Alternating High-Fat and Polysaccharide Diets Modulates Gut Phage-Bacterial Interplay.

Area of Science:

• Microbiology
• Gut Microbiome Research
• Virome Dynamics

Background:

• Bacteriophages (phages) are key players in the human gut virome, regulating bacterial populations.
• Previous studies on diet's impact on gut phages were limited in scale.
• Understanding diet-virome interactions is crucial for gut health.

Purpose of the Study:

• To systematically investigate the impact of diet on the gut virome and phage-bacterial interactions.
• To characterize how different diets, including high-fat and polysaccharide-rich diets, shape the virome.
• To explore phage-mediated gene transfer and metabolic functions influenced by diet.

Main Methods:

• Meta-analysis of 6932 diet-associated human metagenomes.
• Time-resolved mouse model fed a high-fat diet and polysaccharides.
• Analysis of phage-bacterial interactions, abundance, lifestyle, and auxiliary metabolic genes.

Main Results:

• Diet is a major driver of gut virome composition and phage-bacterial crosstalk.
• High-fat diets significantly alter phage abundance and promote a lytic lifestyle, enriching amino acid metabolism genes.
• Fucoidan reversed high-fat diet-induced dysbiosis and increased phage-mediated horizontal gene transfer by 8.5-fold.

Conclusions:

• Dietary interventions, like fucoidan, can modulate gut virome composition and function.
• Specific phages (e.g., crAssphages, Parabacteroides phages) play roles in gene transfer and metabolism.
• Findings offer insights into nutritional strategies for targeted microbiota modulation.