Summary: Akkermansia muciniphila ( A. muciniphila ), an intestinal symbiont colonizing in the mucosal layer, is considered to be a promising candidate as probiotics. A. muciniphila is known to have an important value in improving the host metabolic functions and immune responses. Moreover, A. muciniphila may have a value in modifying cancer treatment. However, most of the current researches focus on the correlation between A. muciniphila and diseases, and little is known about the causal relationship between them. Few intervention studies on A. muciniphila are limited to animal experiments, and limited studies have explored its safety and efficacy in humans. Therefore, a critical analysis of the current knowledge in A. muciniphila will play an important foundation for it to be defined as a new beneficial microbe. This article will review the bacteriological characteristics and safety of A. muciniphila , as well as its causal relationship with metabolic disorders, immune diseases and cancer therapy.

The American Journal of Gastroenterology is published by Nature Publishing Group (NPG) on behalf of the American College of Gastroenterology (ACG). Ranked the #1 clinical journal covering gastroenterology and hepatology*, The American Journal of Gastroenterology (AJG) provides practical and professional support for clinicians dealing with the gastroenterological disorders seen most often in patients. Published with practicing clinicians in mind, the journal aims to be easily accessible, organizing its content by topic, both online and in print. www.amjgastro.com, *2007 Journal Citation Report (Thomson Reuters, 2008)

Adequate bowel preparation is required for magnetic resonance enterography (MRE), which can be achieved by administering contrast solution after mid-gut tubing or taking contrast solution orally. We present the design of randomized controlled trial (RCT) to compare the efficacy and compliance of bowel preparation between mid-gut tubing and oral administering for MRE in patients with Crohn’s disease (CD). This is an open-label, multicenter RCT. Ninety-six patients with CD in need of MRE examination and mid-gut tubing (prepared for fecal microbiota transplantation and/or enteral nutrition), aged ≥ 14 years, will be included. Patients will be randomized 1:1 into either bowel preparation by oral administering (oral group) or bowel preparation through mid-gut transendoscopic enteral tubing (TET) (tubing group). The primary outcome measures are: (1) degree of discomfort before/during/after bowel preparation for MRE using a visual 5-grade scale (1 = few, 5 = very severe); and (2) grade of bowel distention evaluated by a 5-grade scale (1 = 0–20% segmental distention, 2 = 20–40% distention, 3 = 40–60% distention, 4 = 60–80% distention, 5 = 80–100% distention). The secondary outcome measure is the accuracy of lesion detection through MRE confirmed by colonoscopy which is evaluated by a 5-point scale. The outcome of this study is expected to provide a novel effective clinical protocol of bowel preparation for MRE in patients with CD. We hope to highlight the concept of physician–patient satisfaction based on different methods of bowel preparation for MRE. ClinicalTrials.gov, NCT03541733 . Registered on 30 May 2018.

Fecal microbiota transplantation (FMT) has become a research focus of biomedicine and clinical medicine in recent years. The clinical response from FMT for different diseases provided evidence for microbiota-host interactions associated with various disorders, including Clostridium difficile infection, inflammatory bowel disease, diabetes mellitus, cancer, liver cirrhosis, gut-brain disease and others. To discuss the experiences of using microbes to treat human diseases from ancient China to current era should be important in moving standardized FMT forward and achieving a better future. Here, we review the changing concept of microbiota transplantation from FMT to selective microbiota transplantation, methodology development of FMT and step-up FMT strategy based on literature and state experts’ perspectives.

Fecal microbiota transplantation (FMT) by manual preparation has been applied to treat diseases for thousands of years. However, this method still endures safety risks and challenges the psychological endurance and acceptance of doctors, patients and donors. Population evidence showed the washed microbiota preparation with microfiltration based on an automatic purification system followed by repeated centrifugation plus suspension for three times significantly reduced FMT-related adverse events. This washing preparation makes delivering a precise dose of the enriched microbiota feasible, instead of using the weight of stool. Intraperitoneal injection in mice with the fecal microbiota supernatant obtained after repeated centrifugation plus suspension for three times induced less toxic reaction than that by the first centrifugation following the microfiltration. The toxic reactions that include death, the change in the level of peripheral white blood cells, and the proliferation of germinal center in secondary lymphoid follicles in spleen were noted. The metagenomic next-generation sequencing (NGS) indicated the increasing types and amount of viruses could be washed out during the washing process. Metabolomics analysis indicated metabolites with pro-inflammatory effects in the fecal microbiota supernatant such as leukotriene B4, corticosterone, and prostaglandin G2 could be removed by repeated washing. Near-infrared absorption spectroscopy could be served as a rapid detection method to control the quality of the washing-process. In conclusion, this study for the first time provides evidence linking clinical findings and animal experiments to support that washed microbiota transplantation (WMT) is safer, more precise and more quality-controllable than the crude FMT by manual.