A crop of “precision nutrition” startups are racing to develop and engineer individualized diet programs, based on growing evidence that people’s gut microbes—even those of identical twins—respond to food in significantly different ways. The studies reflect the belief among many scientists that more finely-tuned nutrition could help curb the nation’s chronic-disease epidemic.
There are 26,000 chemicals found in foods, [genetic epidemiologist Tim Spector] says. They combine with more than 1,000 different species of microbes in the gut, then mix in your blood with your body’s own chemistry to influence your 20,000 genes and other pathways, he says. A slight change and the whole system can move out of kilter, which can cause long-term problems, he says.
[However,] there is a dearth of rigorous independent research showing how well the new approach works. While there’s strong evidence that the interaction of diet and microbiome plays a big role in health and disease, the research is mostly associative, according to a February 2021 review in the Journal of Human Nutrition and Dietetics. Studies on the relation between health and nutrition are hard to conduct and often inconclusive, according to a 2018 article in the American Society for Nutrition’s journal Advances in Nutrition.