A research team is studying the gut microbiome of individuals with irritable bowel syndrome (IBS) using whole-genome shotgun metagenomic sequencing. They aim to identify not only the species present but also the functional genes that may be involved in the disease. Which of the following statements best describes the advantage of using whole-genome shotgun sequencing over traditional methods like 16S rRNA sequencing in this context?

Whole‑genome shotgun sequencing reads all DNA in a sample, so it can identify every species down to strain level and also reveal the genes each organism carries. In contrast, 16S rRNA sequencing only looks at one marker gene and tells you who is there, not what they can do. By sequencing whole genomes, researchers can see if IBS patients have microbes that produce, say, a gene for a bile‑acid‑modifying enzyme that might irritate the gut. Thus, shotgun sequencing gives both taxonomic detail and functional insight, which is essential for linking microbiome changes to IBS symptoms.