The optimal daily dose of metformin is thought to be 2000 mg, however patients with metformin intolerance cannot reach this target dose. Participate in this study are metformin intolerant. Metformin intolerant patients have been defined as those not able to be treated with the metformin daily dose exceeding 1500 mg due to gastrointestinal upset. Patient's metformin intolerance assessment will be questionnaire based (questionnaire adapted from Laura J. Mc Creight et al.). Patients will fill out questionnaires regarding the gastrointestinal symptoms associated with metformin at a dose they did not tolerate and at a time of reduced daily dose of metformin they do tolerate (patients are accepted to have gastrointestinal symptoms which they accept). Sanprobi Barrier probiotic/placebo will be administrated and the gastrointestinal symptoms will be repeatedly assessed with the use of above mentioned questionnaire at certain time points during the study. Patients will be advice to increase the daily dose of metformin as described below. At certain visits patients will undergo the tests measuring the intestinal permeability (blood and stool zonulin immunoenzymatic tests). Inflammatory state will be assessed by measurement of blood C-reactive protein (CRP) as well as blood and stool calprotectin. Zonulin is an endogenous protease, which concentration provides information about the condition of tight junctions between intestinal cells and has been used a a marker of intestinal permeability. Calprotectin, constitutes up to 60% of soluble cytosolic proteins in human neutrophils. In addition, it occurs in monocytes, macrophages and epithelial cells. Therefore, fecal and serum calprotectin content may be proportional to the number of neutrophils migrating through the gastric and intestinal mucosa and may be associated with inflammatory diseases of the gastrointestinal tract. Calprotectin has been widely used in contemporary clinical practice to monitor inflammation of the gut mucosa. CRP blood concentration is a marker of inflammation. Additionally, fecal samples will be used for microbial analysis (16S ribosomal ribonucleic acid (rRNA) sequencing) and blood samples for oxidative stress parameters, HbA1c, lipogram and alanine aminotransferase activity will be collected. Oxidative stress being a disturbance in oxidative balance, has been associated with type 2 diabetes and linked to adverse health effects, including alterations within the intestinal microbiota and vascular endothelium. Probiotics have already been shown to modify the intestinal microbiota and their usage may exert a beneficial effect on the oxidative stress parameters. This will be a 32 - weeks, prospective, single center, randomized, double-blind, cross-over study consisting of 10 site visits and 4 telephone contacts.
Visit 1. Written informed consent for participation in the study and medical history collection.
Visit 2 - month 0. Randomization visit. (within 3 ± 1 days of the visit 1) Fasting state. Blood pressure, heart rate, body mass index (BMI) measurements, waist-hip ratio (WHR).
Blood collection for zonulin and immunoglobulins against zonulin, calprotectin, CRP, HbA1c, hemoglobin (HGB), red blood cells (RBC), white blood cells (WBC), platelet count (PLT), creatinine, lipogram, alanine aminotransferase (ALT) activity and oxidative stress parameters (antioxidant enzymes: superoxide dismutase (SOD), glutathione peroxidase (GPx); catalase (CAT); glutathione reductase (GR), radical damage indicators of free of lipids and proteins: total oxidation capacity (TOC); concentration of lipid hydroperoxides (LHP); concentration of lipofuscin (LPS) - serum and lysate of erythrocytes; concentration of sulphydryl protein (PSH); malondialdehyde (MDA) concentration - serum and erythrocyte lysate; concentration of reduced glutathione (GSH); non-enzymatic antioxidant system: total antioxidant capacity (TAC) of plasma (total antioxidant status (TAS)) .
Stool collection for microbial analysis, short chain fatty acids, zonulin and calprotectin concentration.
Gastrointestinal symptoms questionnaire administration. Randomization to probiotic/placebo group with the permutation method. Patient will be advised to consume 2 capsules in the morning and 2 capsules in the evening. There will be two groups of probiotic/placebo products namely "A" and "B". Patients who will be randomized to probiotic/ placebo "B" at visit 2 will be switched to probiotic/ placebo "A" at visit 6 and patients who will be randomized to group probiotic/ placebo "A" at visit 2 will be switched to probiotic/ placebo "B" at visit 6. The patient will receive two probiotic/ placebo packs containing 120 capsules each.
Visit 3 - month 1 (4 weeks ± 3 days from the visit 2) Gastrointestinal symptoms questionnaire administration. Return of the empty packages or unused probiotic/placebo issued at the visit 2. The patient will receive two probiotic/ placebo packs containing 120 capsules each.
The current dose of metformin will be increased by 500 mg per day if possible.
Visit 3 A - telephone contact (1 week ± 3 days from the visit 3) Gastrointestinal symptoms will be assessed after increasing the dose of metformin. Decision about the possibility of continuing the increased dose of the drug will be made.
Visit 4 - month 2 (4 weeks ± 3 days from the visit 3) Gastrointestinal symptoms questionnaire administration. Return the empty packages or unused probiotic/placebo issued at the visit 3. The patient will receive two probiotic/ placebo packs containing 120 capsules each. Depending on the patient's clinical symptoms and tolerability of previously increased dose of metformin, increasing the dose of metformin (additional 500 mg/day) will be advised in order to achieve metformin dose of at least 2000 mg. In the case of side-effects from the gastrointestinal system, the dose will be reduced to the dose where there were no symptoms or there were symptoms that patients accepts.
Visit 4 A - Telephone contact (1 week ± 3 days from visit 4) Gastrointestinal symptoms will be assessed after increasing the dose of metformin. Decision about the possibility of continuing the increased dose of the drug will be made.
Visit 5 - month 3 (4 weeks ± 3 days from the the visit 4) Fasting state. Blood pressure, heart rate, BMI measurements, WHR. Blood collection for zonulin and immunoglobulins against zonulin, calprotectin, CRP, HbA1c, HGB, RBC, WBC, PLT, creatinine, lipogram, ALT activity and oxidative stress parameters (SOD, GPx,CAT, GR, TOC, LPS, PSH, MDA, GSH, TAS (TAC).) .
Stool collection for microbial analysis, SCFAs, zonulin and calprotectin concentration.
Gastrointestinal symptoms questionnaire administration. Return the empty packages or unused probiotic/placebo issued at the visit 4. Probiotic / placebo will be discontinued.
Visit 6 - month 4. Cross-over visit. (4 weeks ± 3 days from the visit 5).
Fasting state. Blood pressure, heart rate, BMI measurements, WHR. Blood collection for zonulin and immunoglobulins against zonulin, calprotectin, CRP, HbA1c, HGB, RBC, WBC, PLT, creatinine, lipogram, ALT activity and oxidative stress parameters (SOD, GPx,CAT, GR, TOC, LPS, PSH, MDA, GSH, TAS (TAC).) .
Stool collection for microbial analysis, SCFAs, zonulin and calprotectin concentration.
Gastrointestinal symptoms questionnaire administration. Patient will be cross-over to the different group of probiotic/placebo ("A" or "B" as described on the visit 2) and will be advised to consume 2 capsules in the morning and 2 capsules in the evening.
The patient will receive two probiotic/ placebo packs containing 120 capsules each.
Visit 7 - month 5 (4 weeks ± 3 days from the visit 6) Gastrointestinal symptoms questionnaire administration. Return the empty packages or unused probiotic/placebo issued at the visit 6. The patient will receive two probiotic/ placebo packs containing 120 capsules each.
Depending on the patient's clinical symptoms and tolerability of previously increased dose of metformin, increasing the dose of metformin (additional 500 mg/day) will be advised in order to achieve the metformin dose of at least 2000 mg. In the case of side-effects from the gastrointestinal system, the dose will be reduced to the dose where there were no symptoms or there were symptoms that patients accepts.
Visit 7 A - telephone contact (1 week ± 3 days form the visit 7) Gastrointestinal symptoms will be assessed after increasing the dose of metformin. Decision about the possibility of continuing the increased dose of the drug will be made.
Visit 8 - month 6 (4 weeks ± 3 days from the visit 7) Gastrointestinal symptoms questionnaire administration. Return the empty packages or unused probiotic/placebo issued at the visit 7. The patient will receive two probiotic/ placebo packs containing 120 capsules each.
Depending on the patient's clinical symptoms and tolerability of previously increased dose of metformin, increasing the dose of metformin (additional 500 mg/day) will be advised in order to achieve the metformin dose of at least 2000 mg. In the case of side-effects from the gastrointestinal system, the dose will be reduced to the dose where there were no symptoms or there were symptoms that patients accepts.
Visit 8 A - telephone contact (1 week ± 3 days form the visit 7) Gastrointestinal symptoms will be assessed after increasing the dose of metformin. Decision about the possibility of continuing the increased dose of the drug will be made.
Visit 9 - month 7 (4 weeks ± 3 days from the visit 8) Fasting state. Blood pressure, heart rate, BMI measurements, WHR. Blood collection for zonulin and immunoglobulins against zonulin, calprotectin, CRP, HbA1c, HGB, RBC, WBC, PLT, creatinine, lipogram, ALT activity and oxidative stress parameters (SOD, GPx,CAT, GR, TOC, LPS, PSH, MDA, GSH, TAS (TAC).) .
Stool collection for microbial analysis, SCFAs, zonulin and calprotectin concentration.
Gastrointestinal symptoms questionnaire administration. Return the empty packages or unused probiotic/placebo issued at the visit 8 Probiotic / placebo will be discontinued.
Visit 10 - month 8 (4 weeks ± 3 days from the visit 9) Fasting state. Blood pressure, heart rate, BMI measurements, WHR. Blood collection for zonulin and immunoglobulins against zonulin, calprotectin, CRP, HbA1c, HGB, RBC, WBC, PLT, creatinine, lipogram, ALT activity and oxidative stress parameters (SOD, GPx,CAT, GR, TOC, LPS, PSH, MDA, GSH, TAS (TAC).) .
Stool collection for microbial analysis, SCFAs, zonulin and calprotectin concentration.
Gastrointestinal symptoms questionnaire administration. The patient will finish participation in the study.
