Digestion, General, Inflammation | February 2, 2017 | Author: Naturopath
Gut bugs are a hot topic. You've probably heard about how the types of bacteria living in the colon may influence serious health conditions like autism and depression.
The strains of bacteria (or “microbiota”) found in the gut have been shown to directly influence the immune system and the absorption of nutrients, vitamins, medications, and toxic compounds. So it makes sense that the microbiota profile could have a serious impact on health and a connection to many diseases. In fact, disturbance to the gut microbiota has been linked to many chronic and degenerative conditions, including Alzheimer's disease, multiple sclerosis, autism, and now Parkinson's disease (PD).
PD is the second-most common neurodegenerative disorder, affecting approximately 80,000 Australians . Diagnosis is tricky, and there is often difficulty in confirming PD until the disease has progressed and signature symptoms begin to emerge. The reported accuracy of diagnosis is a wide range of 26 – 92%.
As you can imagine, by the time a diagnosis is made, it's often too late for early intervention treatments that could have slowed down the progression of the disease.
But recent breakthrough research may have found a simple way to screen for early-stages of PD – and it lives in the gut.
Constipation is a very common symptom of PD. It affects up to 80% of patients, and it is usually one of the first symptoms to appear . Chronic constipation with no known cause (such as a pre-existing bowel condition) is an early warning sign of Parkinson's disease . So early, in fact, that it often occurs years before any motor symptoms develop.
PD is characterised by the clumping of proteins, or “Lewy bodies”, around the nervous system and brain. Two nervous systems that influence bowel movement appear to be the first places affected by protein clumping during the early stages of PD onset . The enteric and parasympathetic nervous systems are primarily located in the gut and have significant influence over muscle contraction, mucous secretion and the general flow of stool through the bowel. As the nerves there are attacked by protein-clumping, their function is altered and the bowels slow down.
But constipation is too common a symptom to be a clear indicator for screening.
Extensive research has shown that nervous system health is closely linked to the types of microbes present within the intestines . So when protein-clumping disturbs the enteric and parasympathetic nervous systems, it would also cause disruption to the types of microbes found in the gut.
Simultaneously, anything that disturbs the healthy balance of gut flora could in turn weaken these nervous systems.
For example, drinking coffee and smoking cigarettes are major risk factors for neurodegenerative conditions – and both of these habits promote overgrowth of pathogenic, unhealthy gut bacteria.
Researchers are now investigating whether particular strains of gut bacteria are altered in PD, in hopes of finding a biomarker than will make diagnosis easier. And the results are hopeful – a recent trial showed that the microbiome of participants with Parkinson's disease presented much higher numbers of bacteria from the Prevotellacae family than people without PD .
It also appears that certain strains of bacteria may be associated with severity of some PD symptoms. Researchers also found that PD patients with higher numbers of Enterobacteriacaea bacteria, (a pathogenic type of bacteria), in their large bowel suffered from more severe postural instability, and walking difficulties .
A leap in logic could suggest that having a microbiome robust in Prevotellacae bacterium may prevent Parkinson's disease, or that its absence could trigger the development of PD.
But that's quite a leap – all that this research really tells us is that Parkinson's disease may go hand-in-hand with low levels of Prevotellacae bacteria. Further investigation is needed if we want to find out why this association exists, and whether it has any relevance to clinical treatment of PD.
However, it does tell us that there is hope for early screening techniques – a simple stool test may be able to assess at-risk patients who have a family history, chronic constipation, or other predisposing factors for Parkinson's disease. Rather than waiting for severe symptoms to kick in, early intervention and treatment may be possible.
Obviously a lot more researce has be done before simply supplementing with probiotics to help support a healthy microbiome in PD patients. Even so, beneficial bacteria won't last long in the gut if inflammation is present – and PD is associated with chronic, systemic inflammation.
Research confirms that inflammation is the key in the relationship between the gut microbiota and Parkinson's disease.
High levels of pathogenic bacteria and low levels of beneficial Prevotellacae strains are associated with inflammatory processes that spread from the gut to other systems of the body.
These types of pro-inflammatory bacterial profiles have been seen in other disorders that affect the central nervous system (such as autism) and researchers believe this is evidence that PD may be characterised by an inflamed gut  .
It's a chicken-or-the-egg situation: which came first – the overgrowth of pathogenic bacteria, or the inflamed gut environment that supports it? Regardless of the cause, reducing inflammation in the gut is the key to improving the bacterial profile, and may have impact on the severity of PD symptoms.
Prevotellacae bacteria has many roles in the bowel, including the creation of short-chain fatty acids, and synthesis of thiamine and folate, and without adequate bacteria to synthesise them in the gut, these nutrients may become deficient. Research has shown that supplementation may have potential in reducing severity of symptoms in PD.
Glutamine – A key amino acid needed for the regeneration of cells in the large intestine create a hospitable environment for beneficial bacteria and prevent “leaky gut”.
Fibre – A healthy microbiota sustains itself by fermenting dietary fibre.
Fuel the gut with plenty of fibre from fresh fruits and vegetables, or supplements like psyllium husk and slippery elm powder.
Omega-3 & Vitamin E – Healthy fats and fat-soluble antioxidants reduce inflammation throughout the body, as well as support the structure and function of the enteric and parasympathetic nervous systems.
 NHMRC Department of Health & Human Services Victoria (2016) Parkinson's Disease. https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/parkinsons-disease
 Cersosimo M. G. & Benarroch, E. E. (2012) Pathological correlates of gastrointestinal dysfunction in Parkinson’s disease. Neurobiol Dis, 46, 559–564. https://www.ncbi.nlm.nih.gov/pubmed/22048068
 Shannon, K. M., et al. (2012) Is alphasynuclein in the colon a biomarker for premotor Parkinson’s disease? Evidence from 3 cases. Mov Disord, 27(6), 716–719. https://www.ncbi.nlm.nih.gov/pubmed/22550057
 Noyce, A. J., et al. (2012) Meta-analysis of early nonmotor features and risk factors for parkinson disease. Annals of Neurology, 72, 893–901. http://onlinelibrary.wiley.com/doi/10.1002/ana.23687/full
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