An important intestinal bacterial strain Akkermansia muciniphila contributes to improving carbohydrate and lipid metabolism, thus alleviating obesity symptoms. Here, we find that the Akk membrane protein Amuc_1100 regulates lipid metabolism in 3T3-L1 preadipocytes.

Preeclampsia (PE) is a multisystem disorder with high maternal morbidity and mortality rates. Currently, no practical therapeutic approach is available to prevent PE progression, except for early delivery. Gut dysbiosis is associated with PE development. Previous data showed that the abundance of Akkermansia muciniphila ( Am ) was lower in patients with PE than in normotensive pregnant women. Here, in this study, decreased abundance of Am was observed in a PE mouse model. Also, we found that administration with Am could significantly attenuate systolic blood pressure, promote foetal growth and improve the placental pathology in mice with PE. Moreover, Am ‐derived extracellular vesicles (AmEVs) were transferred from the gastrointestinal (GI) tract to the placenta and mitigated pre‐eclamptic symptoms in PE mice. These beneficial effects of AmEVs were mediated by enhanced trophoblast invasion of the spiral artery (SpA) and SpA remodelling through activation of the epidermal growth factor receptor (EGFR)–phosphatidylinositol‐3‐kinase (PI3K)–protein kinase B (AKT) signalling pathway. Collectively, our findings revealed the potential benefit of using AmEVs for PE treatment and highlighted important host–microbiota interactions.

Recently, the interest in extracellular vesicles released by bacteria has rapidly increased. Bacterial extracellular vesicles (BEVs) have been involved in bacteria‐bacteria and bacteria‐host interactions, which strengthen health or bring about various pathologies. However, BEV separation, characterization, and functional studies require the establishment of guidelines and further optimization in order to stimulate the development of science in BEV research and a following successful transformation into clinical applications. This position paper is authored by the Microbial Vesicles Task Force of the Chinese Society for Extracellular Vesicles (CSEV) composed of experienced medical laboratory specialists, microbiologists, virologists, biologists and material biologists who are actively engaged in BEV research. Herein, we present a concise description of BEV research and discover challenges and critical gaps in current BEV‐based analyses for clinical applications. Finally, we also offer suggestions and considerations to improve experimental reproducibility and interoperability in BEV research to promote progress in the field.