Abstract:

To evaluate the effects of Kluyveromyces marxianus M3, with good fermentation performance and high ability to
produce bile salt hydrolase, isolated from Tibetan kefir on the intestinal flora balance in experimental hypercholesterolemic
rats, 40 rats (43 weeks old) were divided into 4 groups and fed a high fat diet supplemented with low, medium and high
dose of freeze-dried K. marxianus M3 powder for a 7-week experimental period. According to our results, in the first five
weeks, the numbers of 3 kinds of bacteria in rat feces gradually changed, and there was no significant difference between the
three experimental groups and the high-fat model group; at the fifth week, the preventive hypercholesterolemia model was
established successfully, the number of Lactobacillus in the three experimental groups was significantly higher than that in
the high-fat model group (P < 0.01), while the number of Salmonella (P < 0.01) and Clostridium perfringens (P < 0.05) was
significantly lower than in the high-fat model; among all experimental groups, the number of Lactobacillus in the low dose
group was the highest while Salmonella and Clostridium perfringens were the lowest, showing that the effect of low dose
was better than the medium and high doses. These results demonstrated that K. marxianus M3 could promote the growth
of intestinal beneficial bacteria and inhibit the breeding of harmful bacteria in the hypercholesterolemic rats, having a good
effect on the intestinal flora balance.

Key words: Tibetan kefir, Kluyveromyces marxianus, animal experiment, intestinal flora balance