10/17/2026
Word of the Day: Dysbiosis
You’ve probably heard people talk about having an “imbalanced gut.”
But what does that actually mean?
Dysbiosis is a term researchers use to describe a disruption or alteration in the composition or function of a microbial community. In the context of the gut, that can involve changes in which microbes are present, how abundant they are, how diverse the community is, or what those microbes are doing.
And there’s an important misconception worth clearing up:
Dysbiosis isn’t simply a case of “bad bacteria taking over.”
The gut microbiome is an incredibly complex ecosystem. Microbes interact with one another, compete for resources, produce metabolites, and respond to the environment created by our diet and lifestyle.
There also isn’t one universal microbiome that everyone needs to have.
Two healthy people can have substantially different microbial communities.
That’s one reason researchers are increasingly interested not just in which microbes are present, but in their activity and the molecules they produce.
Diet is one of the many factors that can influence this ecosystem. Fiber, for example, can be used by gut microbes to produce short-chain fatty acids and other metabolites that interact with the gut environment. Medications, lifestyle, and other environmental factors can influence the microbiome, too.
So instead of thinking about your gut as a simple balance between “good” and “bad” bacteria, it may be more useful to think of it as an ecosystem that is constantly responding to its environment.
The more we understand that ecosystem, the more interesting personalized nutrition becomes.
Save this post for later, and share it with someone who wants to go beyond the “good bacteria vs. bad bacteria” version of gut health.
