Gut microbiome alterations in type 2 diabetes following COVID-19: A comprehensive review

Abstract

The COVID-19 pandemic has raised growing concern over its long-term effects, particularly in individuals with pre-existing metabolic conditions such as type 2 diabetes. Beyond its well-known impact on the respiratory and immune systems, emerging research highlights the virus's influence on gut microbiota, a key player in metabolic regulation. This review explores how COVID-19-induced inflammation, immune dysregulation, and direct gastrointestinal effects contribute to disruptions in gut microbial composition and function. Such imbalances may worsen insulin resistance, impair glucose metabolism, and aggravate glycemic control in diabetic patients. We discuss current evidence linking gut dysbiosis to metabolic deterioration in post-COVID type 2 diabetes, emphasizing the role of the gut-lung axis and cytokine storm in this interaction. Recognizing the gut microbiome as a modifiable factor opens new possibilities for targeted interventions, such as probiotics, dietary modulation, and microbiota-based therapies. Understanding these mechanisms is essential not only for managing diabetes in the post-COVID context but also for developing integrative strategies that address the gut microbiome's role in metabolic health. This review underscores the need for further research to elucidate causal relationships and optimize gut-targeted therapeutic approaches in diabetes care following COVID-19 infection.