Role of Gut Microbiota in Long COVID: Impact on Immune Function and Organ System Health.

SARS-CoV-2 infection has led to a range of long-lasting symptoms, collectively referred to as long COVID. Current research highlights the critical role of angiotensin-converting enzyme 2 (ACE2) in regulating gut microbiota diversity, vascular function, and homeostasis within the renin-angiotensin system (RAS). ACE2 is utilized by the SARS-CoV-2 virus to enter host cells, but its downregulation following infection contributes to gut microbiota dysbiosis and RAS disruption. These imbalances have been linked to a range of long COVID symptoms, including joint pain, chest pain, chronic cough, fatigue, brain fog, anxiety, depression, myalgia, peripheral neuropathy, memory difficulties, and impaired attention. This review investigates the dysregulation caused by SARS-CoV-2 infection and the long-term effects it has on various organ systems, including the musculoskeletal, neurological, renal, respiratory, and cardiovascular systems. We explored the bidirectional interactions between the gut microbiota, immune function, and these organ systems, focusing on how microbiota dysregulation contributes to the chronic inflammation and dysfunction observed in long COVID symptoms. Understanding these interactions is key for identifying effective therapeutic strategies and interventional targets aimed at mitigating the impact of long COVID on organ health and improving patient outcomes.