Could damage to the blood-brain barrier be detected before the first symptoms of neurological disease appear? This question remains one of the greatest challenges in modern neurology. A team of researchers, including scientists from Wroclaw Medical University, analyzed metabolomics studies from around the world and identified a group of chemical compounds that may serve as early biomarkers of damage to this vital structure. The findings were published in Comprehensive Physiology , a journal awarded 200 points in the Polish Ministry of Science and Higher Education (MEiN) evaluation system.
The blood-brain barrier is one of the body’s most important protective structures. It forms a tightly regulated boundary between the bloodstream and nervous tissue, controlling which substances can enter the brain. In doing so, it protects neurons from toxins, pathogens, and excessive immune activity.
Damage to this barrier plays a key role in the development of numerous diseases, including multiple sclerosis, stroke, Alzheimer’s disease, Parkinson’s disease, and neuroinfections. The challenge is that there are currently no simple methods for detecting early dysfunction of the blood-brain barrier.
Increasing attention is therefore being given to metabolomics, the study of small molecules generated during metabolic processes. These molecules may reflect the earliest biological changes occurring in the body, even before clinical symptoms emerge.
One of the study’s most important findings is that blood-brain barrier disruption is not a single event.
Our study sheds new light on what actually happens when the blood-brain barrier loses its integrity, showing that it is far more than a simple mechanical ‘breach of the dam.’ Instead, it triggers a complex cascade of metabolic events, - says Andrzej Wasilewski, first author of the study, a sixth-year medical student at Wroclaw Medical University and a third-year law student at the University of Wroclaw, as well as founder and president of the Student Research Group of Medicinal Chemistry and Immunochemistry.
The analysis revealed that three groups of metabolic pathways are particularly important:
alanine, aspartate, and glutamate metabolism,
nitrogen metabolism,
biosynthesis of branched-chain amino acids (BCAAs).
These pathways appeared most consistently across the analyzed studies and showed the strongest association with blood-brain barrier damage.
The authors paid particular attention to glutamate and glutamine. Under normal conditions, glutamate is the brain’s primary excitatory neurotransmitter and is essential for learning and memory. Problems arise when its concentration becomes too high.
Our findings show that disrupted glutamate and glutamine metabolism lies at the heart of this neuroinflammatory chaos. In excessive amounts, these molecules lead to excitotoxicity and directly damage the tight junctions that protect the brain,- explains Andrzej Wasilewski.
Excitotoxicity refers to excessive stimulation of nerve cells, leading to their injury and even death. The findings suggest that this mechanism may be a major driver of progressive blood-brain barrier damage.
The study also provided important insights into branched-chain amino acids (BCAAs) – leucine, isoleucine, and valine.
Under normal physiological conditions, these compounds support nervous system function and participate in energy production. However, the study shows that during chronic inflammation, their role may change.
Branched-chain amino acids (BCAAs), including valine, leucine, and isoleucine, play a fascinating dual role. Although they normally support the nervous system, under inflammatory conditions they become destructive, activating enzymes that literally ‘dissolve’ the extracellular barrier, - says the author.
The researchers also observed changes indicating disturbances in cellular energy metabolism, remodeling of cell membranes, and increased nitric oxide activity, all of which further increase vascular permeability.
The authors emphasize that their work has not yet identified a single “ideal biomarker.” However, it has demonstrated that characteristic patterns of metabolic changes occur regardless of the specific neurological disease.
Decoding these recurring biochemical ‘fingerprints’ offers hope that, in the future, a routine and minimally invasive blood test could enable the early detection of brain damage. However, further research is essential before this becomes a clinical reality, - says Andrzej Wasilewski.
The researchers stress that translating these findings into clinical practice will require considerable further work. Existing studies differ in analytical methods, biological samples, and disease models. Large, multicenter studies using standardized methodologies will be necessary before these biomarkers can be implemented in routine diagnostics.
The study also highlights the importance of interdisciplinary collaboration in modern biomedical research.
Metabolomics does not exist in isolation. It is an inherently interdisciplinary field that depends on teamwork. Our project is an excellent example of the synergy achieved when researchers from diverse scientific backgrounds work together, - concludes Andrzej Wasilewski.
Did you know?
The blood-brain barrier acts as a highly selective filter that determines which substances can enter the brain.
Researchers identified 157 metabolites associated with blood-brain barrier damage, 25 of which were found in at least two independent studies.
The most significant metabolic changes involved glutamate, glutamine, and branched-chain amino acid (BCAA) metabolism.
These findings may pave the way for a simple blood test capable of detecting blood-brain barrier damage earlier and monitoring the progression of neurological diseases.
Comprehensive Physiology
Systematic review
Not applicable
Metabolomic Markers and Pathways of Blood-Brain Barrier Damage: A Systematic Review
21-Dec-2025
The authors declare no conflict of interest