Disrupted mucosal barrier in quiescent ulcerative colitis: effect of metronidazole and of a symbiotic preparation in a pilot cross‐over study

OBJECTIVES:  The aims of the present study were to investigate the plasma concentration of endotoxin in patients with inflammatory bowel disease (IBD), the effect of metronidazole (MNZ) and of symbiotics on that concentration, and the relationship to IBD activity. METHODS:  The study group comprised 26 patients with quiescent ulcerative colitis (UC), all of whom were on maintenance mesalazine treatment (1200− 2400 mg/day). The control group comprised 15 subjects. Blood samples were taken from all study subjects to measure: routine blood chemistry, endotoxin concentration, lipopolysaccharide binding protein (LBP) and macrophage-colony stimulating factor (M-CSF). All the IBD patients were randomly enrolled for a 2-week oral daily treatment regimen with either MNZ (250 mg t.i.d.) or the symbiotic mixture SCM-III (Lactobacillus acidophilus, L. helveticus and Bifidobacteria brevis in an ion- and vitamin-enriched medium; 3 mL t.i.d.). Following a 6-week washout period during which the patients continued their maintenance treatment, the cross-over study of the new treatments was begun. Blood parameters were checked at entry and 2 weeks after each treatment schedule. RESULTS:  The concentration of endotoxin level in the UC patients, as a whole, was comparable with that of the control subjects. However, a separate group of patients with long-standing disease and pancolitis showed a statistically significant increase in toxin. SCM-III, but not MNZ, normalized this parameter. There was no statistical change in LBP and plasma endotoxin-inhibiting capacity in the IBD patients. The M-CSF concentration was increased in the UC group, particularly in the pancolitis subgroup. SCM-III, but not MNZ, significantly decreased the M-CSF concentration in the UC patients, but there was only an insignificant trend toward decrease in the subgroup. There was a significant correlation between M-CSF and endotoxin in the pancolitis subgroup (r: 0.74, P < 0.05). CONCLUSIONS:  Although these preliminary results need to be treated with caution, they suggest the effectiveness of long-term administration of probiotics/symbiotics in conjunction with standard treatment in patients with UC, even if there is not gross disease activity.