People with prediabetes and type 2 diabetes experience severe stomach discomfort. Researchers have found that taking probiotics with metformin eases bloating, diarrhoea and other distressful symptoms.
Probiotics helped the study participants take metformin as advised and lowered their blood sugar much more than those taking metformin alone.
“In patients who added probiotic support to metformin treatment, side effects decreased, and better adherence to treatment and better HbA1c [glycated haemoglobin] reduction were observed,” the scientists wrote.
The study, “Metformin with versus without concomitant probiotic therapy in newly diagnosed patients with type 2 diabetes or prediabetes: a comparative analysis in relation to glycaemic control, gastrointestinal side effects, and treatment compliance,” was published in The Turkish Journal of Gastroenterology.
Besides diet and lifestyle advice, metformin is the first-line therapy for individuals with newly diagnosed type 2 diabetes and some with prediabetes. It primarily works by reducing the amount of glucose the liver produces. Metformin also changes the types and functions of bacteria in the gut, encouraging some to produce compounds that can cause bloating, diarrhoea and stomach discomfort. These side effects become unbearable for some patients and stop them from taking the medication.
Probiotics – specific live bacteria and fungi – provide many benefits for gut health, blood sugar control and immunity. Bacteria belonging to the Bifidobacterium family are well-known probiotics that ease stomach complaints such as diarrhoea, bloating and abdominal pain. However, it is unknown if they can relieve these symptoms in people taking metformin.
A research team in Turkey divided 156 participants with prediabetes or type 2 diabetes into two groups; one group received metformin alone, and the other group received metformin and a probiotic – Bifidobacterium BB-12 (BB-12).
Participants’ metformin dose was increased gradually from a minimum dose of 500 mg to a maximum of 2000 mg over four weeks. They recorded their stomach symptoms, including nausea, vomiting, diarrhoea, abdominal pain, bloating and loss of appetite at the study’s start and over the four weeks. The researchers also measured their body mass index (BMI), fasting blood glucose, blood lipids (HDL ‘good’ and LDL ‘bad’ cholesterol) and glycated haemoglobin (HbA1c, average blood sugar levels over two to three months) at the study’s start and after three months of treatment.
Probiotics help Patients take Metformin as Recommended
Participants were mainly women (74.4%) with a mean age of 50. A significantly greater percentage of participants in the probiotics group took metformin as advised compared to those in the metformin-only group, 91.7% vs 71.4%, respectively. Thirty patients did not take metformin as recommended, but 80% of them were in the metformin-only group. Notably, bloating and diarrhoea were the most common reasons for not taking metformin.
HbA1c decreased significantly in both groups after three months, but those taking probiotics had substantially lower HbA1c. In addition, only probiotic group participants lowered their fasting blood sugars significantly.
Interestingly, only those in the metformin-only group increased their HDL ‘good’ cholesterol and lost weight.
Metformin promotes weight loss by suppressing appetite, but it is unclear whether weight loss occurs directly or because of its unpleasant side effects. Considering participants in the probiotic group did not lose weight, the researchers believe that the probiotics protected them from stomach distress and prevented weight loss.
“Given that no reduction in body weight was noted in our metformin plus probiotic group, prevention of gastrointestinal side effects via probiotic in this group may have resulted in a decrease in the weight-loss effect of metformin,” they wrote.
The researchers identified some limitations to the study, including the small sample size, the lack of a placebo group and validated questionnaires to assess patients’ symptoms.
“The present study proposes the benefit of combining probiotics with metformin in the treatment of patients with T2D [type 2 diabetes] or prediabetes in terms of improved glycaemic control and treatment adherence, rather than correction of dyslipidaemia [abnormal lipids] or weight reduction,” the researchers concluded
“Questioning our results in similar studies and supporting them with meta-analyses is extremely important in terms of adding probiotics support to metformin treatment for clinical use,” the researchers wrote.
The Main Takeaway
Probiotics alter bacteria in the gut, boosting immunity and gut health. They also ease bloating, nausea and diarrhoea, side effects commonly seen in people taking metformin for blood sugar control or PCOS. It was unknown if probiotics could reduce these symptoms in people taking metformin, but this study has shown they can.
The results are not generalisable yet because the study was small and only included participants from one medical centre in Turkey. Although we need more extensive studies to confirm and validate these results, probiotics are a valuable addition to your diet. This blog post shares five top probiotic yoghurts to add to your diet.