The impact of gut microbiome and diet on post-acute sequelae of SARS-CoV-2 infection

Long COVID, also known as Post COVID-19 condition by the World Health Organization or Post-Acute Sequelae of SARS-CoV-2 infection (PASC), is defined as the development of symptoms such as post-exertional malaise, dysgeusia, and partial or full anosmia three months after initial SARS-CoV-2 infection. The multisystem effects of PASC make it difficult to distinguish from its mimickers. Further, a comprehensive evaluation of the gut microbiome, nutrition, and PASC has yet to be studied. The gut-brain axis describes bidirectional immune, neural, endocrine, and humoral modulatory interactions between the gut microbiome and brain function. We explore recent studies that support an association between alterations in gut microbiome diversity and the severity of acute-phase COVID-19, and how these may be affected by diets rich in antioxidants and fiber. The Mediterranean Diet (MeDi) has demonstrated promising neuroprotective effects through its anti-inflammatory processes. Further, diets rich in fiber increase gut diversity and increase the amount of short-chain fatty acids (SCFAs) within the body—both shown to protect from acute COVID-19 complications. Long-term changes to the gut microbiome persist after acute infection and may increase susceptibility to PASC. This study builds on existing knowledge of determinants of PASC and highlights a relationship between nutrition, gut microbiome, acute-phase COVID-19, and, subsequently, PASC susceptibility.