Diet Quality Components and Gut Microbiota of Patients on Peritoneal Dialysis.

Objectives: To evaluate the associations between the quality of the diet and its components and microbial diversity and composition in peritoneal dialysis (PD) patients.

Design and methods: This cross-sectional study included PD patients for at least 3 months, aged 18-75 years and clinically stable. The Diet Quality Index (DQI), validated for the Brazilian population, is based on the energy density of 11 components ("sugar and sweets;" "beef, pork, and processed meat;" "refined grains and breads;" "animal fat;" "poultry, fish, and eggs;" "whole cereals, tubers, and roots;" "fruits"; "nonstarch vegetables;" "legumes and nuts;" "milk and dairy products;" and "vegetable oil"). A proportional score-based on the adequacy of the intake to Brazilian dietary guidelines-is calculated, and a final score ranged from 0 (worse) to 100 (better) is obtained. Fecal samples were collected at home, in a sterile material, kept refrigerated, and delivered to the clinic within 12 hours; α-diversity indices (Observed operational taxonomic units, Chao-1, Shannon's, Gini-Simpson's, Pielou eveness, and Faith phylogenetics) and microbial profile were determined by 16S ribosomal DNA with polymerase chain reaction-amplification and sequenced on an Illumina MiSeq platform.

Results: Forty-three participants were included (53.5% men, 52.4 ± 14.1 years, body mass index: 25.9 ± 4.1 kg/m², 30.2% had diabetes mellitus). DQI score was 50.5 (41.9-54.9). The lowest energy density was for the components "animal fat" and "whole cereals and breads, tubers, and roots," and the highest were for "refined grains and bread" and "beef, pork, and processed meat." Diversity indices and Enterorhabdus genus were directly associated with the energy density of the components "whole cereals and breads, tubers, and roots" and inversely with "refined grains and bread," after adjustments for age and diabetes.

Conclusions: Even low, the intake of whole cereals, tubers, and roots has the potential to positively influence the microbiota profile in PD patients.