Spatial Characteristics of Colonic Mucosa-Associated Gut Microbiota in Humans

Area of Science:

• Microbiome research
• Human gut ecology
• Bacterial 16S rRNA gene sequencing

Background:

• Limited data on spatial distribution of human colonic bacteria.
• Understanding gut microbiome heterogeneity is crucial for health and disease.

Purpose of the Study:

• To investigate the spatial distribution and variability of bacterial communities across human colon segments.
• To compare colonic bacteria with rectal and fecal samples.

Main Methods:

• Colonic biopsies from 27 adults across five segments and fecal samples from 13.
• Sequencing of bacterial 16S rRNA V4 region.
• Analysis of amplicon sequence variants (ASVs) using SILVA and functional capacity using Tax4fun.

Main Results:

• No significant differences in richness, evenness, or composition across colon segments.
• Firmicutes and Bacteroidetes were dominant phyla.
• Significant differences observed between rectal and fecal bacteria.
• Inter-individual variability exceeded inter-segment variability.

Conclusions:

• Human colonic bacterial communities are homogeneous across the large intestine.
• Individual variability is a key factor in gut microbiome structure.
• Rectal and fecal bacterial communities exhibit distinct compositions.