Supplement Reduces Liver Triglycerides in People With Fatty Liver Disease
By CELL
PRESS
Resistant starch, a type of indigestible fiber that
undergoes fermentation in the large intestine, has previously demonstrated
promising effects on metabolism in studies conducted on animals. Now, a four-month-long
randomized controlled study involving individuals with non-alcoholic fatty
liver disease (NAFLD) revealed that consuming resistant starch daily can
positively influence gut microbiota dynamics and decrease levels of liver
triglycerides and enzymes that are typically linked to liver damage and
inflammation.
The findings of this study were recently published in the
journal Cell Metabolism.
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. Doctors usually recommend dietary changes and exercise to alleviate the conditions.
“We think it would be very meaningful if we can find an
effective approach, maybe through identifying new therapeutic targets, to
manage NAFLD,” says Huating Li, the paper’s co-corresponding author at Shanghai
Sixth People’s Hospital.
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 at Shanghai Sixth People’s Hospital
and Leibniz Institute for Natural Product Research and Infection Biology –
Hans-Knöll-Institute (HKI) in Germany.
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
strongly linked to the decrease in liver triglyceride
content, liver enzymes, and metabolites observed.
When the team transplanted fecal microbiota from
resistant starch-treatment patients to mice fed with a high-fat
high-cholesterol diet, the mice saw a significant reduction in liver weight and
liver triglyceride levels and improved liver tissue grading 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. 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.
Reference: “Resistant starch decreases intrahepatic
triglycerides in patients with NAFLD via gut microbiome alterations” by
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 and Weiping Jia, 5 September 2023, Cell Metabolism.
DOI:
10.1016/j.cmet.2023.08.002
The study was funded by the National Natural Science
Foundation of China (NSFC), Shanghai Municipal Key Clinical Specialty, Shanghai
Research Center for Endocrine and Metabolic Diseases, the National Key Research
and Development Program of China, the Marie Sklodowska-Curie Actions (MSCA) and
Innovative Training Networks, the National Key Research and Development Program
of China (2022YFA1004804), Shanghai Jiao Tong University School of Medicine,
the Dalian Institute of Chemical Physics, Chinese Academy of Sciences, and the
Key Foundation.