Friday Nov 14, 2014 (foodconsumer.org) - If you live with type 2 diabetes mellitus and you do not well tolerate metformin, a drug indicated to treat the disease, you may want to check out if you are infected with Helicobacter pylori, which can be treated with antibiotics.

A new study led by scientists at Fudan University in China found type 2 diabetes mellitus patients who also suffered H. pylori infection experienced more side effects of metformin, compared to type 2 diabetics without the infection.

H. pylori is the pathogenic bacterium - the major risk factor for stomach cancer that is found in almost half of the Asian population.  The complications of this infection in patients with type 2 diabetes mellitus who are treated with metformin have not been extensively researched.

In the study, 220 patients diagnosed with H. pylori infection and 195 without took metformin in a dose of 500 mg per day progressively, which were expected to be 1,500 mg per day at the end of the 4-week trials.  At baseline, both groups had similar scores of gastrointestinal symptoms.

After the 4-week intervention, of the type 2 diabetes mellitus patients, those who also suffered H. pylori infection were found 100% or over 100% more likely than those patients without the infection to experience gastrointestinal symptoms including stomach pain, nausea, bloating and anorexia.

The final tolerable metformin dose was 951mg per day in type 2 diabetes mellitus who suffered H. pylori, compared to 1209 mg per day in those diabetics without the infection.

In addition to H. pylori infection, female gender, body mass index, blood fat or triglycerides, age, and low-density lipoprotein-cholesterol (good cholesterol) were also found to be the independent parameters linked with gastrointestinal symptoms in diabetes mellitus patients.

The study concluded "Patients with diabetes having H. pylori infection demonstrated more gastrointestinal side effects than those without H. pylori infection after taking metformin."  (david Liu, PHD)

Huang Y, Sun J, Wang X, Tao X, Wang H, Tan W.  Helicobacter pylori Infection Decreases Metformin Tolerance in Patients with Type 2 Diabetes Mellitus.  Diabetes Technol Ther. 2014 Nov 12.