Stem cell-based therapies for diabetes may modestly improve blood sugar control, according to a systematic review and Bayesian network meta-analysis of randomized controlled trials published in Diabetology & Metabolic Syndrome. The analysis found that a combination of mesenchymal stem/stromal cells plus mononuclear cells reduced glycated hemoglobin and fasting plasma glucose more than standard medical therapy, but the credible evidence came mainly from trials in type 2 diabetes, and confidence in many estimates was low or very low.
The researchers searched PubMed, Embase, Web of Science, the Cochrane Library, and ClinicalTrials.gov from inception to June 10, 2026. They included randomized controlled trials of stem cell-based therapies in type 1 or type 2 diabetes. Twenty-one reports representing 19 randomized controlled trials involving 691 participants met the inclusion criteria. Outcomes assessed were glycated hemoglobin (HbA1c), fasting plasma glucose (FPG), fasting C-peptide, total daily insulin dose (TDD), and adverse events.
Because no single trial compared every cellular strategy head to head, the team used a random-effects Bayesian network meta-analysis to estimate mean differences or odds ratios with 95% credible intervals. This statistical approach combines direct comparisons within trials with indirect comparisons across the network of treatments, allowing each therapy to be ranked against standard medical therapy even when trials tested different pairs of options.
Compared with standard medical therapy, combined mesenchymal stem/stromal cell plus mononuclear cell therapy reduced HbA1c by a mean difference of −1.26% (95% credible interval, −1.97 to −0.54; moderate confidence) and reduced fasting plasma glucose by −2.24 mmol/L (95% credible interval, −3.93 to −0.56; moderate confidence). Mesenchymal stem/stromal cell therapy alone also reduced HbA1c versus standard therapy (MD, −0.95%; 95% CrI, −1.70 to −0.09; very low confidence), and mononuclear cell therapy reduced fasting plasma glucose versus standard therapy (MD, −2.03 mmol/L; 95% CrI, −3.75 to −0.35; low confidence).
Combined therapy showed the most favorable ranking probabilities for HbA1c, fasting plasma glucose, and total daily insulin dose. However, its effect on insulin dose was not statistically credible, meaning the analysis could not rule out that the apparent advantage arose from chance or from the sparse data underlying the network. Rankings should be interpreted cautiously because the evidence was sparse and confidence in many estimates was low or very low.
No statistically credible differences were observed for fasting C-peptide, a marker of the body’s own insulin production, or for adverse events. Meta-regression by follow-up duration found no credible evidence of effect modification by diabetes type across the pooled network. The findings for combined therapy were robust in sensitivity analyses restricted to autologous cell products and to 12-month outcome assessments.
In diabetes-type-specific networks, the credible glycemic benefits were confined to the type 2 diabetes network, in which mesenchymal stem/stromal cell therapy, mononuclear cell therapy, and combined mesenchymal stem/stromal cell plus mononuclear cell therapy each reduced HbA1c versus standard medical therapy. No comparison reached statistical credibility in the type 1 diabetes network, where the number of trials and participants was smaller.
The authors note that current glucose-lowering therapies improve glycemic control but do not directly reverse β-cell loss or dysfunction. Stem cell-based therapies may offer disease-modifying potential through immunomodulatory, paracrine, and regenerative mechanisms, but the relative efficacy and safety of different cellular strategies remain uncertain. The new analysis is an attempt to quantify that uncertainty using only randomized evidence, the highest tier of interventional study design.
The review was prospectively registered on PROSPERO (CRD420261420380). The authors conclude that combined mesenchymal stem/stromal cell plus mononuclear cell therapy may provide favorable glycemic effects, with the credible evidence deriving mainly from trials in type 2 diabetes, but that the evidence remains insufficient for firm conclusions or routine clinical use. They call for adequately powered, independently conducted, diabetes-specific multicenter randomized trials to establish whether these cellular approaches can deliver durable benefits.
For people living with diabetes, the practical takeaway is caution: the pooled estimates suggest a signal worth testing, not a treatment ready for the clinic. With 691 participants across 19 trials, the evidence base is thin, confidence ratings are low to moderate at best, and no credible safety differences or C-peptide improvements were demonstrated. Until larger trials report, stem cell therapy for diabetes remains an investigational strategy rather than an established option.
Subject of Research: Comparative efficacy and safety of stem cell-based therapies for type 1 and type 2 diabetes in a systematic review and Bayesian network meta-analysis of randomized controlled trials
Article Title: Comparative efficacy and safety of stem cell-based therapies for diabetes mellitus: a systematic review and Bayesian network meta-analysis of randomized controlled trials
Article References: Wang, S., Tuersun, A., Wang, Z., Yin, A., Zhong, Y., Yu, Q., Pang, L., Liu, H., Hu, X., Wu, Y., Han, B., & Ma, G. (2026). Comparative efficacy and safety of stem cell-based therapies for diabetes mellitus: a systematic review and Bayesian network meta-analysis of randomized controlled trials. Diabetology & Metabolic Syndrome. https://doi.org/10.1186/s13098-026-02332-8
Image Credits: AI Generated
DOI: 10.1186/s13098-026-02332-8
Keywords: stem cell therapy, diabetes, type 2 diabetes, type 1 diabetes, mesenchymal stromal cells, mononuclear cells, HbA1c, network meta-analysis, randomized controlled trials, systematic review, Bayesian analysis, glycemic control
News Source: Drew Townsend. (November 5, 2026). Stem cell therapy for diabetes shows promise in pooled trial analysis, but evidence remains weak. Scienmag.
