The effect of exopolysaccharide-producing probiotic strains on gut oxidative damage in experimental colitis

Oxidative stress plays a role in disease initiation and progression in inflammatory bowel disease (IBD) and manipulation of this pathway may attenuate disease progress. In this study, the effect of exopolysaccharide (EPS)-producing probiotic bacteria on gut oxidative damage was evaluated in a rat model of experimental colitis.

Colitis was induced by intracolonic administration of acetic acid. Rats were treated daily with two probiotic strains, L. delbrueckii subsp. bulgaricus B3 strain (EPS of 211 mg/l; high-EPS group) or L. delbrueckii subsp. bulgaricus A13 strain (EPS of 27 mg/l; low-EPS group), which were given directly into the stomach. Non-colitis-fed control and preventative groups were only treated with the high-EPS producing strain. Antioxidant enzyme activities (superoxide dismutase, catalase, total glutathione, reduced glutathione, glutathione disulfide) and lipid peroxidation were measured in colonic tissue samples after a treatment period of 7 days.

Significant oxidative damage was associated with a higher level of malondialdehyde (MDA) activity and reduced antioxidant enzyme activities in the colitis model group. All antioxidant enzyme activities were higher in both probiotic-treated groups compared with those of the colitis model group (P < 0.001). Lipid peroxidation was significantly ameliorated in both probiotic groups. The improvement of oxidative stress parameters was significantly more in the high-EPS group than in the low-EPS group (P < 0.001).

EPS-producing probiotic bacteria significantly attenuate oxidative stress in experimental colitis. Increased EPS production gives rise to a better probiotic function. These results suggest that EPS molecules could revaluate probiotic strains and exert their beneficial effects on the host and this may have a therapeutic potential.