Adding probiotics to dulaglutide doubles HbA1c improvement and eliminates new hypertension and dyslipidemia in T2DM | Research

The takeaway

RCT of 60 T2DM patients shows dulaglutide + probiotics (Bifidobacterium longum) produced 3x greater HbA1c reduction (-1.06% vs -0.35%), zero new hypertension/dyslipidemia, and superior beta-cell function versus dulaglutide alone over 12 weeks.

3x better glucose control
Adding a cheap probiotic to dulaglutide tripled HbA1c improvement and prevented new cardiovascular risk factors—potentially the most cost-effective GLP-1 drug enhancement

What the researchers found

Combo vs dulaglutide alone: HbA1c -1.06% vs -0.35% (p=0.028). FPG more improved (p=0.010). TNF-α: -43.6% vs -33.3% (p<0.001). HOMA-β: +34.7% vs +23.1% (p=0.034). Lactobacillus: +2.1 vs +1.3 ×10⁶ CFU/g (p<0.001). New HTN: 0% vs 13.3% (p=0.038). New dyslipidemia: 0% vs 16.7% (p=0.020).

Why it matters

Probiotics are cheap, safe, and widely available. Showing they can triple the glucose-lowering effect of a GLP-1 drug while preventing cardiovascular complications is clinically transformative.

How the study worked

RCT. 60 overweight/obese T2DM patients (HbA1c 6.5-11%, BMI ≥24). Control: dulaglutide 1.5mg/week + placebo. Intervention: dulaglutide + Bifidobacterium longum (2×10⁹ CFU). 12 weeks.

What this study cannot tell us

Small RCT (60 patients). Single probiotic strain. 12-week duration. Chinese population. No long-term follow-up. Mechanism via microbiome modulation assumed.

How to read the evidence

Small but well-designed RCT. Striking results needing larger confirmation.

When this study was published

Published in 2025.

The bigger picture

This validates the microbiome-GLP-1 axis as therapeutically exploitable. A simple, cheap probiotic added to existing GLP-1 therapy dramatically improves outcomes—potentially reshaping diabetes treatment guidelines.

Questions still open

Would other probiotic strains provide similar or greater synergy?
Is the effect maintained beyond 12 weeks?
Should all GLP-1 drug patients take probiotics?

Common questions

Should I take probiotics with my GLP-1 drug?

This study found adding Bifidobacterium longum probiotics to dulaglutide tripled blood sugar improvement, prevented new hypertension and high cholesterol, and improved inflammation. While more research is needed, the results suggest probiotics could significantly enhance GLP-1 drug benefits at minimal cost.

How do probiotics enhance GLP-1 drug effects?

By increasing beneficial gut bacteria (Lactobacillus levels increased 61%), probiotics appear to enhance the gut microbiome's role in GLP-1 drug metabolism. The combination also reduced inflammation markers (TNF-α by 44%) and improved pancreatic beta-cell function by 35%—benefits beyond what either treatment achieved alone.

Read the original research

Comparative evaluation of dulaglutide alone vs. dulaglutide combined with probiotics on cardiovascular risk factors in T2DM.

Hormones (Athens, Greece), 24(3), 643-650

View on PubMed ↗Publisher’s paper ↗

Citation

Tian, Jinxia; Yang, Yanfei; Yu, Zijuan; Gao, Yang; Zong, Xiaochun; Wu, Qiaojuan; Su, Haiyan; Cao, Wenjuan; Xu, Dandan. (2025). Comparative evaluation of dulaglutide alone vs. dulaglutide combined with probiotics on cardiovascular risk factors in T2DM.. Hormones (Athens, Greece), 24(3), 643-650. https://doi.org/10.1007/s42000-025-00649-z