Table 1

Basic characteristics of the included literature

ID	Author	Year	Methods	Subjects		Interventions	Scales
ID	Author	Year	Methods	Diagnosis	Sample size (n)	Interventions	Scales
1	Roman et al26	2018	Randomised double blind	Fibromyalgia	31	Three probiotic mixtures or above	STAI
2	Farhangi et al21	2018	Randomised triple blind	T2DM*	62	Resistant dextrin†	GHQ, DASS
3	Schumann et al22	2018	Randomised single blind	IBS	59	Low FODMAP	HADS
4	Sawada et al17‡	2017	Randomised double blind	Healthy individuals§	24	Lactobacillus gasseri	HADS，STAI
5	Sanchez et al23	2017	Randomised double blind	Obesity	105	Lactobacillus rhamnosus	STAI
6	Romijn et al27	2017	Randomised double blind	IBS	79	Two probiotic mixtures†	DASS
7	Pinto-Sanchez et al18	2017	Randomised double blind	IBS	44	Bifidobacterium longum	HADS，STAI
8	Kelly et al20‡	2017	Randomised	Healthy individuals§	29	L. rhamnosus	BAI, STAI
9	Eswaran et al28	2017	Randomised single blind	IBS	84	Low FODMAP†	HADS
10	Colica et al29	2017	Randomised	Healthy individuals	30	At least three probiotic mixtures	HAM-A
11	Azpiroz et al30	2017	Randomised double blind	IBS	79	scFOS	HADS
12	Lyra et al31	2016	Randomised triple blind	IBS	340	Lactobacillus acidophilus†	HADS
13	Steenbergen et al32	2015	Randomised triple blind	Healthy individuals	89	At least three probiotic mixtures	BAI
14	Lorenzo-Zúñiga et al33	2014	Randomised triple blind	IBS	84	At least three probiotic mixtures	VSI
15	Peters et al34‡	2014	Randomised double blind	IBS	22	Supplementation of gluten	STPI
16	Alipour et al35	2014	Randomised double blind	RA*	46	Lactobacillus casei†	STAI
17	Yuman and Yingwei36	2013	Randomised double blind	Healthy individuals	82	Nutritional interventions	HAM-A
18	Messaoudi et al19	2011	Randomised double blind	Healthy individuals	55	Two probiotic mixtures	HADS HSCL-90
19	Simrén et al37	2010	Randomised double blind	IBS	74	At least three probiotic mixtures	HADS
20	Silk et al38‡	2009	Randomised single blind	IBS	44	Trans-galactooligosaccharide mixture	HADS
21	Rao et al39	2009	Randomised double blind	CFS	39	L. casei	BAI

DASS-42 refers to the 42-item self-report questionnaire designed to assess current severity of symptoms relating to depression, anxiety and stress.
*All the subjects were female.
†Studies conducted treatment as usual (TAU) plus interventions regulating intestinal flora (IRIF) interventions.
‡Cross-over study design.
§All the subjects were male.
BAI, Beck Anxiety Inventory; CFS, chronic fatigue syndrome; DASS-42, Depression, Anxiety and Stress Scale; GHQ, General Health Questionnaire; HADS, Hospital Anxiety and Depression Scale; HAM-A, Hamilton Anxiety Rating Scale; HSCL-90, Hopkins Symptom Checklist; IBS, irritable bowel syndrome; RA, rheumatoid arthritis; STAI, State-Trait Anxiety Inventory; STPI, the State Trait Personality Inventory; T2DM, type 2 diabetes mellitus; VSI, Visceral Sensitivity Index; low FODMAP, diet low in fermentable oligosaccharides, disaccharides, and monosaccharides and polyols; scFOS, short-chain fructooligosaccharides.