A Supplement That Could Reduce Liver Triglycerides in People with Fatty Liver Disease
Resistant starch is a nondigestible fiber that ferments in the large intestine, and consumption of it has previously been shown to have a positive effect on metabolism in animal studies.
NAFLD, caused by a buildup of fat in the liver, affects about 30% of the population worldwide. It can lead to severe liver diseases and contribute to other conditions, such as type 2 diabetes and cardiovascular disease. Currently, there is no approved medicine available to treat NAFLD.
Previous research has suggested that NAFLD is associated with perturbed gut microbiota. For example, people with early-stage NAFLD already have an altered gut bacteria profile. So, Li and her team wanted to investigate if resistant starch — a type of fiber known to encourage the growth of beneficial gut bacteria — can help treat NAFLD.
The team recruited 200 NAFLD patients and provided them with a balanced dietary plan designed by a nutritionist. Among them, 100 patients also received a resistant starch powder derived from maize while the other 100 received calorie-matched non-resistant corn starch as a control. They were instructed to drink 20 grams of the starch mixed with 300 mL water (1 ¼ cups) before meals twice a day for 4 months.
After the 4-month experiment, participants who received the resistant starch treatment had nearly 40% lower liver triglyceride levels compared to patients in the control group. In addition, patients who had the resistant starch treatment also saw reductions in liver enzymes and inflammatory factors associated with NAFLD. Importantly, these benefits were still apparent even when statistically adjusted for weight loss.
“Our study shows resistant starch’s impact in improving patients’ liver conditions is independent of body weight changes,” says Yueqiong Ni, the paper’s co-first author.
By analyzing patients’ fecal samples, the team found the resistant starch group had a different microbiota composition and functionality compared with the control. In particular, the treatment-group patients had a lower level of Bacteroides stercoris, a key bacterial species that can affect fat metabolism in the liver through its metabolites. The reduction in B. stercoris is stronglylinked to the decrease in liver triglyceride content, liver enzymes, and metabolites observed.
“We are able to identify a new intervention for NAFLD, and the approach is effective, affordable and sustainable. 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,” Li says.
Yueqiong Ni, Lingling Qian, Sara Leal Siliceo, Xiaoxue Long, Emmanouil Nychas, Yan Liu, Marsena Jasiel Ismaiah, Howell Leung, Lei Zhang, Qiongmei Gao, Qian Wu, Ying Zhang, Xi Jia, Shuangbo Liu, Rui Yuan, Lina Zhou, Xiaolin Wang, Qi Li, Yueliang Zhao, Hani El-Nezami, Aimin Xu, Guowang Xu, Huating Li, Gianni Panagiotou, Weiping Jia. Resistant starch decreases intrahepatic triglycerides in patients with NAFLD via gut microbiome alterations. Cell Metabolism, 2023; 35 (9): 1530 DOI: 10.1016/j.cmet.2023.08.002
Cell Press. “Resistant starch supplement reduces liver triglycerides in people with fatty liver disease.” ScienceDaily. ScienceDaily, 5 September 2023. <www.sciencedaily.com/releases/2023/09/230905124907.htm>.
Photo by Julian Mora