Therapeutic effects of four strains of probiotics on experimental colitis in mice

AIM:To investigate the therapeutic effects of four strains of probiotics(E.feacalis,L.acidophilus,C.butyricum and B.adolescentis) on dextran sulphate sodium(DSS)-induced experimental colitis in Balb/c mice.METHODS:Eighty Balb/c mice were randomly divided into 8 groups.Weight-loss,fecal character,fecal occult blood and hematochezia were recorded daily.Disease activity index(DAI) scores were also evaluated everyday.Length of colon was measured and histological scores were evaluated on the 13th day.Myeloperoxidase(MPO) activity was detected.Interleukin-1(IL-1) and IL-4 expression was detected by ELISA and RT-PCR.RESULTS:The four strains of probiotics relieved the inflammatory condition of DSS-induced experimental colitis in mice.Weight loss was slowed down in all probiotics-treated mice.Even weight gain was observed by the end of probiotics treatment.The DAI and histological scores of probiotics-treated mice were lower than those of mice in the control group(1.9 ± 0.2 vs 8.6 ± 0.4,P < 0.05 for E.faecalis).The length of colon of probiotics-treated mice was longer than that of mice in the control group(10.3 ± 0.34 vs 8.65 ± 0.77,P < 0.05 for E.faecalis).The four strains of probiotics decreased the MP activity and the IL-1 expression,but increased the IL-4 expression.E.faecalis had a better effect on DSS-induced experimental colitis in mice than the other three strains.CONCLUSION:The four strains of probiotics have beneficial effects on experimental colitis in mice.E.faecalis has a better effect on DSS-induced experimental colitis in mice than the other three strains.Supplement of probiotics provides a new therapy for UC.

Efficacy profiles for different concentrations of Lactobacillus acidophilus in experimental colitis

AIM:To determine the efficacy profiles of different concentrations of Lactobacillus acidophilus(L.acidophilus)for treating colitis using an experimental murine model.METHODS:Colitis was established in 64 BALB/c mice by adding 5%dextran sodium sulfate(DSS)to the drinking water and allowing ad libitum access for 7 d.The mice were then randomly divided into the following control and experimental model groups(n=8 each;day 0):untreated model control;negative-treatment model control(administered gavage of 1 mL/10 g normal saline);experimental-treatment models C4-C8(administered gavage of 104,105,106,107,or 108CFU/10 g L.acidophilus,respectively);positive-treatment model control(administration of the anti-inflammatory agent prednisone acetate at 45 g/10 g).Eight mice given regular water(no DSS)and no subsequent treatments served as the normal control group.Body weight,fecal traits,and presence of fecal occult blood were assessed daily.All animals were sacrificed on post-treatment day7 to measure colonic length,perform histological scoring,and quantify the major bacteria in the proximal and distal colon.Intergroup differences were determined by one-way ANOVA and post-hoc Student-Newman-Keuls comparison.RESULTS:All treatments(L.acidophilus and prednisone acetate)protected against colitis-induced weight loss(P<0.05 vs model and normal control groups).The extent of colitis-induced colonic shortening was significantly reduced by all treatments(prednisone acetate>C4>C5>C7>C8>C6;P<0.05 vs untreated model group),and the C6 group showed colonic length similar to that of the normal control group(P>0.05).The C6 group also had the lowest disease activity index scores among the model groups.The bacterial profiles in the proximal colon were similar between all of the experimental-treatment model groups(all P>0.05).In contrast,the bacterial profile in the distal colon of the C6 group showed the distinctive features(P<0.05 vs all other experimental-treatment model groups)of Lactobacillus sp.and Bifidobacterium sp.being the most abundant bacteria and Staphylococcus aureus being the least abundant bacteria.CONCLUSION:The most therapeutically efficacious concentration of L.acidophilus(106CFU/10 g)may exert its effects by modulating the bacterial profile in the distal colon.