Promoting Health in Individuals With End-Stage Renal Disease: Diet, Physical Activity, and Gastrointestinal Microbiota

Introduction Individuals with end-stage renal disease (ESRD) experience multiple symptoms and low quality of life related to the disease itself, comorbid conditions, and treatment they receive, such as renal replacement therapy, which is necessary to sustain life (Kwok, Yuen, Yong, & Tse, 2015). Although the precise mechanism of its contributions is unclear, there is burgeoning evidence that gastrointestinal (GI) microbiota may regulate inflammatory pathways, glucose metabolism and cardiovascular functions that are main contributing factors to kidney health and disease (Clemente, Ursell, Parfrey, & Knight, 2012; Sommer & Bäckhed, 2013; Tremaroli & Bäckhed, 2012). Studies have revealed profound alterations of the GI microbiota in individuals with ESRD. For example, Individuals with ESRD with uremia exhibited increased abundance of families from phyla Actinobacteria, Firmicutes (Clostridia) and Proteobacteria (Gammaproteobacteria and Enterobacteria) and decreased Bifidobacteria and families Bacteroidaceae and Lactobacillaceae (Hida et al., 1996; Vaziri et al., 2013). While therapeutic interventions such as physical activity (Heiwe & Jacobson, 2014; Howden, Coombes, & Isbel, 2015; Painter & Roshanravan, 2013) or dietary nutrition (Kalantar-zadeh et al., 2015), have been reported to influence the GI microbial community (Cerdá et al., 2016; David et al., 2014; Power, O’Toole, Stanton, Ross, & Fitzgerald, 2014; Wilck et al., 2014), the associations between dietary intake and GI microbiota as well as between physical activity and GI microbiota in individuals with ESRD are understudied. Therefore, the purpose of this analysis is to characterize the associations between dietary nutrients and GI microbiota as well as between physical activity and GI microbiota in individuals with ESRD.

Methods A cross-sectional study was conducted on 20 individuals with ESRD who were recruited from a local dialysis clinic during the month of April and May 2018. Individuals included in the study were English speaking, aged 18 years and above, receiving hemodialysis, and experiencing 2 or more kidney disease related symptoms. To promote homogeneity of the study sample, individuals receiving peritoneal dialysis, had kidney transplantation, have a diagnosed gastrointestinal illness such as inflammatory bowel disease, or had received antibiotics or probiotics in the prior 3 months were excluded. Dietary intake was measured with Block 2000-Brief FFQ (NutritionQuest, Berkeley, California), an electronic self-report questionnaire that provides estimates of dietary intake of approximately 125 food items over the past year(McGowan, Curran, & McAuliffe, 2014). Physical activity was measured using the International Physical Activity Questionnaire short form (IPAQ-SF), a 7-item questionnaire that surveys physical activity over the 'last seven-day' period to estimate the level of physical activity (Craig et al., 2003). GI microbiota was measured in stool specimens. The microbial composition and abundance were identified through 16S ribosomal RNA (rRNA) sequencing, a culture-independent gene sequencing method that enables analysis of the entire microbial community within a sample. Descriptive statistics will be used to characterize the variables. A heat map summarizing Spearman correlations (where the degree of association is signified with the intensity of the colors) will be used to inform the associations between nutrients from the FFQ and GI microbiota and between the level of physical activity and GI microbiota.

Results Participants who completed the study (N=19) had a mean age of 61.8 years, with evenly distributed activity levels of high 31.6% (n=6), moderate 36.8% (n=7), and low 31.6% (n=6). Most of the participants were Caucasian (73.7%) and male (75%). Associations between diet and GI microbiota as well as between physical activity and GI microbiota will be reported in a heat map. (Results will be available for the conference.)

Conclusion The basic knowledge gained from this study allows nurses to consider the potential influence of diet and physical activity on the kidney health and disease through the mediating roles of the GI microbiota, such as regulation of inflammatory pathways, glucose metabolism, and cardiovascular functions. Further studies will provide evidence necessary to inform future practice ultimately aimed at improving health and wellness in individuals living with ESRD.