Protection with Electrolyzed Reduced Water on Gut Microbiota in Rats Exposed to Permethrin during Postnatal Development

Objectives: Electrolyzed reduced water (ERW) is a functional drinking water with antioxidant activity due to its negative oxidation reduction potential (ORP = –300 mV) that release electrons by hydrogen (400 ppb). Here, the effect of ERW was investigated in an animal model developing neurodegenerative disease after exposure to permethrin pesticide (PERM) in early life. In particular, the impact of ERW on gut microbiota and permeability was studied. Methods: Rats were treated in early life with permethrin (PERM), vehicle (control), PERM + ERW. At adolescent age (60 days old), feces of rats were collected and submitted to microbiota identification by 16S rRNA gene-amplification (MiSeq Illumina). In addition, fecal short chain fatty acids (SCFA) were measured by GC. In order to measure intestinal barrier permeability, rats were gavaged with a permeability tracer, FITC-dextran 4 Da (500 mg/kg) and 2 h later, blood was withdrawn. Results: PERM group showed an increase of intestinal permeability, a lower abundance of bacterial species and changes of bacterial composition in the feces compared to CONTROL group. The co-treatment with electrolyzed reduced water could not prevent at all the abnormal intestinal permeability induced by PERM but could attenuate the leakiness of the intestinal barrier. Gut microbiota analysis shows that the co-treatment with ERW was effective to increase the bacterial diversity. Higher diversity in bacterial OTUs is advantageous because there are less dominant species who monopolize most of the resources at the expense of the others. Analyzing the composition of bacteria phyla, we observed that ERW increased Firmicutes (55.33%) at the expense of Bacteroides (43.06%), whereas CONTROL and PERM groups did not differ from each other. The co-treatment with ERW was effective to prevent the negative effect of PERM by increasing the abundance of many members of the Lachnospiraceae family. ERW had a positive effect on fecal metabolites with respect to CONTROL group. Conclusion: ERW is an alkaline (pH = 9) and hydrogen molecule-rich water with ROS-scavenging activity. A moderate consumption of alkaline water predisposes to bowel reducing environment promoting the growth of Lachnospiraceae family. These bacteria family have been associated with a low grade intestinal inflammation state which prevents gut barrier alteration and disease development.