In VitroStudy of Bile Salt Hydrolase (BSH) Activity of BSH IsogenicLactobacillus plantarum80 Strains and Estimation of Cholesterol Lowering through Enhanced BSH Activity

Abstract

Growth and bile salt hydrolase (BSH) activity of the isogenic LactobacilZus plantarum 80 (LP80) strains were studied in vitro. In pure culture experiments viability and growth performance of the BSH-LP80 strain was negatively affected by the presence of conjugated bile salts. The LP80 wild type (WT) and BSH overproducing LP80 (pCBH1) strains did not show a die-off upon supplementation of bile salts. The latter strains hydrolysed glyco-conjugated deoxycholate (GDCA) more readily than tauro-conjugated deoxycholate (TDCA), indicating substrate specificity of the enzyme. BSH activities towards TDCA of LP80 WT and LP80 @CBHl) stationary phase cells were 0.17 and 1.02 FmoUmg CDW.h respectively; activities towards GDCA of the respective strains were 3.52 and 54%0 FmoUmg CDW.h respectively. The study of BSH activity as a function of growth revealed a marked difference in behaviour between LP80 WT and LP80 (pCBH1) with LP80 WT hydrolysing GDCA when reaching the exponential phase, whereas LP80 (pCBH 1) immediately started to hydrolyse GDCA. TDCA hydrolysis increased after GDCA hydrolysis was completed. BSH activity of LP80 (pCBH1) in a mixed microbial association, resembling that of the small intestine, was comparable to that determined under pure culture conditions, indicating that BSH activity will probably not be influenced by the presence of the normal intestinal microbiota. Based on the BSH activity of LP80 (pCBH 1) and on physiological data on the bile salt-cholesterol metabolism interrelationship, it was calculated that a daily intake of a realistic amount of highly BSH active Lactobacillus cells, e.g. in the form of yoghurt, might lead to a significant reduction of cholesterol. Hence, this in vitro study indicates that altering BSH activity can be a valid (micro) biological alternative treatment for patients with severe hypercholesterolaemia.

Effects of Dietary Saccharomyces cerevisiae and Butyric Acid Glycerides on Performance and Serum Lipid Level of Broiler Chickens

“…Reduction in circulating levels of cholesterol and LDL with supplemental yeast was reported by other researchers [8,9] who stated that probiotics could contribute to the regulation of serum cholesterol concentrations by deconjugating bile salts.…”

“…Deconjucated bile acids are less soluble at low pH and less absorb in the intestine and are more likely to be excreted in feces [28] . Since the excretion of deconjucated bile acids is enhanced and cholesterol is its precursor, more molecules are spent for recovery of bile acids [8] . As a result of increased synthesis of this acids, it is expected the level of serum cholesterol to be reduced.…”

Bile Salt Hydrolase Activity in Probiotics

“…Since unconjugated bile acids are less efficient than conjugated molecules in the emulsification of dietary lipids and the formation of micelles, BSH activity may compromise normal lipid digestion, and the absorption of fatty acids and monoglycerides could be impaired (22). Microbial BSH activity has been related to growth defects in chickens (32,33) but not in mice (2).…”

Effects ofLactobacillus acidophilus43121 and a Mixture ofLactobacillus caseiandBifidobacterium longumon the Serum Cholesterol Level and Fecal Sterol Excretion in Hypercholesterolemia-Induced Pigs

“…In addition, dietary fat and cholesterol are highly correlated with the blood cholesterol concentration. 4,5) The pig is one of the most suitable models to study atherosclerosis because its distribution of coronary arteries and atherosclerotic characteristics resemble those of a human. Furthermore, apart from their similar digestive systems, pigs and human subjects have also been reported to have a similar lipoprotein metabolism and extensive apolipoprotein homology.…”