The hepatic fetus occurs when the breath smells strong and musty, indicating that the liver is having difficulty filtering out toxic substances. This is usually due to serious liver disease, which causes sulphurous substances to enter the bloodstream and reach the lungs. As a result, dimethyl sulfide increases in the air we exhale, producing a noticeable smell in the breath. A recent study published in the Journal of Chromatography B used gas chromatography and mass spectrometry (GC-MS) to determine if odorous compounds in the breath could be indicative of liver disease.
Additionally, a paper published in the journal EBioMedicine suggests that high levels of limonene, a natural compound found in fruits and vegetables, could be an early sign of liver disease and cause bad breath. If your breath has a strong, musty smell similar to that of rotten eggs and garlic, it may be a sign that your liver is struggling to filter out toxins. This is likely due to liver disease, as Dr. Nancy Moyer wrote for Healthline.
While brushing your teeth or chewing on a refreshing piece of gum can help temporarily, if the bad breath doesn't go away, it could be an indication of an underlying health problem.