Patil D H, Westaby D, Mahida Y R, Palmer K R, Rees R, Clark M L, Dawson A M, Silk D B
Gut. 1987 Mar;28(3):255-9. doi: 10.1136/gut.28.3.255.
Lactitol, an unabsorbed sugar with defined laxative threshold and superior taste properties has been suggested as an alternative to lactulose in the treatment of hepatic encephalopathy. In the present study we have compared the colonic metabolism of the two sugars using an in vitro faecal incubation system. Both sugars were readily metabolised by faecal bacteria producing volatile fatty acids and the metabolism was inhibited by neomycin. The effect of lactitol and lactulose on terminal ileal and colonic pH was monitored in six normal subjects using a radiotelemetry technique. Both sugars significantly lowered right colonic pH (basal -6.51 +/- 0.48 vs lactitol -5.63 +/- 0.50; lactulose -5.18 +/- 0.82, p less than 0.05). The pH of rest of the colon and terminal ileum was unaffected. Neomycin given concurrently with lactulose abolished acidification of right colon. As lactitol and lactulose have similar effects within the colon, lactitol would appear to have a role in the treatment of hepatic encephalopathy. As neomycin antagonises the effect of lactulose in the colon, its concurrent use may be less effective in the treatment of hepatic encephalopathy.
乳糖醇是一种未被吸收的糖，具有明确的致泻阈值和良好的口感特性，已被提议作为乳果糖治疗肝性脑病的替代药物。在本研究中，我们使用体外粪便培养系统比较了这两种糖在结肠中的代谢情况。两种糖都很容易被粪便细菌代谢产生挥发性脂肪酸，且新霉素可抑制这种代谢。使用无线电遥测技术在6名正常受试者中监测了乳糖醇和乳果糖对回肠末端和结肠pH值的影响。两种糖均显著降低右结肠pH值（基础值-6.51±0.48，乳糖醇-5.63±0.50；乳果糖-5.18±0.82，p<0.05）。结肠其余部分和回肠末端的pH值未受影响。与乳果糖同时给予新霉素可消除右结肠的酸化。由于乳糖醇和乳果糖在结肠内具有相似的作用，乳糖醇似乎在肝性脑病的治疗中具有一定作用。由于新霉素拮抗乳果糖在结肠中的作用，其同时使用在肝性脑病治疗中可能效果较差。
