Crohn's Disease: Is the Cold Chain Hypothesis Still Hot?

Endoscopic and video capsule endoscopic observation of Yersinia enterocolitis

A woman in her late 20s suffered from epigastralgia following lower abdominal pain with diarrhea. Kampo medicine relieved the complaints, but the pain recurred a month later. She had immigrated from Vietnam to Japan 6 months before the onset of the abdominal pain. Blood test findings were almost within normal limits, except for mild C-reactive protein elevation and positive Helicobacter pylori antibody findings. Colonoscopy revealed an edematous cobblestone-like appearance at the end of the ileum with irregular ulceration mimicking Crohn's disease. Video capsule endoscopy was performed to detect lesions in the small intestine and demonstrated irregular ileal ulcer, reminiscent of Crohn's disease. A biopsy performed during colonoscopy demonstrated granulomatous inflammation with a moderate accumulation of plasma cells and mononuclear cells. The bacterial culture of the biopsy specimen proved the growth of Yersinia enterocolitica. Levofloxacin 500 mg for 7 days rapidly relieved abdominal pain. Yersinia enterocolitis is rare in developed countries, but as a differential diagnosis for Crohn's disease, it is important to treat. This is the first case report of the video capsule endoscopy findings of Yersinia enterocolitis. Video capsule endoscopy can help to confirm the spread of the lesions of Yersinia enterocolitis.

Yersinia enterocolitica in Crohn’s disease

Increasing attention is being paid to the unique roles gut microbes play in both physiological and pathological processes. Crohn’s disease (CD) is a chronic, relapsing, inflammatory disease of the gastrointestinal tract with unknown etiology. Currently, gastrointestinal infection has been proposed as one initiating factor of CD. Yersinia enterocolitica, a zoonotic pathogen that exists widely in nature, is one of the most common bacteria causing acute infectious gastroenteritis, which displays clinical manifestations similar to CD. However, the specific role of Y. enterocolitica in CD is controversial. In this Review, we discuss the current knowledge on how Y. enterocolitica and derived microbial compounds may link to the pathogenesis of CD. We highlight examples of Y. enterocolitica-targeted interventions in the diagnosis and treatment of CD, and provide perspectives for future basic and translational investigations on this topic.

Cold stress induces colitis-like phenotypes in mice by altering gut microbiota and metabolites

Introduction

The modernized lifestyle has been paralleled by an epidemic of inflammatory bowel disease (IBD). Excessive consumption of cold beverages is especially common among the modern humans. However, whether cold stress contributes directly to the gut barrier and gut-brain axis is not clear.

Methods

We conducted a cold stress model induced by cold water. The mice were treated with 14 consecutive days of intragastric cold or common water administration. We observed changes in gut transit and gut barrier in the colon. We also employed RNA sequencing-based transcriptomic analysis to identify the genes potentially driving gut injury, and simultaneously examined the gut microbiota and metabolites in the feces.

Results

We found that cold stress disturbed the intestinal function and increased gut permeability. A set of core genes related to immune responses were consistently overexpressed in the cold stress group. Additionally, cold stress induced decreased bacterial diversity, ecological network, and increased pathogens mainly belonging to Proteobacteria. The dopamine signaling pathway-related metabolites were largely reduced in the cold stress group.

Conclusion

This study revealed that cold stress could trigger an IBD-like phenotype in mice, implying that cold stress is a possible risk factor for IBD development.

Tongxie-Yaofang formula regulated macrophage polarization to ameliorate DSS-induced colitis via NF-κB/NLRP3 signaling pathway

BACKGROUND

Macrophages infiltration and activation play multiple roles in maintaining intestinal homeostasis and participate in the occurrence and development of UC. Thus, the restoration of immune balance can be achieved by targeting macrophage polarization. Previous studies have reported that TXYF could effectively ameliorate DSS-induced colitis. However, the underlying mechanisms of TXYF for DSS-induced colitis are still ill-defined.

METHODOLOGY

This study was designed to explore the therapeutic effect of TXYF and its regulation in macrophages polarization during DSS-induced mice. In C75BL/6 mice, dextran sulfate sodium (DSS) was used to induce colitis and concomitantly TXYF was taken orally to evaluate its curative effect. In vitro experiment was implemented on BMDMs by lipopolysaccharide, IFN- and ATP.

RESULTS

Here, we found that TXYF ameliorated clinical features in DSS-induced mice, decreased macrophages M1 polarization but remarkably increased M2 polarization. Mechanically, TXYF treatment effectively inhibited the activities of nuclear transcription factor NF-κB, which further contributed to the decrease of the inflammasome genes of NLRP3, limiting the activation of NLRP3 inflammasome in vivo and in vitro.

CONCLUSION

Our findings demonstrated administration of TXYF can interfere with macrophage infiltration and polarization to improve the symptoms of acute colitis, by repressing NF-κB/NLRP3 signaling pathway activation. This enriches the mechanism and provides new prospect for TXYF in the treatment of colitis.

Yersiniosis in New Zealand

The rate of yersiniosis in New Zealand (NZ) is high compared with other developed countries, and rates have been increasing over recent years. Typically, >99% of human cases in NZ are attributed to Yersinia enterocolitica (YE), although in 2014, a large outbreak of 220 cases was caused by Yersinia pseudotuberculosis. Up until 2012, the most common NZ strain was YE biotype 4. The emergent strain since this time is YE biotype 2/3 serotype O:9. The pathogenic potential of some YE biotypes remains unclear. Most human cases of yersiniosis are considered sporadic without an identifiable source. Key restrictions in previous investigations included insufficient sensitivity for the isolation of Yersinia spp. from foods, although foodborne transmission is the most likely route of infection. In NZ, YE has been isolated from a variety of sick and healthy domestic and farm animals but the pathways from zoonotic reservoir to human remain unproven. Whole-genome sequencing provides unprecedented discriminatory power for typing Yersinia and is now being applied to NZ epidemiological investigations. A "One-Health" approach is necessary to elucidate the routes of transmission of Yersinia and consequently inform targeted interventions for the prevention and management of yersiniosis in NZ.