Gut Bacteria Byproduct: Blood-Brain Barrier Compromised

Researchers have identified a potential link between gut microbiota metabolism and the development of neurodegenerative processes associated with Alzheimer's disease. According to a study published in Nature Communications, a bacterial byproduct of histidine metabolism called imidazole propionate (ImP) may increase the permeability of the blood-brain barrier (BBB).

The study analyzed blood samples and cognitive performance of 1,200 adults with an average age of 61. The data revealed that higher concentrations of ImP correlate with a faster decline in cognitive functions. This association was also linked to the presence of specific biomarkers of nerve tissue damage, including pTau-217 and neurofilament light chain (NfL).

To explore the underlying mechanism, scientists conducted experiments on genetically modified mice. These tests confirmed that the accumulation of ImP can facilitate the entry of abnormal proteins into the brain, which subsequently triggers neuron death.

Biological Context and Limitations

The presence of ImP-producing bacteria in the gut is not considered a pathology. Histidine, the precursor to ImP, is an essential amino acid required for normal metabolism. Researchers emphasize that restricting protein-rich foods containing histidine is not a proven method for dementia prevention.

Professor Frederico Rei noted that microorganisms do not need to be present in large quantities to affect the host. The study found that approximately 43% of participants had genetic characteristics that promote increased ImP synthesis, suggesting a connection to broader metabolic and endocrine factors.

At this stage, evidence does not support the claim that lowering ImP levels will prevent Alzheimer's disease. The results are observational and based partly on animal models. The molecule is currently viewed as a potential target for future pharmacological interventions designed to block this specific metabolic pathway without disrupting general nutrition.

Clinical Perspective

Therapist Anna Kuznetsova stated that such findings remind clinicians that neurodegenerative processes may begin long before obvious clinical symptoms appear in a patient's psychiatric status. Clinical pharmacologist Aleksey Ryabtsev added that the data regarding the link between metabolism and neuron damage requires cautious interpretation, as the exact biological mechanisms are still being identified.

Important: This article is for general information and does not replace medical advice. Do not start, stop, or change treatment without a qualified clinician.

Source: This article was adapted from an original Russian-language publication by Pravda.Ru.