Table 2.

Methodological quality of included trials

Reference	Adequate sequence generation?	Allocation concealment?	Blinding?	Incomplete outcome data addressed?
B LACTIS
Barclay 2003 [4] plus unpublished data	Unclear*	Yes	Yes	No**
Gibson 2009 [7]	Yes	Yes	Yes	Yes
Holscher 2012 [8]	Unclear	Unclear	Yes	Yes
Urban 2008 [5] plus unpublished data	Yes	Yes	Yes	No**
Velaphi 2008 [9]	Unclear	Unclear	Yes	No**
Weizman 2006 [3]	Yes	Unclear	Yes	Yes
Ziegler 2003 [10]	Unclear	Unclear	Unclear	No**
LACTOBACILLUS GG
Scalabrin 2009 [12]	Yes	Yes	Yes	No
Vendt 2006 [11]	Yes	Unclear	Yes	Yes

In all cases, an answer of ‘yes’ indicates a low risk of bias, and an answer of ‘no’ indicates a high risk of bias.

* The randomization procedure was changed during the study because of a problem with formula supply.

** A drop-out rate >20%.