The aims of this study were to analyze cytokine profiles in patients with COVID-19, gain insights into the immune response during acute infection, identify cytokines associated with disease severity and post-COVID complications, and explore potential biomarkers for prognosis and therapeutic targets. Using a multiplex analysis, we studied the cytokine pattern in 294 acute COVID-19 and post-COVID patients with varying severities of infection. Our findings revealed that disease severity was associated with elevated levels of IL-15, IL-8, and fractalkine. Severe/extremely severe forms in comparison with mild/moderate disease were associated with MCP-1, IFNa2, IL-7, IL-15, EGF, IP-10, IL-8, Eotaxin, FGF-2, GROa, sCD40L, and IL-10. The key cytokines of post-COVID are FGF-2, VEGF-A, EGF, IL-12(p70), IL-13, and IL-6. By the sixth month after recovering from a coronavirus infection, regardless of disease severity, some patients may develop complications such as arterial hypertension, type 2 diabetes mellitus, glucose intolerance, thyrotoxicosis, atherosclerosis, and rapid progression of previously diagnosed conditions. Each complication is characterized by distinct cytokine profiles. Importantly, these complications can also be predicted during the acute phase of the coronavirus infection. Understanding cytokine patterns can aid in predicting disease progression, identifying high-risk patients, and developing targeted interventions to improve the outcomes of COVID-19.

Main focuses of the review were that during the pandemic of SARS-CoV-2 were gastrointestinal disorders were accompanying. Viral RNA and viral particles are found in feces for more than 30 days. Although SARS-CoV-2 primarily causes lung infection through binding to ACE2 receptors, intestinal epithelial cells, especially enterocytes of the small intestine, also express ACE2 receptors. It is also known that a respiratory viral infection causes disturbances in the gut microbiota. Diet, environmental factors, and genetics play an important role in the formation of gut microbiota, which can affect immunity. The diversity of gut microbiota diminishes in old age, and Covid-19 has been mostly fatal in older patients, further indicating the role that gut microbiota may play in this disease. It is therefore plausible that the gut microbiota could be a new therapeutic target and that probiotics could have a role in the management of these patients.