Effect of antibacterial and probiotic therapy on the restoration of low fecal elastase levels in patients without imaging findings of pancreatic injuries

Introduction. The small intestinal bacterial overgrowth (SIBO) with low levels of fecal elastase-1 (FE-1) often mimics the symptoms of of exocrine pancreatic insufficiency (EPI). In this case, enzyme replacement therapy with pancreatin preparations proves ineffective. Aim. To study the therapeutic efficacy of rifaximin alfa in patients with low FE-1 levels without imaging findings of pancreatic injury. Materials and methods. The study included 35 outpatients with low FE-1 levels (less than 200 μg/g), refractory clinical manifestations specific to lower gastrointestinal tract diseases, and no signs of pancreatic injuries seen on cross sectional imaging. The total duration of treatment was 15 weeks, during which patients received 6 alternating cycles each lasting 14 days: rifaximin alfa and a probiotic. Rifaximin alfa was administered at a dose of 1,200 mg per day split in 3 doses of 400 mg each for 14 days. Probiotic therapy for 14 days included Lacticaseibacillus paracasei DG (L. paracasei DG) due to the fact that patients had both diarrhea and constipation. L. paracasei DG without prebiotic was prescribed to patients with diarrheapredominant irritable bowel syndrome. L. paracasei DG with a prebiotic was recommended to patients with constipationpredominant irritable bowel syndrome at a dose of 1 capsule/sachet once a day for 3 weeks. Results. A statistically significant regression (p < 0.05) of all primary complaints was observed. The median FE-1 levels significantly increased from 76.0 (95% CI: 48.9–113.0) to 290 (95% CI: 260.0–332.3) μg/g (p < 0.0001). Normalization of FE-1 levels was observed in 32 patients (91.4%) (p < 0.0001). Conclusion. SIBO can be one of the dominant causes of low FE-1 levels in patients with intestinal symptoms and no objective signs of pancreatic injuries. Cyclic therapy with rifaximin-alpha and probiotic based on the strain L. paracasei DG allowed to achieve regression of clinical manifestations, improve the quality of life and normalize FE-1 levels after 15-week therapy in most patients.