Table 2.

Summary of randomized controlled trials of probiotics for the management of chronic constipation

References	Population	Intervention	Comparator	Author’s conclusion
Tabbers et al. (2011)	n = 159 (control n = 80, intervention n = 79)	B. lactis DN-173 010	Acidified milk without probiotics	Increased stool frequency, but not statistically significant compared with control group
Coccorullo et al. (2010)	n = 44 (control n = 22, intervention n = 22)	L. reuteri DSM 17938	Identical placebo	Increased bowel frequency
Favretto et al. (2013)	n = 30 (control n = 15, intervention n = 15)	B. lactis Bi-07	Fresh cheese without probiotics	Beneficial effects
Yang et al. (2008)	n = 126 (control n = 63, intervention n = 63)	B. lactis DN-173010	Acidified milk without probiotics	Beneficial effects on stool frequency, defecation condition and stool consistency
Ishizuka et al. (2012)	n = 17 (cross-over design)	B. lactis GCL2505	Milk-like drink	Beneficial effects
Waller et al. (2011)	n = 100 (control n = 34, Intervention: high dose n = 33 low dose n = 33)	B. lactis HN019	Capsules with rice maltodextrin	Decreased whole gut transit time in a dose-dependent manner
Mazlyn et al. (2013)	n = 90 (control n = 43, intervention n = 47)	L. casei Shirota	Fermented milk without probiotics	Improvement in constipation severity
Riezzo et al. (2012)	n = 20 (cross-over design)	L. paracasei IMPC 2.1	Artichokes without probiotics	Beneficial effects
Koebnick et al. (2003)	n = 70 (control n = 35, intervention n = 35)	L. casei shirota	Beverage without probiotics	Beneficial effects on self-reported severity of constipation and stool consistency