This study was performed to examine the effect of dietary polyphenols on fecal secondary bile acids, such as deoxycholic acid and lithocholic acid, the risk factors of colon cancer, in rats fed a high-fat diet. In experiment 1, rats were fed a 30% beef tallow diet containing 0.5% polyphenols for 3 weeks. Dietary curcumin and caffeic acid significantly reduced the fecal concentration of deoxycholic acid. Dietary caffeic acid, catechin, rutin, and ellagic acid significantly reduced fecal lithocholic acid. Fecal hyodeoxycholic acid, a metabolite of lithocholic acid, was markedly lowered by dietary curcumin, caffeic acid, catechin, and rutin. In experiment 2, rats were fed a 30 or 5% beef tallow diet with or without the addition of 0.5% curcumin. In the rats without receiving curcumin, the fecal level of deoxycholic acid was significantly higher in the high-fat diet group than in the low-fat diet group. Fecal deoxycholic acid was significantly reduced by dietary curcumin in the high-fat diets but not in the low-fat diets. The results suggest novel effects of some polyphenols favorable for colon health by reducing secondary bile acids in animals fed a high-fat diet.

This study demonstrated that 0.5% dietary rutin, ellagic acid, or curcumin markedly increased cecal succinate levels in rats fed a high-fat diet, whereas catechin, caffeic acid, and quercetin did not. Other organic acids were modestly or hardly affected by polyphenols. To clarify the effects of succinate levels increased by polyphenols, this study examined the effects of succinate on the growth and proliferation of colon cancer cells and angiogenesis. The growth and proliferation of HT29 human colon cancer cells and angiogenesis in an ex vivo model were significantly inhibited by succinate at a dose close to that in the cecum of rats fed polyphenols. Furthermore, succinate inhibited the migration of human umbilical vein endothelial cells. These findings suggest that the consumption of some polyphenols affects the health and diseases of the large intestine by elevating succinate.

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Background and Objectives: In transpapillary biliary drainage, metal stents (MSs) exhibit a lower incidence of a biliary obstruction than plastic stents (PSs). However, few studies have compared recurrent biliary obstruction (RBO) when MSs and PSs are used in EUS-guided hepaticogastrostomy (EUS-HGS) and choledochoduodenostomy (EUS-CDS). We retrospectively evaluated the RBO for both stents in each procedure. Patients and Methods: Between November 2012 and December 2020, 85 and 53 patients who underwent EUS-HGS and EUS-CDS for unresectable malignant biliary obstruction, respectively, were enrolled. Factors associated with RBO were assessed. Clinical outcomes were compared between the MS and PS groups using propensity score matching. Results: The clinical success rate and procedure-related adverse events were similar in the MS and PS groups. Multivariate analysis identified the use of PS as a factor associated with RBO (EUS-HGS, P = 0.03; EUS-CDS, P = 0.02). After matching, the median time to RBO in EUS-HGS (MS: 313; PS: 125 days; P = 0.01) in the MS group was longer than that in the PS group. The cumulative incidence of RBO at 1, 3, and 6 months in the MS group was significantly lower than that in the PS group for EUS-HGS (MS: 4.0%, 8.2%, and 8.2%; PS: 12.4%, 24.9%, and 39.5%, respectively, P = 0.01). Conclusions: MS exhibited a lower rate of RBO than PS for EUS-HGS and EUS-CDS.