Handling of spurious sequences dictates the outcome of high-throughput 16S rRNA gene amplicon profiling

Handling of artefact sequences during bioinformatic processing of 16S rRNA gene amplicon data requires careful attention. A threshold of relative abundance of 0.25% seems more appropriate than the commonly used singleton removal approach, although study-specific analysis strategies are mandatory. We propose the concept of normalized richness, the use of which will help comparison of results across studies.