Table 1. Characteristics of included trials .
| Auther | Journal | Year | Country | No. of Subjects in case group | No. of controls | Gender | Age (years) | Clinical Condition of Subjects | Follow-up Duration | Prebiotic or Synbiotic compounds | Dosage | Significant Outcome | Jadad score |
| Asemi et al. | Clinical Nutrition | 2014 | Iran | 31 | 31 | F/M | 35-70 | T2DM | 6 weeks | Synbiotic | Lactobacillus sporogenes (1 107 CFU), 0.04 g inulin (HPX) as prebiotic with 0.38 g isomalt, 0.36 g sorbitol and 0.05 g stevia as sweetener per 1 g, three times a day in a 9 g package |
Reduction in serum insulin, FPG, triglyceride and hs-CRP; increase in HDL-C, total GSH and uric acid | 3 |
| Bonsu et al. | Int J Diabetes & Metab | 2012 | Canada | 12 | 14 | F/M | >40 | T2DM | 12 weeks | Prebiotic | 10 g of inulin-based fiber/pelacpo:xylitol | No significant outcome | 5 |
| Dehghan et al. | Complementary Therapies in Medicine | 2016 | Iran | 27 | 22 | F | 30-65 | T2DM | 2 months | Prebiotic | 10 g of oligofructose-enriched inulin | Reduction in BMI,WC, HC, DBP, fasting serum glucose, HbA1c, serum lipids, IL-12, IFN-ϒ; increase in IL-4 | 5 |
| Dehghan et al. | Int J Food Sci Nutr | 2013 | Iran | 24 | 25 | F | 20-65 | T2DM | 8 weeks | Prebiotic | 10g/d inulin/10g/d maltodextrin(placebo) | Reduction in FBS, HbA1c, total cholesterol, TG, LDL-C, LDL-C/HDL-C ratio, TC/HDL-C ratio; increase in HDL-c | 5 |
| Ebrahimi et al. | J diabetes metabolic disorders | 2017 | Iran | 35 | 35 | F M | 58(average) | T2DM | 9 weeks | Synbiotic | 500 mg/day Streptococus thermophilus, Fructo oligosaccharide, 0.5 mg lactose |
Improve the HbA1c, BMI and Microalbuminuria |
4 |
| Luo et al. | Human Nutrition and Metabolism | 2000 | France | 10 | 10 | F/M | 57(average) | T2DM | 4 weeks | Prebiotic | 20 g/d Short-chain fructooligosaccharides (FOS)/ sucrose(placebo) | No significant outcome | 1 |
| Moroti et al. | Lipids Health Dis. | 2012 | Brazil | 10 | 10 | F | 50-60 | T2DM | 4 weeks | Synbiotic | 200 mL of a symbiotic shake containing 108 UFC/mL Lactobacillus acidophilus, 108 UFC/mL Bifidobacterium bifidum and 2 g oligofructose/placebo:200 ml of shake without synbiotic | Increase in HDL-c, reduction in fasting glycemia | 2 |
| Pourghassem et al. | Complementary Therapies in Medicine | 2013 | Iran | 24 | 25 | F | 20-65 | T2DM | 8weeks | Prebiotic | 10 g/day of inulin/ maltodextrin(placebo) | Reduction in FPG, HbA1c and MDA; increase in total antioxidant capacity and superoxide dismutase activity | 5 |
| Pourghassem et al. | Complementary Therapies in Medicine | 2015 | Iran | 28 | 32 | F | 30-65 | T2DM | 8 weeks | Prebiotic | 10g/d Resistant Starch (RS2)[2 packages of 5 g] | Reduction in HbA1c, TNF-α, triglyceride, increase in HDL-c | 4 |
| Shakeri et al. | Lipids | 2014 | Iran | 26 | 26 | F/M | 35–70 | T2DM | 8 weeks | Synbiotic | 40 g package of synbiotic bread or probiotic bread for a total of 120 g/day | Reduction in serum TAG, VLDL-C, TC/HDL-C; increase in HDL-c | 5 |