TIPP-SD: A new method for species detection in microbiomes

In this study, we present TIPP-SD (i.e., TIPP for Species Detection), a new technique for species detection in a microbiome sample. TIPP-SD uses a substantially modified version of TIPP3, which is a recently developed abundance profiling tool based on maximum likelihood phylogenetic placement into marker gene taxonomies. TIPP-SD depends on a parameter (i.e., "threshold") for the required support for species detection, thus allowing us to compute a precision-recall curve as we vary this parameter. In comparing the precision-recall curves for TIPP-SD, TIPP3, Kraken2, Bracken, Metabuli, and Metapresence, we find that TIPP-SD improves on the other methods with respect to accuracy under conditions where there is a highly variable distribution of species abundance or where there is sequencing error. Under other conditions, TIPP-SD is close to the best of these methods. Finally, although TIPP-SD is slower than the other methods, it is still fast enough to be used on large datasets. TIPP-SD is available in github as part of the TIPP3 software package.