Search for: All records

Abstract The unpredictable oral bioavailability of established drugs like tacrolimus and sulfasalazine presents a significant clinical challenge. This variability can lead to either toxicity or insufficient therapeutic effect. It is known that alterations in drug transporters and metabolic enzymes influence drug bioavailability. Recent evidence suggests that the indirect metabolism by gut microbes could influence transporters and enzymes which can affect the bioavailability of oral drugs. In this study, the pharmacokinetics of tacrolimus and sulfasalazine are modeled under varying host colonic conditions induced by the bacteriaE. coli Nissle 1917andBifidobacterium adolescentis. Insight is provided into the sensitivity of pharmacokinetics to the bacterial influence on expression of intestinal drug transporters and cytochrome p450 enzymes. Our findings demonstrate that bacterial modulation reduces tacrolimus peak blood concentration compared to healthy renal transplant patients. Conversely, bacterial presence leads to a two‐fold increase in sulfasalazine's peak plasma concentration compared to healthy subjects. These results suggest that incorporating the gut bacteria's influence on colonic transporters and enzymes can improve the explanation of pharmacokinetic variability. This approach has the potential to refine pharmacokinetic models and ultimately address the challenge of variable oral drug bioavailability. 

The coronavirus disease 2019 (COVID-19) pandemic began in January 2020 in Wuhan, China, with a new coronavirus designated SARS-CoV-2. The principal cause of death from COVID-19 disease quickly emerged as acute respiratory distress syndrome (ARDS). A key ARDS pathogenic mechanism is the “Cytokine Storm”, which is a dramatic increase in inflammatory cytokines in the blood. In the last two years of the pandemic, a new pathology has emerged in some COVID-19 survivors, in which a variety of long-term symptoms occur, a condition called post-acute sequelae of COVID-19 (PASC) or “Long COVID”. Therefore, there is an urgent need to better understand the mechanisms of the virus. The spike protein on the surface of the virus is composed of joined S1–S2 subunits. Upon S1 binding to the ACE2 receptor on human cells, the S1 subunit is cleaved and the S2 subunit mediates the entry of the virus. The S1 protein is then released into the blood, which might be one of the pivotal triggers for the initiation and/or perpetuation of the cytokine storm. In this study, we tested the hypothesis that the S1 spike protein is sufficient to activate inflammatory signaling and cytokine production, independent of the virus. Our data support a possible role for the S1 spike protein in the activation of inflammatory signaling and cytokine production in human lung and intestinal epithelial cells in culture. These data support a potential role for the SARS-CoV-2 S1 spike protein in COVID-19 pathogenesis and PASC.