The contribution of sulphate reducing bacteria and 5-aminosalicylic acid to faecal sulphide in patients with ulcerative colitis

Abstract

Background-Butyrate oxidation within the colonocyte is selectively inhibited by hydrogen sulphide, reproducing the metabolic lesion observed in active ulcerative colitis. Aims-To study generation of hydrogen sulphide by sulphate reducing bacteria (SRB) and the eVects of 5-aminosalicylic acid (5-ASA) in patients with ulcerative colitis in order to identify a role of this noxious agent in pathogenesis. Patients-Fresh faeces were obtained from 37 patients with ulcerative colitis (23 with active disease) and 16 healthy controls. Methods-SRB were enumerated from fresh faecal slurries and measurements made of sulphate reducing activity, and sulphate and hydrogen sulphide concentrations. The eVect of 5-ASA on hydrogen sulphide production was studied in vitro. Results-All controls and patients with active ulcerative colitis carried SRB and total viable counts were significantly related to the clinical severity grade. SRB were of two distinct types: rapidly growing strains (desulfovibrios) which showed high sulphate reduction rates, present in 30% of patients with ulcerative colitis and 44% of controls; and slow growing strains which had little activity. In vitro, 5-ASA inhibited sulphide production in a dose dependent manner; in patients with ulcerative colitis not on these drugs faecal sulphide was significantly higher than in controls (0.55 versus 0.25 mM, p=0.027). Conclusions-Counts and carriage rates of SRB in faeces of patients with ulcerative colitis are not significantly diVerent from those in controls. SRB metabolism is not uniform between strains and alternative sources of hydrogen sulphide production exist in the colonic lumen which may be similarly inhibited by 5-ASA. The evidence for hydrogen sulphide as a metabolic toxin in ulcerative colitis remains circumstantial. (Gut 2000;46:64-72)

Taurocholic acid metabolism by gut microbes and colon cancer

“…Fecal H 2 S is significantly elevated in UC patients experiencing active disease. [95][96][97][98] However, other reports have reported no significant increase. 99 It has been argued that UC is an "energy deficiency" disease due to the observation that high levels of H 2 S inhibits butyrate oxidation in vitro [100][101][102] and in vivo, 100 the primary energy source for colonocytes.…”

Hydrogen Sulfide Induces Direct Radical-Associated DNA Damage

“…In clinical studies, the presence of either H 2 S or SRB in the intestine has been associated with certain chronic diseases including inflammatory bowel disease and colorectal cancer (6)(7)(8)(9)(10)(11), although a causal relationship has not been established for either disorder. Pitcher et al (12) did not detect differences between counts and carriage rates of SRB in feces of ulcerative colitis patients versus control subjects. Moreover, Fite et al (13) present evidence that SRB may be ubiquitously present in the human colon.…”

Sulfate-reducing bacteria of the human intestine. II. The role in the diseases development

“…Сучасні методи терапії зводяться до застосування протиза-пальних препаратів, антибіотиків і стероїдів [20,52,54]. У разі їх неефективності здійснюють часткове або повне видалення кишки хірургічним способом [8].У кишечнику хворих на ВК людей виявлено збільшену кількість СВБ, порівняно зі здоровими [31,38,78,79]. G. R. Gibson та співавтори встановили, що 92% усіх СВБ, виділених від хворих на ВК людей, належать до роду Desulfovibrio, зокрема Desulfovibrio desulfuricans.…”

“…У кишечнику хворих на ВК людей виявлено збільшену кількість СВБ, порівняно зі здоровими [31,38,78,79]. G. R. Gibson та співавтори встановили, що 92% усіх СВБ, виділених від хворих на ВК людей, належать до роду Desulfovibrio, зокрема Desulfovibrio desulfuricans.…”

“…C. Pitcher зі співавторами встановили, що кількість життєздатних клітин СВБ є більшою у фекаліях хворих з активною стадією хвороби, порівняно з при-хованою [78]. Фізіолого-біохімічні характеристики цих бактерій, виділених від хворих із різними стадіями колітів, були різні.…”