To confirm the anti-H. pylori activity of LPS16 further, a
cell-free culture supernatant of LPS16 was incubated with
H. pylori ATCC43504. After 15 minutes’ incubation, viable
H. pylori were reduced to 101 colony-forming units (CFU;
Fig. 1C), whereas viable H. pylori in MRS broth remained at
108 CFU even after 60 minutes (Fig. 1C). The viable H. pylori
in the cell-free culture supernatant from L. reuteri
ATCC55730 was also reduced, but more than in LPS16 supernatant
after 15 minutes’ incubation (unpaired t test,
p < 0.01, Fig. 1C).
To determine if the protein component was required for
bactericidal activity in LPS16, cell-free culture supernatant
of LPS16 was boiled and incubated with H. pylori
ATCC43504. No significant difference was found between
boiled and un-boiled LPS16 cultured supernatant (unpaired
t test, p > 0.05, Fig. 1C).