Novel and unscrutinized immune entities of the zebrafish gut

The zebrafish model offers a unique opportunity to study gut immunity due to its diverse applicability within several fields of research, combined with an evolutionarily conserved immune system, transparency, and genetic tractability. This review highlights recent advances in understudied immune cell types in the zebrafish gut, emphasizing their potential to illuminate immune processes of the vertebrate immune system. The biological function of the gut is highly conserved in zebrafish, which makes them a relevant model to study intestinal immune cells with advanced molecular and imaging techniques that enable in vivo visualization of immune mechanisms and cell trajectories. Rodent and pig models have successfully contributed to our understanding of many aspects of the immune system, while zebrafish have so far been underestimated in their potential role in furthering our knowledge in this field. We suggest how future study directions can help elucidate the complex nature of gut immunity and highlight similarities between mammalian and zebrafish immune systems. Provided that immune cell functions are conserved, zebrafish can offer great opportunities for translational studies and have an important impact in improving human health.