Critical complex network structures in animal gastrointestinal tract microbiomes.

Area of Science:

• Microbiome research
• Network analysis
• Ecology

Background:

• Living organisms form complex interaction networks.
• Animal gastrointestinal microbiomes (AGMs) exhibit core/periphery and high-salience skeleton network structures.
• These structures, including core species, periphery nodes, and network backbones, are crucial for ecosystem function and stability.

Purpose of the Study:

• To analyze critical network structures in animal gastrointestinal microbiomes (AGMs).
• To compare AGM network structures with human gut microbiome networks.
• To investigate the influence of host phylogeny and diet on AGM network composition.

Main Methods:

• Analysis of 36 pairs of core/periphery network (CPN) and high-salience skeleton network (HSN) for AGMs.
• Utilized data from 4903 gastrointestinal-microbiome samples across 318 animal species.
• Integrated host phylogeny and diet types into network analyses.

Main Results:

• AGM network structures are qualitatively and structurally similar to human gut microbiomes.
• Evolutionary trends of key microbial phyla (Bacteroidetes, Firmicutes, Proteobacteria) in animals do not mirror modern human phylogenetic patterns.
• Diet type consistency was observed in microbial phyla abundance-ratios.

Conclusions:

• Human gut microbiome composition has diverged from evolutionary trends seen in animals.
• This divergence is potentially linked to the Anthropocene, agriculture, and industrial revolution.
• Modern human gut microbiomes may differ significantly from those of ancestral populations and other animals.