Dose-response effect of Bifidobacterium lactis HN019 on whole gut transit time and functional gastrointestinal symptoms in adults

Abstract

Objective: To assess the impact of Bifidobacterium lactis HN019 supplementation on whole gut transit time (WGTT) and frequency of functional gastrointestinal (GI) symptoms in adults.

Material and methods: We randomized 100 subjects (mean age: 44 years; 64% female) with functional GI symptoms to consume a proprietary probiotic strain, B. lactis HN019 (Fonterra Research Centre, Palmerston North, New Zealand), at daily doses of 17.2 billion colony forming units (CFU) (high dose; n = 33), 1.8 billion CFU (low dose; n = 33), or placebo (n = 34) for 14 days. The primary endpoint of WGTT was assessed by X-ray on days 0 and 14 and was preceded by consumption of radiopaque markers once a day for 6 days. The secondary endpoint of functional GI symptom frequency was recorded with a subject-reported numeric (1-100) scale before and after supplementation.

Results: Decreases in mean WGTT over the 14-day study period were statistically significant in the high dose group (49 ± 30 to 21 ± 32 h, p < 0.001) and the low dose group (60 ± 33 to 41 ± 39 h, p = 0.01), but not in the placebo group (43 ± 31 to 44 ± 33 h). Time to excretion of all ingested markers was significantly shorter in the treatment groups versus placebo. Of the nine functional GI symptoms investigated, eight significantly decreased in frequency in the high dose group and seven decreased with low dose, while two decreased in the placebo group. No adverse events were reported in any group.

Conclusions: Daily B. lactis HN019 supplementation is well tolerated, decreases WGTT in a dose-dependent manner, and reduces the frequency of functional GI symptoms in adults.

Figure 1

Timeline of study activities. DDQ = digestive discomfort questionnaire; FFQ = food frequency questionnaire.

Figure 2

CONSORT patient flow diagram. High dose, 17.2 billion CFU Bifidobacterium lactis HN019; Low dose, 1.8 billion CFU B. lactis HN019. CFU = colony forming unit.

Figure 3

Change in whole gut transit time over 14 days by study group. Values represent mean ± 95% confidence interval. High dose, 17.2 billion CFU Bifidobaaerium lactis HN019; Low dose, 1.8 billion CFU B. lactis HNO19. CFU = colony forming unit.

Figure 4a

Time to radiopaque marker excretion at pre-treatment by study group. High dose, 17.2 billion CFU Bifidobacterium lactis HNO 19; Low dose, 1.8 billion CFU B. lactis HN019. CFU = colony forming unit.

Figure 4b

Time to radiopaque marker excretion at 14 days post-treatment by study group. High dose, 17.2 billion CFU B. lactis HNO 19; Low dose, 1.8 billion CFU B. lactis HNO 19. CFU = colony forming unit.