Journal of IiMER the 16S rRNA gene provides species-specific signature sequences. We obtained an average of 98,000 sequence reads per sample, more than ample to identify almost all of the bacterial diversity. To determine how many reads are needed, the number of species detected per number of sequences can be graphed to produce a ‘rarefaction curve’ (Figure 2). As more sequences are obtained, the number of species detected increases until a plateau is reached, where few additional species will be found despite a large number of additional sequence reads. For our samples, it is evident that 30,000 reads would be more than sufficient. For the example shown of a theoretical sample with low diversity, 5000 reads would have been adequate, while the high-diversity example indicates that even 30,000 reads would not suffice. A conclusion that can be drawn from Figure 2 is that ME cases have reduced bacterial diversity in comparison to healthy controls. Such reduced diversity has been observed in other diseases such www.investinme.org Page 27 of 82
28 Publizr Home