Related Experiment Video
Updated: Jun 10, 2026
06:39
Isolation and Purification of Bacterial Extracellular Vesicles from Human Feces Using Density Gradient Centrifugation
Published on: September 1, 2023
Bacterial Extracellular Vesicles as Systemic Messengers: Integrating Their Roles in Gut-Liver-Brain Communication and
Farzaneh Hasanian-Langroudi1,2,3,4, Hessam Yaghmaei5,4, Erfan Soroush4,6
1Student Research Committee, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Probiotics and Antimicrobial Proteins
|June 9, 2026
Summary
Bacterial extracellular vesicles (BEVs) are key communicators between the gut and organs, influencing health and disease. Their dual roles depend on cargo and host context, offering therapeutic potential.
Area of Science:
- Microbiology
- Immunology
- Metabolic Diseases
Background:
- Bacterial extracellular vesicles (BEVs) are nanoscale structures released by bacteria, carrying diverse biomolecules.
- Emerging evidence highlights BEVs as active mediators in gut-organ communication, impacting host physiology.
- This review focuses on BEVs' role in gut-liver and gut-brain axes.
Purpose of the Study:
- To synthesize current knowledge on BEV composition, isolation, and host interactions.
- To elucidate the mechanisms of BEV-mediated gut-liver and gut-brain cross-talk.
- To propose a framework for understanding BEVs' context-dependent pathogenic and protective roles.
Main Methods:
- Literature review synthesizing current research on bacterial extracellular vesicles.
- Analysis of BEV cargo, isolation techniques, and host interaction pathways.
- Exploration of BEVs' roles in gut-liver and gut-brain communication.
Main Results:
- BEVs interact with host pattern-recognition receptors, influencing gut barrier integrity and cytokine signaling.
- Systemic BEVs can promote liver inflammation and fibrosis, while commensal BEVs enhance barrier function.
- BEVs impact host metabolism, insulin signaling, and neuroinflammation, with effects modulated by cargo and host state.
Conclusions:
- BEV functions are context-dependent, influenced by cargo, host cellular state, and exposure dynamics, explaining their dual roles.
- Understanding BEV biology is crucial for developing targeted interventions in chronic metabolic and inflammatory diseases.
- Future research should focus on standardized protocols, in vivo studies, and engineered BEV therapeutics.
Related Concept Videos
01:36Overview of Exosomes
Exosomes are stable, lipid bilayer-enclosed vesicles capable of crossing biological barriers. They can carry a wide range of molecules required for intercellular communication. Once exosomes are released from the cell where they originated, they enter a recipient cell through various pathways such as fusion, receptor-mediated endocytosis, macropinocytosis, and phagocytosis.
Stahl et al. discovered exosomes in 1983, but the exosomes were initially considered waste products released from the...
Stahl et al. discovered exosomes in 1983, but the exosomes were initially considered waste products released from the...
01:22Gut-Brain Axis
The gut–brain axis is a bidirectional communication system that connects the gastrointestinal tract and the brain. This interaction is mediated through multiple pathways, including the vagus nerve, hormonal signals, immune responses, and chemical messengers produced by gut microbes.Microbial Contributions to Brain FunctionGut microbiota contributes significantly to brain function by producing neuroactive compounds. These include neuroactive compounds that influence neurotransmitters such as...
01:38Intralumenal Vesicles and Multivesicular Bodies
Intraluminal vesicles (ILVs) are small vesicles 50-80 nm in diameter formed during the maturation of early endosomes. A specialized endosome containing numerous ILVs is called a multivesicular body (MVB). ILVs contain internalized molecules such as antigens, nucleic acids, proteins, and metabolites. Some of these molecules are released from the MVBs inside exosomes and are transported to other cells. Other MVBs contain molecules that are retained in the ILVs and are later degraded within the...
01:23Bacteriophages of the Human Virome
Bacteriophages are found throughout the human body. They may even outnumber eukaryotic viruses, forming an important and dynamic component of the human virome. Indeed, phages represent the most abundant viral entities, with densities in the gut reaching up to 10⁹ particles per gram of fecal matter, and many belonging to orders such as Caudovirales and Microviridae, while a substantial proportion remains unclassified as viral “dark matter.”Lysogeny and Genetic ExchangeIn the gut, bacteriophages...
01:30Bacterial Signaling
Bacterial signaling can occur within bacteria (intracellular) or between bacteria (intercellular). At times, a group of bacteria behaves like a community. To achieve this, they engage in quorum sensing, the perception of higher cell density that causes changes in gene expression. Quorum sensing involves both extracellular and intracellular signaling. The signaling cascade starts with a molecule called an autoinducer (AI). Individual bacteria produce AIs that move out of the bacterial cell...
01:26Bacterial Translocation and Protein Secretion
Bacterial protein secretion involves translocation systems to ensure proteins reach their designated locations, including the plasma membrane, periplasm, outer membrane, or the external environment. These translocation systems are vital for bacterial physiology, supporting processes like membrane assembly, enzymatic activity in the periplasm, and interactions with the external environment. The division of labor between Sec and Tat pathways ensures efficiency in handling proteins with diverse...