The aim of the study is to confirm that the new generation state of the art breath analyzer gives equivalent results to the previous model of the Exalenz breath analyzer.

Healthy and chronic liver disease subjects of all grades will be tested to see that the two devices give equivalent results in both devices. Subjects will be connected to both devices at the same time and will be tested for one hour.

The breath test includes automatic baseline breath collection, 13C-Methacetin ingestion in solution and breath collection post ingestion.

Inclusion Criteria:

1. Over 18 years of age

2. Ability and willingness to sign the Informed Consent Form

   For patient group:

3. a. Known chronic liver disease (based on medical history)

For healthy volunteers:

3.b. No known liver disease (based on medical history)

Exclusion Criteria:

1. Gastric bypass surgery or extensive small bowel resection
2. Total parenteral nutrition
3. Pregnant or breast feeding
4. Allergy to acetaminophen and/or other related medications.
5. Documented drug-related concurrent hepatotoxicity or drug-related silent steatosis or drug-related fibrosis (e.g. amiodarone, methotrexate and tamoxifen).
6. Uncontrolled malabsorption or diarrhea
7. Placement of a transjugular intrahepatic portosystemic shunt (TIPS)
8. Subject should not have taken any of the following for at least 48 hours prior to the breath test: Acyclovir, allopurinol, carbamazepine, cimetidine, ciprofloxacin, daidzein, (herbal) disulfiram, echinacea, enoxacin, famotidine, fluvoxamine, methoxsalen, mexiletine, montelukast, norfloxacin, phenylpropanolamine, phenytoin, propafenone, rifampin, terbinafine, ticlopidine, thiabendazole, verapamil, zileuton or oral contraceptives or any medication that might interfere with Methacetin metabolism or might affect CYP 1A2
9. Subject should not have taken amiodarone within the last 30 days prior to the breath test