Reproducible profiling of the gut microbiota using surplus clinical faecal immunochemical test samples

Area of Science:

• Microbiome research
• Molecular diagnostics
• Public health screening

Background:

• Quantitative faecal immunochemical testing (qFIT) is widely used for fecal hemoglobin screening.
• The potential for using leftover qFIT cassettes for bacterial 16S rRNA gene sequencing is unexplored.
• Investigating the stability and comparability of qFIT samples for microbiome analysis is crucial.

Purpose of the Study:

• To assess the temporal stability of bacterial 16S rRNA gene sequencing results from qFIT cassettes.
• To compare qFIT-derived microbiome data with results from larger stool samples.
• To determine the suitability of qFIT samples for large-scale population-based studies.

Main Methods:

• Stool samples from healthy volunteers were tested using qFIT, with samples analyzed at 0, 4, 7, and 14 days.
• Bacterial 16S rRNA gene sequencing was performed on qFIT samples and compared to larger whole-stool samples.
• DNA was extracted from 100 surplus qFIT samples from symptomatic patients to assess DNA yield.

Main Results:

• Bacterial composition and diversity in qFIT samples remained stable for up to 14 days, showing minor variations from baseline.
• qFIT results were comparable to those obtained from larger whole-stool samples.
• At least 75% of symptomatic patient qFIT samples yielded sufficient DNA for 16S rRNA gene sequencing.

Conclusions:

• qFIT samples are stable over 14 days and comparable to control samples for microbiome analysis.
• Leftover qFIT cassettes can be utilized for cost-effective, large-scale population-based intestinal microbiota studies.
• This approach offers a valuable tool for advancing microbiome research and understanding gut health.