Neurodegenerative diseases theory

The HMI has identified probable infectious agents  that may trigger the onset and progression of Alzheimer’s disease, Parkinson’s disease, and dementia. As such, our data comprises the first evidence that these disorders might be contagious and can be spread among humans.These agents are bacteriophages, or viruses that attack bacteria.

Age-related neurodegenerative diseases, such as Alzheimer’s disease, Parkinson’s disease, and dementia are incurable, terminal illnesses characterized by progressive nervous system dysfunction. These diseases are considered multifactorial and eventually result in immune system dysfunction and the onset of systemic inflammation. One of the causes of systemic inflammation is increased intestinal permeability, known as leaky gut syndrome, which leads to the translocation of gut microbiota (also known as the gut microflora) and bacterial products into systemic circulation.

To the best of our knowledge, our research provides the first evidence that increased intestinal permeability might be induced by infection of the microbiota by bacteriophages, which solely target bacteria and do not affect eukaryotic cells. Given the ubiquitous nature of bacteriophages, we propose that increased intestinal permeability may be a contagious condition that develops upon exposure to certain bacteriophages. If true, this finding indicates that certain neurodegenerative disorders that are triggered by leaky gut syndrome may also be contagious and can be spread between humans via bacteriophages that infect the gut microbiota.


We try to make our data available to the whole scientific community. The HMI welcomes collaborative studies to unravel the pathogenesis of human diseases associated with the microbiota. However, we ask that you respect the rights of first publication and cite our work as follows:

Bacteriophages as potentially new mammalian pathogens.

Bacteriophage infections of microbiota can lead to leaky gut in an experimental rodent model.