Effects of oral supplementation with the symbiotic (bifidobacterium longum w11 + fos actilight) on IBS with constipation: a randomized, dose finding trial, versus fibers,

Background and aim: Irritable bowel syndrome (IBS) is characterized by disturbed intestinal motility and sensations. Modulation of intestinal microflora has the potential to target both the disturbances but, to date, few studies have evaluated the efficacy and safety of probiotic administration in IBS. The aim of this study was to evaluate the effect of a symbiotic preparation (Bifidobacterium longum W11 5 × 10 9 viable bacteria + fructooligosaccharide –FOS- 2.5 gr per sachet) in IBS patients with constipation. Material and methods: A total of 30 IBS patients with constipation (22 women, age 18-46 years) according to the Roma III criteria were en- rolled. Patients were randomized into 3 groups receiving 2 or 6 sachets of the symbiotic plus 5 g of partially hydrolyzed guar gum (PHGG), or 5 g of PHGG5 alone, respectively. A daily visual analog score-based questionnaire, investigating the severity of abdominal pain, bloating and the feeling of incomplete evacuation, was administered during 2 run-in weeks and 4 treatment weeks, respectively; also, the number of weekly evacuation and the laxative consumption were considered. At baseline and at the end of the treatment the Bristol scale, the colonic transit time and the SF-36 were also evaluated. Results: At the end of the study, none of the patients reported ad- verse effects. Regardless of the treatment there was no significant improvement of abdominal pain or feeling of incomplete evacuation. A significant reduction of bloating severity was observed in subjects receiving 2 sachets of the symbiotic (4 ± 2vs1.6 ± 1 mm, p=0.01) compared to those receiving 6 or fibers alone (3 ± 2vs2 ± 1and2 ± 1 vs 1.5 ± 1 mm, respectively p=NS). The treatment regimens were similarly and significantly effective in improving frequency of defecation, colonic transit time and the stool consistency, as measured by the Bristol scale, whereas no significant improvement of both mental and physical component of the SF-36 questionnaire was observed. Conclusions: Our data demonstrate the utility of symbiotics over fibres in improving the severity of abdominal bloating in patients with IBS with constipation