The Gut Microbiome May Play a Role in the Pathogenesis of Meniere's Disease.

Meniere's disease (MD) was first described 650 years ago. It is now considered to be a multifactorial disorder involving immunological mechanisms, blood-labyrinth barrier breakdown, endolymphatic hydrops, vascular compromise, and genetic susceptibility. Chronic inflammation from both innate and adaptive immunity is evident in the inner ear, with autoimmunity and allergy possibly playing a role. Despite its long history, significant knowledge gaps in its pathogenesis remain. For example, there may be root causes from elsewhere that are contributing to these pathological processes occurring in the inner ear. In recent years, rapid progress has been made in research on the contributions of gut microbiome to human health and disease. In particular, changes in gut microbiome have been found to be associated with many disorders of the brain. The brain and the inner ear share similar vascular networks that create a physical barrier to limit paracellular diffusion. Emerging evidence shows gut dysbiosis can potentially result in sensori-neural hearing loss. Early evidence suggests changes in gut microbiome may be associated with MD, possibly via dysregulation of the arginine vasopressin/vasopressin type 2 receptor/aquaporin-2 (AVP-V2R-AQP2) signaling pathway in the inner ear from increased brain secretion of AVP. It remains to be seen if the belief that gut dysbiosis contributes to the pathogenesis of MD can be substantiated by future research. If so, addressing gut issues may prove to be an important strategy in the overall management of MD.