Tag Archives: gut/brain axis

Parkinson’s Disease: Origins in the Gut?

January 15, 2018

Within the last few weeks, researchers at Mount Sinai have found strong correlations between Parkinson’s disease and the gut, confirming earlier studies that indicate the association.

A new genetic study demonstrates that several variants in the LRRK2 gene raise or lower risk not only for Parkinson’s, but also for Crohn’s disease: an inflammatory bowel disorder. The researchers identified a new functional risk variant, N2081D, which increases LRRK2’s kinase activity, in addition to a protective variant that inactivates lRRK2. The study’s researchers confirm that these findings may provide insight into underlying disease mechanisms, and point toward improved therapeutic approaches: LRRK2 inhibits being developed for Parkinson’s may help people with Crohn’s, while anti-inflammatory approaches could likewise benefit Parkinson’s patients.

Moreover, an earlier study published in Neurology, the official journal of the American Academy of Neurology, investigates the role of the vagus nerve in Parkinson’s disease–suggesting that a resection of the nerve might stop or delay the spreading of Parkinson’s disease, and providing further concrete evidence of the link between Parkinson’s and the gut.

Historically cited as the pneumogastric nerve, the theory suggests that the vagus nerve might serve as the channel for transporting the protein alpha-synuclein from stomach to brain, where it forms ‘telltale clumps in Parkinson’s sufferers.’

If accurate, the hypothesis points to a clear origin of the neurodegenerative brain disorder: the gut. Moreover, it would explain and confirm the critical importance of the enigmatic protein, whose exact role in Parkinson’s has previously not been well understood.  Perhaps most importantly, it would point to a potential way to block the development and progression of Parkinson’s: a surgical procedure known as a vagotomy, which is generally used in people with severe gastric ulcers, and involves cutting the vagus nerve in order to completely sever the ‘pathway from gut to brain.’

The objective of the published research was to examine whether vagotomy decreases the risk of Parkinson’s. Using comprehensive data from nationwide Swedish registers, the authors conducted a matched-cohort study of 9,430 vagotomized patients and 377,200 non-vagotomized patients. The researchers were aiming to find if the process of a vagotomy—in addition to a treatment for peptic ulcers—might lower the risk of Parkinson’s by blocking the route of alpha-synuclein to the brain.

After analyzing the data and assessing the subset of patients who received the most drastic version of the procedure, a truncal vagotomy—which removes the vagus nerve from contact with the liver, stomach, pancreas, gall bladder, small intestine, and proximal colon—they found that Parkinson’s disease was 22% less common than it was amongst people in the non-vagotomized comparison group.

While this study delivers clear epidemiological evidence to support the theory that Parkinson’s originates in the gut, previous studies further indicate that this may indeed be true. Alpha-synuclein protein clumps have been detected in the guts of patients with very early-onset Parkinson’s; in mice who had alpha-synuclein from the brains of human Parkinson’s patients implanted in their intestinal walls, researchers have seen movement of those proteins in the vagus nerve.

Our upcoming 26th Annual Spring Congress will focus on brain diseases and disorders, including the prevalence of Parkinson’s disease and related conditions. Our Module IV: Gastroenterology will also spotlight the gut-brain axis, and discuss the strong correlation between the gut microbiome and brain conditions.

The Link Between Parkinson’s & Gut Bacteria

November 8, 2017

Recent findings have confirmed a long assumed, yet never officially proven, hypothesis regarding a functional link between the gut’s bacteria and the onset of Parkinson’s disease. While previous research has demonstrated strong correlations between the gut and the disease, no research has shown the exact relationship.

One of the world’s most prevalent neurodegenerative disorders, Parkinson’s affects approximately 1 million people in the United States. A progressive and chronic movement disorder, Parkinson’s involves the malfunction and ultimate death of the brain’s vital nerve cells: neurons. As the neurons that typically produce normal levels of dopamine—the chemical that communicates with the segment of the brain that controls coordination and movement—regularly decrease and dopamine levels lessen, a person becomes unable to control movement. Worsening symptoms include the gradual deterioration of motor symptoms: body tremors, bradykinesia/slowness of movement, rigidity, and severe postural instability.

The studies suggest a new, unprecedented way of treating the disease and its symptoms: targeting the gut, rather than the brain, and developing next-generation probiotics: a more sophisticated version than those readily available for purchase and consumption today.

Through conducting trials during which mice were fed certain short-chain fatty acids that are commonly produced by bacteria in the gut, in addition to actual samples of gut bacteria from human Parkinson’s patients and healthy human controls, the team found that the mice either exhibited symptoms, or did not produce symptoms, respectively. The team’s researchers expressed their hope in the possibility of the prescription of drugs that contain bacteria to prevent Parkinson’s, or treat the disease symptoms. Moreover, the studies imply that Parkinson’s is less related to hereditary genetics than environmental factors—including the onset of age.

At A4M, our overarching goal is to treat—and ultimately prevent—the onset of diseases associated with aging. Attend our upcoming events and learn about the advancement of technology and biomedical engineering, coupled with the most recent research & inquiries into methods that optimize the human aging process.
 
Be on the forefront of public health and healthcare. Better yourself, your practice, and your patients through our advanced education opportunities.

The Gut Microbiome & Its Influence

March 31, 2017

While scientists remain uncertain about the specific causes of rheumatoid arthritis, an emerging body of research has led many to suspect that the microbiome—the bacteria that live in the gastrointestinal tract—may be to blame.

Rheumatoid arthritis occurs when the body attacks its own joints: several recent studies have found additional correlations between gut microbes and other diseases in which the body’s immune system goes ‘awry,’ and begins to attack its own tissue.

In 2013, Jose Scher, a rheumatologist at New York University, published a study that found people with rheumatoid arthritis were far more likely to have a bug called Prevotella copri in their intestines than people without the disease. Another study two years later indicated that aptients with psoriac arthritis, another type of autoimmune joint disease, had significantly lower levels of other types of intestinal bacteria.

Scher’s work is part of a growing effort by researchers across the globe to understand the ways in which the microbiome affects overall health. The gut contains up to one thousand different species of bacteria, which collectively weight between one and three pounds. This mass contains trillions of cells, more than the number of cells that make up our bodies. Throughout the past several years, scientists have compiled a growing collection of evidence that confirms links between these bugs and overall wellness.

These microbes can directly affect the immune system, even with diseases not located in the gut. An immunologist at the Mayo Clinic, Veena Taneja, has found striking differences in the bacterial populations of mice bred to be genetically prone to rheumatoid arthritis. Scher, director of NYU’s Microbiome Center for Rheuamtology and Autoimmunity, believes this is “frontier stuff…a shift in paradigm. By including the microbiome, we’ve added a new player to the game.”

Other research has focused on the influence of these bacteria on the immune system, as recent decades have seen a spike in the incidence of many autoimmune diseases. Several researchers state that this rise is, at least partially, due to changes in our bacterial ecosystem: altered diet, the proliferation of antibiotic use, and decreasing contact with the ‘microbe-packed natural world of animal plants’ have transformed the bacteria. NYU microbiologist Martin Blaser argues that because we lose microbes with each generation, “They are going extinct. These changes have consequences.”

Blaser’s own research has pinpointed the gut bacteria of U.S. children, finding that a specific species of bacteria thought to reduce the risk of asthma was very low. The decline of this bacteria in the West, as opposed to its appearance in the vast majority of the developing world, could have medical consequences. Blaser suspects that asthma is one of the primary illnesses affected by the changing microbiome; rates have escalated in the U.S. for the past three decades, growing over 28 percent between 2001 and 2011.

Dozens of researchers are looking into a range of potential strategies to use bacteria as medicine for immune disorders. Scher believes that eventually, it will be possible to treat arthritis, and other immune disorders, by adjusting the microbiome. At the Mayo Clinic, Taneja has found that a species of bacteria can prevent or halt the mouse versions of both rheumatoid arthritis, and multiple sclerosis—an autoimmune disease of the brain and nerves. Harvard University microbiologist Dennis Kasper, who discovered a targeted compound in the gut that protects mice from certain autoimmune diseases, including MS, is optimistic: “In 10 or 15 years, I think the microbiome will be a key therapeutic option for some of these diseases. There will be challenges, but I don’t see why it can’t happen. This isn’t science fiction.”