Table 1.

Characteristics of included studies

Reference	Total participants (N probiotic: N control)	Healthcare setting and age of patients	Probiotic species	Daily probiotic dose (cfu)	Duration of probiotic therapy	Control	Outcome (AAD) measurement
Allen et al41	2941 (1470:1471)	Inpatient ≥65	L. acidophilus, B. bifidum	60×109	21 days	Placebo	≥3 loose stools (5–7 Bristol Stool Scale) in 24 hours
Beausoleil et al42	89 (44:45)	Inpatient 54–85	L. acidophilus, L. casei (Bio-K+CL1285, Bio-K+International, Canada)	50×109	Duration of antibiotic	Placebo	≥3 loose stools (5–7 Bristol Stool Scale) in 24 hours
Beniwal et al43	202 (105:97)	Inpatient >18	L. acidophilus, L. bulgaricus, S. thermophilus	0.002×109	8 days	Nothing	>2 loose stools per day
Bravo et al44	86 (41:45)	Outpatient >15	S. boulardii	10.2×109	12 days	Placebo	≥3 loose stools per day for ≥2 days
Can et al35	151 (73:78)	Inpatient 25–50	S. boulardii	Not noted	Not noted	Placebo	Not noted
Chatterjee et al45	343 (176:167)	Outpatient >18	L. acidophilus LA-5, B. animalis ssp lactis BB-12	4×109	Duration of antibiotic	Placebo	≥3 loose stools (5–7 Bristol Stool Scale) for ≥2 days
Cimperman et al46	23 (13:10)	Inpatient >18	L. reuteri ATCC 55730 (BioGaia Biologics, Sweden)	0.2×109	28 days	Placebo	≥3 loose stools (5–7 Bristol Stool Scale) for ≥2 days
Cindoruk et al47	124 (62:62)	Inpatients being treated for H. pylori	S. boulardii	1 g (cfu not noted)	14 days	Placebo	Not noted
de Vrese et al33	88 (30:29:29) (probiotic:pasteurised: acidified)	Outpatients being treated for H. pylori	L. acidophilus, LA-5, B. animalis ssp lactis, BB-12, S. thermophilus	0.25×109	56 days	Pasteurised and acidified placebos	≥3 watery stools in 1 day
Duman et al48	389 (204:185)	Outpatients being treated for H. pylori	S. boulardii	1 g (cfu not noted)	14 days	Nothing	≥3 loose stools per day for ≥2 consecutive days
Ehrhardt et al49	477 (246:231)	Inpatient 40–77	S. boulardii	36×109	Duration of antibiotic+7 days	Placebo	≥3 loose stools (5–7 Bristol Stool Scale) in 24 hours
Evans et al50	160 (80:80)	Healthy outpatients 18–50	L. helveticus+L. rhamnosus	4×109	Duration of antibiotic+7 days	Placebo	≥3 loose stools (5–7 Bristol Stool Scale) in 24 hours
Gao et al28	255 (86:85:84) (high:low:placebo)	Inpatient 50–70	L. acidophilus CL1285, L. casei LBC80R	100×109, 50×109	Duration of antibiotic+7 days	Placebo	≥3 loose stools (5–7 Bristol Stool Scale) in 24 hours
Gotz et al51	79 (36:43)	Inpatient >18	L. acidophilus (gasseri), L. helveticus (bulgaricus) (Lactinex)	4×109	5 days	Placebo	≥3 stools more than normal number of evacuations in 24 hours
Helps et al52	85 (44:41)	Inpatient >18	L. casei Shirota (Yakult)	6.5×109	Duration of antibiotic+7 days	Placebo	≥3 loose stools in 24 hours
Hickson et al53	113 (57:56)	Inpatient >50	L. casei defensis, L. bulgaricus, S. thermophilus (Actimel)	0.21×109	Duration of antibiotic+5 days	Placebo	≥3 loose stools (5–7 Bristol Stool Scale) in 24 hours
Horosheva et al23	271 (91:90:90) (species1:species 2: placebo)	Outpatient ≥45	(1) B. subtilis 3 and B. licheniformis 31, (2) B. licheniformis only	4×109	Duration of antibiotic+7 days	Placebo	≥3 loose stools (5–7 Bristol Stool Scale) for ≥2 days
Iamharit et al54	46 (26:20)	Inpatient	Lyophilized live L. acidophilus+B. bifidum (Infloran)	6×109	14 days	Placebo	≥3 loose stools per day for ≥2 consecutive days or ≥5 loose stools in a day
Imase et al29	19 (5:7:7) (high:low:nothing)	Inpatients being treated for H. pylori	C. butyricum (CMB588)	0.02×109, 0.01×109	7 days	Nothing	Loose or mostly loose stools
Khanal et al55	40 (20:20)	Outpatients undergoing treatment for H. pylori	S. boulardii, Lactobacillus and B. longum	5×109	14 days	Nothing	≥3 loose stools per day
Koning et al56	38 (19:19)	Healthy 18–65	B. bifidum W23, B. lactis W18, B. longum W51, E. faecium W54, L. acidophilus W37 and W55, L. paracasei W72, L. plantarum W62, L. rhamnosus W71, L. salivarius W24	2×109	14 days	Placebo	≥3 loose stools (5–7 Bristol Stool Scale) in 24 hours
Lewis et al57	69 (33:36)	Inpatient >18	S. boulardii	Not noted	Duration of antibiotic	Placebo	≥3 loose stools (on simplified Bristol Stool Scale) in 24 hours
Lönnermark et al58	163 (80:83)	Inpatient >16	L. plantarum 299v	10×109	Duration of antibiotic+7 days	Placebo	≥3 loose stools (5–7 Bristol Stool Scale) for ≥2 days
McFarland et al59	193 (97:96)	Inpatient >18	S. boulardii	Not noted	Duration of antibiotic+3 days	Placebo	≥3 loose stools (5–7 Bristol Stool Scale) for ≥2 days
Ouwehand et al30	503 (168:168:167) (high:low:placebo)	Inpatient 30–70	L. acidophilus NCFM (ATCC700396), L. paracasei Lpc-37 (ATCC SD5275), B. lactis Bi-07 (ATCC SD5220), B. lactis Bl-04 (ATCC SD5219)	17×109, 4.17×109	Duration of antibiotic+7 days	Placebo	≥3 loose stools (5–7 Bristol Stool Scale) in 24 hours
Pirker et al60	678 (340:338)	Inpatient >18	L. casei Shirota (Yakult)	6.5×109	Duration of antibiotic+3 days	Nothing	≥3 loose stools per day for ≥3 days
Plomer et al61	130 (65:65)	Outpatients 18–65 being treated for H. pylori	B. clausii	6×109	Duration of antibiotic+7 days	Placebo	Not noted
Plummer et al62	20 (69:69)	Inpatient >18	L. acidophilus, B. bifidum	20×109	20 days	Placebo	Not noted
Pozzoni et al63	204 (106:98)	Inpatient >50	S. boulardii	10×109	Duration of antibiotic+7 days	Placebo	≥3 loose stools (5–7 Bristol Stool Scale) for ≥2 days
Rajkumar et al64	1126 (549:577)	Inpatient ≥55	L. casei DN114001, L. delbrueckii subspecies bulgaricus, S. thermophilus	20.4×109	Duration of antibiotic+7 days	Placebo	≥2 loose stools (5–7 Bristol Stool Scale) in 24 hours
Safdar et al65	39 (23:16)	Inpatient >18	L. acidophilus	60×109	Duration of antibiotic+14 days	Placebo	≥2 consecutive days of Stool Consistency Continuum score 1, 2 or 3
Sampalis et al66	437 (216:221)	Inpatient >18	L. acidophilus+L. casei (Bio-K+CL1285, Bio-K+International, Canada)	50×109	Duration of antibiotic+5 days	Placebo	≥1 day of ≥1 episode of loose stool
Selinger et al67	122 (61:61)	Inpatient >18	B. breve, B. longum, B. infants, L. acidophilus, L. plantarum, L. paracasei, L. delbrueckii subspecies bulgaricus, S. thermophilus (VSL#3)	900×109	Duration of antibiotic+7 days	Placebo	≥3 loose stools (5–7 Bristol Stool Scale) in 24 hours
Shimbo et al68	35 (18:17)	Outpatients >18 being treated for H. pylori	C. butyricum MIYAIRI 588	Not noted	14 days	Nothing	Not noted
Song et al69	214 (103:111)	Inpatient >18	L. rhamnosus R0011+L. acidophilus R0052	4×109	14 days	Placebo	≥3 loose stools (5–7 Bristol Stool Scale) in 24 hours
Surawicz et al70	180 (116:64)	Inpatient >18	S. boulardii	Not noted	Duration of antibiotic+14 days	Placebo	≥3 loose or watery stools per day for ≥2 consecutive days
Thomas et al71	267 (133:134)	Inpatient >18	L. rhamnosus GG	20×109	14 days	Placebo	Loose stools (1–3 on Stool Consistency Continuum) for ≥2 or more consecutive days, or ≥3 more than patient’s normal daily number of bowel movements
Velasco et al27	314 (122:125:67) (probiotic:placebo: nothing)	Inpatient >18	L. acidophilus La-5, L. casei Lc-01, B. lactis Bb-12 as probiotics and S. thermophilus STY-31, L. bulgaricus LBY-27 as starter strains in both yoghurt drinks	17–23×109 plus starter strains	Duration of antibiotic+5 days	Placebo and nothing control groups	≥3 loose stools (5–7 Bristol Stool Scale) for ≥2 days
Wenus et al72	63 (34:29)	Inpatient >18	L. rhamnosus GG (LGG), L. acidophilus La-5 and B. animalis subspecies lactis BB-12	52.5×109	Not noted	Placebo	≥3 loose stools per day for consecutive 2 days during the test period
Wong et al73	158 (76:82)	Inpatient >18	L. casei Shirota (Yakult)	6.5×109	Duration of antibiotic+7 days	Nothing	≥3 loose stools (5–7 Bristol Stool Scale) for ≥2 days
Wright et al74	86 (41:46)	Inpatient >65	L. casei Shirota (Yakult)	13×109	Duration of admission	Placebo	≥3 loose stools (5–7 Bristol Stool Scale) for ≥2 days
Wu et al31	196 (65:67:64) (high:low:nothing)	Inpatient >18	B. longum, L. acidophilus, E. faecalis	48×109 or 24×109	14 days	Nothing	Not noted

AAD, antibiotic-associated diarrhoea.