Linking Smoking, Coffee, Urate, and Parkinson’s Disease – A Role for Gut Microbiota?

Abstract

Abstract. While the etiology and pathogenesis of Parkinson's disease (PD) is still obscure, there is evidence for lifestyle factors influencing disease risk. Best established are the inverse associations with smoking and coffee consumption. In other contexts there is evidence that health effects of lifestyle factors may depend on gut microbiome composition. Considering the gastrointestinal involvement in PD, it was recently speculated, that the associations between smoking, coffee, and PD risk could be mediated by gut microbiota. Here we review such a possible mediatory role of gut microbiota taking into account recent findings on microbiome composition in PD and extending the scope also to urate.

The gut-brain axis: is intestinal inflammation a silent driver of Parkinson’s disease pathogenesis?

“…Specifically, both smoking and drinking coffee are associated with significantly reduced incidence of PD, and it has been proposed that protective effects of tobacco and coffee may be mediated at least in part by modulation of the microbiota. 92,102 Some evidence now suggests that changes in certain bacterial taxa that are observed with smoking and coffee consumption resemble the microbiota differences reported in controls compared to PD cases. 102 This raises the possibility that some states of the microbiome may be protective with regard to PD, but it is also possible that the smoking and coffee-associated microbial compositions reflect changes in the intestinal environment or function.…”

“…92,102 Some evidence now suggests that changes in certain bacterial taxa that are observed with smoking and coffee consumption resemble the microbiota differences reported in controls compared to PD cases. 102 This raises the possibility that some states of the microbiome may be protective with regard to PD, but it is also possible that the smoking and coffee-associated microbial compositions reflect changes in the intestinal environment or function. Nicotine has well-established anti-inflammatory properties, and coffee increases gut motility, 102 both of which may contribute to an intestinal environment that is resistant to PD-associated pathology.…”

“…102 This raises the possibility that some states of the microbiome may be protective with regard to PD, but it is also possible that the smoking and coffee-associated microbial compositions reflect changes in the intestinal environment or function. Nicotine has well-established anti-inflammatory properties, and coffee increases gut motility, 102 both of which may contribute to an intestinal environment that is resistant to PD-associated pathology. Alternatively, some have suggested that PD-related impairment of neurochemical reward systems may lead individuals with PD, even in the pre-motor stages, to consume less nicotine and caffeine, 92 rendering associated intestinal differences an artifact of lifestyle activities.…”

How strong is the evidence that Parkinson's disease is a prion disorder?

“…Interestingly, a epidemiological study on a large Danish cohort reported a controversial finding describing a significantly reduced future PD risk in patients who underwent truncal vagotomy as a treatment for peptic ulcer in 1977–1995 (55). Recently, it was speculated that changes in gut microbiome (56,57), e.g. as a consequence of smoking or coffee (known modifiers of PD risk), could reduce the likelihood of inflammatory events that might trigger α-synuclein misfolding in the gut wall (58,59).…”

Air pollution and Parkinson’s disease – evidence and future directions

“…Finally, the involvement of the human gut microbiome and PD (56)(57)(58)(59)(60) is an exciting emergent area of research. It is possible that larger particles such as PM 10 , PM 2.5 and PM 2.5−10 , although being too large to cross the blood-brain barrier, could still enter the body via another route.…”