Gut bacteria exacerbates TNBS-induced colitis and kidney injury through oxidative stress.

Gut microbiota has been implicated in the initiation and progression of various diseases; however, the underlying mechanisms remain elusive and effective therapeutic strategies are scarce. In this study, we investigated the role and mechanisms of gut microbiota in TNBS-induced colitis and its associated kidney injury while evaluating the potential of dietary protein as a therapeutic intervention. The intrarectal administration of TNBS induced colitis in mice, concurrently with kidney damage. Interestingly, this effect was absent when TNBS was administered intraperitoneally, indicating a potential role of gut microbiota. Depletion of gut bacteria with antibiotics significantly attenuated the severity of TNBS-induced inflammation, oxidative damage, and tissue injury in the colon and kidneys. Mechanistic investigations using cultured colon epithelial cells and bone-marrow macrophages unveiled that TNBS induced cell oxidation, inflammation and injury, which was amplified by the bacterial component LPS and mitigated by thiol antioxidants. Importantly, in vivo administration of thiol-rich whey protein entirely prevented TNBS-induced colonic and kidney injury. Our findings suggest that gut bacteria significantly contribute to the initiation and progression of colitis and associated kidney injury, potentially through mechanisms involving LPS-induced exaggeration of oxidative cellular damage. Furthermore, our research highlights the potential of dietary thiol antioxidants as preventive and therapeutic interventions.

Magnification Effect of Foveal Avascular Zone Measurement Using Optical Coherence Tomography Angiography.

PURPOSE: The aim of this study was to evaluate the foveal avascular zone (FAZ) of healthy subjects and examine the magnification effect. METHODS: A total of 33 healthy volunteers were enrolled and all subjects were eligible for analysis. Optical coherence tomography angiography (OCTA) examination scanned 3 × 3 mm of the macular area. The FAZ area was measured on the superficial OCTA en face image with and without correction by axial length. The relationship between changes in the FAZ area after correction with the axial length was examined. RESULTS: The mean age was 21.9 ± 0.6 years. The mean axial length was 24.87 ± 1.17 mm and mean spherical equivalent (SE) value was -3.64 ± 2.83 diopters (D). The FAZ area was 0.26 ± 0.10 mm2 before the axial length correction and 0.27 ± 0.10 mm2 after the correction. In the eyes that had an axial length longer than or equal to 26 mm or SE less than or equal to -6 D, the FAZ area after correction was significantly larger than that before correction (p < 0.01). The change of FAZ area after correction with axial length was significantly correlated with the axial length (R 2 = 0.88, p < 0.01) or SE value (R 2 = 0.55, p < 0.01). CONCLUSION: FAZ areas were comparable to previous reports. In high myopic cases, the magnification effect needs to be considered when evaluating the FAZ area.