Exploration of Neuroprotective Therapy

Table 1. Summarizing documented clinical manifestations, gut microbial profiles, and conventional and new microbial-related therapies in proteinopathies

ND	Hallmarks	Clinical manifestations	Conventional therapies	Gut microbial profile	New microbial-related therapies
PD	Lewy bodies	Bradykinesia, tremor or postural instability Constipation	L-DOPA, dopaminergic agonists, MAO-B inhibitors and COMT inhibitors	Reduction of anti-inflammatory species and greater abundance of pro-inflammatory Enterobacteriaceae [13, 53, 66, 69, 70] SIBO and Helicobacter pylori infection [79, 87, 88]	Probiotic containing Lactobacillus casei Shirota and Bifidobacerium strains [79, 89–91] Regular intake of Bacillus spp. [66, 94, 95] Regular consumption of synbiotics [96] FMT [101, 102]
AD	Senile plaques, neurofibrillary tangles	Progressive loss of memory, language and learning capabilities	To increase acetylcholine levels To decrease NMDA glutamate receptors activity	Reduction in gut microbiota diversity [123] Differences in Firmicutes:Bacteroidetes ratio [124] Helicobacter pylori infection [125, 126] Larger proportion of pro-inflammatory Escherichia/ Shigella spp. taxa and lower proportion of anti-inflammatory Eubacterium rectale spp. taxa [127]	Multibiotics [147] Lactobacilli and Bifibodbacterium combinations [148] Probiotic mixture combined with selenium as prebiotic [149] Daily consumption of probiotic-fermented kefir [150] FMT [154]
HD	mHTT aggregations	Depression, dementia, motor alterations and GIT dysfunction	Dopamine inhibitors, anti-excitotoxic compounds and antipsychotic drugs	Differences in richness and diversity [173]	Currently under investigation

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Declarations

Author contributions

Conceptualization was agreed by EMP and RM who scanned the literature, retrieved and extracted information from articles referenced in the review. PAG analyzed the literature and also extracted information from articles. EMP and PAG compiled all the information and wrote the first version of the manuscript. RM critically read the manuscript and prepared a second version of the article. All authors edited the manuscript and revised the final submitted version.

Conflicts of interest

The authors declare that they have no conflicts of interest.

Ethical approval

Not applicable.

Consent to participate

Not applicable.

Consent to publication

Not applicable.

Availability of data and materials

Not applicable.

Funding

Not applicable.

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