Bile Acid Metabolism, Bacterial Bowel Flora and Intestinal Function Following Ileal Pouch-Anal Anastomosis in Dogs, with Reference to the Influence of Administration of Ursodeoxycholic Acid

Abstract

The pathophysiology following a total colectomy with ileal pouch-anal anastomosis (IPAA) has not been sufficiently clarified yet. We investigated bile acid metabolism, bacterial bowel flora and transit of the alimentary tract after IPAA, with reference to administration of ursodeoxycholic acid (UDCA) in dogs undergoing IPAA. Ten adult beagle dogs underwent IPAA at one stage, and were observed for 12 months. UDCA (100 mg/day) was administered orally to five dogs, and the other five did not. In the UDCA(+) group, UDCA replaced other bile acids, especially cholic acid, accounting for 16.5% of gallbladder bile at 12 months after surgery. Both plasma levels and postprandial increase of total bile acids remained unchanged in the UDCA(+) group, but decreased in the UDCA(-) group at 12 months. Fecal excretion of bile acids tended to be smaller in the UDCA(+) group, and the ratio of secondary to primary bile acids was larger in the UDCA(-) group. Almost all the bile acids were in free form in stool, and UDCA constituted 19% in the UDCA(+) group. The transit time of the whole alimentary tract was elongated by administering UDCA, especially at an early period after IPAA. Although both anaerobic and aerobic bacteria decreased after IPAA, the latter decreased more in stool, resulting in an increase in the ratio of total anaerobes/total aerobes, especially in the UDCA(-) group. The decrease in Bacteroidaceae and Lactobacillus after IPAA was slightly smaller in the UDCA(+) group. Administration of UDCA following IPAA was efficient to induce rapid intestinal adaptation and also to keep the bile acid fraction in the ileal pouch less harmful.

A commercial grain-free diet does not decrease plasma amino acids and taurine status but increases bile acid excretion when fed to Labrador Retrievers

“…In addition to urinary losses, fecal loss of taurine occurs when the BA are not reabsorbed through the enterohepatic circulation ( Hickman et al, 1992 ; Ajouz et al, 2014 ; Dawson and Karpen, 2015 ). In the dog, most of the primary BA (cholic acid and chenodeoxycholic acid) are synthesized from cholesterol and conjugated with taurine ( Czuba and Vessey, 1981 ; Imamura et al, 2000 ) rather than glycine ( Zhang et al, 2016 ) before being secreted into the small intestine. Hamsters who consume greater dietary taurine experienced increased BA secretion ( Bellentani et al, 1987 ); while this is yet to be measured in dogs, dietary taurine supplementation could also lead to an increase in BA secretion in dogs; however, it is generally accepted that the supplementation of taurine will lead to excretion in the urine ( Chesney et al, 2010 ).…”

Changes in the faecal bile acid profile in dogs fed dry food vs high content of beef: a pilot study

“…In contrast to the possible cytotoxic effects of DCA and LCA on colonic cells, UDCA is believed to have chemoprotective potential [ 19 , 48 ]. A previous study of ten laboratory dogs described that oral treatment with UDCA resulted in lower ratio of secondary to primary BA [ 10 ]. Interestingly, the quantity of faecal UDCA in humans appear to be low in general [ 49 ], in contrast to the levels in dogs observed in this study.…”

“…The primary BA, cholic acid (CA) and chenodeoxycholic acid (CDCA) are synthetized from cholesterol and conjugate with either glycine or taurine in the liver. The latter is the most common in dogs [ 10 , 11 ]. Most conjugated BA (> 95%) are reabsorbed in the ileum [ 12 ] and are returned to the liver through the enterohepatic circulation.…”

Ursodeoxycholic acid dose‐dependently improves liver injury in rats fed a methionine‐ and choline‐deficient diet

“…Elevated endogenous ethanol is a result of bacterial overgrowth in animals and patients with NASH 38 . The administration of UDCA suppressed the decrease of bowel aerobic bacteria in dogs following a total colectomy, maintaining the intestinal environment close to preoperative state 39 . The spectra of intestinal microflora significantly changed after the treatment with UDCA in patients with cholesterol gallstones.…”