Effects of Adding Lactobacillus plantarum I-UL4 Metabolites in Drinking Water of Rats

Abstract: The objectives of this experiment were to study the effect of adding different levels of Lactobacillus plantarum I-UL4 (UL4) metabolite in drinking water on the growth performance, plasma cholesterol concentration, faecal LAB and Enterobacteriaceae counts and pH in postweaning rats. A total of 15 female and 15 male post weaning rats were randomly assigned to three groups of drinking water: 100 % drinking water, 65 % drinking water + 35 % UL4 metabolite (35 % UL4) and 30 % drinking water + 70 % UL4 metabolite (70 % UL4) for a period of four weeks. The bacteriocin activity for UL4 was 266.67 AU/ml. Daily feed intake, water intake and weekly live weight were measured. Blood plasma from each rat for total cholesterol analysis was obtained at the end of treatment. Faecal samples were taken directly from rectum from each rat and cultured for LAB and Enterobacteriaceae a day before commencement of the experiment, and then on days 7, 14, 21, and 28 after feeding the metabolite. The growth performance of control rats was better than the UL4 groups. The 35 and 70 % UL4 rats had a lower total plasma cholesterol concentration compared to the control group. The UL4 groups had significantly lower Enterobacteriaceae counts on week 3 and significantly (p<0.05) higher LAB counts after 2 weeks of experiment. The 35 % UL4 rats had lower faecal pH than other treatment groups. In conclusion, the results showed that the addition of UL4 metabolite in the drinking water reduced the growth rate of rats, especially those treated with 70 % UL4, decreased the total cholesterol concentration, increased the faecal LAB counts, reduced Enterobacteriaceae counts and faecal pH