AIM.: The lactic bacteria are Gram-positive microorganisms with coccus or stick shape, which share a number of physiological and biochemical properties. Several experimental evidences suggest the possibility of using
lactic acid bacterial as a preventive or therapeutic potential approaches, alternative or complementary to prevention or treatment protocols currently followed in several pathological conditions. Lactobacillus brevis is able, through the
arginine-deiminase activity, to subtract the substrate (
arginine) to
nitric oxide synthase, and to inhibit in vitro generation of
nitric oxide from rat's peritoneal macrophages. These data led us to study the in vivo L. brevis anti-inflammatory effect choosing as experimental model the
gingivitis. MATERIALS AND METHODS.: In our study were examined 21 subjects, 16 males and 5 females, aged between 5 and 12 years, with marginal
gingivitis problems who have been given
chewing gum containing the principle to test in measure of three per day. RESULTS.: At the time T1,
after treatment, 18 patients no longer showed
inflammation; 2 of them had a slight
inflammation and only 1 patient still showed a moderate
inflammation. CONCLUSIONS.: From our research, as confirmed by clinical and laboratory investigation, results an effective anti-inflammatory action of
arginine-deiminase system that some bacteria possessing.