HOW A GUT DNA TEST WORKS
Gut microbiome sequencing tests cost anywhere from $150-$400. Companies send out home stool-collection kits by post (uBiome and Microba tests can be done in Australia; DayTwo is currently only available in the US and Israel, but is expanding globally soon). They then sequence the DNA, before using metagenomics to decode the microbial species present.
uBiome gives customers a simple read-out of the microbes detected, along with information about what they do inside your body. DayTwo and Microba provide personalised dietary advice based on the microbes they find. DayTwo says it can identify foods that will help control blood sugar and thus protect against diabetes, obesity and heart disease.
To offer this advice, the firm utilises an algorithm developed by Weizmann researchers. Using data from 800 people, the researchers trained a machine-learning algorithm to predict the best blood-sugar- lowering diets for each individual based on their set of gut microbes. They then validated these results in a follow-up trial of 26 people.
Microba takes a broader approach. It offers dietary advice to boost 17 types of bacteria associated with reduced risks of developing a range of diseases. For example, it measures the levels of faecalibacterium prausnitzii, which is thought to protect against bowel cancer and inflammatory bowel disease. If customers have below-average levels, the company recommends eating blueberries, watermelon, asparagus, broccoli and other foods that promote the bacteria’s growth.
But it’s unclear whether this will actually make much difference to your health. “It’s a good start, but there are thousands of other bacteria in our gut as well and we’re only just beginning to understand which ones are important and how they work together,” says Loughman.
Microba hasn’t conducted clinical trials to validate its dietary recommendations yet. “At the moment, the test should mainly be treated like a neat informational tool. We’re not at the point where we can diagnose or treat disease,” says Alena Pribyl, one of the company’s biologists.
Pribyl says Microba’s services help people by explaining why they should be eating certain foods. “We’re all told to eat more fruit and vegetables, but we don’t know why and so most of us don’t,” she says. “If you know that eating blueberries will promote the exact bacteria that you’re deficient in and potentially protect against disease, that might be more motivating.”