In the world of wellness and health content, few areas of our anatomy attract more interest lately — and specious claims — than the gut microbiome.This vast ecosystem of bacteria and microorganisms within our intestines shapes our health in profound ways that go well beyond digesting food — our immune system, mood, cognition, metabolism and much more.But public awareness of the microbiome's central role in our well-being has also given rise to a market of advice-givers and products playing up the idea that we need to constantly test, reset, or somehow optimize this network of bugs inside us.Gut researchers say, in many cases, what's being promoted has leapfrogged the evidence.Here's what some of the leading scientists in the field want you to know:It's a fundamental challenge for the field: In healthy people, the specific makeup of the gut microbiome can vary considerably based on geography, lifestyle, diet, genetics and other factors.Even though the field has made major strides, there's "no clinical or scientific consensus around what constitutes a healthy microbiome," says Hannah Holscher, a professor of nutrition at the University of Illinois in Urbana-Champaign.This is why there's no single metric that can deliver a reasonably straightforward assessment of your gut health like there is for cholesterol or blood pressure.Want the latest stories on the science of healthy living? Subscribe to NPR's Health newsletter.Broadly speaking, however, scientists do have clues about what tend to be desirable characteristics for the microbiome.Research shows a higher diversity of microorganisms can be one indicator.You can also look at how well the microbiome resists change in the face of disruptions like illness or antibiotics, and the ability to bounce back after that.
Scientists have also identified certain groups of bacteria that are correlated with health.While none of these are universal markers — because in some instances, higher diversity can actually be asso...