DNA testing is better than a culture because it can identify all the bacteria present. Culturing cannot do this. While culturing was relevant during the pre-PCR era, it is now a rarely used, legacy method with plenty of draw backs. The limitation of culturing include the following.
- It does not identify all bacteria present. The human gut contains bacteria that require different conditions to culture; at least 12 different culturing conditions are needed to accurately measure the majority of species. Most labs only perform a single culture plate for aerobic bacteria, which eliminates the possibility of detecting all other types of bacteria, including the 90% of bacterial species that are are anaerobic.
- Interpretation in stool microscopy is very subjective. Multiple microbes look similar under a microscope and require a specialized technician to review. Imagining this in a high throughput setting, it is easy to predict the error rates that it would entail.
- Finally, DNA testing via PCR is not new. Bacteria gene information is now readily available to develop primers. Vibrant has an advantage in primer development due to the ability to try multiple primers and check hybridization on a proprietary DNA microarray and then pick the best primers. This helped Vibrant develop and have very specific primers for colonic bacteria detection.
