Probiotics Improves Obesity-associated Dyslipidemia And Insulin Resistance In High-fat Diet-fed Rats

Objective To establish the obese rat model induced by high fat diet. Then, toobserve the differences in height, body weight, abdominal circumference, Lee’s index,and serum levels of fasting glucose, fasting insulin, lipid, and insulin sensitivity index,insulin resistance index as well as insulin secretion index after administration ofLactobacillus acidophilus and Bifidobacterium breve in obese rats. Finally, to explorethe relationship between obesity, serum lipid and insulin resistance, and evaluate theeffect of probiotics on serum lipid, serum insulin and insulin resistance in obese rats.Methods Male Sprague Dawley rats, three weeks old, weighing50±5g, wererandomly divided into two groups: HFD, forty rats were fed with high fat diet, andcontrol, ten rats were fed with standard rodent chow. Four weeks later, thirty-six ratsfrom the HFD group, whose weight was20%higher as compared to the control group,were divided into three groups of twelve rats each:group A were fed with high fat dietand normal saline(1ml/100g body weight), group B were fed with high fat diet andLactobacillus acidophilus(1ml/100g body weight), group C were fed with high fat dietand Bifidobacterium breve(1ml/100g body weight), while control group N were fedwith were fed with standard rodent chow and normal saline(1ml/100g body weight). Atthe end of the study, height, body weight and abdominal circumference of rats weredetermined, fasting blood was collected and separated for determining lipid, fastingglucose and fasting insulin, then calculated Lee’s index, insulin sensitivity index,insulin resistance index as well as insulin secretion index.Then the data was analyzed bySPSS17.0software.Results The rats that come from the HFD group were larger, more water intakeand urine output, less activity when compared with the control group during themodeling. After treatment with Lactobacillus acidophilus and Bifidobacterium breve forfour weeks, they all slightly returned to the baseline. As for body weight, abdominal circumference, Lee’s index, TC, TG and LDL, group A were significantly higher thanthose in control group(P<0.05), group B and group C were dramatically lower thanthose in group A(P<0.05), but there was no stastistically siginificant difference betweengroup B and group C(P>0.05). As for height, there was no siginificantly difference in allgroups(P>0.05). As for HDL, group A was significantly lower than those in controlgroup(P<0.05), group B and group C were dramatically higher than those in groupA(P<0.05), but there was no stastistically siginificant difference between group B andgroup C(P>0.05). As for fasting glucose, fasting insulin, insulin resistance index, insulinsecretion index and insulin sensitivity index, group A was significantly higher thanthose in control group(P<0.05), group B and group C were dramatically lower thanthose in group A(P<0.05),and group C was lower than those in group B (P>0.05).Conclusion During four weeks’ observation, high fat diet can induce obesity inyoung rats. Obesity induces dyslipidemia, hyperglycemia, hyperinuslinemia and insulinresistance in young rats. Lactobacillus acidophilus can decrease the level of serum lipidand glucose, improve insulin resistance in obese rats, so does Bifidobacterium breve.While there is no side effect on the growth and development of rats. Lactobacillusacidophilus has similar therapeutic effect on lowering weight and regulatingdyslipidemia as compared to Bifidobacterium breve in obese rats. However, thetherapeutic effect of Lactobacillus acidophilus on attenuating insulin resistance is not asgood as Bifidobacterium breve.