Excessive alcohol consumption is one of the main causes of liver damage. Alcohol abuse is also associated with impacts on the gut microbiome. Scientists seek to explain how this happens, considering that the greatest absorption of alcohol happens in the stomach.
In a new study, published in the scientific journal Nature Communicationsresearchers at the University of California at San Diego, USA, suggest that changes in the gut microbiota may be caused by acetate produced by the liver, which spreads around the intestines, where it becomes a source of carbon to support bacterial growth.
“You can think of it a bit like pouring fertilizer into a garden,” said lead researcher Karsten Zengler, a professor in the departments of Pediatrics and Bioengineering at the University of California School of Medicine and the Jacobs School of Engineering. “The result is an explosion of unbalanced biological growth, benefiting some species but not others,” he adds.
Acetate is a nutrient used in cellular metabolism and has functions in appetite regulation, energy expenditure and immune response. At moderate levels, it promotes overall health, from improving heart function to red blood cell production and memory functioning. In excessive levels, it is associated with metabolic changes linked to diseases, including cancer.
In the recent study, researchers fed mice a molecule that could be broken down into three acetates in the rodent gut. The researchers noticed that the animals’ gut microbiota was altered by the additional acetate in a similar way to what they observed when feeding the mice alcohol, but without liver-damaging effects.
“Chronic alcohol consumption is associated with lower intestinal expression of antimicrobial molecules. People who suffer from alcohol-related liver disease often have bacterial overgrowth in their intestines,” Zengler said.
The expert says the findings suggest that the microbial metabolism of ethanol does not significantly contribute to the imbalance of the gut microbiome. “The acetate-altered microbiome does not play a major role in liver damage,” he says.
According to Zengler, the findings lead to further investigations that seek to explain whether changes in the gut microbiome are related to ethanol consumption itself.
“The situation is more complicated than previously assumed. It’s not as simple as more alcohol equates to microbiome changes and therefore microbiome dysbiosis equates to more liver disease,” he explains.
Zengler says that while the discovery won’t translate into immediate new treatments for alcoholic liver disease, it could help delineate acetate’s effect on the microbiota and refine future study designs.
Source: CNN Brasil
