The Effects of High-Salt Gastric Intake on the Composition of the Intestinal Microbiota in Wistar Rats

BACKGROUND A high-salt diet may result in chronic disease and changes in the intestinal microbiota. This pilot study aimed to investigate the microbial composition of the intestine in Wistar rats given intragastric high-salt infusions for four weeks. MATERIAL AND METHODS Six 4-week-old male Wistar rats were fed standard chow and divided into the high-salt group (n=3) and the control study group (n=3). Rats in the high-salt group were given 1 ml of 10% NaCl solution intragastrically three times per week for four weeks. The fecal pellets were collected, and the microbiota was characterized using 16S rRNA gene sequencing that targeted the V4 region. The relative abundance of microbial populations was compared using linear discriminant analysis effect size (LEfSe) statistical analysis for the identification of biomarkers between two or more groups, principal component analysis (PCA), and linear discriminant analysis (LDA). Microbial genome prediction was performed using the phylogenetic investigation of communities by reconstructing the unobserved states (PICRUSt) bioinformatics software. RESULTS There was no significant difference in the alpha diversity of the fecal microbiota between the high-salt group and the control group. However, PCA showed structural segregation between the two groups. Further analysis using LEfSe showed that the intestinal contents in the high-salt group had significantly reduced populations of Lactobacillus and Prevotella NK3B31, and a significant increase in Alloprevotella and Prevotella 9, without physiological or pathological changes. CONCLUSIONS A pilot study in Wistar rats showed that high-salt intake was associated with a change in the composition of the intestinal microbiota.