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Updated: Apr 16, 2026

Guided Protocol for Fecal Microbial Characterization by 16S rRNA-Amplicon Sequencing
Published on: March 19, 2018
Development and utility of the FDA 'GutProbe' DNA microarray for identification, genotyping and metagenomic analysis
J N Patro1, P Ramachandran1, J L Lewis1
1Division of Molecular Biology, Center for Food Safety & Applied Nutrition, U.S. Food and Drug Administration, Muirkirk Rd Laurel, MD, USA.
Aim:
Lactic acid bacteria are beneficial microbes added to many food products and dietary supplements for their purported health benefits. Proper identification of bacteria is important to assess safety as well as proper product labelling. A custom microarray (FDA GutProbe) was developed to verify accurate labelling in commercial dietary supplements.
Methods And Results:
Strain-specific attribution was achieved with GutProbe array which contains genes from the most commonly found species in probiotic supplements and food ingredients. Applied utility of the array was assessed with direct from product DNA hybridization to determine (i) if identification of multiple strains in one sample can be conducted and (ii) if any lot-to-lot variations exist with eight probiotics found on the US market.
Conclusions:
GutProbe is a useful tool in identifying a mixture of microbials in probiotics and did reveal some product variations. In addition, the array is able to identify lot-to-lot differences in these products. These strain level attribution may be useful for routine monitoring of batch variation as part of a 'Good Manufacturing Practices' process.
Significance And Impact Of The Study:
The FDA GutProbe is an efficient and reliable platform to identify the presence of microbial ingredients and determining microbe differences in dietary supplements. The GutProbe is a fast, rapid method for direct community profiling or food matrix sampling.
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Modern Molecular Taxonomy
Automated Microbial Diagnostics
Applications of Molecular Taxonomy
Probiotics
DNA Microarrays

