September 2021

PRECISION NUTRITION IS ON THE RISE

 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 that more finely-tuned nutrition could help curb the nation’s chronic-disease epidemic.  Many of the new ventures engineer diets that they say reduce inflammation, improve digestion and counter autoimmunity, with weight loss often a byproduct.  Programs typically consist of a test kit, genetic sequencing analysis of stool samples (and in some cases blood) against a database of gene-sequenced microbes, and an app that explains and makes recommendations; in some cases, there are dietary supplements.  The companies collect genetic information in databases they say they hope will one day be large enough to tackle chronic disease. 

Traditional medicine hasn’t paid much attention to nutrition, and still doesn’t.  But research has exploded in the past five years, suggesting the importance of the gut microbiome to overall health, and the ways it can be affected by food.  It’s really important to break the mold about what we’ve been told about nutrition.  Low-calorie, low-fat and eat-this-not-that approaches aren’t working.  We have amazing advice about nutrition that’s gotten us nowhere. Gut health depends on a complex interaction between the food you eat and the microbes in your gut.  There are 26,0000 chemicals founds in foods.  They combine with more than 1000 different species of microbes in the gut, then mix with your own chemistry to influence your 20,000 genes and other pathways. 

There is a dearth of rigorous research showing how well the new approach works.  While there is strong evidence that the interaction of diet and microbiome plays a big role in health and disease, the research is mostly associative.  Studies of the relation between health and nutrition are difficult to conduct and often inconclusive.  Many studies that do exist have been sponsored by the nutrition companies themselves, sometimes in collaboration with academics at elite institutions like Harvard, Stanford University and King’s College.  Dietary guidance based on a patient’s microbiome is all new.  We don’t know how helpful it is, or how useful it is.  There is a lot of heterogeneity, and not a lot of evidence.  Dietitians can’t yet recommend it to patients.

One early microbiome startup has failed. In March, its founders were charged with healthcare and securities fraud.  A quantum leap in DNA-sequencing technology has made the study of gut microbes faster and cheaper, along with the ability to monitor health changes in real time with smartphones and glucose monitors.  The field has drawn intense interest from scientists, academics and physicians. Two companies have sold several hundred thousand kits to collect samples, send them in for analysis and receive personalized nutrition advice, and, in some cases, customized supplements. These companies analyze blood and stool to provide ratings on metrics including gut health and immune health, and design individualized supplement packages. The diet advice can be surprising.  There is no such thing as a universally healthy food.

Betsy Morris