Combined effect of prebiotic and probiotic strains restores cognitive impairment via attenuating synaptosis in the hippocampus of mice fed with high fat diet and streptozotocin diabetes‐induced dementia

AbstractBackgroundDementia is known as neurodegenerative disease which causes decline in the cognitive domains of memory and thinking, leading to memory loss of an individual especially the aged. Diabetes mellitus causes brain structure changes and cognitive decline, and it has been estimated that diabetes doubles the risk for dementia. Probiotics combined with prebiotics on the other hand, seem to have a positive effect and reverse memory lossMethodThis study employed ninety (90) male bulb/c albino mice weighing between 25 and 28 grams (n = 15). Animals were housed in plastic cages at room temperature under good hygienic conditions, had free access to animal pellets and water ad libitum. Mice were fed with a high fat diet to imitate obesity after which Diabetes was induced by one administration of STZ (50 mg/kg, IP) freshly dissolved in citrate buffer following an overnight fasting on 22nd day. Probiotic strains and Prebiotics were administered with prepared suspension containing 107 and 109 CFU/ml of probiotics and prebiotics (3mg and 5 mg) body weight orally for pretreatment and posttreatment after streptozotocin induction.ResultResults from this study shown that there was a significant decrease in glucose levels of animals treated with probiotics and prebiotics combined supplementation in both pretreatment (HFDS +109 CFU/ml + 5 mg) and post‐treatment group (HFDS +109 CFU/ml + 5 mg) with insulin resistance. AChE levels significantly reduced at the combined probiotics and prebiotics pretreatment (HFDS +109 CFU/ml + 5 mg) and post‐treatment group (HFDS +109 CFU/ml + 5 mg). With relation to BDNF gene expression analysis, combined probiotics and prebiotics showed high expression of the BDNF gene in the combined probiotics and prebiotics pretreatment (HFDS +109 CFU/ml + 5 mg) and post‐treatment group (HFDS +109 CFU/ml + 5 mg). Administration of combined probiotics and prebiotics improved memory and learning, insulin resistance, animal weight, glucose levels and BDNF expression.ConclusionCombined probiotics and prebiotics demonstrated neuroprotective and anti‐neuroinflammatory activity in the experimental animals and was able to attenuate synaptosis and promote synaptogenesis in diabetic mice which started receiving treatment. The combined supplementation also restores cognitive impairment and memory function.