Xenogene
Patient Test

GC · ALIENTO

Breath test · Fructose intolerance

Breath test that detects fructose malabsorption by measuring exhaled hydrogen and methane after a controlled oral load.

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Description

The fructose intolerance breath test assesses the intestinal absorption capacity for this monosaccharide. When fructose is not correctly absorbed in the small intestine, it reaches the colon, where the microbiota ferments it and produces gases that are detected in the breath.

Fructose malabsorption is a frequent cause of digestive symptoms after consuming fruit, juices, sweeteners and foods rich in fructose or with an excess of fructose over glucose.

Method

Gas chromatography

After an oral fructose load, serial breath samples are collected and analysed by gas chromatography. Both hydrogen and methane are quantified, which improves sensitivity in methanogenic patients, in whom an H₂-only test could underestimate fermentation.

Sample

Serial breath

Collection of samples over approximately 3 hours after ingestion of the substrate. Prior dietary preparation is required according to the instructions to ensure the validity of the result.

Results

Fermentation curve

The report shows the evolution of the exhaled gases and their interpretation against the malabsorption thresholds. Reading gains precision within an integrated panel (metagenomic NGS + functional biochemistry): the AI assistant Sophia contrasts the result with the microbiota profile to distinguish malabsorption from fermentative dysbiosis.

See the integrated profiles for the joint study of the digestive axis.

Clinical indications

Symptoms after fructose-rich foods

Differential diagnosis