Selection for oligotrophy among bacteria inhabiting host microbiomes.

Area of Science:

• Microbial Ecology
• Evolutionary Biology
• Genomics

Background:

• Host-associated microbes adapt to host environments, sometimes becoming obligate symbionts.
• Free-living microbes primarily adapt to their external surroundings.
• Understanding these selective pressures is key to predicting microbial evolution.

Purpose of the Study:

• To investigate the selective pressures from both host and external environments on host-associated bacteria.
• To determine how these pressures shape the functional potential of bacteria within host microbiomes.
• To understand the complex evolutionary forces acting on microbial communities.

Main Methods:

• Comparative genomic analysis of host-associated bacterial populations.
• Assessment of functional gene content related to nutrient acquisition.
• Correlation analysis between bacterial traits and environmental nutrient levels.

Main Results:

• Host-associated heterotrophic bacteria exhibit trait selection influenced by external environmental nutrient availability.
• This selection occurs despite the nutrient-rich conditions within the host microbiome.
• Evidence suggests a complex interplay of host and external selective pressures.

Conclusions:

• Bacterial functional potential in host microbiomes is shaped by a mix of host and external environmental factors.
• External nutrient availability plays a significant role in trait selection for host-associated bacteria.
• These findings help predict microbial functional shifts in response to environmental changes.