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

Figures & data

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.

Table I. Baseline subject characteristics.

Characteristic	High dose (n = 33)	Low dose (n = 26)	Placebo (n = 29)	p
Age, yr (mean ± sd)	43 ± 12	44 ± 11	45 ± 11	0.78
Female gender, n (%)	20 (61)	16 (62)	20 (69)	0.76
Ethnicity, n (%)				0.64
-African American	19 (58)	16 (61)	18 (62)
-Hispanic	7 (21)	7 (27)	4 (14)
-White	6 (18)	3 (12)	7 (24)
-Asian	1 (3)	0	0
Body mass index, kg/m^2 (mean ± sd)	32 ± 8	30 ± 7	32 ± 8	0.73
Whole gut transit time, h (mean ± sd)
-Right colon	17 ± 11	22 ± 15	13 ± 9	0.04
-Left colon	17 ± 15	23 ± 17	17 ± 19	0.18
-Rectosigmoid	15 ± 14	16 ± 11	11 ± 12	0.19
-Total	49 ± 30	60 ± 33	42 ± 31	0.13
GI symptom frequency (mean ± sd)*
-Upper GI symptoms
-Vomiting	14.8 ± 21.7	11.0 ± 20.2	8.0 ± 18.6	0.44
-Regurgitation	30.7 ± 27.7	24.9 ± 28.7	18.4 ± 22.6	0.20
-Abdominal pain	34.6 ± 26.6	43.8 ± 30.6	36.0 ± 29.6	0.44
-Nausea	28.6 ± 24.7	29.9 ± 26.8	23.2 ± 26.8	0.60
-Gurgling	47.7 ± 30.9	45.1 ± 29.4	38.3 ± 26.4	0.45
-Lower GI symptoms
-Constipation	68.7 ± 22.0	75.7 ± 30.4	60.9 ± 32.5	0.16
-Diarrhea	14.8 ± 20.0	9.8 ± 21.9	23.2 ± 31.0	0.13
-Irregular bowel movements	61.7 ± 28.8	61.7 ± 32.0	53.8 ± 36.3	0.57
-Flatulence	59.7 ± 32.8	49.0 ± 32.6	46.7 ± 34.0	0.26

Abbreviations: GI = gastrointestinal; sd = standard deviation; *self-rated on a numeric scale anchored at 1 = never and 100 = always.

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 Bifidobacterium lactis HN019; Low dose, 1.8 billion CFU B. lactis HN019. CFU = colony forming unit.

Table II. Whole gut transit time by treatment group and study day.

Whole gut transit time	High dose (n = 33)	Low dose (n = 26)	Placebo (n = 29)
Day 0, mean h	49.2	59.5	42.5
95% CI	39.2 to 59.2	46.7 to 72.3	31.3 to 53.7
Min, median, max	0, 49, 135	9, 68, 111	0, 35, 131
Day 14, mean h	21.0	41.0	43.8
95% CI^†	-	-	-
Min, median, max	0, 5, 131	0, 26.5, 141	0, 46, 131
Absolute change, mean h*	-28.1	-18.5	1.3
95% CI	-38.9 to -17.3	-32.3 to -4.6	-5.7 to 8.3
Min, median, max	-87, -33, 65	-84, -18, 67	-35, 5, 39
Relative change, mean %*	-32.6^‡	-24.5	16.7^‡
95% CI^†	-	-	-
Min, median, max	-100, -94, 600	-100, -48, 214	-100, 11, 286

Abbreviation: CI = confidence interval; *p < 0.001 among groups; ^†CIs were not calculated when distributions were non-normal; ^‡relative change could not be calculated for a denominator of 0, resulting in exclusion of one subject each from the high dose and placebo groups.

Figure 4a. Time to radiopaque marker excretion at pre-treatment by study group. High dose, 17.2 billion CFU Bifidobacterium lactis HN019; 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 HN019; Low dose, 1.8 billion CFU B. lactis HN019. CFU = colony forming unit.

Table III. Mean absolute change in GI symptom frequency score over the 14-day supplementation period.

Symptom*	High dose (n = 33)	Low dose (n = 26)	Placebo (n = 28)
Upper GI symptoms
Vomiting	-9.8*	-7.4	-2.2
Regurgitation	-14.9*	-11.3*	-2.3
Abdominal pain	-17.9^†	-26.6^‡	-8.2
Nausea	-13.8*	-13.8^†	-3.5
Gurgling	-12.9*	-23.9^‡	-4.7
Lower GI symptoms
Constipation	-29.0^‡	-35.8^‡	-14.2*
Diarrhea	-2.9	0.0	-9.4*
Irregular bowel movements	-19.0^†	-22.8^†	-9.5
Flatulence	-14.0*	-15.3*	-5.9

Abbreviation: GI = gastrointestinal; *self-rated on a numeric scale anchored at 1 = never and 100 = always; *p < 0.05, ^† p < 0.01, ^‡ p < 0.001.