Nonalcoholic fatty liver disease is an umbrella term for liver-affecting disorders. The principal feature of this organ is the production of fat. Can a natural compound help in preventing and treating this condition?
According to recent data, non-alcoholic fatty liver disease (NAFLD) has a global prevalence of about 25 percent and is the leading cause of chronic liver problems in populations worldwide.
One of NAFLD’s most serious risks is obesity, which also has associations with higher levels of systemic inflammation. In addition, this can cause NAFLD symptoms even worse.
Since disorders in the liver and obesity are so common, researchers are always looking for new, efficient ways to prevent and treat them when they happen.
A team of Texas A&M University specialists recently conducted a study in conjunction with colleagues from other research institutions that indicates that a specific natural compound, called indole, can improve NAFLD.
Some types of indole, especially cruciferous vegetables such as broccoli, sprouts from Brussels and cabbage, are present in certain vegetables.
“Based on this research, we conclude that healthy foods with high indole production capacity are important to the prevention of NAFLD, and are beneficial to the health of those with it,” says co-investigator Dr. Chaodong Wu.
“This is another example where diet alteration can help prevent or treat illness and improve the individual’s well-being,” he adds.
Links between indole and liver health
The researchers performed their study in human subjects, as well as in animal models and individual cells— whose results appear in the journal Hepatology.
“There is no published study addressing the indole / human NAFLD relationship,” the authors of the study explain in their paper.
To find out if this compound might actually be beneficial in the NAFLD context, the researchers first investigated its role with human participants collaborating.
The team has recruited 137 Chinese participants aged between 20 and 80 because of research ties with Chongqing Medical University in China. Among these, 51 participants were overweight, and 11 were obesity.
The investigators measured the rates of indole circulating among the participants, as well as the biomarkers of obesity and liver fat content.
They found that individuals with higher body mass indexes (BMIs) also appeared to have less indole circulating amongst the sample cohort. In addition, indole levels were significantly lower among those with obesity than in individuals with modest BMIs.
Most notably, those with low levels of indole also had a higher fat buildup content in their livers.
The researchers believe that, regardless of their ethnicity, such similarities are likely to be true for everyone. However, since they only worked in this current study with Chinese participants, they can’t confirm that.
More indole, less fat buildup
To demonstrate the possible relevance of indole to liver health, the researchers conducted a series of mice experiments in which they induced similar effects to those caused by NAFLD in humans.
They fed a group of mice with a high-fat diet to cause these effects, and compared their biomarkers with those of control mice who had eaten a low-fat diet.
“Comparisons of animal models fed a low fat diet and a high fat diet gave us a better understanding of how indole is important to NAFLD,” notes Dr. Gianfranco Alpini, co-author of the study.
When the researchers treated the NAFLD-like mouse models with indole, less fat accumulated, and lower inflammation levels formed in the livers of the mice.
The investigators have found that indole not only works on the liver but also on the cells in the intestines, “prompting” them into sending out anti-inflammatory signals.
“The link between the intestine and the liver adds another layer of complexity to the[ NAFLD] findings, and future studies are much needed to fully understand the role of indole,” states co-author Dr. Shannon Glaser.
A compound with therapeutic potential
Following the current results, the research team is now suggesting that the use of indole in NAFLD therapy may be feasible in future.
“Foods with a high capacity of indole production or medicines that mimic its effects may be new therapies for the treatment of NAFLD.”
– Dr. Chaodong Wu
The natural compound may also play a vital role in preventing damage to the liver, Dr. Wu says.
“Preventing the production and progression of NAFLD can rely on nutritional approaches to ensure that gut microbes enable effective functioning of indole and other metabolites,” Dr. Wu says.
“There is a need for future research to explore how certain diets can do that,” he adds.