Is It Chronic Fatigue? Listen to Your Gut, Research Suggests

Key TakeawaysAn accurate diagnostic tool for chronic fatigue syndrome (CFS) may be needed as some doctors remain skeptical that it's a real physical diseaseNew research may be close to achieving that goal: Scientists were 90% accurate in spotting CFSThese advances might also have implications for spotting and treating long COVID.TUESDAY, July 29, 2026 (HealthDay News) — Artificial intelligence (AI) may be guiding doctors towards a gut-focused means of accurately diagnosing chronic fatigue syndrome (CFS), new research shows.The illness appears to disrupt relationships between a person’s gut microbiome, immune system and metabolism, explained a team led by Julia Oh. She’s a microbiologist and professor at Duke University, but worked on the study while at The Jackson Laboratory (JAX) in Farmington, Conn. In Oh’s view, the new findings' importance goes beyond diagnostics.“Our goal is to build a detailed map of how the immune system interacts with gut bacteria and the chemicals they produce,” she explained in a JAX news release. “By connecting these dots we can start to understand what’s driving the disease and pave the way for genuinely precise medicine that has long been out of reach.” The study involved 153 people with CFS, matched to 96 healthy individuals. Participants were tracked over four years. The findings were published July 25 in Nature Medicine.Chronic fatigue syndrome (also known as myalgic encephalomyelitis, or ME) is characterized by persistent fatigue, sleep abnormalities, dizziness and chronic pain, all of which can severely curtail daily living. The U.S. Centers for Disease Control and Prevention (CDC) says anywhere from 836,000 to 3.3 million Americans may be affected by CFS, costing the nation up to $51 billion in lost productivity and medical bills.CFS is often linked with long COVID, since both can follow an infection. It’s, therefore, possible that the new findings have relevance to long COVID, as well, the research team said.The current study builds on prior work linking CFS to disruptions in immune system function. Oh’s group used high-tech AI to analyze relationships between the immune system and bacterial colonies in the gut (microbiome) and related metabolites. They cross-referenced those gut/immune relationships with specific symptoms that are common to CFS: Sleep disturbances, headaches, fatigue and dizziness, as well as other symptoms. “We integrated clinical symptoms with cutting-edge ‘-omics’ technologies to identify new biomarkers of ME/CFS,” Oh explained. “Linking symptoms at this level is crucial, because ME/CFS is highly variable. Patients experience a wide range of symptoms that differ in severity and duration, and current methods can’t fully capture that complexity.”The team found that an analysis of immune cell function could help pinpoint the severity of a patient’s CFS, while the microbiome helped predict gastrointestinal, emotional and sleep disturbances. Overall, “our study achieved 90% accuracy in distinguishing individuals with chronic fatigue syndrome, which is significant because doctors currently lack reliable biomarkers for diagnosis,” study co-author Dr. Derya Unutmaz, a professor in immunology at JAX, said.Any advance in CFS diagnosis is valuable, he said, because “some physicians doubt it as a real disease due to the absence of clear laboratory markers, sometimes attributing it to psychological factors.”Furthermore, the research suggests that in CFS disruptions in related biological networks “become more entrenched over time,” Unutmaz said in the news release. “That doesn’t mean longer-duration ME/CFS can't be reversed, but it may be more challenging,“ he explained.Oh stressed that the effects of CFS on the body remain a moving target.“The microbiome and metabolome are dynamic,” she explained. “That means we may be able to intervene — through diet, lifestyle or targeted therapies.”And certain patterns did appear as the team’s research progressed.“Common disease signatures emerged in fatty acids, immune markers and metabolites,” Oh explained. “That tells us this is not random. This is real biological dysregulation.”More informationThere’s more on CFS at Johns Hopkins Medicine.SOURCE: The Jackson Laboratories, news release, July 25, 2025 .What This Means For YouScientists may be getting closer to a highly accurate means of diagnosing chronic fatigue syndrome..Sign up for our weekly HealthDay newsletter