An endolysin containing 15 distinct domains as highlighted in the abstract seems to be very unlikely, but it is not easy to identify the 15-domain lysin in the manuscript. The authors could use spaed.ca to identify and delineate the domains. Possibly multiple domains are in fact a single domain (something frequently observed in CBDs). The authors can also have a glance on phalp.ugent.be and make a comparison of the lysins found in the gut phageome and the 755k lysins found in this database, largely derived from the metagenomic EnVhogDB database. It would be interesting to know how the phageome differentiates in properties from the full metavirome (as we know it today) in terms of lysin diversity.