S1359 Determinants and Outcomes of Pre-Test Elevation in Hydrogen/Methane Breath Testing for SIBO

Background. The microbiome-derived trimethylamine-N-oxide (TMAO) and the intestinal permeability marker zonulin are considered to be linked with depression. Moreover, carbohydrate malabsorption (CMA) was shown to be associated with signs of depression. This study is aimed at investigating possible sex-specific associations between TMAO and zonulin and the presence of depressive signs in individuals with and without CMA. Methods. Serum concentrations of TMAO and zonulin were determined in 115 and 136 individuals with the presence or absence of CMA. All 251 study participants underwent lactase gene C/T-13910 polymorphism genotyping and fructose H2/CH4 breath testing. Additionally, they filled in the Beck Depression Inventory (BDI-II) questionnaire. Results. The median TMAO and zonulin serum concentrations were 2.66 (1.93–4.14) μmol/L and 40.83 (34.73–47.48) ng/mL. Serum TMAO levels were positively correlated with depressive symptoms (P=0.011, ρ=0.160). The strongest correlations were observed in 87 females (P=0.010, ρ=0.274) and 49 males (P=0.027, ρ=0.315) without CMA, whereas 115 patients with CMA showed no significant correlations. Zonulin tended to be negatively correlated with the BDI-II score in 49 males without CMA (P=0.062, ρ=−0.269). Conclusion. This study demonstrates a positive correlationship between the serum TMAO concentrations and the severity of depressive symptoms in females and males without CMA. Serum zonulin levels were negatively correlated with signs of depression in males without CMA. These findings suggest a gender-specific relationship between the serum TMAO and zonulin concentrations, depression, and CMA.

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Exam 1: Breath Testing for Small Intestinal Bacterial Overgrowth: Maximizing Test Accuracy

Clinical Gastroenterology and Hepatology ◽

10.1016/j.cgh.2014.10.004 ◽

2014 ◽

Vol 12 (12) ◽

pp. e119-e120

Keyword(s):

Bacterial Overgrowth ◽

Small Intestinal Bacterial Overgrowth ◽

Test Accuracy ◽

Intestinal Bacterial Overgrowth ◽

Breath Testing ◽

Small Intestinal

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1-13C-propionate breath testing as a surrogate endpoint to assess efficacy of liver-directed therapies in methylmalonic acidemia (MMA)

Genetics in Medicine ◽

10.1038/s41436-021-01143-8 ◽

2021 ◽

Author(s):

Irini Manoli ◽

Alexandra R. Pass ◽

Elizabeth A. Harrington ◽

Jennifer L. Sloan ◽

Jack Gagné ◽

...

Keyword(s):

Clinical Laboratory ◽

Oxidative Capacity ◽

Methylmalonic Acidemia ◽

Cognitive Test ◽

Therapeutic Effects ◽

Transplant Recipients ◽

Mineral Density ◽

Link Type ◽

Breath Testing ◽

Propionate Oxidation

Abstract Purpose To develop a safe and noninvasive in vivo assay of hepatic propionate oxidative capacity. Methods A modified 1-13C-propionate breath test was administered to 57 methylmalonic acidemia (MMA) subjects, including 19 transplant recipients, and 16 healthy volunteers. Isotopomer enrichment (13CO2/12CO2) was measured in exhaled breath after an enteral bolus of sodium-1-13C-propionate, and normalized for CO2 production. 1-13C-propionate oxidation was then correlated with clinical, laboratory, and imaging parameters collected via a dedicated natural history protocol. Results Lower propionate oxidation was observed in patients with the severe mut0 and cblB subtypes of MMA, but was near normal in those with the cblA and mut− forms of the disorder. Liver transplant recipients demonstrated complete restoration of 1-13C-propionate oxidation to control levels. 1-13C-propionate oxidation correlated with cognitive test result, growth indices, bone mineral density, renal function, and serum biomarkers. Test repeatability was robust in controls and in MMA subjects (mean coefficient of variation 6.9% and 12.8%, respectively), despite widely variable serum methylmalonic acid concentrations in the patients. Conclusion Propionate oxidative capacity, as measured with 1-13C-propionate breath testing, predicts disease severity and clinical outcomes, and could be used to assess the therapeutic effects of liver-targeted genomic therapies for MMA and related disorders of propionate metabolism. TRIAL REGISTRATION This clinical study is registered in www.clinicaltrials.gov with the ID: NCT00078078. Study URL: http://clinicaltrials.gov/ct2/show/NCT00078078

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Random breath‐testing

The Medical Journal of Australia ◽

10.5694/j.1326-5377.1984.tb113124.x ◽

1984 ◽

Vol 141 (5) ◽

pp. 319-319

Author(s):

W. R. Heeler

Keyword(s):

Breath Testing

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