Probiotic legacy effects on gut microbial assembly in tilapia larvae

Area of Science:

• Aquaculture
• Microbiology
• Fish Health

Background:

• Understanding early life gut microbial colonization in fish is crucial for aquaculture.
• Limited knowledge exists on host-environment interactions shaping early gut communities.

Purpose of the Study:

• To investigate the long-term effects of early microbial exposure on tilapia gut microbiota.
• To determine if early probiotic administration influences gut community structure and variation.

Main Methods:

• Tilapia larvae were reared under axenic, probiotic (Bacillus subtilis), or active suspension conditions.
• 16S rRNA gene amplicon sequencing (Illumina HiSeq) was used for microbial characterization.
• Gut microbiota composition was analyzed at later life stages.

Main Results:

• Bacillus subtilis was detected in tilapia guts during the 7-day probiotic exposure period.
• Gut microbiota of probiotic-exposed fish remained significantly different from controls post-exposure.
• Early probiotic contact led to reduced inter-individual variation in gut microbiota.

Conclusions:

• Early-life microbial exposure, even transiently, can establish a lasting impact on fish gut microbiota.
• Probiotic interventions may enhance gut microbial stability and reduce variation in farmed fish.
• This highlights the importance of early life stages for modulating gut health in aquaculture.