Function Health vs Biome, What Each Test Actually Covers

Here's the short version. Function Health runs recurring blood biomarker panels, a snapshot of your body chemistry today, retaken later to see what moved. Biome runs DNA and whole genome tests, a one-time read of the genetic code you were born with. Different inputs. Different questions. I get asked which one someone should buy at least once a week, and honestly, the answer is usually both, just not for the same reason.

That distinction sounds obvious once you say it out loud. But I keep seeing the two categories lumped together in "health testing" roundups, like they're competing products. They're not. And that mix-up is exactly where people end up buying the wrong thing for what they actually want to know.

Function Health tests what's happening in your blood right now

Blood biomarkers are a moving target by design. They're supposed to move. Cholesterol, inflammation markers, hormone levels, blood sugar: all of it shifts with what you ate this month, how you slept last week, whether you started a new medication. A biomarker panel is a photograph of a body that keeps changing, taken again and again to build a timeline.

Function Health's whole category is built around exactly that: repeat testing over time, so a change between draws tells you something actually happened. It's the right tool for tracking whether an intervention worked. I don't have Function Health's own published biomarker list in front of me here, so if you want the exact panel and cadence, go check their site directly. Don't take a secondhand number from anywhere else, including this post.

What that kind of testing measures, biologically, is the part of you that responds to inputs. Diet is one of the biggest inputs there is. I dug into a 2024 review covered by Medical News Today, and it put it plainly: "Polyphenols found in foods, herbs, and spices used in a healthy person's typical diet could have a positive impact on gut health." That's a body chemistry claim. It's true precisely because gut bacteria populations, unlike your genome, actually change based on what you put in your mouth.

Same pattern shows up elsewhere, and once you notice it you'll see it everywhere. Medical News Today's coverage of gut and skin research noted that probiotic, prebiotic, and synbiotic supplements "could be beneficial for skin health, especially for managing" certain conditions, according to a review discussed in a 2026 article. A separate piece on gut microbiome and type 2 diabetes argued that "integrating microbiome-targeted therapies with conventional diabetes management could lead to more effective and holistic patient care." Every one of those findings describes something you can shift. That's the whole point of measuring it more than once.

Biome tests what's fixed in your DNA, not what's in your blood

Biome sells two things: a DNA test and a whole genome test. That's the product line, full stop. Everything else in this section is about what that category of testing does generally, not a specific Biome claim I'm making up on the spot.

DNA doesn't respond to your breakfast. It's the sequence you were born with, and short of rare somatic mutation, it reads the same on day one and decade three. So a DNA or whole genome test isn't something you retake to catch a change, because most of the time there's nothing to catch. You take it once and the result is a reference document, not a data point on a timeline.

That's a real limitation and a real feature at the same time. Limitation: it can't tell you what your cholesterol is doing this month. Feature: you're not paying for a repeat draw to find out something that hasn't moved at all.

Why this distinction actually matters

I like to think of it as software versus hardware, sort of. Your genome is closer to fixed architecture. Your blood chemistry is the running process, shaped by that architecture but also by sleep, stress, food, age, medication, and a hundred other variables stacked on top.

Gut microbiome composition sits in an interesting middle zone here, and it's worth flagging because it trips people up constantly. It's biological and it's measurable, like a blood biomarker, and Healthline's overview of probiotics describes them as supporting health "by crowding out harmful pathogens, improving your intestinal barrier function, and promoting" broader gut function. That's a state, not a fixed trait. States change. A companion Healthline piece on probiotics and prebiotics makes the same point: eating both "in balanced amounts can support a healthier gut microbiota, strengthen the gut barrier, and may benefit immunity, inflammation, and mental health." None of that is genetic destiny. It's responsive. Which is exactly why it belongs in the recurring-measurement category with blood biomarkers, not the one-time-read category with DNA.

So when you're deciding what to buy, ask yourself what you're actually trying to answer. Want to know if your last three months of changes moved a number? That's a repeat-panel question. Want to know what's built into your biology from birth, the kind of thing a diet change this month won't touch no matter what? That's a DNA question.

Function Health vs Biome at a glance

	Function Health	Biome
What it measures	Blood biomarkers, a snapshot of current body chemistry	DNA, inherited genetic variants
Changes over time?	Yes, that's the point of retesting	No, your sequence stays the same
How many times you'd typically test	Repeated, on a recurring basis	Once
Product lineup	Blood biomarker panel (check their site for the current list)	DNA test and whole genome test

FAQ

Is Function Health a genetic test? No. It's built around blood biomarker panels, a measure of current body chemistry, not DNA sequencing. Check Function Health's own published test list for exactly what's included.

Does Biome test cholesterol, blood sugar, or hormone levels? No. A DNA or whole genome test reads inherited genetic variants tied to risk and predisposition. It doesn't measure what's circulating in your blood at this moment.

Can gut microbiome results change between tests? Yes, and honestly, that's expected. Research covered by Medical News Today and Healthline points to diet, herbs, and supplements as things that shift gut bacteria populations. Retest for that reason: microbiome and biomarker measurements move, so a single check won't catch it.

Should I pick one or do both? They answer different questions, so honestly, this isn't really an either-or. Blood biomarker testing tracks what's changing in your body right now. DNA testing reads the fixed genetic layer underneath it. Plenty of people I've talked to use genetics as the one-time foundation and layer recurring blood work on top.

Which one tells me if a supplement is working? A recurring blood or biomarker panel, not a DNA test, since DNA doesn't move in response to a supplement. If you're testing whether probiotics changed something, you want a measurement you can retake. Same logic behind the gut health research cited above.