Evaluation of the Probiotic Effect of Bifido Bacterium Bifidum on Hippocampal Neuronal Density in Alzheimer's Rats

Memory and learning are the most important behavioral processes that occur at the highest functional levels of the central nervous system. On the other hand, probiotics are living microorganisms that, if used adequately, can improve host health. Therefore, the aim of the present study was to evaluate the effect of the probiotic Bifido bacterium bifidum on the neuronal density of the hippocampus in Alzheimer's rats.

In the current experimental study, 30 male Wistar rats, weighing about 200 to 250 g, were prepared and randomly divided into 5 control groups, Alzheimer's, and 3 treatment groups. To induce Alzheimer's disease, streptozotocin was injected at a dose of 5 mg/kg with a volume of 5 μl in each lateral ventricle of mice via stereotaxic method. In the treatment groups, probiotics were injected intraperitoneally with doses of 10-6, 10-7, and 10-8 ml/CFU, simultaneously with STZ injection for 21 days. After 21 days, the rats treated with rampon and ketamine were anesthetized and after perfusion method, the brain was removed from the skull and placed in 10% saline formalin. After tissue passage, seven-micron sections were prepared from the brain and stained with toluidine blue and erythrosine. CA1, CA2, and CA3 DG regions were imaged and neuronal density was calculated using a dissector and stereology method and the results of the groups were compared using ANOVA test.

The results showed that in the groups treated with the probiotic Bifido bacterium bifidum in all regions of the hippocampus, neuronal density increased compared to the Alzheimer's group (significant p <0.001).

Therefore, the probiotic Bifido bacterium bifidum with its anti-inflammatory and antioxidant effects could prevent lesions of the nervous system