Consumption of both the probiotic Bifidobacterium longum and prebiotic psyllium for four weeks led to improvements in the ‘quality of life’ of 120 people suffering from ulcerative colitis (UC), a type of inflammatory bowel disease.
Researchers from the Nippon Medical School in Tokyo report that individual supplementation with the probiotic or the prebiotic did not produce statistically significant improvements in the quality of life, and that only the synbiotic approach was effective.
The results are published online ahead of print in the journal Nutrition.
“This is the first report of a randomized trial comparing the efficacy of probiotics and prebiotics with combined therapy with synbiotics for sustained remission in patients with ulcerative colitis,” wrote lead author Shunji Fujimori.
According to the FAO/WHO, probiotics are defined as "live microorganisms which when administered in adequate amounts confer a health benefit on the host". Prebiotics are "nondigestible substances that provide a beneficial physiological effect on the host by selectively stimulating the favourable growth or activity of a limited number of indigenous bacteria". Synbiotics are a combination of the two.
The researchers divided the 120 volunteers with UC into three groups. One group received daily a daily B. longum supplement (Bificolon, Nisshin Kyorin Pharmaceutical Co., Tokyo), providing two billion colony forming units. The second group received a daily psyllium supplement (8 grams, Isagol, Fibro Pharmacy, Co., Tokyo). The third group received daily supplements that combined the two (synbiotic).
At the end of four weeks, Fujimori and co-workers report that only 94 people completed the trial. According to scores attained using the inflammatory bowel disease questionnaire (IBDQ), scores improved within the groups, indicating an improvement in the quality of life of the participants.
Only scores of emotion increased significantly in the probiotic group, but no improvements in bowel functions were recorded. In the prebiotic group, no improvements in scores were observed after four weeks, said the researchers, but bowel function did improve significantly.
Participants in the synbiotic group experienced significant increases in all the scores, but bowel function changes were not significant, they said.
Furthermore, the researchers noted decreases in the levels of a protein associated with inflammation called C-reactive protein (CRP) in the synbiotic group.
What’s really happening?
Multiple mechanisms may be behind the effects, wrote the researchers, with previous studies noting beneficial effects on immune and inflammatory markers, while psyllium has also been reported to improve the consistency of faeces.
The study has obvious limitations, including the lack of a placebo group for complete comparison. Also, the researchers did not measure UC disease activity using endoscopic examination, but based their results on results from a questionnaire.
“Although in our study four weeks of synbiotic [supplements] was shown to gradually resolve inflammation in patients with active UC disease, we are still not sure whether this short [...] period is adequate enough to properly evaluate the effect of our test therapies on the maintenance of remission in patients with UC,” they added.
Source: NutritionPublished online ahead of print 8 February 2009, doi: 10.1016/j.nut.2008.11.017: "A randomized controlled trial on the efficacy of synbiotic versus probiotic or prebiotic treatment to improve the quality of life in patients with ulcerative colitis"Authors: S. Fujimori, K. Gudis, K. Mitsui, T. Seo, M. Yonezawa, S. Tanaka, A. Tatsuguchi, C. Sakamoto