Dancey C P, Attree E A, Brown K F
University of East London, UK.
Nutr J. 2006 Jun 8;5:16. doi: 10.1186/1475-2891-5-16.
Dietary nucleotide supplementation has been shown to have important effects on the growth and development of cells which have a rapid turnover such as those in the immune system and the gastrointestinal tract. Work with infants has shown that the incidence and duration of diarrhoea is lower when nucleotide supplementation is given, and animal work shows that villi height and crypt depth in the intestine is increased as a result of dietary nucleotides. Dietary nucleotides may be semi-essential under conditions of ill-health, poor diet or stress. Since people with Irritable Bowel Syndrome tend to fulfil these conditions, we tested the hypothesis that symptoms would be improved with dietary nucleotide supplementation.
Thirty-seven people with a diagnosis of Irritable Bowel gave daily symptom severity ratings for abdominal pain, diarrhoea, urgency to have a bowel movement, incomplete feeling of evacuation after a bowel movement, bloating, flatulence and constipation for 28 days (baseline). They were then assigned to either placebo (56 days) followed by experimental (56 days) or the reverse. There was a four week washout period before crossover. During the placebo and experimental conditions participants took one 500 mg capsule three times a day; in the experimental condition the capsule contained the nutroceutical substances. Symptom severity ratings and psychological measures (anxiety, depression, illness intrusiveness and general health) were obtained and analysed by repeated measures ANOVAs.
Symptom severity for all symptoms (except constipation) were in the expected direction of baseline>placebo>experimental condition. Symptom improvement was in the range 4 - 6%. A feeling of incomplete evacuation and abdominal pain showed the most improvement. The differences between conditions for diarrhoea, bloating and flatulence were not significant at the p < .05 level. There were no significant differences between the conditions for any of the psychological measures.
Dietary nucleotide supplementation improves some of the symptoms of irritable bowel above baseline and placebo level. As expected, placebo effects were high. Apart from abdominal pain and urgency to have a bowel movement, the improvements, while consistent, are modest, and were not accompanied by improvements in any of the psychological measures. We suggest that the percentage improvement over and above the placebo effect is a physiological effect of the nucleotide supplement on the gut. The mechanisms by which these effects might improve symptoms are discussed.
膳食核苷酸补充剂已被证明对免疫系统和胃肠道等快速更新的细胞的生长和发育具有重要影响。对婴儿的研究表明，补充核苷酸时腹泻的发生率和持续时间较低，动物研究表明，膳食核苷酸会使肠道绒毛高度和隐窝深度增加。在健康状况不佳、饮食不良或压力大的情况下，膳食核苷酸可能是半必需的。由于肠易激综合征患者往往符合这些情况，我们检验了补充膳食核苷酸会改善症状这一假设。
37名被诊断为肠易激综合征的患者连续28天（基线期）每天对腹痛、腹泻、排便紧迫感、排便后未排空感、腹胀、肠胃气胀和便秘的症状严重程度进行评分。然后他们被分配接受安慰剂治疗（56天），随后接受试验治疗（56天），或者顺序相反。交叉前有四周的洗脱期。在安慰剂和试验治疗期间，参与者每天服用一粒500毫克胶囊，一天三次；在试验治疗期间，胶囊含有营养保健品成分。获取症状严重程度评分和心理指标（焦虑、抑郁、疾病侵扰和总体健康状况），并通过重复测量方差分析进行分析。
所有症状（便秘除外）的症状严重程度呈基线期>安慰剂期>试验治疗期的预期趋势。症状改善幅度在4%-6%之间。未排空感和腹痛改善最为明显。腹泻、腹胀和肠胃气胀在各阶段之间的差异在p<0.05水平上不显著。任何心理指标在各阶段之间均无显著差异。
补充膳食核苷酸可改善肠易激综合征的一些症状，改善程度高于基线期和安慰剂水平。正如预期的那样，安慰剂效应很大。除腹痛和排便紧迫感外，虽然改善是持续一致的，但幅度较小，并且任何心理指标均未得到改善。我们认为，超过安慰剂效应的改善百分比是核苷酸补充剂对肠道的生理效应。本文讨论了这些效应可能改善症状的机制。
