What Research Says About Probiotics and Blood Sugar in Type 1 and Type 2 Diabetes

Probiotics in Type 2 Diabetes

Multiple meta-analyses confirm probiotics reduce FBG by 3-13 mg/dL and HbA1c by about 0.3-0.5% in T2D patients, especially over 6-12 weeks with multi-strain formulas. Effects are more pronounced in non-insulin users and those with baseline FBG over 130 mg/dL, alongside improvements in HOMA-IR and lipids. Network meta-analyses rank high-dose, multi-strain probiotics highest for glycemic efficacy.

Evidence for Type 1 Diabetes

T1D trials are fewer; a multispecies probiotic study showed trends toward lower HbA1c and insulin needs after 12 weeks, without statistical significance. Synbiotics reduced HbA1c, FBG, and hs-CRP significantly in an 8-week T1D trial. Pediatric meta-analyses note small HbA1c drops (~0.25%) but call for larger studies.

Probiotic Yogurt Findings

Probiotic yogurt trials in T2D lowered FBG, HbA1c, LDL, and blood pressure versus plain yogurt, with benefits after 4 weeks. A meta-analysis of yogurt-specific RCTs supports modest glycemic improvements, tied to strains like Lactobacillus.

Synbiotic Supplements

Synbiotics (probiotics + prebiotics) further cut FBG by 14 mg/dL in metabolic syndrome and T1D/T2D, outperforming probiotics alone in some glycemic markers. Meta-analyses highlight time-dependent effects: 6-8 weeks for HbA1c/insulin reductions.

Key Limitations and Advice

Effects vary by strain, dose, duration, and baseline control; probiotics work best as adjuncts. Consult doctors before starting, especially with insulin; monitor personal responses.

1. https://www.dovepress.com/the-beneficial-effects-of-a-multispecies-probiotic-supplement-on-glyca-peer-reviewed-fulltext-article-DMSO
2. https://www.sciencedirect.com/science/article/abs/pii/S0899900718303411
3. https://pmc.ncbi.nlm.nih.gov/articles/PMC8166562/