BACKGROUND AND AIMS: Neurodegenerative disorders affecting the brain and spinal cord are caused by a large number of factors. More recently, imbalances in gut microbiota are found to be one factor linked directly to neurological dysfunction. Probiotics prevent cognitive decline. For the first time, the effect of probiotics was assessed by monitoring the concentrations of the neurodegeneration biomarker neurofilament light chains (NfL) in a well-defined group of community-dwelling individuals. The aim of this study was to determine whether administration of our new probiotics could reduce NfL concentrations. METHODS: The serum NfL concentrations were measured in total of 190 serum samples of 85 older community-dwelling individuals. The participants were randomly divided into two groups: the PROPLA group and the PLAPRO group. Individuals in the PROPLA group started with a three-month use of probiotics and continued with a three-month use of placebo while the order was reversed in the PLAPRO group. The participants underwent detailed examinations at three time points: at baseline, in three and six months. The serum NfL concentrations were determined using ultrasensitive single-molecule array (SIMOA) assay. RESULTS: Longitudinal comparisons of NfL concentrations between samplings at different time points in the PROPLA and PLAPRO groups showed no statistically significant differences. Baseline NfL concentrations at the beginning of the study and in the succeeding samplings were not significantly different for the two groups in cross-sectional comparisons. CONCLUSIONS: Serum NfL concentrations were not influenced by the three-month use of probiotics.

• Klíčová slova
• cognition, gastrointestinal microbiome, neurofilament light chain, probiotics, serum,
• MeSH
• biologické markery krev   MeSH
• dvojitá slepá metoda MeSH
• lidé středního věku MeSH
• lidé MeSH
• neurofilamentové proteiny * krev   MeSH
• probiotika * terapeutické užití   MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• střevní mikroflóra MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• multicentrická studie MeSH
• randomizované kontrolované studie MeSH
• Názvy látek
• biologické markery MeSH
• neurofilament protein L MeSH Prohlížeč
• neurofilamentové proteiny * MeSH

BACKGROUND: Serum neurofilament light chain (S NfL) is a non-specific marker of neuronal damage, including Alzheimer's disease (AD). We aimed to verify the reference interval (RI) of serum NfL using a highly sensitive ELISA, and to estimate the optimal cut-off value for neuronal damage. Our second objective was to compare NfL in cerebrospinal fluid (CSF) and serum (S) with the routine neurodegeneration biomarkers used in AD, and to assess their concentrations relative to the degree of cognitive deficit. METHODS: Samples from 124 healthy volunteers were used to estimate the S NfL RI. For the comparison study, we used CSF and S samples from 112 patients with cognitive disorders. Cognitive functions were assessed using the mini-mental state examination. ELISA assays were used to determine the CSF and S NfL levels, CSF β-amyloid peptide42 (Aβ42), CSF β-amyloid peptide40 (Aβ40), CSF total tau protein (tTau), CSF phosphorylated tau protein (pTau), and CSF alpha-synuclein (αS). RESULTS: The estimated RI of S NfL were 2.25-9.19 ng.L-1. The cut-off value of S NfL for assessing the degree of neuronal impairment was 10.5 ng.L-1. We found a moderate statistically significant correlation between S NfL and CSF Aβ42 in the group with movement disorders, without dementia (rs = 0.631; p = 0.016); between S NfL and CSF Aβ40 in the group with movement disorder plus dementia (rs = -0.750; p = 0.052); between S NfL and CSF tTau in the control group (rs = 0.689; p = 0.009); and between S NfL and CSF pTau in the control group (rs = 0.749; p = 0.003). The non-parametric Kruskal-Wallis test revealed statistically significant differences between S NfL, CSF NfL, CSF Aβ42, CSF tTau, and CSF pTau and diagnosis within groups. The highest kappa coefficients were found between the concentrations of S NfL and CSF NfL (κ = 0.480) and between CSF NfL and CSF tTau (κ = 0.351). CONCLUSION: Our results suggested that NfL and tTau in CSF of patients with cognitive decline could be replaced by the less-invasive determination of S NfL using a highly sensitive ELISA method. S NfL reflected the severity of cognitive deficits assessed by mini-mental state examination (MMSE). However, S NfL is not specific to AD and does not appear to be a suitable biomarker for early diagnosis of AD.

• Klíčová slova
• cognitive deficit, high-sensitivity ELISA, mini-mental state examination, neurofilament light chain, serum,
• Publikační typ
• časopisecké články MeSH