I’ve looked at gut from both sides now: Gastrointestinal tract involvement in the pathogenesis of SARS-CoV-2 and HIV/SIV infections

Abstract

The lumen of the gastrointestinal (GI) tract contains an incredibly diverse and extensive collection of microorganisms that can directly stimulate the immune system. There are significant data to demonstrate that the spatial localization of the microbiome can impact viral disease pathogenesis. Here we discuss recent studies that have investigated causes and consequences of GI tract pathologies in HIV, SIV, and SARS-CoV-2 infections with HIV and SIV initiating GI pathology from the basal side and SARS-CoV-2 from the luminal side. Both these infections result in alterations of the intestinal barrier, leading to microbial translocation, persistent inflammation, and T-cell immune activation. GI tract damage is one of the major contributors to multisystem inflammatory syndrome in SARS-CoV-2-infected individuals and to the incomplete immune restoration in HIV-infected subjects, even in those with robust viral control with antiretroviral therapy. While the causes of GI tract pathologies differ between these virus families, therapeutic interventions to reduce microbial translocation-induced inflammation and improve the integrity of the GI tract may improve the prognoses of infected individuals.

Walk on the wild side: SIV infection in African non-human primate hosts—from the field to the laboratory

“…Salient features of non-pathogenic SIV infections in natural hosts that differentiate them from pathologic infections include preservation of the mucosal barrier, preservation of the Th-17 cells (the T-cell subset that protects mucosa against bacterial and fungal infection) in the gut and periphery ( 31 , 32 ), a lack of microbial translocation, and a lack of chronic inflammation and T-cell immune activation ( 121 – 123 ), which suggest that gut health is a key determinant of the pathogenic or non-pathogenic course of infection.…”

“…( 2 ) Therefore, stabilization of the natural microbiome, preserving and/or enriching beneficial taxa, manipulation of community composition, and metabolic activity is another possible therapeutic direction. Attempts to reduce gut inflammation through modification of the enteric microbiome using selected bacterial strains as probiotics alone or combined with prebiotics, or bacterial metabolic products, such as short-chain fatty acids, brought mixed results ( 123 ). Results of the administration of selected microbial strains ranged from a lack of effect on systemic inflammation ( 195 ), no effect on immune activation biomarkers ( 196 , 197 ) through reduced systemic inflammation markers, but not microbial translocation markers (LPS or sCD14) ( 198 ), to a significant decrease of enterocyte apoptosis and increase in Th17 cells in the gut ( 199 ).…”

Gut Microbiome (Bacteria, Fungi, and Viruses) and HIV Infection: Revealing Novel Treatment Strategies

“…[15] The gut microbiota, together with the hundreds of metabolites and proteins that it produces, plays an essential role in human health, including nutritional, developmental, defensive, and physiological processes, by affecting cellular metabolism, immune regulation, and inflammatory processes. [12,17] Therefore, gut dysbiosis or adverse changes in the microbiota contribute to inflammatory diseases, autoimmunity, and carcinogenesis and affect the progression of infectious diseases. In addition, the balance of gut microbiota is important for maintaining homeostasis, pathogenesis, and protection against pathogens.…”

“…In addition, the balance of gut microbiota is important for maintaining homeostasis, pathogenesis, and protection against pathogens. [17][18][19] Recently, compositional and functional changes in the gut microbiota have been extensively studied in various diseases, like autoimmune diseases, obesity, diabetes, cancer, and infectious diseases. [17] The application of microbiota-based treatment, prognosis, diagnosis, and monitoring technologies has played a significant role in the current treatment of disease.…”

“…[17][18][19] Recently, compositional and functional changes in the gut microbiota have been extensively studied in various diseases, like autoimmune diseases, obesity, diabetes, cancer, and infectious diseases. [17] The application of microbiota-based treatment, prognosis, diagnosis, and monitoring technologies has played a significant role in the current treatment of disease. [18] For instance, probiotics are not only used to treat diarrhea, obesity, urinary tract infection, irritable bowel syndrome, and diabetes, but also for the prevention and treatment of cancer.…”