Fiber’s Role in Protecting Against Sugar Damage Uncovered by UC Irvine Study

A new study from the University of California, Irvine School of Medicine has revealed how dietary fiber, specifically inulin, can reshape gut bacteria to mitigate the harmful effects of fructose before it reaches the liver.

Researchers found that inulin, a naturally occurring fiber abundant in vegetables like onions, garlic, and artichokes, promotes the consumption of dietary fructose by gut bacteria in the small intestine. This process prevents an overload of fructose from reaching the liver, which can lead to fat buildup. The findings, published today in Nature Metabolism, demonstrate a previously unknown level of protection offered by fiber beyond its traditional digestive benefits.

“We found that consuming a type of dietary fiber called inulin… changes the bacteria in the gut to promote the consumption of harmful dietary fructose,” explained lead researcher Cholsoon Jang, PhD, of UCI’s Nutrient Metabolism & Disease Lab. The study also showed that “priming” gut bacteria with inulin could reverse signs of fatty liver disease, reducing fat accumulation and increasing the liver’s antioxidant capacity. This research is particularly significant as non-alcoholic fatty liver disease is becoming increasingly prevalent worldwide.

Jang emphasized that the research demonstrates not all calories are created equal and provides insight into how fiber safeguards health against detrimental nutrients like fructose. The study focused on non-obese participants, highlighting that metabolic damage can occur even in individuals who appear healthy if their gut microbes are not equipped to handle excess fructose. Understanding the gut microbiome is increasingly important in preventative healthcare; learn more about the gut microbiome from the National Institutes of Health.

Researchers plan to investigate whether other common fibers can elicit similar protective effects, potentially opening doors to new treatments for conditions like fatty liver disease, diabetes, obesity, and even cancer.