Table 3. Basic characteristics of the included studies.

Author of study	Age (probiotics group)	Age (control group)*	M/F (probiotics group)	M/F (control group)*	Type of patients included
Nista et al.	46 ± 13	43 ± 13	33/27	22/38	Free of gastrointestinal symptoms
Navarro- Rodriguez et al.	50.4	48.4	21/34	19/33	51 PU patients and 56 dyspepsia patients
Cremonini et al.	–	–	–	–	Free of gastrointestinal symptoms
Cindoruk et al.	45.82 ± 13.35	47.56 ± 13.53	26/36	18/44	Dyspepsia patients
Manfredi et al.	46.4	50.6	39/34	37/39	Free of gastrointestinal symptoms
Shavakhi et al.	42.3 ± 13.3	42.2 ± 13.2	49/41	60/30	Patients with history of PU
Myllyluoma et al.	57.3	53.8	10/13	8/16	Free of gastrointestinal symptoms
Armuzzi et al.	–	–	–	–	Free of gastrointestinal symptoms
Ziemniak et al.	44.4 ± 13.3	43.7 ± 10.3	14/39	78/114	Patients with PU or gastritis
de Bortoli et al.	51.5±13.7	50.1 ± 15.2	56/49	54/47	Free or mild of gastrointestinal symptoms, among 25 PU patients
Sheu et al.	47.8	45.9	40/40	38/42	84 PU patients and 76 dyspepsia patients
Song et al.	49.76±11.7	49.84 ± 11.4	185/145	219/112	Patients with gastrointestinal symptoms, among 492 PU patients
Park et al.	45.2±19.8	47.6 ± 18.5	96/80	95/81	Patients with gastrointestinal symptoms, among 142 PU patients
Kim et al.	48.1 ± 12.4	53.7 ± 12.0	71/97	89/90	113 PU patients and 234 dyspepsia patients
Yasar et al.	38.32 ± 10.66	36.95 ± 8.62	11/27	14/24	Dyspepsia patients
Canducci et al.	–	–	–	–	Dyspepsia patients or patients with history of PU
Armuzzi et al.	–	–	–	–	Free of gastrointestinal symptoms
Medeiros et al.	50.7	53.8	18/13	14/17	Patients with history of PU
Scaccianoce et al.	50	48	7/8	6/10	Free of gastrointestinal symptoms
Deguchi et al.	55.9	57.8	76/39	68/46	Patients with history of PU
Imase et al.	–	–	–	–	Patients with history of PU

*In this table, the control group contains groups with or without a placebo.

**PU = peptic ulcer.