Liver Sinusoidal Endothelium: The Hidden Interface in the Gut–Liver Axis in Metabolic Dysfunction-Associated Steatotic Liver Disease?

Background/Objectives: Recent studies show that the gut microbiome plays a pivotal role in the (patho)physiology of metabolic dysfunction-associated steatotic liver disease (MASLD), likely via metabolites they produce that are transported via the portal vein towards the liver where they first encounter liver sinusoidal endothelial cells (LSECs). LSECs may modulate the effects the gut microbes have on the liver, e.g., on the progression of MASLD. Methods: This review aims to describe the current knowledge on the role of LSECs in mediating the effect of gut microbial products in MASLD. Results: Various studies show that LSECS have a contributing role in MASLD pathogenesis, suggesting that proper LSEC functionality is required to protect the liver from gut-driven attacks. Conclusions: Dedicated studies on the role and effects of gut-derived molecules on LSEC functionality are lacking, likely because such studies depend on labor-intensive techniques such as scanning electron microscopy (SEM).