Gut microbial methionine impacts circadian clock gene expression and reactive oxygen species level in host gastrointestinal tract

Circadian system disorder induced by aberrantly activated EFNB2-EPHB2 axis leads to facilitated liver metastasis in gastric cancer

BACKGROUND

Liver is one of the most preferred destinations for distant metastasis of gastric cancer (GC) and liver metastasis usually predicts poor prognosis. The achievement of liver metastasis requires continued cross-talk of complex members in tumor microenvironment (TME) including tumor associated macrophages (TAMs).

METHODS

Results from 35 cases of ex vivo cultured living tissues of GC liver metastasis have elucidated that circadian rhythm disorder (CRD) of key molecules involved in circadian timing system (CTS) facilitates niche outgrowth. We next analyzed 69 cases of liver metastasis from patients bearing GC and designed co-culture or 3D cell culture, discovering that TAMs expressing EFNB2 could interact with tumor cell expressing EPHB2 for forward downstream signaling and lead to CRD of tumor cells. Moreover, we performed intrasplenic injection models assessed by CT combined 3D organ reconstruction bioluminescence imaging to study liver metastasis and utilized the clodronate treatment, bone marrow transplantation or EPH inhibitor for in vivo study followed by exploring the clinical therapeutic value of which in patient derived xenograft (PDX) mouse model.

RESULTS

Ex vivo studies demonstrated that CRD of key CTS molecules facilitates niche outgrowth in liver metastases. In vitro studies revealed that TAMs expressing EFNB2 interact with tumor cells expressing EPHB2, leading to CRD and downstream signaling activation. The underlying mechanism is the enhancement of the Warburg effect in metastatic niches.

CONCLUSION

Overall, we aim to uncover the mechanism in TAMs induced CRD which promotes liver metastasis of GC and provide novel ideas for therapeutic strategies.

Washed microbiota transplantation via colonic transendoscopic enteral tube rescues severe acute pancreatitis: A case series

Background

Gut microbiota dysbiosis plays a significant role in the development of acute pancreatitis (AP). However, a recent randomized trial reported negative findings regarding the use of fecal microbiota transplantation (FMT) via the mid-gut tube in severe AP. The case series presents the feasibility of washed microbiota transplantation (WMT) as a new methodology of FMT and its delivery via colonic transendoscopic enteral tubing (TET) for severe AP.

Case series

We presented two cases of severe AP rapidly rescued using WMT via colonic TET. Symptoms related to severe AP and the acute physiology and chronic health evaluation-II score improved soon after WMT. In Case 1, bilirubin and infection indexes continuously decreased after the initial WMT and the patient was successfully weaned off the ventilator and recovered from multiple organ system failures (MSOF) within ten days. In Case 2, the patient's consciousness rapidly improved within one day after WMT, with normal bowel sounds and stable blood pressure without vasoactive drug maintenance. Both Case 1 and Case 2 completed follow-ups of seven months and twenty-two months, respectively, with no reports of new-onset diabetes.

Conclusion

WMT via colonic TET played a critical therapeutic role in rescuing severe AP cases. This is the first report providing direct evidence for the clinical value of targeting microbiota through colonic TET in rescuing severe AP.

Circadian orchestration of host and gut microbiota in infection

Circadian rhythms are present in almost every organism and regulate multiple aspects of biological and physiological processes (e.g. metabolism, immune responses, and microbial exposure). There exists a bidirectional circadian interaction between the host and its gut microbiota, and potential circadian orchestration of both host and gut microbiota in response to invading pathogens. In this review, we summarize what is known about these intestinal microbial oscillations and the relationships between host circadian clocks and various infectious agents (bacteria, fungi, parasites, and viruses), and discuss how host circadian clocks prime the immune system to fight pathogen infections as well as the direct effects of circadian clocks on viral activity (e.g. SARS-CoV-2 entry and replication). Finally, we consider strategies employed to realign normal circadian rhythmicity for host health, such as chronotherapy, dietary intervention, good sleep hygiene, and gut microbiota-targeted therapy. We propose that targeting circadian rhythmicity may provide therapeutic opportunities for the treatment of infectious diseases.

Colonic Transendoscopic Enteral Tubing Is a New Pathway to Microbial Therapy, Colonic Drainage, and Host-Microbiota Interaction Research

The limitation of traditional delivery methods for fecal microbiota transplantation (FMT) gave birth to colonic transendoscopic enteral tubing (TET) to address the requirement of frequent FMTs. Colonic TET as a novel endoscopic intervention has received increasing attention in practice since 2015 in China. Emerging studies from multiple centers indicate that colonic TET is a promising, safe, and practical delivery method for microbial therapy and administering medication with high patient satisfaction. Intriguingly, colonic TET has been used to rescue endoscopy-related perforations by draining colonic air and fluid through the TET tube. Recent research based on collecting ileocecal samples through a TET tube has contributed to demonstrating community dynamics in the intestine, and it is expected to be a novel delivery of proof-of-concept in host-microbiota interactions and pharmacological research. The present article aims to review the concept and techniques of TET and to explore microbial therapy, colonic drainage, and microbial research based on colonic TET.