Research led by Texas A&M AgriLife Research scientists reveal a natural compound found in many well-known and widely consumed vegetables can also be used to fight fatty liver disease
. The new study demonstrates how non-alcoholic fatty liver disease
, or NAFLD
, can be controlled by indole
, a natural compound found in gut bacteria and in cruciferous vegetables such as cabbage, kale, cauliflower and Brussels sprouts.
The findings from the study also indicates that this natural compound may lead to new treatments or preventive measures for NAFLD
. The study was published in Hepatology journal.
Dr Chaodong Wu, M.D., Ph.D., a Texas A&M AgriLife Research Faculty Fellow and principal investigator for the study told Thailand Medical
News, "Based on this research, we believe healthy foods with high capacity for indole
production are essential for preventing NAFLD
and are beneficial for improving the health of those with it. This is another example where altering the diet can help prevent or treat disease and improve the well-being of the individual."
Non-alcoholic fatty liver disease
occurs when the liver becomes "marbled" with fat, sometimes due to unhealthy nutrition, such as excessive intake of saturated fats. If not properly addressed, this condition can lead to life-threatening liver disease, including cirrhosis or liver cancer.
A variety of factors contribute to NAFLD
. Fatty liver is seven to 10 times more common in people with obesity than in the general population. In addition, obesity causes inflammation in the body. Driving this inflammation are macrophages, types of white blood cells that normally battle infection. This inflammation exacerbates liver damage in those with liver disease.
The microbiome in the gut can also have an effect, either positive or negative on the progression of fatty liver disease
. These bacteria produce many different compounds, one of which is indole
. This product of the amino acid tryptophan has been identified by clinical nutritionists and nutrition scientists as likely having preventive and therapeutic benefits to people with NAFLD
The US National Cancer Institute also notes the benefits of indole
-3-carbinol found in cruciferous vegetables, including their anti-inflammatory and cancer-fighting properties.
The research examined the effect of indole
concentrations on people, animal models and individual cells to help determine indole's effect on liver inflammation and its potential benefits to people with NAFLD
. It inv
estigated the extent to which indole
alleviates non-alcoholic fatty liver disease
, incorporating previous findings on gut bacteria, intestinal inflammation and liver inflammation. It also incorporated investigation into how indole
improves fatty liver in animal models.
The researchers investigated the effects of indole
on individuals with fatty livers. As research collaborator Qifu Li, M.D., was also a physician at Chongqing Medical University in China, the research team decided he should lead the clinical research using Chinese participants.
The research team discovered among the 137 participants, people with a higher body mass index tended to have lower levels of indole
in their blood. Additionally, the indole
levels in those who were clinically obese were significantly lower than those who were considered lean. And in those with lower indole
levels, there was also a higher amount of fat deposition in the liver.
This findings will likely extend to other ethnicities, Li noted, though ethnic background may have some influence on gut bacteria populations and the exact levels of metabolites.
To determine the impact of indole
, the research team used animal models fed a low-fat diet as a control and high-fat diet to simulate the effects of NAFLD
Dr Gianfranco Alpini, M.D., a study collaborator and former distinguished professor of Texas A&M Health Science Center, now the director of the Indiana Center for Liver Research said, "The comparisons of animal models fed a low-fat diet and high-fat diet gave us a better understanding of how indole
is relevant to NAFLD
Dr Alpini said treatment of NAFLD
-mimicking animal models with indole
significantly decreased fat accumulation and inflammation in the liver.
The team also studied how indole
affected individual cells. Dr Shannon Glaser, M.D., a professor of Texas A&M Health Science Center, said that in addition to reducing the amount of fat in liver cells, indole
also acts on cells in the intestine, which send out molecular signals that dampen inflammation.
Dr Glaser added, "The link between the gut and the liver adds another layer of complexity to studies on non-alcoholic fatty liver disease
, and future studies are very much needed to fully understand the role of indole
Dr Wu said, “Adding prevention is another important aspect to consider. Foods with a high capacity of indole
production or medicines that mimic its effects may be new therapies for treatment of NAFLD
. Preventing NAFLD
's development and progression may depend on nutritional approaches to ensure that gut microbes allow indole
and other metabolites to function effectively. Future research is needed to investigate how certain diets may be able to achieve this."
Dr Wu said in future research he hopes to collaborate with food scientists and clinical nutritionists to examine what healthy foods can alter gut microbiota and increase indole
Reference : Linqiang Ma et al, Indole
Alleviates Diet‐induced Hepatic Steatosis and Inflammation in a Manner Involving Myeloid Cell PFKFB3, Hepatology (2020). DOI: 10.1002/hep.31115