13C-breath tests in the study of mitochondrial liver function

Area of Science:

• Hepatology
• Biochemistry
• Medical Diagnostics

Background:

• Dynamic liver function tests using breath analysis have been explored for years.
• Carbon-labeled breath tests evaluate mitochondrial, microsomal, and cytosolic liver functions, aiding in disease staging and prognosis.
• Interest is growing in breath tests for liver mitochondrial function due to its impairment in diverse liver diseases.

Purpose of the Study:

• To review the application of carbon-labeled breath tests for assessing liver mitochondrial function.
• To discuss the potential of these tests in evaluating liver diseases of genetic or acquired origin.
• To highlight the need for further studies to validate breath tests for clinical use.

Main Methods:

• Utilizing carbon-labeled substrates like ketoisocaproic acid and methionine to probe mitochondrial function.
• Assessing the impairment of mitochondrial oxidative metabolism and hepatic energy state recovery.
• Investigating structural alterations in liver diseases affecting mitochondrial function.

Main Results:

• Mitochondrial function, including oxidative metabolism and energy recovery, is impaired in many liver diseases.
• Ketoisocaproic acid and methionine are key substrates for studying mitochondrial damage.
• Breath tests are simple, cost-effective, and safe but require further validation for clinical approval.

Conclusions:

• Carbon-labeled breath tests show promise for evaluating liver mitochondrial function in various liver conditions.
• Despite their advantages, these tests need to meet stringent requirements for widespread clinical adoption.
• Continued research is essential to identify optimal substrates for assessing complex mitochondrial metabolism in healthy and diseased livers.