Alzheimer’s is the most common form of dementia which is the term for memory loss and loss of other abilities that severely limits the ability to proceed with life in a normal fashion. Although many people associate memory loss as a part of aging, there is early-onset Alzheimer’s which does effect people that are not in that 65 and older category. There is currently no cure and thus this illness is currently heavily researched with many people trying to find the reason that it occurs and how to treat it so as to cure it completely. Those who have had to care for family members (especially immediate family) know the challenges of the illness, but also that they are themselves at a higher risk of developing the disease as it is likely they also carry the risk genes. There are two types of genes that are believed to be related to Alzheimer’s: risk genes and deterministic genes. 99% of Alzheimer’s cases are caused by risk genes rather than deterministic. Having deterministic genes for the illness means that someone is definitely going to get Alzheimer’s whereas risk genes place them at a higher probability of getting Alzheimer’s. As with any genes, these require accumulations of mutations that then cause the person to get Alzheimer’s.
In a study by Frontiers in Aging Neuroscience, researchers found that brain inflammation that occurs due to bacterial infection may contribute to developing Alzheimer’s. According to the study, post-mortem brain exams showed those with Alzheimer’s had 10x higher ratio of Actinobacteria to Proteobacteria than a healthy brain. Further research is needed to determine if this shows any causality and to what extent if any does neuroinflammation play a role in the neurodegeneration.
Furthermore, the University of Manchester has reported that researchers have identified a major cause of dementia- the category of cognitive impairment in which Alzheimer’s also falls. In this case, excess urea in the brain is believed to cause the brain damage leading to development of dementia in Huntington’s Disease. Huntington’s disease is also a devastating illness that results in the breakdown of nerve cells in the brain and typically begins in the 30s and 40s. It is a fatal illness that is rare but nonetheless inherited.
Researchers at Kashan University of Medical Sciences, and Islamic Azad University preformed a double blind experiment to test if daily dose probiotics could yield an improvement in the score of elderly Alzheimer’s patients on the MMSE (Mini-Mental State Examination) scale. Of the probiotics tested, the results found that Lactobacillus and Bifidobacterium bacteria taken daily for 12 weeks resulted in a moderate improvement on the MMSE scale. This is a landmark study as probiotics have previously only shown improved cognition in mice and hasn’t been applied to cognitively impaired humans. The treatment with probiotics results in lower levels of triglycerides, vdl (very low density lipoprotein) ,and hs-CRP (high sensitivity C-reactive protein) in the blog of the patients in the study. There was also a reduction, in HOMA-IR and HOMA-B, of insulin resistance and the activity of insulin producing cells in the pancreas. This may show according to Professor Mahmoud Salami from Kashan Unviersity, “[that] metabolic adjustments might be a mechanism by which probiotics affect Alzheimer’s and possibly other neurological disorders.” Several other studies are also pointing to a possible link between the gut microbiome and Alzheimer’s.
Scientists at Johns Hopkins University suggest, in the results of a study, that analysis of brain imaging and spinal fluid analysis could assess the risk of Alzheimer’s decades before the first recognizable symptoms appear. After giving subjects cognitive tests longitudinally, they also confirmed elevated levels of the protein tau in those displaying some manner of cognitive impairment and those at risk of developing Alzheimer’s.
University of Alberta scientists have discovered three viable biomarkers for Alzheimer’s and mild cognitive impairment that appear in saliva samples. They plan on expanding their sample size to validate their findings from this preliminary study. This is a great step in the clinical diagnosis of such diseases as it would allow for a quick and non-invasive method to get a diagnosis. Furthermore, the use of these biomarkers can be used in other studies to determine if various treatments are efficiently treating the illnesses.
In a study by Lund University in collaboration with various medical centers, published in JAMA Neurology, researchers from the Swedish BioFINDER study (and german participants as well) aimed to look into the efficacy and practicality of blood tests for diagnosis of Alzheimer’s. However, the level of accuracy required for its clinical usage in diagnosis is just now getting approached. Furthermore, it is important to not just test those with Alzheimer’s already, such as in the study, but a population where the presence of underlying Alzheimer’s is lower.
It is believed that the brain’s neurons die and break down as a result of Alzheimer’s. This process is known to involve high levels of amyloid and tau- a peptide and a protein respectively. According to the Alzheimer’s association website is also believed that plaque deposits of beta-amyloid build up between nerve cells and tangles (twisted fibers of tau) build up inside cells. Those with Alzheimer’s are believed to develop more of these than people who are normally aging. But, ultimately, their role in Alzheimer’s is still being researched. However, other factors are currently being explored as possibly playing a role in the neurodegenerative effects of the illness. For instance, neuroinflammation is currently undergoing extensive research to determine its role in the cognitive impairments such as Alzheimer’s.