INTRODUCTION: Chitinase-3-like protein 1 (CHI3L1) is a glycoprotein implicated in various neurological conditions. It is associated with neuroinflammation and tissue remodeling. The study aimed to validate the reference interval (RI) of serum (S) CHI3L1 in a control group, to correlate S CHI3L1 values with other biomarkers of neurodegenerative damage, and to estimate the diagnostic accuracy of S CHI3L1. METHODS: Samples from 108 healthy volunteers were used to estimate the S CHI3L1 RI. For the comparison, we used cerebrospinal fluid (CSF) and serum (S) samples from 121 patients with cognitive disorders, and cognitive deterioration was assessed using the Mini-Mental State Examination (MMSE). ELISA assays were used to determine the S CHI3L1, CSF, and S neurofilament light chain (NfL) levels; CSF and plasma β-amyloid peptide42; CSF and plasma β-amyloid peptide40; CSF total tau protein; CSF phosphorylated tau protein; and CSF alpha-synuclein. RESULTS: The estimated RI of S CHI3L1 was 14.44 to 63.11 µg/L. The cut-off value of S CHI3L1 was 34.37 µg/L. ROC analysis showed that S CHI3L1 has 81.4% sensitivity and 76.9% specificity. We found a moderate Spearman's rank correlation coefficient between the S CHI3L1 and age (rS = 0.486; p < 0.001) and between S CHI3L1 and S NfL (rS = 0.489; p < 0.001) in all groups. The Kruskal-Wallis test showed a significant overall difference in S CHI3L1 among diagnostic groups (p = 0.013). S CHI3L1 and CSF NfL had statistically significant effects on MMSE values (multiple R2 was 0.431). CONCLUSIONS: Our results suggest that S CHI3L1 reflects the severity of cognitive deficits assessed by MMSE. It can be used as a supportive biomarker in neurodegenerative diseases.

• Keywords
• Alzheimer's disease, CHI3L1, biomarkers, dementia,
• MeSH
• alpha-Synuclein cerebrospinal fluid   blood   MeSH
• Amyloid beta-Peptides blood   cerebrospinal fluid   MeSH
• Biomarkers blood   cerebrospinal fluid   MeSH
• Adult MeSH
• Cognitive Dysfunction * blood   cerebrospinal fluid   diagnosis   MeSH
• Middle Aged MeSH
• Humans MeSH
• Neurofilament Proteins cerebrospinal fluid   blood   MeSH
• Movement Disorders * blood   cerebrospinal fluid   diagnosis   MeSH
• Chitinase-3-Like Protein 1 * blood   cerebrospinal fluid   MeSH
• tau Proteins cerebrospinal fluid   blood   MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Check Tag
• Adult MeSH
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Comparative Study MeSH
• Names of Substances
• alpha-Synuclein MeSH
• Amyloid beta-Peptides MeSH
• Biomarkers MeSH
• CHI3L1 protein, human MeSH Browser
• neurofilament protein L MeSH Browser
• Neurofilament Proteins MeSH
• Chitinase-3-Like Protein 1 * MeSH
• tau Proteins MeSH

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.

• Keywords
• cognition, gastrointestinal microbiome, neurofilament light chain, probiotics, serum,
• MeSH
• Biomarkers blood   MeSH
• Double-Blind Method MeSH
• Middle Aged MeSH
• Humans MeSH
• Neurofilament Proteins * blood   MeSH
• Probiotics * therapeutic use   MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Gastrointestinal Microbiome MeSH
• Check Tag
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Multicenter Study MeSH
• Randomized Controlled Trial MeSH
• Names of Substances
• Biomarkers MeSH
• neurofilament protein L MeSH Browser
• Neurofilament Proteins * MeSH