Clinical Medicine Insights: Gastroenterology

Background: There is increased interest in combining nutritional modalities with pharmacological therapies for managing patients with diarrhea-predominant IBS (IBS-D).

Aim: A randomized, double-blind, placebo-controlled study to evaluate the impact of oral serum-derived bovine immunoglobulin/protein isolate (SBI) on gastrointestinal symptom scores and quality of life (QoL) in subjects with IBS-D.

Methods: Study subjects previously diagnosed with IBS-D according to ROME II criteria were recruited from London, Ontario, Canada and assigned to receive 5 g/day SBI, 10 g/day SBI, or placebo for 6 weeks. Daily symptom frequency and severity scores and a modified IBS-36 questionnaire assessed the impact of nutritional intervention. Laboratory assessments were performed at screening and end of treatment (EOT) to evaluate safety. Within-group comparisons of changes in number of days per week with symptoms and symptom severity were conducted on the per-protocol population of subjects using a t-test.

Results: Subjects who received SBI at 10 g/day (N = 15) had statistically significant within-group reductions in abdominal pain (p , 0.01), loose stools (p , 0.01), bloating (p , 0.05), flatulence (p , 0.01), urgency (p , 0.05) and any symptom (p , 0.01) at EOT vs. baseline. Subjects receiving 5 g/day of SBI (N = 15) realized statistically significant within-group reductions in days with flatulence (p , 0.035), incomplete evacuation (p , 0.05), and any symptom (p , 0.01). There were no significant changes in QoL scores or in hematology or clinical chemistry among treatment groups.

Conclusions: This pilot study showed that nutritional therapy with either 10 g/day or 5 g/day of SBI in 30 patients was well tolerated and resulted in statistically significant within group improvements in both symptom days and in daily symptom scores in subjects with IBS D. Additional studies are underway with larger numbers of subjects to validate these findings.