Nisin F, intraperitoneally injected, may have a stabilizing effect on the bacterial population in the gastro-intestinal tract, as determined in a preliminary study with mice as model.

AIMS: To determine if nisin F has an effect on the bacterial population in the gastro-intestinal tract. METHODS AND
RESULTS: Six male C57BL/6 mice were intraperitoneally injected with 200 μl sterile saline and six with nisin F (200 μl, equivalent to 640 arbitrary units). Fecal samples were collected before injection and 8, 24 and 48 h after injection, and the bacteria amplified by PCR-DGGE using 16S rDNA primers. The composition of the bacterial population in the gastro-intestinal tract (GIT) of mice that were injected with saline changed during 48 h, whereas the bacterial population in the GIT remained relatively unchanged in animals injected with nisin F.
CONCLUSIONS: These results suggest that nisin F inhibits the growth of specific bacteria in the GIT within the first 4 h. Furthermore, the species remained repressed for at least 44 h after one intraperitoneal injection with nisin F. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first report suggesting that nisin F may have a stabilizing effect on the bacterial population in the gastro-intestinal tract.