Bile tolerance, Bile Deconjugation and Cholesterol reducing properties

their conjugated counterparts, and are lost from the body through feces

(Center et al., 1990). This process could lead to a higher metabolism of

cholesterol and, subsequently, the reduction of serum cholesterol (Reynier

et al., 1981). According to the theory of Klaver & Van der Meer (1993),

Bile deconjugation will lead to drop the pH of fermentation media due

to natural acid production by culture, cholesterol micelles destabilized

and cholesterol co-precipitated with free bile acids. It was estimated that

the highest bile salt Molarities throughout the small intestine is between

2.4 and 4.0 mM (Hofmann, 1977). With the high deconjugation activity by

PD2 and PH5 followed by other strains towards sodium taurocholate at

concentration that resemble the human bile, we postulate that these strains

mayȱdeliverȱgoodȱinȱvivoȱdeconjugationȱeffectsȱasȱobservedȱfromȱinȱvitroȱ

experiment.

In vitro cholesterol assimilation

Direct cholesterol assimilation in the intestine may be important in

reducing the absorption of dietary cholesterol from the digestive system

to blood. Cholesterol assimilation capacities vary with the strains of lactic

acid bacteria.

The results of cholesterol assimilation by individual strains of lactobacilli

after 24 and 48 h of incubation under reduced O ₂ tension maintained in gas

pack jar are presented in table 2. In vitro cholesterol reduction by test strains

varied from 13.65 to 76.85 % within 48 h. Cultures PD2 and PH5 showed

maximum reduction within 48 h. However, PFC21, probably being slow

in growth showed only 21.02 % reduction in 24 h, but increased to 47.81 %

in 48 h. PC27 showed consistent increase in cholesterol reduction reaching

to 42.12 % in 48 h from 28.59 in 24 h. PSC6 showed the least reduction in

cholesterol level both at 24 and 48 h of incubation.

Khedkar et al., (1993) obtained a positive in vitro result with the strains

of lactobacilli taking horse serum as the source of cholesterol. The same

procedure was repeated by Ashar & Prajapati (1998) by taking human

blood serum as a source of cholesterol during their research. Considering

this fact we used human serum as the source of cholesterol. Other research

workers have also reported such an in vitro reduction of cholesterol from

broth medium during the growth of lactobacilli under reduced conditions

(Walker and Gilliland, 1993; Staley and Bush, 1984 and Khedkar et al.,

(1993). This was shown by the appearance of cholesterol in the cells

during growth, which was associated with decrease in the concentrations

of cholesterol in the growth medium. Ashar and Prajapati (1998) have

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