Microbiome and Metabolome Restoration After Administration of Fecal Microbiota, Live-jslm (REBYOTA®) for Preventing Recurrent Clostridioides difficile Infection.

BACKGROUND: Microbiota-based treatments are effective in preventing recurrent Clostridioides difficile infection (rCDI). Fecal microbiota, live-jslm (REBYOTA®; RBL, previously RBX2660) was shown to prevent rCDI in a phase 3, randomized, double-blinded placebo controlled clinical trial (PUNCH™ CD3). METHODS: Stool samples from participants in PUNCH™ CD3 who received a single blinded dose of rectally administered RBL or placebo were sequenced to determine microbial community composition and calculate the Microbiome Health Index for post-antibiotic dysbiosis (MHI-A). The composition of bile acids (BAs) in the same samples was quantified by liquid chromatography mass spectrometry. Relationships between BA composition and microbiota community structure and correlations with treatment outcomes were assessed. RESULTS: Before administration, Gammaproteobacteria and Bacilli dominated the microbiota community and primary BAs were more prevalent than secondary BAs. Clinical success after administration correlated with shifts to predominantly Bacteroidia and Clostridia, a significant increase in MHI-A, and a shift from primary to secondary BAs. Several microbiota and BA changes were more extensive in RBL-treated responders compared to placebo-treated responders, and microbiota changes correlated with BA changes. CONCLUSIONS: Clinical response and RBL administration were associated with significant restoration of microbiota and BA composition. CLINICAL TRIALS REGISTRATION: NCT03244644.

An angiotensin system inhibitor (losartan) potentiates antitumor efficacy of cisplatin in a murine model of non-small cell lung cancer.

Objective: Previous studies have demonstrated synergistic antitumor effects of angiotensin system inhibition (ASI) combined with cisplatin therapy in pancreatic cancer. This study examines whether or not synergistic antitumor effects occur with combination ASI and cisplatin treatment in lung cancer, and whether or not ASI-induced changes in epithelial-mesenchymal transition play a role in the mechanism of this antitumor phenomenon. Methods: A set of lung cancer cell lines representing a spectrum of epithelial to mesenchymal phenotypes were identified and characterized. Response of epithelial-mesenchymal transition markers to losartan was characterized. Cell culture models of lung cancer were next treated with losartan, cisplatin, or combination of both. Markers of epithelial-mesenchymal transition or surrogates of other signaling pathways (AKT, Stat3, and programmed death-ligand), and cell viability were quantified. Findings were confirmed in both allogenic and syngeneic in vivo murine flank tumor models. Results: Losartan treatment significantly increased E-cadherin and reduced vimentin in human lung cancer cell lines. Combination treatment with losartan and cisplatin enhanced epithelial markers, reduced mesenchymal markers, inhibited promesenchymal signaling mediators, and reduced cell viability. Findings were confirmed in vivo in a murine flank tumor model with transition from mesenchymal to epithelial phenotype and reduced tumor size following combination losartan and cisplatin treatment. Conclusions: Combination losartan and cisplatin treatment attenuates the epithelial-mesenchymal transition pathway and enhances the cytotoxic effect of chemotherapy with in vitro and in vivo models of non-small cell lung cancer. This study suggests an important role for ASI therapy in the treatment of lung cancer.