What Rainforest Ecology Analytical Methods Can Reveal About Alcohol-Associated Liver Disease and Potentially Other Chronic Illnesses

Alcohol-associated hepatitis is one of the more severe complications of long-term heavy drinking. The liver fails acutely, patients develop jaundice and fluid accumulation, and between 20% and 40% die within 90 days of onset. That mortality rate has not meaningfully changed in 60 years, and the only approved treatment is corticosteroids, which have limited efficacy. Why the liver fails the way it does in these patients is still not well understood. There is currently no reliable way to predict which patients will decompensate, let alone good therapeutic targets for which drug candidates could be developed and tested. The potential scale of the problem is large. Approximately one in 10 Americans has an alcohol use disorder, which translates to an estimated 30 million people at increased risk for liver disease, including alcohol-associated hepatitis.

A first of its kind study from the Division of Gastroenterology, Hepatology and Nutrition at UPMC and the University of Pittsburgh applied an unconventional analytical framework to study the problem and has generated new insights.

The senior author of the paper is Gavin E. Arteel, PhD, FAASLD, professor of medicine, Division of Gastroenterology, Hepatology and Nutrition at UPMC and the University of Pittsburgh. Dr. Arteel also is associate vice chair, Faculty Development, associate chief, Basic Science, and Pilot and Feasibility Core Director, Pittsburgh Liver Research Center.

Dr. Arteel and colleagues used RNA sequencing data from liver biopsies to analyze the hepatic transcriptome through standard differentially expressed gene (DEG) analysis, but also through a new approach they created related to alpha diversity borrowed from the field of ecology.

The study, titled “Alpha Diversity Analysis of Hepatic Transcriptome Reveals Distinct Pathways in Alcohol-Associated Hepatitis,” was published in January 2026 in JCI Insight.

In addition to the summary below, you can also read a Q&A interview with Dr. Arteel in which he goes into more detail about the team’s study, the new methodology they created, and the possible broader applicability it may have for studying other chronic conditions in different organs.

About the Study and its Findings

The conceptual framework of Dr. Arteel and colleague’s research study comes from the field of ecology. Healthy ecosystems, like rainforests, support a wide variety of species in relatively balanced numbers. When an ecosystem comes under sustained environmental stress of one kind or another, that diversity is challenged. Rare species are typically the first to disappear. As more species are lost, a handful of dominant ones come to account for nearly all activity in the system. Eventually, if the stress continues, the ecosystem collapses entirely. Dr. Arteel and colleagues applied that same analytical lens to the liver, treating the full set of genes active in liver tissue as an ecosystem and each individual gene as a species, and the outside stress, alcohol.

"Alcohol-associated hepatitis is now understood as a kind of metabolic collapse, where the liver has been so damaged over time that it loses its identity as a liver," Dr. Arteel says. "What that reminded me of is ecosystem collapse. When an ecosystem is under severe and sustained pressure, diversity collapses to a point, and then the whole system goes. The math we used to describe that in ecology turns out to describe what's happening in the liver, too."

What Dr. Arteel and colleagues found is very similar to the ecological pattern. As liver disease progressed from healthy tissue to early alcohol-associated steatohepatitis and then severe alcohol-associated hepatitis, the diversity of gene expression in the liver declined. A progressively smaller set of genes accounted for a larger and larger share of the liver's total transcriptional activity. The genes that dropped off first were those expressed at lower levels, while the most highly expressed genes remained relatively stable, much as dominant species persist longest under environmental pressure in an ecological setting, like the rainforest.

Developing a New Analytical Tool – Differential Shannon Diversity

The study also introduced a new analytical tool the team developed called Differential Shannon Diversity (DSD). Standard gene analysis methods – in the case of this study, DEG, evaluate genes individually, asking whether each one is more or less active. This approach has a known limitation: genes expressed at lower levels often don't register as significant because their variability is statistically overshadowed by more dominant genes. DSD addresses this gap by evaluating each gene's change in the context of what is happening to gene expression overall in the liver.

When the two methods were compared, they were similar on most findings. But DSD analysis also identified several pathways that standard DEG analysis missed, including ones involved in fatty acid oxidation, cholesterol metabolism, and tissue remodeling, all of which are consistent with what is known about how alcohol damages the liver over time.

The near-term application of this work is in biomarker development. Biopsy-based analysis is not a practical screening tool for a potential population of 30 million people at risk. But by identifying which genes shift at the critical transition between early adaptation and disease progression, the research from Dr. Arteel and colleagues may be able to point toward biomarker targets that could be detected in a patient’s blood. "

We know who is broadly at risk, namely people who drink a lot and do so for a long time, but we have no practical means of stratifying those individuals or predicting who could decompensate and suffer the worst outcomes," Dr. Arteel says. "By understanding these mechanisms in more detail, we can look for signals in the blood. The liver produces most of the body's circulating proteins, so the genes involved at the tipping point of alcohol-associated hepatitis are plausible candidates for a blood-based test."

Dr. Arteel and colleagues also are currently applying this approach and the DSD analysis they created to other chronic disease contexts.

“We are working from a hypothesis that the kind of progressive narrowing of gene expression we are seeing in liver disease through this analysis may be a common feature of chronic diseases in general,” Dr. Arteel says. “In that regard, I think this line of research has the potential to be applicable to a lot more than just studying alcohol-associated liver disease. That is an exciting prospect and we’re already moving our studies of the approach in that direction.”

Study Reference

Chaudhary S, Liu JJ, Liu S, Di M, Beier JI, Bataller R, Argemi J, Benos PV, Arteel GE. Alpha Diversity Analysis of Hepatic Transcriptome Reveals Distinct Pathways in Alcohol-Associated Hepatitis. JCI Insight. 2026. Jan 8: e200727. Online ahead of print.
Note: Paper is open access.