Dietary whey protein protects against Crohn's disease by orchestrating cross-kingdom interaction between the gut phageome and bacteriome.

BACKGROUND

The gut microbiome and diet are important factors in the pathogenesis and management of Crohn's disease (CD). However, the role of the gut phageome under dietary influences is unknown.

OBJECTIVE

We aim to explore the effect of diet on the gut phageome-bacteriome interaction linking to CD protection.

DESIGN

We recruited CD patients and healthy subjects (n=140) and conducted a multiomics investigation, including paired ileal mucosa phageome and bacteriome profiling, dietary survey and phenome interrogation. We screened for the effect of diet on the gut phageome and bacteriome, as well as its epidemiological association with CD risks. The underlying mechanisms were explored in target phage-bacteria monocultures and cocultures in vitro and in two mouse models in vivo.

RESULTS

On dietary screening in humans, whey protein (WP) consumption was found to profoundly impact the gut phageome and bacteriome (more pronounced on the phageome) and was associated with a lower CD risk. Indeed, the WP reshaped gut phageome can causally attenuate intestinal inflammation, as shown by faecal phageome versus bacteriome transplantation from WP-consuming versus WP-non-consuming mice to recipient mice. Mechanistically, WP induced phage (a newly isolated phage AkkZT003P herein) lysis of the mucin-foraging bacterium , which unleashed the symbiotic bacterium to counteract intestinal inflammation.

CONCLUSION

Our study charted the importance of cross-kingdom interaction between gut phage and bacteria in mediating the dietary effect on CD protection. Importantly, we uncovered a beneficial dietary WP, a keystone phage AkkZT003P, and a probiotic that can be used in CD management in the future.