At the center of this loop is Clostridium perfringens, a gut microbe that, when it proliferates, churns out copious amounts of ammonia. The gas does not simply pass through; it chemically erodes the intestinal epithelium, compromising the tight junctions that seal the gut barrier. With the barrier weakened, microbial products that should remain confined to the digestive tract—including ammonia itself—leak into the portal circulation and flood the liver. The liver, in turn, mounts an aggressive immune response characterized by a dangerous hyperactivation of CD8+ T cells. This cascade of inflammation and tissue damage is the hallmark of MASH progression.

The Michigan team, led by senior author Eugene Chen, the Frederick G. L. Huetwell Professor of Cardiovascular Medicine, confirmed this mechanism before testing DT-109. They showed that ammonia-driven breakdown of the epithelial wall is a primary trigger, not a bystander event. “We see clear evidence that DT-109 protects the gut epithelial barrier, reducing the systemic influx of harmful microbial products that are thought to contribute to MASH development and progression,” Chen said.

DT-109 appears to intervene at the very origin of the problem. In both mice and nonhuman primates, the tripeptide drastically reduced the abundance of Clostridium perfringens and slashed intestinal ammonia concentrations. Without the constant chemical assault, the gut lining repaired itself and regained its integrity. This physical barrier restoration meant that fewer bacterial toxins reached the liver, and the hyperactive T cell response subsided. The liver inflammation that drives MASH—visible as ballooning hepatocytes, immune infiltrates and early fibrotic changes—was dramatically reversed in the primate models, whose liver architecture and gut microbiota closely mirror those of humans.

“DT-109 connects microbiota modulation with liver protection by restoring gut barrier integrity and limiting the systemic translocation of ammonia and other pro-inflammatory microbial products within the gut-liver axis,” explained co-author Jifeng Zhang, a research professor of cardiovascular medicine. “We also found that DT-109 primarily acts in the gastrointestinal tract, but its reach stretches much further.” That extended reach is no small detail: earlier studies have shown that the same compound can limit the formation of atherosclerosis plaques and halt vascular calcification in nonhuman primates, positioning it as a potential two-for-one therapy for liver and cardiovascular disease.

The gut-liver axis has long been invoked in metabolic disease, but DT-109 provides one of the clearest molecular narratives yet linking a single microbial culprit, its metabolic waste product and a specific immune consequence. The work underscores the idea that MASH is as much a disease of barrier failure as it is of fat accumulation. Because intestinal barrier dysfunction is implicated in conditions such as inflammatory bowel disease, the team suspects DT-109 could eventually find applications beyond hepatology.

The compound’s path to the clinic still runs through the mandatory gauntlet of human trials, but the early data are undeniably compelling. The research team is now focused on further preclinical evaluation to build a safety and dosing package that could support an investigational new drug application. “What patients with MASH need is a safe and effective therapy capable of improving their liver and heart health—of course we are excited about these developments,” said Elliot Tapper, Academic Director of Hepatology at Michigan Medicine.

DT-109’s story also highlights how peptide-based drugs, long overlooked because of stability concerns, are staging a quiet renaissance in metabolic medicine. The glycine backbone provides structural simplicity, yet the tripeptide manages to reach the colonic microbiota and reshape it in ways that blunt a distant organ’s deterioration. The study serves as a vivid reminder that some of the most sophisticated therapeutic solutions come not from synthetic complexity but from targeting the ancient, evolutionary conversation between our microbes and our metabolism.

Subject of Research: Animals
Article Title: Metabolic dysfunction–associated steatohepatitis exacerbated by Clostridium perfringens–derived ammonia is attenuated by tripeptide DT-109
News Publication Date: 12-May-2026
Web References: https://dx.doi.org/10.1172/JCI200522
References: Journal of Clinical Investigation, DOI: 10.1172/JCI200522
Image Credits: Not provided
Keywords: MASH, steatohepatitis, DT-109, glycine tripeptide, gut-liver axis, Clostridium perfringens, ammonia, intestinal barrier, CD8+ T cells, drug development, fatty liver disease, cardiovascular disease