Association of small intestinal bacterial overgrowth and non-alcoholic fatty liver disease in children

Abstract

Background. Non-alcoholic fatty liver disease (NAFLD) is a leading etiological factor of chronic liver diseases in children in industrialized countries. The high prevalence of small intestinal bacterial overgrowth (SIBO) is common in patients with NAFLD. Therefore, the purpose of our work is to study the impact of SIBO on the structural and functional parameters of the liver in obese/overweight children. Materials and methods. We examined 73 children aged 6 to 17 years, mean age of patients was (11.41 ± 2.68) years. Depending on the presence of overweight/obesity and the results of glucose hydrogen breath test (HBT), patients were divided into 2 groups: group 1 — 30 overweight/obese persons with SIBO, group 2 — 28 overweight/obese children without SIBO. The control group consisted of 15 apparently healthy children with normal weight and without SIBO. The presence of liver steatosis was established by means of transient elastography with controlled attenuation parameter. Additionally, we performed lactose HBT and a biochemical blood test with biochemical hepatogram, determination of lipid and carbohydrate parameters. Results. It was found that 70 % of children in group 1 had NAFLD, compared to 32 % in group 2. Also, erythrocyte sedimentation rate was higher in group 1 than in groups 2 and 3 (p < 0.05). Patients of group 1 had 1.5 times higher levels of triglycerides and very low-density lipoproteins. There was a tendency towards higher values of insulin and homeostatic model assessment in group 1 compared to group 2. Lactose malabsorption was diagnosed in 17 (56.7 %) children with NAFLD, lactose-dependent SIBO — in 15 (50.0 %). Among obese patients without NAFLD, lactose malabsorption was found in 10 (35.7 %) cases, and lactose-dependent SIBO — in 9 (32.1 %). Thus, in children with NAFLD, lactose malabsorption was detected 1.6 times more frequently than in children without NAFLD. Conclusions. It has been found that NAFLD is a risk factor for SIBO development. SIBO was associated with low-grade inflammation and adverse metabolic profile. The high frequency of lactose malabsorption and lactose-dependent SIBO among children with NAFLD was demonstrated.

Keywords

• non-alcoholic fatty liver disease
• children
• small intestinal bacterial overgrowth syndrome
• lactose malabsorption