Comparison of two next-generation sequencing technologies for resolving highly complex microbiota composition using...

Area of Science:

• Microbial ecology
• Molecular biology
• Bioinformatics

Background:

• High-throughput molecular technologies enable high-resolution profiling of microbial communities, particularly in complex environments such as the human intestinal microbiota.
• Next-generation sequencing (NGS) advancements offer increasingly finer resolution for microbial community analysis.

Purpose of the Study:

• To compare the performance of longer (454 Titanium) and shorter, paired-end (Illumina) sequence reads for phylogenetic profiling of microbial communities.
• To investigate the limitations and potentials of different 16S rRNA gene variable regions when analyzed with these sequencing technologies.
• To assess the impact of sequencing technology and variable region choice on microbial community classification accuracy.

Main Methods:

• Microbial DNA was extracted from a human fecal sample.
• Phylogenetic profiling was performed using both 454 Titanium (longer reads) and Illumina (paired-end, shorter reads) sequencing technologies.
• Six tandem combinations of 16S rRNA gene variable regions were targeted for sequencing.
• In silico evaluations and experimental sequencing were conducted to assess classification accuracy and identify biases.

Main Results:

• In silico analysis predicted high classification accuracy for V3/V4 and V4/V5 regions with both technologies.
• Experimental sequencing identified significant amplification bias in the V3/V4 region, highlighting the need for primer validation.
• While both 454 Titanium and Illumina showed improvements and relative consistency, Illumina's shorter reads and higher error rates limited genus-level classification.
• Despite limitations, Illumina's greater coverage capacity holds promise for analyzing highly diverse microbial communities.

Conclusions:

• Experimental validation of primer pairs is essential to mitigate amplification bias in microbial community profiling.
• Current Illumina technology, despite shorter reads, offers high coverage beneficial for complex environments, but read length and error rates impact classification depth.
• Advancements in sequencing technologies provide enhanced resolution for studying microbial ecosystems, with careful consideration of variable regions and potential biases necessary.