ABSTRACT
The gut microbiota plays an important role in regulating the body's physiological system, and more recently its impact on bile acid metabolism and cognitive function has been investigated by many studies. In addition to their conventional function in fat digestion and absorption, bile acids are now considered crucial signaling molecules that control several metabolic processes and immunological responses. For this purpose, the authors conducted comprehensive research using relevant terms in an attempt to understand more about the gut microbiota and its impact on bile acid metabolism and cognitive health. The gut-brain axis refers to the network of routes through which gut bacteria communicate with the brain. Through its capacity to bio-transform primary bile acids into secondary bile acids, the gut microbiota plays a significant role in bile acid metabolism. Bile acids function as signaling molecules and act on the brain through nuclear and membrane-bound receptors, influencing neurotransmitter production, neuroinflammation, and neuroplasticity to modify this communication. Any dysregulation in this axis can result in cognitive dysfunction. The link between gut microbiota, bile acids, and cognitive health cannot be ignored. It is imperative to explore this link further by conducting large-scale trials to improve the cognitive health of patients with multiple comorbidities, especially those involving the gastrointestinal tract and nervous system.
ABSTRACT
INTRODUCTION: Current evidence in the literature is inconclusive due to conflicting results with regards to an association between B/L (B/L) oophorectomy and Parkinson's disease (PD). We included large, powered studies to assess the association of PD in women who have undergone B/L oophorectomy. METHODS: We conducted a comprehensive search across three databases from inception to October 2022 for observational studies including pre-menopausal or post-menopausal women undergoing B/L oophorectomy. Primary outcome of interest was incidence of PD or parkinsonism. The results for these associations were presented as Risk Ratios (RR) with 95% confidence intervals (CI), which were pooled using a generic invariance weighted random effects model using Review Manager (RevMan). RESULTS: Data was included from a total of 4 studies. No significant association was found between B/L oophorectomy and PD (RR: 1.38; 95% CI: 0.76 to 2.49; I2:89 %) in contrast significant association was found with parkinsonism (RR: 1.80; 95% CI: 1.29 to 2.52). Age at surgery didn't significantly affect Parkinsonism incidence (RR: 0.88; 95% CI: 0.59 to 1.3). No significant association was found between ovarian indication and Parkinsonism (RR: 1.08; 95% CI: 0.69 to 1.68). B/L oophorectomy with hysterectomy was associated with higher Parkinson's risk compared to without hysterectomy (RR: 1.4; 95% CI: 1.13 to 1.74). Lastly, there was no significant association between Post Menopausal Hormonal (PMH) use and Parkinson's disease (RR: 1.07; 95% CI: 0.92 to 1.26). CONCLUSION: Our findings suggest that B/L oophorectomy is significantly associated with the incidence of Parkinsonism. Further research is needed to understand the potential relationship between oophorectomy and Parkinson's disease.