Serious Studies Needed into Role of Microbes in Alzheimer’s and, Potentially, Parkinson’s, Researchers Say

In an editorial published in the Journal of Alzheimer’s Disease, scientists and clinicians working in Alzheimer’s disease (AD) voiced concern over largely ignored research indicating that certain microbes — namely, the herpes simplex virus type 1 (HSV1), Chlamydia pneumoniae, and several types of spirochaete — might be involved in Alzheimer’s pathogenesis. The editorial stressed the importance of further clinical research to determine if antimicrobial agents offer a successful pathway for new AD treatments with, importantly, relevance to the treatment of other neurological diseases, such as Parkinson’s.

The full editorial, “Microbes and Alzheimer’s Disease,” is available online.

The authors stress the need to re-evaluate the “status quo” theory of Alzheimer’s pathological causes, suggesting enough studies already indicate a possible infectious etiology. Deposition of amyloid-β (Aβ) peptide and abnormal forms of tau protein are established hallmarks of the disease, but it is still unknown if these are actually causes of Alzheimer’s. The authors summarize and comment on the extensive research implicating microbes like Chlamydia pneumoniae in the development of AD, dividing the studies into evidence for an infectious/immune component, evidence for causation, and evidence regarding the role of amyloid protein.

Moreover, the authors stress that such studies, currently about 100 on HSV1 alone, have been largely ignored and dismissed as controversial. Despite theories dating back almost three decades, when the first observations of HSV1 in AD brains were reported, clinical trial funding propositions have been largely refused. This failure, they noted, stands in stark contrast to the funding of over 400 unsuccessful clinical trials based on other concepts over the last decade. The authors also compare the opposition to the fierce resistance that first met suggestions, since proven, that certain types of viruses could cause cancer.

“We are saying there is incontrovertible evidence that Alzheimer’s Disease has a dormant microbial component, and that this can be woken up by iron dysregulation. Removing this iron will slow down or prevent cognitive degeneration — we can’t keep ignoring all of the evidence,” Professor Douglas Kell of The University of Manchester’s School of Chemistry and Manchester Institute of Biotechnology, an author of the editorial, said in a press release. He further stressed that sterile red blood cells have been shown to contain dormant microbes, an important factor for blood transfusions.

Thirty-one scientists and clinicians are cited as co-authors on the editorial.