively associated with relative abundance of Haemophilus parainfluenza that was related to elevated total IS levels. The consumption of food items considered unhealthy, like animal fats, sweets and desserts were associated with bacteria linked to higher IS and pCS (total and free) concentrations.
Conclusions: The quality of diet and food selections may influence uremic toxin generation via the gut microbiota in adults receiving hemodialysis. However, well-designed dietary intervention trials are still needed to establish causality.
Ms Stanford is a PhD scholar at the University of Wollongong. She is an Accredited Practising Dietitian and graduated with first class honours in Nutrition and Dietetics. She has a broad range of experience in nutrition and health service delivery research as well as having worked in clinical health, public health and private industry settings. Jordan is currently investigating nutrition-based therapies and the human microbiome in adults with chronic kidney disease designed to elicit beneficial gut microbiome alterations and improved clinical outcomes.