Thakkar et al.

L. plantarum , L. brevis , L. rhamnosus , L. casei , L. paracasei, L. delbrueckii ,

L. reuteri, L. vaginalis, L. gastricus and L. salivarius. Probiotics are generally

believed to help host regulate the immune response, inhibit pathogenic

bacteria,ȱmodulateȱgutȱflora,ȱlowerȱbloodȱlipidȱconcentration,ȱetc.ȱAmongȱ

theseȱfunctions,ȱtheȱhypocholesterolemicȱeffectȱisȱofȱgreatȱsignificanceȱforȱ

the maintenance of human cardiovascular health (FAO/WHO, 2002).While

selectingȱ theȱ culturesȱ forȱ desirableȱ traitȱ likeȱ cholesterolȱ loweringȱ effect,ȱ

featuresȱ likeȱ hostȱ specificity,ȱ bileȱ tolerance,ȱ bileȱ saltȱ hydrolaseȱ activity,ȱ

bile deconjugation and cholesterol assimilation are required to be checked

(Walker and Gilliland, 1993).

Elevated level of blood cholesterol is known to endorse atherosclerosis

and facilitate the occurrence of myocardial infarction and stroke (Kaplan et

al., 1988). When the sum of the cholesterol synthesized and obtained from

the diet exceeds the amount required for the synthesis of membranes,

steroids and bile salts; accumulation of cholesterol in the blood vessels

can occur, resulting in obstruction of the vessels. Heart failure from

occluded coronary arteries is the one of the principal reason of fatality

in industrialized societies (Ashar and Prajapati, 2001). Blood cholesterol

reductionȱ throughȱ dietaryȱ modificationȱ isȱ preferredȱ overȱ drugsȱ byȱ

physicians treating hyperlipemic patients, being a natural means without

sideȱ effects.ȱ Increasingȱ evidenceȱ suggestsȱ thatȱ selectedȱ membersȱ ofȱ theȱ

lacticȱacidȱbacteria,ȱwhenȱconsumedȱinȱsufficientlyȱlargeȱamounts,ȱexertȱ

therapeuticȱeffectsȱinȱhumansȱasȱwellȱasȱanimalsȱ(Khedkarȱ et al., 1993).

Differentȱmechanismsȱhasȱbeenȱadvancedȱtoȱexplainȱcholesterolȱremovalȱ

effect,ȱ includingȱ directȱ bindingȱ orȱ assimilationȱ ofȱ cholesterolȱ (Gillilandȱ

et al., 1985), enzymatic hydrolysis of conjugated bile salts (Corzo et al., 1999)

and co-precipitation of cholesterol with deconjugated bile salt (Klaver et

al., 1993) by probiotic lactic acid bacteria. Hence, the required culture that

can grow well in presence of bile, deconjugate bile salts and assimilate

cholesterol would be more useful in establishing and functioning well in

the gastrointestinal tract.

Bile salts are synthesized in the liver from cholesterol and are secreted from

the gall bladder into the duodenum in the conjugated form in volumes

ranging from 500 to 700 ml per day. Probiotic lactobacilli could resist the

relevant physiological concentrations of human bile range from 0.1 to 0.3%

(Dunne et al., 2001). Bile salt is the major route of eliminating cholesterol

from the body (Turley et al., 1988), as well as one of the important pathways

of cholesterol metabolism (Chen et al., 1995). Most excreted conjugated bile

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