Intestinal bacteria-derived extracellular vesicles in metabolic dysfunction-associated steatotic liver disease: From mechanisms to therapeutics.

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a progressive disease that affects the health of approximately one-third of the world's population. It is the primary cause of end-stage liver disease, liver malignancy, and liver transplantation, resulting in a great medical burden. No medications have yet been approved by the US Food and Drug Administration for treating MASLD without liver inflammation or scarring. Therefore, the development of specific drugs to treat MASLD remains a key task in the ongoing research objective. Extracellular vesicles (EVs) play an important role in the communication between organs, tissues, and cells. Recent studies have found that intestinal microbiota are closely related to the pathogenesis and progression of MASLD. EVs produced by bacteria (BEVs) play an indispensable role in this process. Thus, this study provides a new direction for MASLD treatment. However, the mechanism by which BEVs affect MASLD remains unclear. Therefore, this study investigated the influence and function of intestinal microbiota in MASLD. Additionally, we focus on the research progress of BEVs in recent years and explain the relationship between BEVs and MASLD from the perspectives of glucose and lipid metabolism, immune responses, and intestinal homeostasis. Finally, we summarized the potential therapeutic value of BEVs and EVs from other sources, such as adipocytes, immunocytes, stem cells, and plants.