By Tarun Sai Lomte Reviewed by Susha Cheriyedath, M.Sc. Jun 16 2026 Researchers found that even in otherwise healthy adults, fatigue was associated with gut microbial shifts, lower energy-related metabolites, and patterns that overlapped most strongly with ME/CFS and psychiatric disorder datasets. Study: Fatigue-associated gut bacteria in Japanese healthy adults characterized by metagenomic analysis . Image Credit: Sinhyu Photographer / Shutterstock In a recent study published in the journal