Methane production and small intestinal bacterial overgrowth in children living in a slum

Abstract

Aim: To analyze small intestinal bacterial overgrowth in school-aged children and the relationship between hydrogen and methane production in breath tests.

Methods: This transversal study included 85 children residing in a slum and 43 children from a private school, all aged between 6 and 10 years, in Osasco, Brazil. For characterization of the groups, data regarding the socioeconomic status and basic housing sanitary conditions were collected. Anthropometric data was obtained in children from both groups. All children completed the hydrogen (H(2)) and methane (CH(4)) breath test in order to assess small intestinal bacterial overgrowth (SIBO). SIBO was diagnosed when there was an increase in H(2) ≥ 20 ppm or CH(4) ≥ 10 ppm with regard to the fasting value until 60 min after lactulose ingestion.

Results: Children from the slum group had worse living conditions and lower nutritional indices than children from the private school. SIBO was found in 30.9% (26/84) of the children from the slum group and in 2.4% (1/41) from the private school group (P = 0.0007). Greater hydrogen production in the small intestine was observed in children from the slum group when compared to children from the private school (P = 0.007). A higher concentration of hydrogen in the small intestine (P < 0.001) and in the colon (P < 0.001) was observed among the children from the slum group with SIBO when compared to children from the slum group without SIBO. Methane production was observed in 63.1% (53/84) of the children from the slum group and in 19.5% (8/41) of the children from the private school group (P < 0.0001). Methane production was observed in 38/58 (65.5%) of the children without SIBO and in 15/26 (57.7%) of the children with SIBO from the slum. Colonic production of hydrogen was lower in methane-producing children (P = 0.017).

Conclusion: Children who live in inadequate environmental conditions are at risk of bacterial overgrowth and methane production. Hydrogen is a substrate for methane production in the colon.

Keywords: Bacterial overgrowth; Breath test; Children; Colon; Hydrogen; Methane; Small intestine.

Figure 1

Small intestinal bacterial overgrowth in school-aged children and the relationship between hydrogen and methane production in breath test. A: Mean concentrations of hydrogen (ppm) in breath samples collected after fasting and at 15, 30, 45, 60, 90, 150 and 180 min after lactulose ingestion from children in the slum (n = 84) and private school (n = 41) groups; B: Mean concentrations of hydrogen (ppm) in breath samples collected after fasting and at 15, 30, 60, 90, 120, 150 and 180 min after lactulose ingestion from children in the slum group with (n = 26) and without (n = 58) small intestinal bacterial overgrowth (SIBO); C: Mean concentrations of methane (ppm) in breath samples collected after fasting and at 15, 30, 60, 90, 120, 150 and 180 min after lactulose ingestion from children in the slum group with (n = 26) and without (n = 58) SIBO; D: Mean concentrations of hydrogen (ppm) in breath samples collected after fasting and at 15, 30, 60, 90, 120, 150 and 180 min after lactulose ingestion from methane-producing (n = 53) and non-producing (n = 31) children in the slum group. Student’s t-test; comparison between groups for collection time during the breath test (complementation of the analysis of area under the curve). ^aP < 0.05 vs the private school group; ^cP < 0.05 vs the slum group without SIBO in relation of the hydogen production in breath test; ^eP < 0.05 vs the slum group without SIBO in relation of the methane production in breath test; ^gP < 0.05 vs the slum group non-methene producing in relation of the hydrogen production in breath test.