Banks, W. These host of neurological disorders encompass hemodynamic impairments (e.g., stroke), vascular dementia, cognitive deficits (mild to moderate), as well as a number of neurochemical, electrophysiological and behavioral alterations. The transports of mannose and the poorly metabolized hexoses 2-deoxyglucose and 3-O-methylglucose were similarly reduced. Of those, 397 had mild cognitive impairment, which can be a precursor to dementia, 191 had Alzheimer’s disease dementia and 228 people had no memory and thinking problems. Of those, 19 had type 2 diabetes and 21 did not have diabetes. The content of dopamine increased in the medial hypothalamus, putamen, and medial and lateral pallidus. By unravelling the pathogenesis, targets for pharmacotherapy can be identified.
Such stress changes may also extend to other common disease states, including diabetes. The relation between diabetes mellitus and insulin has been extensively studied for peripheral tissues but not for central nervous system tissues. Our gut bacteria have co-evolved along with humans, and that co-evolution, along with work that shows the importance of gut bacteria to good health, suggests a certain symbiosis or mutualism. Such an adaptation could operate to decrease the net flux of glucose into the brain during sustained hyperglycemia. The buildup of tangles may contribute to this loss of brain tissue. On a test of learning and memory, the scores of the people with diabetes decreased by 12 percent, from 46 points to 41 points over the two years of the study, while the scores of those without diabetes stayed the same, at 55 points. Several studies have now shown that stress can reduce the diversity in the microbiome–and, vice versa, such a lack of bacterial diversity can also influence brain states and behavior.
Such microbiome “conflicts” may have the power to negatively affect brain function, including processes such as inhibition and attentional control. Christopher Fagundes, a psychologist at Rice University, has long been interested in how stress affects the immune system. These results show that there is an increased uptake of I-Ins by the brain in the diabetic state that is not due to acute changes in the serum levels of glucose or insulin, altered vascular space, or catabolic events. He and Fagundes examined health and cognitive data from more than 800 middle-aged adults who were tested twice over a period of two years. Included were cognitive and psychological batteries, as well as interleukin-6 (IL-6) measures, a common measure of stress and inflammation, and glucose levels. Volunteers who exhibited low inhibition (by being more vulnerable to distraction on cognitive tasks) were more likely to have more anxiety, have more inflammation as measured by IL-6 levels, and, consequently, go on to develop diabetes. A neurologist is a doctor with specialized training in diagnosing, treating and managing disorders of the brain and nervous system such as Alzheimer’s disease, stroke, migraine, multiple sclerosis, concussion, Parkinson’s disease and epilepsy.
A lack in the brain’s executive functioning seemed to lead to the kind of inflammation that led to disease. The results were published on May 18, 2016, in Psychoneuroendocrinology. This link between executive functioning, inflammation, and disease provides clinicians a unique opportunity to help people prevent, or at least more effectively manage, conditions like obesity and diabetes in the future, including with novel therapies, Fagundes says. While he and Murdock did not look at microbiome changes in this study, he thinks that scientists need to take a multi-disciplinary, bio-behavioral approach to assess people’s psychological health as well as their physiology to better understand the root of modern diseases. Changes to the microbiome could be a part of that assessment. Alcock agrees. Physicians need to be more educated about the links between the microbiome, stress, and various health outcomes so they can do a better job of treating patients—and, perhaps, preventing the onset of common chronic diseases like Type 2 diabetes, he says.