Neuroprotection Of Fasting Mimicking Diet On MPTP-induced Parkinson's Disease Mice

Parkinson's disease(PD)is a common degenerative disease of the motor nervous system.It is clinically characterized by motor sympotoms such as resting tremor,bradykinesia,rigidity and non-motor symptoms such as dysbacteriosis and constipation,which is resulted from a selective loss of dopaminergic neurons in the substantia nigra pars compacta.Although a larger number of studies showed that inflammation,oxidative stress,mitochondrial dysfunction and apoptosis were involved in PD,the exact pathogenesis of PD is still not clear yet.Classical therapeutic interventions in PD include pharmacotherapy and surgical treatment.However,drugs are not disease modifying and adverse effects develop over time hence compromising efficacy.Also,surgical treatment is not suitable for all PD patients,which is very expensive,and is difficult for family to afford the economic and care burden.Parkinson's disease is strongly associated with life style,especially dietary habits,which have gained attention as disease modifiers.Recent studies have shown that dietary intervention or neuroprotective effects on PD.Here we report a fasting mimicking diet(FMD),fasting 3 days followed by 4 days of re-feeding for 3 one-week cycles,that mimics the beneficial effects of fasting but minimizes the side effects of fasting.According to previous studies,FMD contributed to on diabetes,cardiovascular diseases,cancer and other diseases related to aging and multiple sclerosis.In addition,it also plays an important role in immune system regeneration,hippocampal neurogenesis,cognitive function improvement,and life extension.In this study,8 weeks aged male C57BL/6J mice were administered intraperitoneal with MPTP(20 mg/kg dissolved in sterilized saline)in a volume of 10 mL/kg of body weight on four occasions,with each administration separated by a 2-h interval.In experiments involving FMD,MPTP was administered on the last day of the second FMD cycle.After 3 cycles of FMD,we explored the neuroprotection of FMD by behavioral test,immunofluorescence staining,high performance liquid chromatography(HPLC),western blot,ELISA,16 S and 18 S rRNA sequencing,gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry.In addition,in order to investigate whether the FMD-induced microbial shift directly contributes to neuroprotection in PD mice,microbiota from normal saline-ad libitum(NS-AL)and normal saline-fasting mimicking diet(NS-FMD)mice,referred as AL microbiota and FMD microbiota,were transplanted to antibiotic-pretreated PD mice.Furthermore,microbiota from NS-FMD mice were first heat-killed,then transplanted to antibiotic-pretreated PD mice.The results showed that FMD can alleviate motor dysfunction in PD mice,reduce the loss of dopaminergic neurons in the substantia nigra,increase the levels of DA and 5-HT in the striatum,and up-regulate the expression of TH and BDNF in the striatum.In addition,FMD inhibited the activation of glial cells in the substantia nigra of PD mice and reduced the release of TNF-? and IL-1? in the striatum,indicating that FMD could inhibit neuroinflammation in PD mice.16 S and 18 S rRNA sequencing of fecal microbiota showed that FMD treatment modulated the shifts in gut microbiota composition,including higher abundance of Firmicutes,Tenericutes and Opisthokonta,and lower abundance of Proteobacteria at the phylum level in PD mice.Gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry revealed that FMD modulated the MPTP-induced lower propionic acid and isobutyric acid,and higher butyric acid and valeric acid and other metabolites.Transplantation of fecal microbiota,from normal mice with FMD treatment,to antibiotic-pre-treated PD mice increased dopamine levels in the recipient PD mice,suggesting that gut microbiota mediated the neuroprotection of FMD for PD.These findings demonstrate that FMD can be a new means of preventing and treating PD through promoting a favorable gut microbiota composition and metabolites.