Researchers at the Shanghai Sixth People’s Hospital in China have shown early success in treating non-alcoholic fatty liver disease (NAFLD) with the use of dietary supplements containing resistant starch, a non-digestible fibre from maize that acts as food for beneficial bacteria in our guts.
The development assumes significance as there are currently no medications or therapies to treat NAFLD, a condition that is estimated to affect over 30 per cent of the world’s population. Doctors currently rely only on dietary and lifestyle changes to alleviate the condition.
It also contributes to other health conditions, such as type 2 diabetes, chronic kidney disease and cardiovascular diseases.
The experimental therapy works by changing the composition of bacteria in our guts by feeding them with resistant starch, a type of carbohydrate that does not get digested in the small intestine and instead ferments in the large intestine.
“We think it would be meaningful if we can find an effective approach by identifying new therapeutic targets such as gut microbiota, to manage NAFLD,” said Huating Li in a statement, the paper’s co-corresponding author at Shanghai Sixth People’s Hospital.
In the study, published in the journal Cell Metabolism, the researchers detailed results of a trial involving 200 people diagnosed with NAFLD who were provided with a balanced dietary plan designed by a nutritionist.
While 100 participants were given a resistant starch powder derived from maize that they had to dissolve in water and consume twice daily for four months, the remainder received a calorie-matched non-resistant corn starch (easily digestible) as a control.
At the end of the four-month trial, the group whose diet was supplemented with resistant starch had nearly 40 per cent lower liver triglyceride levels compared to those in the control group. Moreover, the group receiving the experimental therapy showed reductions in liver enzymes and inflammatory factors associated with NAFLD.
Importantly, these benefits were still apparent independent of the participant’s weight loss.
“Our study shows that resistant starch’s impact in improving liver conditions of people is independent of body weight changes,” said Yueqiong Ni, the paper’s co-first author at Shanghai Sixth People’s Hospital and Leibniz Institute for Natural Product Research and Infection Biology – Hans-Knöll-Institute (HKI) in Germany.
The research team further analysed faecal samples of participants of their study and found that the group that received resistant starch supplements had a different microbiota composition and functionality compared with people in the control group.
In particular, the people supplemented with resistant starch had a lower level of Bacteroides stercoris, a key bacterial species that can affect fat metabolism in the liver through the metabolites it produces.
The reduction in B. stercoris is strongly linked to the decrease in liver triglyceride content, liver enzymes, and metabolites in NAFLD.
They then transplanted faecal microbiota from the resistant starch supplemented group to mice fed with a high-fat high-cholesterol diet. These mice showed reduction in liver weight and liver triglyceride levels and improved liver tissue health compared with mice that received microbiota from the control group.
“We are able to identify a new intervention for NAFLD, and the approach is effective, affordable and sustainable,” said Li. Compared with strenuous exercise or weight loss treatment, adding resistant starch to a normal and balanced diet is much easier for people to follow through, she added.
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