Long-term alcohol use may affect multiple organs at the same time, Ohio University researchers find

A new study by researchers at Ohio University found that long-term alcohol exposure caused widespread damage to the gut, liver and metabolism in mice, offering new insight into how chronic alcohol use may harm the body over time.

The study, published in the Journal of Comparative Physiology, was led by Ohio University postdoctoral researcher Muni Swamy Ganjayi, Ph.D., along with Thomas Krauss, D.O./Ph.D. student, Gage Dempster, OMS III, Shaohua Wang, Ph.D., and Cory Baumann, Ph.D., with the Heritage College of Osteopathic Medicine; Se-Hyung Park, Ph.D., Garrett Anspach and Robert Helsley, Ph.D., with the University of Kentucky; and Sarah Anthony and Michael Tranter, Ph.D., with The Ohio State University.

The team examined how chronic alcohol exposure affected multiple organs and systems at the same time, including the gut microbiome, liver, fat tissue and metabolism.

“Our findings show that chronic alcohol exposure doesn’t just affect one organ,” said Baumann, the Osteopathic Heritage Foundation Ralph S. Licklider, D.O. Endowed Faculty Fellow in Aging Systems Physiology and an investigator in the Ohio Musculoskeletal and Neurological Institute and the Institute for Molecular Medicine and Aging. “It creates a chain reaction throughout the body, especially along the gut-liver axis, leading to inflammation, metabolic problems and tissue damage.”

In addition to reducing muscle strength and endurance and changing body fat and lean muscle mass, researchers also discovered that exposure to alcohol over a long period was associated with important changes in the gut microbiome. Mice exposed to alcohol had lower levels of beneficial bacteria such as Lactobacillus and reduced levels of short-chain fatty acids, compounds that help maintain gut health and reduce inflammation.

“These gut changes appear to weaken the intestinal barrier and may allow toxins to move from the gut to the liver,” said Baumann. “That can increase inflammation and contribute to liver injury.”

The team also found evidence of unusual protein buildup, called amyloid deposition, in the liver tissue. Amyloid buildup is associated with several serious diseases and may represent another way chronic alcohol harms the liver.

Although the mice consumed slightly fewer calories than the control group, they still developed major metabolic problems, including poor glucose control and abnormal blood lipid levels.

Researchers say the findings highlight the complex and widespread effects of chronic alcohol use and may help scientists develop microbiome-targeted therapies that could reduce alcohol-related tissue damage. 

“Our study suggests that restoring healthy gut bacteria and improving communication between the gut and liver could become important strategies for treating alcohol-related disease,” Baumann said.

The study was funded in part by the American Heart Association (23CDA1051959 to RNH), and the National Institutes of Health (R01DK139147 and K01DK128022 to RNH and R01HL158671 to MT).