Table 1

Basic characteristics of the included literature

DiagnosisSample size (n)
1Roman et al262018Randomised double blindFibromyalgia31Three probiotic mixtures or aboveSTAI
2Farhangi et al212018Randomised triple blindT2DM*62Resistant dextrin†GHQ, DASS
3Schumann et al222018Randomised single blindIBS59Low FODMAPHADS
4Sawada et al172017Randomised double blindHealthy individuals§24Lactobacillus gasseriHADS,STAI
5Sanchez et al232017Randomised double blindObesity105Lactobacillus rhamnosusSTAI
6Romijn et al272017Randomised double blindIBS79Two probiotic mixtures†DASS
7Pinto-Sanchez et al182017Randomised double blindIBS44Bifidobacterium longumHADS,STAI
8Kelly et al202017RandomisedHealthy individuals§29L. rhamnosusBAI, STAI
9Eswaran et al282017Randomised single blindIBS84Low FODMAP†HADS
10Colica et al292017RandomisedHealthy individuals30At least three probiotic mixturesHAM-A
11Azpiroz et al302017Randomised double blindIBS79scFOSHADS
12Lyra et al312016Randomised triple blindIBS340Lactobacillus acidophilusHADS
13Steenbergen et al322015Randomised triple blindHealthy individuals89At least three probiotic mixturesBAI
14Lorenzo-Zúñiga et al332014Randomised triple blindIBS84At least three probiotic mixturesVSI
15Peters et al342014Randomised double blindIBS22Supplementation of glutenSTPI
16Alipour et al352014Randomised double blindRA*46Lactobacillus caseiSTAI
17Yuman and Yingwei362013Randomised double blindHealthy individuals82Nutritional interventionsHAM-A
18Messaoudi et al192011Randomised double blindHealthy individuals55Two probiotic mixturesHADS
19Simrén et al372010Randomised double blindIBS74At least three probiotic mixturesHADS
20Silk et al382009Randomised single blindIBS44Trans-galactooligosaccharide mixtureHADS
21Rao et al392009Randomised double blindCFS39L. caseiBAI
  • 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.