Effect of inulin containing fermented milk administration on human intestinal bacterial flora

This study is to understand whether ingestion of inulin containing fermented milk would alter the human intestinal bacterial flora. The human clinical trial employed randomized, placebo controlled, double blind design. 48 healthy participants with aged 18 to 27 years were randomly divided into three groups. The daily meals were supplied during the 7 weeks of experimental period, including an initial one week without fermented milk (run-in period), 4 weeks with two bottles (330 mL each) per day of fermented milk, inulin containing fermented milk, and placebo, respectively (administration period), and 2 weeks follow-up period. The total aerobic bacteria, Bifidobacterium spp., Lactobacillus spp., E coil, and Clostridium pertfringens of each fresh stool sample were analyzed. Results showed the Bifidobacterium / total anerobic becteria in stool was significantly increased (p < 0.05) whereas the harmful E. coli / total anerobic becteria and Clostridium pertfringens / total anerobic becteria were decreased after ingesting the fermented milk and inulin containing fermented milk for 4 weeks, even during the follow-up period when supplement consumption was discontinued, but no significant difference was found for placebo. In conclusion, ingestion of fermented milk or inulin containing fermented milk for 4 weeks is beneficial in improving the intestinal function by increasing the number of stool Bifidobacteria and suppressed E. coli and Clostridium pertfringens.