Table 2.

Richness, alpha diversity, beta diversity.

Reference	[42]	[43]	[34]	[35]	[36]	[37]	[38]	[39]	[40]	[41]
Indexes/Method	YF	PR	Ill Miseq					Ill Hiseq		Ro
Faecal bacterial counts	>	n	n	n	n	n	n	n	n	n
Alpha diversity/Richness on at least one taxonomic level (Chao 1 index, *other indexes)	n	n	>	n	-	-	<*	-	n	-
Overall Beta diversity (weighted Unifrac, °other indexes)	n	n	sd	sd	sd °	sd °	n	°		sd

This table shows the significant differences in faecal bacterial counts, alpha diversity/richness and beta diversity between healthy controls (HC) and Parkinson’s disease (PD). > symbolizes a higher abundance in HC when compared to PD; < symbolizes a lower abundance in HC when compared to PD; - symbolises that no statistical significant difference was found between HC and PD; sd indicates a statistically significantly difference; n symbolizes, that no information was given. The methods used by the studies are Yakult Intestinal Flora-SCAN (YF), 96-well block of the ABI PRISM 7900HT Sequence Detection System (PR), Illumina Miseq sequencing (Ill Miseq), Illumina Hiseq sequencing (Ill Hiseq), Roche 454 GS FLX Titanium sequencing (Ro). * symbolzises that other alpha diversity indexes where used, like Shannon, Simpson and Richness (Margalef) [38]. ° symbolzises, that other beta diversity indexes where used, like unweighted Unifrac [36], Shannon [37] or univariate tests [39]