Materials and Methods: Thirty-Two adult Wistar male rats aging 2.5 to 3 months divided to four groups of 8 rats. Enterotoxigenic E. coli (serotype 0114) used to infect the rats. Onions prepared from the district Ilkhichi, Iran which were used for two groups. Following the infection, pathologic samples were prepared from the tissue of the sperms which were investigated through hematoxylin & eosin (H & E) staining. In addition, the motility, vitality, the number of sperms, total antioxidant capacity (TAC), luteinizing hormone (LH), and testosterone were evaluated as well.

Results: Results indicated that in the control group all the seminiferous tubules are sticking together and all the lines of sexual germ cells observed;while, in E. coli group were disunited and the line of sexual cells were destroyed. In the groups infected by E. coli and treated by A. cepa juice, the effects of bacteria reduced considerably. The number of sperms, sperms vitality and motility decreased significantly in E. coli infected group, while in the A. cepa juice + E.coli the effects of infectious was reduced. The results of the study showed that A. cepa juice significantly increases TAC and testosterone.

Conclusion: The results indicated A. cepa juice has protective effects against E .coli bacteria and fertility, testis tissue and antioxidants improvement and the effects of the bacteria decreased significantly.