ANALYSIS OF THE RELATIONSHIP BETWEEN ENDOCRINE AND MICROBIOTA FACTORS AND THE SEVERITY OF PARKINSON’S DISEASE

Abstract

Purpose: To evaluate the clinical significance of hyperthyroidism and gut microbiota alterations in Parkinson’s disease (PD) and to determine their association with disease severity. Methods: The study employed clinical-neurological, laboratory (TSH, TG, T3, T4), microbiota analysis (metagenomic PCR – Streptococcus mutans, Bacteroides, Firmicutes) to determine microbial composition, as well as neuroimaging methods. The Hoehn–Yahr and UPDRS scales, and the MMSE (Mini-Mental State Examination) test were used. Multifactorial statistical analysis methods were applied. Results: The obtained results showed that hyperthyroidism, through thyroid hormones, may accelerate the pathogenesis of PD by influencing dopamine metabolism. Dysbiosis of the gut microbiota, particularly the overgrowth of Streptococcus mutans, increases ImP (imidazole propionate) levels, which enhances mitochondrial stress and α-synuclein aggregation. The elevated Streptococcus mutans population and ImP concentration have a neurotoxic effect on dopaminergic neurons. Therefore, a combined analysis of endocrine and microbiota parameters is essential for assessing PD pathogenesis. Conclusion: In the first (control) group—patients with PD and hypothyroidism—and in the second (comparative) group—patients with PD only—it was observed that hyperthyroidism and microbiota imbalance contributed to increased tremor intensity and progressive cognitive impairment. Assessing motor and cognitive dysfunction dynamics at different stages of the disease, as well as timely correction of endocrine disorders in collaboration with endocrinologists and neurologists, may help maintain disease stability. It is recommended to evaluate microbiota composition and thyroid function in PD patients, and conversely, to assess PD symptoms in patients with hypo- or hyperthyroidism.