Evaluation of Gastrointestinal and Nutritional Diagnostic Tests as Potential Screening Tools for Metabolic Body Odor and Halitosis

Many yet uncharacterized medical conditions including inborn and acquired errors of metabolism or skewed microbiome could be responsible for unpredictable and uncontrollable episodes of body odor and halitosis. These conditions have dramatic impact on the quality of life and socioeconomic outcomes of sufferers. Yet clinics and specialized malodor centers do not provide tests for diagnosing malodor other than trimethylaminuria (TMAU). Self-reported odor problems are often dismissed if are not organoleptically evaluated by trained odor judges that are not readily available during malodor flare-ups.

The aim of this study is to analyze effectiveness of existing gastrointestinal and nutritional tests for the assessment and investigation of self-reported malodors.

Diagnostic tests included:

• Gut Permeability Profile. PEG 400 is used as a probe and measured in urine passed for the following 6 hours at 11 different molecular weights to establish the quantity of each absorbed through the gut wall. Extraction and separation of PEG from urine is done by ion exchange chromatography and capillary GLC.
• Gut Fermentation Profile. Blood alcohols - ethanol, methanol, butanol, propanol and short chain fatty acids - are measured by gas-liquid chromatography.
• D-lactate test. D-lactate is measured by centrifugal analysis using the specific enzyme D-lactate dehydrogenase, which does not react with L-lactate
• The urine indicans (Obermeyer) test. Detection of indican in the urine depends upon its decomposition and subsequent oxidation of indoxyl to indigo blue and its absorption into a chloroform layer
• Breath test for small intestinal dysbiosis. Breath hydrogen and methane are measured by gas-liquid chromatography. The patient is given 10 gm of lactulose in 200 ml of water and alveolar air samples are collected every 20 minutes for 3 hours
• Functional B vitamins profile, by measuring the activation of a red cell enzyme that is dependent upon an adequate concentration of a particular vitamin for full activity. The assay relies on normal metabolism of the vitamin to its native form and the presence of other non-vitamin cofactors.