The Lactobacillus acidophilus probiotic effect on the il10 gene expression in Zebrafish infected with E. coli O157:H7

 Defensive barrier is important in preventing infection and disease progression caused by E.coli O157:H7. Among beneficial effects of probiotics, immune system modulation by producing cytokines is one of the most common reported benefits. The aim of this study was to investigate the Lactobacillus acidophilus probiotic effect on il10 cytokine gene expression in Zebrafish infected with E. coli O157:H7 as a laboratory model.

 The 300 pieces of fish were grouped equally; control group (C1A1) received basic diet, group (B1A1) received basic diet and faced E.coli O157:H7, treatment 1 group (T1A1) received basic diet containing L. acidophilus and no exposure to E. coli O157:H7, treatment 2 group (T2A2) received basic diet containing L. acidophilus and exposed to E. coli O157:H7. During the 30-day period of testing, intestinal tissue samples were taken on days 15, 27 and 30 for il10 gene expression and bacterial colonization studies.

 The findings indicated bacterial colonization in fish intestines. Also, the expression of il10 gene in the experimental groups decreased after exposure to E. coli O157:H7 (P<0.01). This decrement was less with the regulation of il10 in the groups fed with L. acidophilus compared to the control group. In Zebrafish fed with L. acidophilus, the expression of the il10 gene increased gradually (day15, day27 and 30; P<0. 01).

 Overall, the results showed that the L. acidophilus was able to increase il10 gene expression, boost the immune system in Zebrafish as a laboratory model. Therefore, L. acidophilus La5 probiotic can be used as a possible useful candidate against E. coli O157:H7.