Probiotic supplementation decreases intestinal transit time: Meta-analysis of randomized controlled trials

Table 5 Subgroup analysis of study- and subject-related factors on intestinal transit time

Study	SMD	95%CI	P-value(within groups)	P-value(between groups)
Subject condition
Constipation/IBS-C (n = 7)	0.59	0.39-0.79	< 0.001	0.01
Healthy (n = 6)	0.17	-0.08-0.42	0.18
Age
≥ 40 years (n = 7)	0.59	0.39-0.79	< 0.001	0.01
< 40 years (n = 6)	0.17	-0.08-0.42	0.18
Study design
Parallel groups (n = 8)	0.49	0.24-0.75	< 0.001	0.23
Cross-over (n = 5)	0.25	-0.06-0.56	0.11
Body mass index1
≥ 25 kg/m2 (n = 4)	0.61	0.27-0.95	< 0.001	0.29
< 25 kg/m2 (n = 4)	0.34	-0.02-0.70	0.06
Female gender proportion
≥ 75% (n = 6)	0.44	0.17-0.76	< 0.01	0.47
< 75% (n = 7)	0.32	0.05-0.60	0.02
Treatment duration
< 20 d (n = 7)	0.43	0.18-0.67	< 0.001	0.62
≥ 20 d (n = 6)	0.32	-0.02-0.66	0.07
Daily probiotic dosage
≥ 1010 cfu (n = 8)	0.41	0.14-0.68	< 0.01	0.84
< 1010 cfu (n = 5)	0.36	0.05-0.68	0.02

¹Body mass index not reported for 5 treatment effects. IBS-C: Irritable bowel syndrome, constipation predominant; SMD: Standardized mean difference.