Full Papers

Effects of a synbiotic containing Lactobacillus acidophilus ATCC 4962 on plasma lipid profiles and morphology of erythrocytes in hypercholesterolaemic pigs on high- and low-fat diets

Min-Tze Liong^a1 c1, Frank R. Dunshea^a2 and Nagendra P. Shah^a3

^a1 School of Industrial Technology, Food Technology Division, University of Science Malaysia, 11800 Minden, Penang, Malaysia

^a2 Faculty of Land and Food Resources, The University of Melbourne, Parkville, Victoria 3010, Australia

^a3 School of Molecular Sciences, Victoria University, Werribee Campus, PO Box 14428, Melbourne, Victoria 8001, Australia

Abstract

The aim of this study was to evaluate the effect of a synbiotic containing Lactobacillus acidophilus ATCC 4962, fructooligosaccharide, inulin and mannitol on plasma lipid profiles and erythrocyte membrane properties in hypercholesterolaemic pigs on high- and low-fat diets. Twenty-four white male Landrace pigs were randomly allocated to four treatment groups for 8 weeks (n 6). Treatment factors were the supplementation of synbiotic (with and without) and dietary fat (5 and 15 %). The supplementation of synbiotic reduced plasma total cholesterol (P = 0·001), TAG (P = 0·002) and LDL-cholesterol (P = 0·045) for both dietary fats. A higher concentration of esterified-cholesterol in HDL of pigs supplemented with synbiotic than the control regardless of dietary fat (P = 0·036) indicated that cholesterol was reduced in the form of cholesteryl esters. Reduced concentration of cholesteryl esters (P < 0·001) and increased concentration of TAG (P = 0·042) in LDL of pigs on synbiotic suggested that LDL-cholesterol was reduced via the hydrolysis of smaller and denser LDL particles. The erythrocytes of pigs without any synbiotic showed more prevalence of spur cells than those given the synbiotic, as supported by the higher cholesterol: phospholipid ratio in erythrocytes (P = 0·001). Also, membrane fluidity and rigidity were improved as supported by the decreased fluorescence anisotropies in the Hb-free erythrocyte membrane of pigs given synbiotic (P < 0·001). The administration of the synbiotic reduced plasma TAG, total cholesterol and LDL-cholesterol in hypercholesterolaemic pigs, possibly in the form of cholesteryl esters, via the interrelated pathways of lipid transporters (VLDL, LDL and HDL). The synbiotic also reduced deformation of erythrocytes via improved membrane fluidity and permeability.

(Received December 20 2006)

(Revised February 28 2007)

(Accepted March 12 2007)

Key Words:

• Lactobacillus;
• Cholesterol;
• Fructooligosaccharide;
• Inulin;
• Mannitol

Correspondence:

^c1 Corresponding author: Dr Liong Min Tze, fax +604 657 3678, email mintze.liong@usm.my

Footnotes

Abbreviations: ANS, 8-anilino-1-napthalenesulphonic acid; CE, cholesteryl esters; C/P, ratio of cholesterol/phospholipids; DPH, 1,6-diphenyl-1,3,5-hexatriene; FAn, fluorescence anisotropy; FOS, fructooligosaccharide; TMA-DPH, 1-(4-trimethylammonium)-6-phenyl-1,3,5-hexatriene.