Yuanyuan Lei

Cholecystectomy represents the most prevalent biliary surgical procedure for gallbladder abnormalities. Growing evidence suggests that cholecystectomy is associated with an elevated risk of colorectal cancer. However, the underlying mechanism remains elusive. Here we show that cholecystectomy exacerbates colorectal tumorigenesis in both AOM/DSS and APC^min/+ mice models. Metagenomic sequencing and targeted metabolomics show that cholecystectomy leads to a decrease of Bifidobacterium breve (B. breve) and an increase of Ruminococcus gnavus (R. gnavus), along with increased levels of glycoursodeoxycholic acid (GUDCA) in human and tauroursodeoxycholic acid (TUDCA) in mice. Fecal microbiota transplantation, single bacterial colonization and bile acid supplementation demonstrate that cholecystectomy-related gut microbiota perturbations promote the production of TUDCA and facilitate colorectal tumorigenesis. RNA-sequencing and co-immunoprecipitation reveal that the compromised bile acid metabolism inhibits farnesoid X receptor (FXR) signaling, disrupts the FXR/β-catenin interaction, and ultimately exacerbates colorectal tumorigenesis. Significantly, FXR agonist obeticholic acid (OCA) averts cholecystectomy-related colorectal tumorigenesis. The gut microbiota holds a crucial position in cholecystectomy-induced colorectal tumorigenesis, and modulation of the gut microbiota-bile acid-FXR axis represents a promising preventive strategy.

Intrahepatic cholestasis of pregnancy (ICP) is a female pregnancy-specific disorder that is characterized by increased serum bile acid and adverse fetal outcomes. The aetiology and mechanism of ICP are poorly understood; thus, existing therapies have been largely empiric. Here we show that the gut microbiome differed significantly between individuals with ICP and healthy pregnant women, and that colonization with gut microbiome from ICP patients was sufficient to induce cholestasis in mice. The gut microbiomes of ICP patients were primarily characterized by Bacteroides fragilis (B. fragilis), and B. fragilis was able to promote ICP by inhibiting FXR signaling via its BSH activity to modulate bile acid metabolism. B. fragilis-mediated FXR signaling inhibition was responsible for excessive bile acid synthesis and interrupted hepatic bile excretion to ultimately promote the initiation of ICP. We propose that modulation of the gut microbiota-bile acid-FXR axis may be of value for ICP treatment.

Nonalcoholic steatohepatitis (NASH) has been linked with the gut-liver axis. Here, we investigate the potential for repurposing disulfiram (DSF), a drug commonly used to treat chronic alcoholism, for NASH. Using a mouse model, we show that DSF ameliorates NASH in a gut microbiota-dependent manner. DSF modulates the gut microbiota and directly inhibits the growth of Clostridium. Administration of Clostridium abolishes the ameliorating effects of DSF on NASH. Mechanistically, DSF reduces Clostridium-mediated 7α-dehydroxylation activity to suppress secondary bile acid biosynthesis, which in turn activates hepatic farnesoid X receptor signaling to ameliorate NASH. To assess the effect of DSF on human gut microbiota, we performed a self-controlled clinical trial (ChiCTR2100048035), including 23 healthy volunteers who received 250 mg-qd DSF for 7 days. The primary objective outcomes were to assess the effects of the intervention on the diversity, composition and functional profile of gut microbiota. The pilot study shows that DSF also reduces Clostridium-mediated 7α-dehydroxylation activity. All volunteers tolerated DSF well and there were no serious adverse events in the 7-day follow-up period. Transferring fecal microbiota obtained from DSF-treated humans into germ-free mice ameliorates NASH. Collectively, the observations of similar ameliorating effects of DSF on mice and humans suggest that DSF ameliorates NASH by modulating the gut microbiota and bile acid metabolism.

Background: The objective of this study was to investigate the association between participation of sports activity (SA) and quality of life (QoL) among Chinese women with early stage breast cancer (BC) during the first five years post BC diagnosis. Methods: BC survivors underwent assessment of QoL and level of SA at 3 time-points: 18-, 36- and 60-months after diagnosis. SA was measured using a validated modified Chinese Baecke questionnaire in the prior 12 months; QoL was measured using EORTC-QLQC30. Results: In total, 1289, 1125 and 1116 BC survivors were included at 18-, 36- and 60-month follow-up, respectively. At 18-month, the percentages of patients belonged to no [0 metabolic equivalent of task (MET)-hours per week], low-level (Conclusions: Findings from the present study support the notion that SA has beneficial effect on QoL during the first 5 years of BC survivorship. Health promotion programs should encourage participation for SA after breast cancer diagnosis.Acknowledgements: This work was supported by World Cancer Research Fund International (Grant Number WCRF 2010/249 and WCRF 2014/1197) and Madam Diana Hon Fun Kong Donation for Cancer Research. Citation Format: Winnie Yeo, Yuanyuan Lei, Kali Cheung, Roselle Lee, Carol Kwok, Ashely Cheng, Ashely Cheng, Frankie Mo, Suzanne Ho. Association of sports activity during the first five years of survival with quality of life among Chinese breast cancer survivors [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P4-11-10.

A novel recurrence-associated metabolic prognostic model for risk stratification and therapeutic response prediction in patients with stage I lung adenocarcinoma

Type 2 diabetes mellitus (T2DM), characterized by insulin resistance and unclear pathogenesis, is a serious menace to human health. Bile acids are the end products of cholesterol catabolism and play an important role in maintaining cholesterol homeostasis. Furthermore, increasing studies suggest that bile acids may regulate glucose tolerance, insulin sensitivity, and energy metabolism, suggesting that bile acids may represent a potential therapeutic target for T2DM. This study summarizes the metabolism of bile acids and, more importantly, changes in their concentrations, constitution, and receptors in diabetes. Furthermore, we provide an overview of the mechanisms underlying the role of bile acids in glucose and lipid metabolism, as well as the occurrence and development of T2DM. Bile acid-targeted therapy may represent a valid approach for T2DM treatment.