Effects of Dietary Fiber Interventions on Gut Health and Glycemic Control in Type 2 Diabetes Mellitus: A Systematic Review of Human Intervention Studies
Downloads
Type 2 diabetes mellitus (T2DM) is a rapidly increasing global health burden, with dietary fiber proposed as a modifiable nutritional strategy to improve glycemic control and gut health. However, clinical evidence regarding different fiber types and underlying mechanisms remains heterogeneous. This systematic review aimed to evaluate the effects of dietary fiber interventions on gut microbiota composition and glycemic outcomes in adults with T2DM. A systematic literature search was conducted in PubMed, ScienceDirect, the Cochrane Library, and Europe PMC in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Human intervention studies, including randomized controlled trials, crossover trials, and controlled clinical trials involving adults with T2DM receiving dietary fiber supplementation or high-fiber dietary interventions, were eligible for inclusion. Risk of bias was assessed using the Joanna Briggs Institute (JBI) Critical Appraisal Checklist.Twenty-six studies involving 1,601 participants were included. Dietary fiber interventions consistently improved glycemic outcomes, with the most consistent effects observed in reductions in fasting glucose and glycated hemoglobin (HbA1c), particularly with psyllium and inulin supplementation. Improvements in postprandial glucose responses were demonstrated across multiple fiber types in acute and short-term interventions. Dietary fiber supplementation may improve glycemic control in individuals with T2DM, with preliminary evidence suggesting that modulation of gut microbiota may contribute to these effects. Standardized, long-term clinical trials integrating metabolic and microbiota-related outcomes are required to further clarify these mechanisms.
Abutair, A. S., Naser, I. A., & Hamed, A. T. (2016a). Soluble fibers from psyllium improve glycemic response and body weight among diabetes type 2 patients (randomized control trial). Nutrition Journal, 15(1). https://doi.org/10.1186/s12937-016-0207-4
Abutair, A. S., Naser, I. A., & Hamed, A. T. (2016b). Soluble fibers from psyllium improve glycemic response and body weight among diabetes type 2 patients (randomized control trial). Nutrition Journal, 15(1), 1–7. https://doi.org/10.1186/s12937-016-0207-4
Anderson, J. W., Allgood, L. D., Turner, J., Oeltgen, P. R., & Daggy, B. P. (1999a). Effects of psyllium on glucose and serum lipid responses in men with type 2 diabetes and hypercholesterolemia. American Journal of Clinical Nutrition, 70(4), 466–473. https://doi.org/10.1093/ajcn/70.4.466
Anderson, J. W., Allgood, L. D., Turner, J., Oeltgen, P. R., & Daggy, B. P. (1999b). Effects of psyllium on glucose and serum lipid responses in men with type 2 diabetes and hypercholesterolemia. American Journal of Clinical Nutrition, 70(4). https://doi.org/10.1093/ajcn/70.4.466
Birkeland, E., Gharagozlian, S., Birkeland, K. I., Valeur, J., Måge, I., Rud, I., & Aas, A. M. (2020a). Prebiotic effect of inulin-type fructans on faecal microbiota and short-chain fatty acids in type 2 diabetes: a randomised controlled trial. European Journal of Nutrition, 59(7), 3325–3338. https://doi.org/10.1007/s00394-020-02282-5
Birkeland, E., Gharagozlian, S., Birkeland, K. I., Valeur, J., Måge, I., Rud, I., & Aas, A. M. (2020b). Prebiotic effect of inulin-type fructans on faecal microbiota and short-chain fatty acids in type 2 diabetes: a randomised controlled trial. European Journal of Nutrition, 59(7). https://doi.org/10.1007/s00394-020-02282-5
Birkeland, E., Gharagozlian, S., Gulseth, H. L., Birkeland, K. I., Hartmann, B., Holst, J. J., Holst, R., & Aas, A. M. (2021a). Effects of prebiotics on postprandial GLP-1, GLP-2 and glucose regulation in patients with type 2 diabetes: A randomised, double-blind, placebo-controlled crossover trial. Diabetic Medicine, 38(10). https://doi.org/10.1111/dme.14657
Birkeland, E., Gharagozlian, S., Gulseth, H. L., Birkeland, K. I., Hartmann, B., Holst, J. J., Holst, R., & Aas, A. M. (2021b). Effects of prebiotics on postprandial GLP-1, GLP-2 and glucose regulation in patients with type 2 diabetes: A randomised, double-blind, placebo-controlled crossover trial. Diabetic Medicine, 38(10), 1–10. https://doi.org/10.1111/dme.14657
Dehghan, P., Gargari, B. P., Jafar-Abadi, M. A., & Aliasgharzadeh, A. (2014a). Inulin controls inflammation and metabolic endotoxemia in women with type 2 diabetes mellitus: A randomized-controlled clinical trial. International Journal of Food Sciences and Nutrition, 65(1). https://doi.org/10.3109/09637486.2013.836738
Dehghan, P., Gargari, B. P., Jafar-Abadi, M. A., & Aliasgharzadeh, A. (2014b). Inulin controls inflammation and metabolic endotoxemia in women with type 2 diabetes mellitus: A randomized-controlled clinical trial. International Journal of Food Sciences and Nutrition, 65(1), 117–123. https://doi.org/10.3109/09637486.2013.836738
Ding, X., Hernandez-Serrano, A. I., Young, J. J., & Pickwell-MacPherson, E. (2024). Variation of skin hydration profile with biophysical factors and lifestyle revealed by in vivo terahertz sensing. Biomedical Optics Express, 15(9), 5180–5198. https://doi.org/10.1364/BOE.527731
Kim, E. K., Oh, T. J., Kim, L. K., & Cho, Y. M. (2016a). Improving effect of the acute administration of dietary fiber-Enriched cereals on blood glucose levels and gut hormone secretion. Journal of Korean Medical Science, 31(2), 222–230. https://doi.org/10.3346/jkms.2016.31.2.222
Kim, E. K., Oh, T. J., Kim, L. K., & Cho, Y. M. (2016b). Improving effect of the acute administration of dietary fiber-Enriched cereals on blood glucose levels and gut hormone secretion. Journal of Korean Medical Science, 31(2), 222–230. https://doi.org/10.3346/jkms.2016.31.2.222
Li, H., Zhang, L., Li, J., Wu, Q., Qian, L., He, J., Ni, Y., Kovatcheva-Datchary, P., Yuan, R., Liu, S., Shen, L., Zhang, M., Sheng, B., Li, P., Kang, K., Wu, L., Fang, Q., Long, X., Wang, X., … Jia, W. (2024). Resistant starch intake facilitates weight loss in humans by reshaping the gut microbiota. Nature Metabolism, 6(3). https://doi.org/10.1038/s42255-024-00988-y
Li, X., Cai, X., Ma, X., Jing, L., Gu, J., Bao, L., Li, J., Xu, M., Zhang, Z., & Li, Y. (2016). Short-and long-term effects of wholegrain oat intake on weight management and glucolipid metabolism in overweight type-2 diabetics: A randomized control trial. Nutrients, 8(9). https://doi.org/10.3390/nu8090549
Lu, Z. X., Walker, K. Z., Muir, J. G., & O’Dea, K. (2004). Arabinoxylan fibre improves metabolic control in people with type II diabetes. European Journal of Clinical Nutrition, 58(4). https://doi.org/10.1038/sj.ejcn.1601857
Makki, K., Deehan, E. C., Walter, J., & Bäckhed, F. (2018). The Impact of Dietary Fiber on Gut Microbiota in Host Health and Disease. Cell Host and Microbe, 23(6), 705–715. https://doi.org/10.1016/j.chom.2018.05.012
Moreira, F. D., Mendes, G. F., Nascimento, G. D. M., Reis, C. E. G., Gallassi, A. D., & Welker, A. F. (2024a). Postprandial hyperglycemia in patients with type 2 diabetes is reduced by raw insoluble fiber: A randomized trial. Nutrition, Metabolism and Cardiovascular Diseases, 34(12), 2673–2679. https://doi.org/10.1016/j.numecd.2023.09.013
Moreira, F. D., Mendes, G. F., Nascimento, G. D. M., Reis, C. E. G., Gallassi, A. D., & Welker, A. F. (2024b). Postprandial hyperglycemia in patients with type 2 diabetes is reduced by raw insoluble fiber: A randomized trial. Nutrition, Metabolism and Cardiovascular Diseases, 34(12), 2673–2679. https://doi.org/10.1016/j.numecd.2023.09.013
Noureddin, S., Mohsen, J., & Payman, A. (2018a). Effects of psyllium vs. placebo on constipation, weight, glycemia, and lipids: A randomized trial in patients with type 2 diabetes and chronic constipation. Complementary Therapies in Medicine, 40. https://doi.org/10.1016/j.ctim.2018.07.004
Noureddin, S., Mohsen, J., & Payman, A. (2018b). Effects of psyllium vs. placebo on constipation, weight, glycemia, and lipids: A randomized trial in patients with type 2 diabetes and chronic constipation. Complementary Therapies in Medicine, 40(February), 1–7. https://doi.org/10.1016/j.ctim.2018.07.004
Ojo, O., Feng, Q. Q., Ojo, O. O., & Wang, X. H. (2020a). The role of dietary fibre in modulating gut microbiota dysbiosis in patients with type 2 diabetes: A systematic review and meta-analysis of randomised controlled trials. Nutrients, 12(11). https://doi.org/10.3390/nu12113239
Ojo, O., Feng, Q. Q., Ojo, O. O., & Wang, X. H. (2020b). The role of dietary fibre in modulating gut microbiota dysbiosis in patients with type 2 diabetes: A systematic review and meta-analysis of randomised controlled trials. Nutrients, 12(11), 1–21. https://doi.org/10.3390/nu12113239
Ojo, O., Ojo, O. O., Zand, N., & Wang, X. (2021a). The Effect of Dietary Fibre on Gut Microbiota, Lipid Profile, and Inflammatory Markers in Patients with Type 2 Diabetes: A Systematic Review and Meta-Analysis of Randomised Controlled Trials. Nutrients, 13(2), 1805. https://doi.org/10.1080/13813455.2021.1987477
Ojo, O., Ojo, O. O., Zand, N., & Wang, X. (2021b). The Effect of Dietary Fibre on Gut Microbiota, Lipid Profile, and Inflammatory Markers in Patients with Type 2 Diabetes: A Systematic Review and Meta-Analysis of Randomised Controlled Trials. Nutrients, 13(2), 1805. https://doi.org/10.1080/13813455.2021.1987477
Pedersen, C., Gallagher, E., Horton, F., Ellis, R. J., Ijaz, U. Z., Wu, H., Jaiyeola, E., Diribe, O., Duparc, T., Cani, P. D., Gibson, G. R., Hinton, P., Wright, J., La Ragione, R., & Robertson, M. D. (2016a). Host-microbiome interactions in human type 2 diabetes following prebiotic fibre (galacto-oligosaccharide) intake. British Journal of Nutrition, 116(11), 1869–1877. https://doi.org/10.1017/S0007114516004086
Pedersen, C., Gallagher, E., Horton, F., Ellis, R. J., Ijaz, U. Z., Wu, H., Jaiyeola, E., Diribe, O., Duparc, T., Cani, P. D., Gibson, G. R., Hinton, P., Wright, J., La Ragione, R., & Robertson, M. D. (2016b). Host-microbiome interactions in human type 2 diabetes following prebiotic fibre (galacto-oligosaccharide) intake. British Journal of Nutrition, 116(11). https://doi.org/10.1017/S0007114516004086
Pick, M. E., Hawrysh, Z. J., Gee, M. I., Toth, E., Garg, M. L., & Hardin, R. T. (1996). Oat bran concentrate bread products improve long-term control of diabetes: A pilot study. In Journal of the American Dietetic Association (Vol. 96, Number 12, pp. 1254–1261). https://doi.org/10.1016/S0002-8223(96)00329-X
Pugh, J. E., & Chambers, E. S. (2025a). Dietary fibre and the gut microbiome: implications for glucose homeostasis. Current Opinion in Clinical Nutrition and Metabolic Care, 28(6), 483–488. https://doi.org/10.1097/MCO.0000000000001160
Pugh, J. E., & Chambers, E. S. (2025b). Dietary fibre and the gut microbiome: implications for glucose homeostasis. Current Opinion in Clinical Nutrition and Metabolic Care, 28(6), 483–488. https://doi.org/10.1097/MCO.0000000000001160
Reimer, R. A., Wharton, S., Green, T. J., Manjoo, P., Ramay, H. R., Lyon, M. R., Gahler, R. J., & Wood, S. (2021). Effect of a functional fibre supplement on glycemic control when added to a year-long medically supervised weight management program in adults with type 2 diabetes. European Journal of Nutrition, 60(3). https://doi.org/10.1007/s00394-020-02328-8
Saeedi, P., Petersohn, I., Salpea, P., Malanda, B., Karuranga, S., & Unwin, N. (2019). Global and regional diabetes prevalence estimates for 2019 and projections for 2030 and 2045: Results from the International Diabetes Federation Diabetes Atlas, 9th edition. Diabetes Research and Clinical Practice, 157, 107843. https://doi.org/10.1016/j.diabres.2019.107843
Torsdottir, I., Alpsten, M., Holm, G., Sandberg, A. S., & Tolli, J. (1991). A small dose of soluble alginate-fiber affects postprandial glycemia and gastric emptying in humans with diabetes. Journal of Nutrition, 121(6), 795–799. https://doi.org/10.1093/jn/121.6.795
Ziai, S. A., Larijani, B., Akhoondzadeh, S., Fakhrzadeh, H., Dastpak, A., Bandarian, F., Rezai, A., Badi, H. N., & Emami, T. (2005a). Psyllium decreased serum glucose and glycosylated hemoglobin significantly in diabetic outpatients. Journal of Ethnopharmacology, 102(2), 202–207. https://doi.org/10.1016/j.jep.2005.06.042
Ziai, S. A., Larijani, B., Akhoondzadeh, S., Fakhrzadeh, H., Dastpak, A., Bandarian, F., Rezai, A., Badi, H. N., & Emami, T. (2005b). Psyllium decreased serum glucose and glycosylated hemoglobin significantly in diabetic outpatients. Journal of Ethnopharmacology, 102(2). https://doi.org/10.1016/j.jep.2005.06.042
Copyright (c) 2026 Qyana Al Farisi, Ade Erni Tanjung, Ziya Ulhaq
This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.
