Emerging role of bacterial outer membrane vesicle in gastrointestinal tract

Abstract

Bacteria form a highly complex ecosystem in the gastrointestinal (GI) tract. In recent years, mounting evidence has shown that bacteria can release nanoscale phospholipid bilayer particles that encapsulate nucleic acids, proteins, lipids, and other molecules. Extracellular vesicles (EVs) are secreted by microorganisms and can transport a variety of important factors, such as virulence factors, antibiotics, HGT, and defensive factors produced by host eukaryotic cells. In addition, these EVs are vital in facilitating communication between microbiota and the host. Therefore, bacterial EVs play a crucial role in maintaining the GI tract’s health and proper functioning. In this review, we outlined the structure and composition of bacterial EVs. Additionally, we highlighted the critical role that bacterial EVs play in immune regulation and in maintaining the balance of the gut microbiota. To further elucidate progress in the field of intestinal research and to provide a reference for future EV studies, we also discussed the clinical and pharmacological potential of bacterial EVs, as well as the necessary efforts required to understand the mechanisms of interaction between bacterial EVs and gut pathogenesis.

DNA characterization reveals potential operon-unit packaging of extracellular vesicle cargo from a gut bacterial symbiont

“…Some studies allude to the possibility of EVs serving as bioactive molecule carriers, transporting proteins and nucleic acids that can reshape cellular activities 16,48,59 . We speculate that EVs might serve as dynamic regulatory entities, possibly engaged in specialized transcriptional functions within these vesicular structures, potentially serving a direct role in interactions with microbes in its surrounding extracellular environments 12,[60][61][62] . Contrasting to the findings of Sartorio et al 48 and Elhenawy et al 16 identifying EV's specialized role as a glycan-degrader, we find a significant presence of DNA copies in EVs associated with coding for proteins in glycosyltransferase domains, particularly those from the membrane-associated GT-B family hinting at EV's potential role in altering the surface glycans of recipient cells.…”

Unseen Weapons: Bacterial Extracellular Vesicles and the Spread of Antibiotic Resistance in Aquatic Environments

“…BEVs, the tiny bubble-like messengers released by bacteria, play a surprising role in spreading resistance against critical antibiotics like β-lactams. These BEVs, acting like miniature Trojan Horses, can carry potent β-lactamase enzymes that are packaged into BEVs and released into the surrounding water, eventually causing an imbalance in the aquatic ecosystems [ 104 ].…”

Bacterial membrane vesicles in the pathogenesis and treatment of inflammatory bowel disease

“… 97 , 127 On the other hand, MVs from pathogenic bacteria can damage the host’s mucosal barrier, causing harmful inflammatory storms to the host. 128 …”

“…The cargo delivered by MVs to the intestinal microflora, including enzymes, functional genes, and essential nutrients, enable them to thrive in the constantly changing microenvironment of the intestine. 128 Although the intestines are host to a great diversity of bacteria, not all these bacteria have the capacity to produce MVs.…”