Interwoven processes in fish development: microbial community succession and immune maturation

Area of Science:

• Aquatic immunology
• Microbiome research
• Fish health and disease

Background:

• Fishes host diverse microorganisms (microbiota) crucial for growth, immunity, and pathogen defense.
• Current aquaculture disease prevention (vaccination, disinfection, antibiotics) has drawbacks, including stress, cost, and antibiotic resistance.
• The fish microbiota is vital for host development, health, and survival, highlighting the need to understand host-microbe interactions.

Approach:

• This review synthesizes current knowledge on the bidirectional communication between fish microbiota and the immune system during development.
• It examines how microbes influence immune system ontogeny and how immune development impacts microbial colonization.
• The review details immune system development, microbiota diversity, and their interactions across fish life stages, using zebrafish as a model.

Key Points:

• Microbiota composition varies by host, organ, and developmental stage.
• Healthy microbiota promotes immune maturation, inflammation modulation, and immune homeostasis.
• Immune equilibrium is linked to microbiota stability and microbial community succession.

Conclusions:

• Considering microbiota-immune system interactions enhances our understanding of fish immunology.
• Developing tolerance to microbiota early in life supports a healthy adult microbial community.
• Balanced host-microbiota interactions prevent harmful inflammation and maintain immunological and microbiological homeostasis.