Effects of barley variety, dietary fiber and β-glucan content on bile acid composition in cecum of rats fed low- and high-fat diets

Abstract

Diet-induced obesity and insulin resistance have been linked to changes in bile acid (BA) profiles, which in turn are highly dependent on the dietary composition and activity of the gut microbiota. The objective of the present study was to investigate whether the type and level of fiber had an effect on cecal BA composition when included in low- and high-fat diets. Groups of rats were fed two barley varieties, which resulted in three test diets containing three levels of β-glucans and two levels of dietary fiber. BAs were preconcentrated using hollow fiber liquid-phase microextraction and quantified by gas chromatography. The amount of the secondary BAs, lithocholic-, deoxycholic- and hyodexycholic acids was generally higher in groups fed high-fat diets compared with corresponding acids in groups fed low-fat diets (P<.05). In contrast, most of the primary and the secondary BAs, ursodeoxycholic acid and β- and ω-muricholic acids, were two to five times higher (P<.05) in groups fed low-fat diets than in groups fed high-fat diets. This was particularly true for groups fed the highest level of β-glucans and in some cases also the medium level. The BA profile in the gut was strongly dependent on the amount and type of dietary fiber in the diet, which may be useful in the prevention/treatment of diseases associated with changes in BA profiles.

Lithocholic Acid Improves the Survival of Drosophila Melanogaster

“…This caused a shift of colon‐associated bacteria towards the small intestine resulting in a bacterial overgrowth, which could be reversed by the application of bile acids . In addition, the bile acid profile in the rat gut has been changed either by shaping the intestinal microbiota or by the gut bacteria associated fermentation of different amounts and types of fiber, indicating an essential role of the gut bacteria on the composition of bile acids . In the present study, the impact of LCA supplementation on the life expectancy was also abrogated in AB‐treated flies (Figure d), reinforcing an involvement of the intestinal bacteria in mediating the observed effects of LCA.…”

Effects of dietary fibres on gut microbial metabolites and liver lipid metabolism in growing pigs

“…Additionally, dietary fibres can bind the conjugated primary BAs in small intestine and reduce the reabsorption of BAs, leading to an increase in faecal BAs excretion and a decreased intestinal BAs concentration (Ghaffarzadegan, Zhong, Fåk Hållenius, & Nyman, 2018; Molinaro, Wahlström, & Marschall, 2017). A lack of intestinal or hepatic BAs will inhibit BAs receptor farnesoid X receptor ( FXR ), subsequently initiating HNF‐4α‐mediated BAs synthesis pathway (Chiang, 2004; Pandak & Kakiyama, 2019).…”

The Improvement of Parturition Progress by High Intake of Dietary Fibre in Late Gestation is Associated with the Altered Gut Microbiome and Metabolome in Sows

“…Furthermore, dietary bre can serve as the metabolism substrate for speci c bacteria producing secondary bile acids [35]. Our untargeted metabolomic analysis showed the decreased faecal level of 3b- [37,38], whilst soluble beta-glucans increased faecal levels of primary and secondary bile acids [39].…”