Gut microbial trimethylamine is elevated in alcohol-associated hepatitis and contributes to ethanol-induced liver injury in mice.

There is mounting evidence that microbes residing in the human intestine contribute to diverse alcohol-associated liver diseases (ALD) including the most deadly form known as alcohol-associated hepatitis (AH). However, mechanisms by which gut microbes synergize with excessive alcohol intake to promote liver injury are poorly understood. Furthermore, whether drugs that selectively target gut microbial metabolism can improve ALD has never been tested. We used liquid chromatography tandem mass spectrometry to quantify the levels of microbe and host choline co-metabolites in healthy controls and AH patients, finding elevated levels of the microbial metabolite trimethylamine (TMA) in AH. In subsequent studies, we treated mice with non-lethal bacterial choline TMA lyase (CutC/D) inhibitors to blunt gut microbe-dependent production of TMA in the context of chronic ethanol administration. Indices of liver injury were quantified by complementary RNA sequencing, biochemical, and histological approaches. In addition, we examined the impact of ethanol consumption and TMA lyase inhibition on gut microbiome structure via 16S rRNA sequencing. We show the gut microbial choline metabolite TMA is elevated in AH patients and correlates with reduced hepatic expression of the TMA oxygenase flavin-containing monooxygenase 3 (FMO3). Provocatively, we find that small molecule inhibition of gut microbial CutC/D activity protects mice from ethanol-induced liver injury. CutC/D inhibitor-driven improvement in ethanol-induced liver injury is associated with distinct reorganization of the gut microbiome and host liver transcriptome. The microbial metabolite TMA is elevated in patients with AH, and inhibition of TMA production from gut microbes can protect mice from ethanol-induced liver injury.

Dietary Choline Supplementation Attenuates High-Fat-Diet-Induced Hepatocellular Carcinoma in Mice.

BACKGROUND: Hepatocellular carcinoma (HCC) is the third most common cause of cancer-related death in the world. Choline deficiency has been well studied in the context of liver disease; however, less is known about the effects of choline supplementation in HCC. OBJECTIVE: The objective of this study was to test whether choline supplementation could influence the progression of HCC in a high-fat-diet (HFD)-driven mouse model. METHODS: Four-day-old male C57BL/6J mice were treated with the chemical carcinogen, 7,12-dimethylbenz[a]anthracene, and were randomly assigned at weaning to a cohort fed an HFD (60% kcal fat) or an HFD with supplemental choline (60% kcal fat, 1.2% choline; HFD+C) for 30 wk. Blood was isolated at 15 and 30 wk to measure immune cells by flow cytometry, and glucose-tolerance tests were performed 2 wk prior to killing. Overall tumor burden was quantified, hepatic lipids were measured enzymatically, and phosphatidylcholine species were measured by targeted MS methods. Gene expression and mitochondrial DNA were quantified by quantitative PCR. RESULTS: HFD+C mice exhibited a 50-90% increase in both circulating choline and betaine concentrations in the fed state (P ≤ 0.05). Choline supplementation resulted in a 55% decrease in total tumor numbers, a 67% decrease in tumor surface area, and a 50% decrease in hepatic steatosis after 30 wk of diet (P ≤ 0.05). Choline supplementation increased the abundance of mitochondria and the relative expression of ß-oxidation genes by 21% and ∼75-100%, respectively, in the liver. HFD+C attenuated circulating myeloid-derived suppressor cells at 15 wk of feeding (P ≤ 0.05). CONCLUSIONS: Choline supplementation attenuated HFD-induced HCC and hepatic steatosis in male C57BL/6J mice. These results suggest a therapeutic benefit of choline supplementation in blunting HCC progression.

Persistent Dysphagia After Induction Chemotherapy in Patients with Esophageal Adenocarcinoma Predicts Poor Post-Operative Outcomes.

PURPOSE: Preoperative therapy is frequently employed in the management of esophageal adenocarcinoma. However, many patients are found to have advanced pathologic stage and have poor outcomes. A prognostic factor which identifies this patient population before surgery would be desirable, as alternative treatment strategies may be warranted. METHODS: Between 2/08 and 1/12, 60 evaluable patients with locally advanced esophageal adenocarcinoma enrolled in single-arm phase II trial of induction chemotherapy, surgery, and post-operative adjuvant chemo-radiotherapy (CRT). A clinical stage of T3, N1, or M1a (AJCC 6th) was required for eligibility. Induction chemotherapy with epirubicin 50 mg/m2 d1, oxaliplatin 130 mg/m2 d1, and fluorouracil 200 mg/m2/day continuous infusion for 3 weeks, was given every 21 days for 3 cycles and was followed by surgical resection. Adjuvant CRT consisted of 50-55 Gy @ 1.8-2.0 Gy/day and 2 cycles of cisplatin (20 mg/m2/day) and fluorouracil (1000 mg/m2/day) given as 96-h infusions during weeks 1 and 4 of radiotherapy. Dysphagia was assessed at baseline and after induction chemotherapy. RESULTS: Persistent dysphagia was associated with worse distant metastatic control [HR 3.48 (1.43-8.43), p = 0.006], recurrence free survival [HR 3.04 (1.34-6.92), p = 0.008], and overall survival [HR 3.31 (1.43-7.66), p = 0.005]. Persistent dysphagia was associated with more advanced pathologic T descriptor (pT) (p = 0.048) and N descriptor (pN) (p = 0.002), a greater median number of involved lymph nodes (3 v 1, p = 0.003), and greater residual tumor viability (p = 0.05). No patients with persistent dysphagia had pT0-T2 or pN0 disease. CONCLUSIONS: Persistent dysphagia after induction chemotherapy is associated with more advanced pathologic stage and inferior outcomes.

Colonic perforation as a complication of collagenous colitis in a series of 12 patients.

OBJECTIVES: The rare complication of colonic perforation in collagenous colitis following colonoscopy or barium enema is reported in this series of 12 patients. METHODS: Patients with collagenous colitis complicated by perforation were collected from the authors' consultation files between 1992 and 2007. Colectomy and biopsy specimens were reviewed and the corresponding clinical data were analyzed. RESULTS: The patients ranged in age from 44 to 80 yr, with a female-to-male ratio of 11:1. Perforation occurred during colonoscopy in 2 patients, within 0-5 days following colonoscopy in 8 patients, and during barium enema in 2 patients. The most notable colonoscopic findings were bleeding linear ulcers of the right colon in 9 patients, several of which developed under direct visualization during endoscopy. The perforation culminated in right hemicolectomy in 11 patients. Linear fissuring ulcers were identified in the resections of 8 patients along with features of perforation, including pneumatosis in 4 patients and barium extravasation within the muscularis propria in 2 patients. CONCLUSIONS: This is the largest published series to date, and the first to uncover several novel clinicopathologic features of perforation in collagenous colitis, including the right colonic predilection (corresponding to disease severity), the association with not only colonoscopy, but also barium enema, the occurrence of recognizable perforation actually developing during the procedure, and a more detailed information on the marked histologic severity of these patients' collagenous colitis. An awareness of this rare but potentially fatal complication of collagenous colitis may facilitate its diagnosis and management.