Adding fiber to your diet is promoted as a good way to ensure you maintain healthy digestion and elimination. But it turns out fiber plays a much more important role in your health. Scientists at the University of California, Irvine have discovered increased fiber intake has the ability to improve metabolic health by triggering gut bacteria to prevent sugar from damaging the liver and causing disease.

Researchers found the soluble dietary fiber inulin stimulates the breakdown of dietary fructose by gut bacteria in the small intestine which reduces spillover to the colon and liver. This prevents the conversion of sugar to triglycerides for storage and also helps support antioxidant synthesis so the liver is protected from fat accumulation and oxidative stress.

"We found that consuming a type of dietary fiber called inulin, abundant in vegetables, changes the bacteria in the gut to promote the consumption of harmful dietary fructose," says Cholsoon Jang, Ph.D., an assistant professor of biological chemistry who leads the Nutrient Metabolism & Disease Lab in the School of Medicine. "This leads to less fructose spillover to the liver, preventing fructose-induced fatty liver disease and insulin resistance. Inulin also helps the liver make more of its antioxidant to prevent inflammation."

The findings published in the journal Nature Metabolism show how inulin drives positive change in gut bacteria and improves metabolic health. The research could be very valuable in helping people avoid liver damage and insulin resistance.

"We focused on these diseases that occur in non-obese individuals, which are particularly hard to diagnose due to their normal body weight," says Jang. "Our study provides a mechanistic insight into how fiber protects our health from harmful nutrients like fructose."

Researchers plan to look at other dietary fibers to see what impact they have on fructose-induced diseases like diabetes, obesity, fatty liver disease and cancer.

"By identifying specific gut bacteria and metabolic pathways involved, our findings can guide personalized nutrition strategies," says Jang. "For example, by checking how well someone's gut bacteria clears fructose before the body absorbs it, we can choose the right prebiotic or probiotic supplement for that person to improve results and reduce side effects."

Click here to read more in the journal Nature Metabolism.