Probiotics as Additives on Therapy in Allergic Airway Diseases: A Systematic Review of Benefits and Risks

Table 2

Characteristics of studies excluded from the review.

Study	Reason for exclusion
Trapp et al. 1993 [20]	Groups 1 and 2 randomized and double blinded, but group 3 were those who did not want to eat yogurt.
Ishida et al. 2005 [21]	Randomized single-blind study with quality score = 0.