• Investigating the effect of azithromycin on intestinal microbiome and memory in male Wistar rats
  • ali abdoli,1,* Nilufar Darbandi,2 Majid Kamijani,3
    1. Biology Department, Faculty of Basic Sciences, Arak University
    2. Biology Department, Faculty of Basic Sciences, Arak University
    3. Biology Department, Faculty of Basic Sciences, Arak University


  • Introduction: The covid-19 pandemic caused by the acute respiratory syndrome coronavirus (SARS-CoV-2) has affected millions of people around the world.Respiratory viral infections make patients susceptible to other infections and lead to increased mortality.The meta-analysis showed that the antibiotic azithromycin was prescribed the most to prevent and deal with secondary infections in patients with Covid-19.Despite the beneficial effects of antibiotics in preventing the growth of pathogenic bacteria and causing disease, these compounds can have adverse effects on the intestinal microbiome and change the intestinal bacterial population.New research suggests that there is a complex two-way relationship between the gut microbiome and the host that plays a role in human health as well as in disease pathogenesis. Changes in the composition and function of gut microbiota can affect gut permeability, digestion, metabolism, immune responses, and memory and learning. Based on this, in the present study, the effect of the antibiotic azithromycin on the gut microbiome and memory recall was investigated.
  • Methods: In this experimental study, adult male Wistar rats weighing 220-250 grams were divided into control and antibiotic groups.In the control group, normal saline (0.6 ml) and in the antibiotic treatment group, azithromycin (15 mg/rat with a volume of 0.6 ml) was gavage daily for 7 days.In order to investigate the effect of azithromycin on the intestinal microbiome, in both groups of the PCR test (to identify and investigate three bacterial species:Enterococcus faecalis and Lactobacillus acidophilus and E.coli) And stool culture was used before and after treatment.At the end of the treatment, the memory was evaluated with the help of the passive avoidance test and the new object recognition test and motor activity was checked by the locomotion device.
  • Results: In the passive avoidance test, azithromycin gavage significantly reduced memory recall compared to the control group (P<0.001).In the new object recognition test, a significant difference was seen in the memory evaluation between the control group and the experimental group (P<0.05). Examining motor activity did not show any significant difference between the control and azithromycin groups (P>0.05). Stool culture and comparing the number of bacterial colonies before treatment in both groups showed a significant difference. It did not show any difference between the control group and the azithromycin group (P>0.05), but stool culture and counting of bacterial colonies after treatment showed a significant decrease in the number of bacterial colonies in the group receiving azithromycin compared to the control group. (P<0.05).Also, by conducting PCR test, it was found that the antibiotic azithromycin caused the destruction of two species (Enterococcus faecalis and Lactobacillus acidophilus) out of the three bacterial species studied in the test. ‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬
  • Conclusion: The results of this research show that the use of the antibiotic azithromycin with its effect on the gut microbiome leads to the destruction of beneficial bacterial species and probably in this way it can have a destructive effect on memory and learning.
  • Keywords: Azithromycin antibiotic, Covid-19, memory, gut microbiome, rat