This week I spent 20 glorious minutes to myself reading a fascinating article about the gut microbiome.
Heads up: like so many things involving the gut microbiome and nutrition, we still have a lot to learn. None of these findings are likely to change how you eat or practice, but they are a good reminder to remain skeptical as we’re bombarded with microbiome tests, supplements, and products claiming to improve our “gut health.”
If you’re fascinated by the microbiome like I am, it’s worth the read on the beach or en route to your next vacation.
Whether a bacterium is “healthy” may depend on its environment
One of the most interesting themes throughout the article was that bacteria don’t behave the same way in every population, and that defining a microbiome as “healthy” isn’t as simple as we might think.
For example, one bacterial genus that’s considered a marker of illness in many wealthier countries is completely normal in some lower-income populations.
Bifidobacterium, a group of bacteria often linked to better digestion and lower levels of inflammation in Western microbiomes, has been linked to a higher BMI in a study of adults in Paraguay.
Even more surprising: healthy people in Western countries tend to have less diverse gut microbiomes than people in some lower-income countries. Less diversity is generally associated with poorer gut health. But these same Western microbiomes also carry higher levels of two bacterial species that may help fight inflammation.
Researchers think our microbiomes may be adapting to factors like diet, geography, sanitation, medications, and other environmental exposures in real time, though that’s still a theory they’re actively investigating.
Bottom line: the same microbes play different roles (helpful, harmful, or neutral) depending on the environment they’re living in, so interpreting microbiome findings isn’t as simple as calling them “good” or “bad.”
Some gut bacteria may influence cholesterol metabolism
Researchers have identified microbes that convert cholesterol into a form that can be excreted rather than absorbed.
We’re a long way from applying that clinically, but I couldn’t help thinking about the millions of people living with high cholesterol and wondering what this line of research might reveal in the future.
Certain gut bacteria may even influence our own GLP-1 production
There’s already a substantial body of research linking the microbiome to obesity, though scientists have struggled to explain why the association exists.
One researcher found that children at high risk for obesity were missing a gut bacterium thought to play a role in the production of GLP-1.
That’s notable because it may offer a plausible mechanism for an association researchers have observed for years but couldn’t fully explain.
If there was one point the article kept making, it’s this: we need a lot more data before we can confidently interpret these findings or translate them into therapies.
And I had a good chuckle at one of the closing quotes. When asked what scientists can say with confidence right now, one researcher joked: “Fiber is probably good for you.”
I’m relieved to know our recommendation to “eat a variety of fiber-rich plant foods” still stands.
The practical takeaway
Don’t wait for perfect information before making meaningful changes, like eating more fiber. But you can protect your bank account (and your expectations) when it comes to the flood of products claiming to “fix” your gut health through the microbiome.
Curiosity builds trust
When a patient brings up a microbiome test or influencer-recommended “gut health” supplement they’ve tried, my instinct used to be to immediately steer them away. Now, I get curious.
Maybe they already spent the money. Maybe they genuinely feel better, and who’s to say how much of that is placebo versus a true physiological effect?
Shutting the conversation down doesn’t help either of us. I wrote more about this here: How to Respond to Nutrition Misinformation (Without Losing Trust).
