Beyond abundance: ecological and functional relevance of intestinal fungi in the fish gut microbiome.

Intestinal fungi play a crucial ecological and functional role in the fish gut microbiome, despite their low abundance in sequencing data.

• Why it matters: Understanding the full complexity of the fish gut microbiome is essential for insights into host health and disease, yet fungi are often overlooked or dismissed as contaminants.
• What they did: The study analyzed fish gut samples, revealing recurrent, context-dependent fungi that influence host outcomes through enzymatic activity, immune modulation, and ecological interactions, regardless of low read fractions.
• The result: Incorporating fungi into microbiome models highlights their ecological filtering and functional roles, emphasizing the need to move beyond abundance metrics to better understand microbiome dynamics and host interactions.