| [ Summary ] |
We investigated the differences between the intestinal flora of colorectal cancer patients and healthy subjects and assessed the possibility of using probiotics to prevent colorectal carcinogenesis. The subjects consisted of 10 colorectal cancer patients and 20 healthy individuals. Stool specimens and peripheral blood specimens were collected from the patients and 10 of the healthy subjects to analyze their intestinal flora and measure natural killer (NK) cell activity and levels of IL-1β intheir blood. Probiotics (Lactobacillus gasseri OLL2716：LG21)were then administered once daily to 10 of the healthy subjects for 12 weeks. Samples were collected 4 weeks, 8 weeks, and 12 weeks after administration, and the same examinations were performed. The Lactobacillus detection rate was significantly higher inthe healthy group thaninthe colorectal cancer group, and the total Clostridium perfringens detectionrate was higher in the colorectal cancer group. The stool pH of the colorectal cancer group indicated alkalosis, and the total amount of short-chain fatty acids in the stools tended to be lower thaninthe healthy group. After ingestionof probiotics, the Lactobacillus detection rate increased. A decrease in the total amount of Clostridium perfringens was seen, fecal pH indicated acidosis, synthesis of fecal putrefaction products was inhibited, and an increase in the shortchainfatty acid isobutyric acid was observed. Blood IL-1β and NK cell activity values were significantly higher from the 4th week onward than the values before ingestion of probiotics. A deterioration of the intestinal environment was observed in colorectal cancer patients as compared to the healthy control subjects. The intestinal environment was considered to have improved when probiotics was consumed. These findings suggest the possibility of preventing colorectal carcinomas with probiotics. |