Topic

Gut Microbiome

Domain: Gut Microbiome

PEM-relevant research

3 studies in the atlas

Alterations in gut bacterial composition and gut-brain axis signaling in ME/CFS.

What We Know

Microbiome studies show reduced diversity and specific bacterial depletion in ME/CFS cohorts. Gut permeability (leaky gut) findings suggest systemic immune activation from gut-derived signals.

What We Think

Fecal microbiota transplant trials and detailed metabolomics of gut-derived compounds are emerging research areas.

What We Don't Know

Microbiome composition is highly variable between individuals and influenced by many confounders including diet and geography. Causal relationships are not established.

Studies in this Topic

E0 ConsensusPEM ?Moderate confidenceReviewed

Causes of symptoms and symptom persistence in long COVID and myalgic encephalomyelitis/chronic fatigue syndrome.

Komaroff, Anthony L, Dantzer, Robert·Cell reports. Medicine·2025

This review examines why long COVID and ME/CFS cause such severe, lasting symptoms. Researchers found that both conditions share similar biological problems, including immune system misbehavior, problems with blood vessel function, and issues with how cells produce energy. The study suggests that symptoms may come from both these biological problems and from ancient survival responses in the brain that were meant to protect us during serious illness.

NeuroinflammationGut Microbiome

E0 ConsensusPEM ✓Moderate confidenceReviewed

Gut Microbiome and Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS): Insights into Disease Mechanisms.

Nikolova, Ralitsa, Donchev, Deyan, Vaseva, Katya et al.·International journal of molecular sciences·2025

This review examines the connection between gut bacteria and ME/CFS, a condition characterized by exhaustion that worsens after activity. The authors explain how an imbalance in gut bacteria may damage the intestinal barrier, allowing bacterial particles to enter the bloodstream and trigger inflammation throughout the body. They also discuss how changes in gut bacteria might affect the brain, contributing to the brain fog and cognitive problems many ME/CFS patients experience.

Post-Exertional MalaiseImmune DysregulationGut Microbiome

E3 PreliminaryPEM ✗PreliminaryReviewed

Profiling Antibody Reactivity to Gut Microbes in ME/CFS Patients.

Seton, Katharine A, Carding, Simon R·Methods in molecular biology (Clifton, N.J.)·2025

This study looks at how the immune system of ME/CFS patients reacts to bacteria in the gut. Many ME/CFS patients have changes in their gut bacteria and a leaky gut lining that allows bacteria and their toxic products to enter the bloodstream, potentially triggering widespread inflammation. The researchers developed methods to measure specific immune proteins (antibodies) that ME/CFS patients produce in response to these gut bacteria, compared to healthy household members.

Immune DysregulationGut Microbiome