In nonalcoholic fatty liver disease (NAFLD), excess fat builds up in the liver, thereby inhibiting its normal functioning.
Certain people are more at risk of developing this condition, and this includes those with obesity, high blood pressure, and type 2 diabetes.
It is hard to diagnose NAFLD in its early stages, however, as it does not display many telling symptoms at first.
This might mean that the condition may remain "hidden" until it has reached a more advanced stage, causing liver damage.
For this reason, researchers have been looking for ways of detecting liver disease as it begins to develop, so that it can be addressed as soon as possible.
Specialists from Britain, Italy, Spain, and France now say that it may be possible to detect NAFLD early on by looking at certain gut biomarkers.
"We have discovered exciting connections between gut microbiota composition, fatty liver, and carbohydrate metabolism," explains Prof. José Manuel Fernández-Real, from the University of Girona in Spain.
"This contributes," he adds, "to better understand[ing] why 30 percent of [people] with massive obesity do not develop a fatty liver despite dramatically increased fat mass."
A detailed analysis revealed that raised levels of a compound called phenylacetic acid (PAA), which is released by certain gut bacteria, was linked to the excess fat buildup in the liver and early onset of NAFLD.
This means that PAA could be considered as a NAFLD biomarker, and diagnosing this condition would therefore be just one simple blood test away.
"Through this work we may have uncovered a biomarker for the disease itself," notes study leader Dr. Lesley Hoyles, from Imperial College London in the United Kingdom. "Overall, it demonstrates the microbiome is definitely having an effect on our health."
But the scientists also found that NAFLD was associated with certain changes in the composition of the gut microbiome.