A man in China who, after eating high-carbohydrate or sugary meals, became so intoxicated that he blacked out, has led researchers to discover strains of bacteria in the human gut that could be an important driver of the world’s most common liver disease.
That condition, nonalcoholic fatty liver disease (NAFLD), affects an estimated 1 billion people worldwide, and nearly one in three Americans. The excess fat in liver cells that is characteristic of the disease usually does not cause any symptoms, but in about 25% of people with NAFLD, the accumulation progresses and sometimes causes life-threatening cirrhosis or liver cancer. Scientists found that that the Chinese man’s odd malady stems from gut bacteria that synthesize alcohol from his meals. Researchers say the finding could lead to better ways of predicting who will develop severe forms of NAFLD and may even suggest ways to thwart its progression.
Obesity, diabetes, and other conditions are associated with NAFLD, but no single underlying mechanism explains why fat builds up in the liver of so many people. Some studies have tied gut bacteria to NAFLD, but the idea has remained controversial. The complexity of intestinal flora makes it difficult to sort the contributions of single species. The new finding, published in Cell Metabolism today, focuses on a novel strain of Klebsiella pneumoniae that predominates in a small cohort of NAFLD patients and also caused liver damage in mouse experiments. “I have to admit this is pretty impressive,” says infectious disease specialist David Haslam of Cincinnati Children’s Hospital Medical Center in Ohio, who has been circumspect about earlier attempts to tie intestinal microbes to NAFLD.... and more at the link above.