Rated 4.4 on Trustpilot · 317 verified reviews on ★ Trustpilot

When your gut’s off, it doesn’t stay in your gut

It starts in your stomach — then it follows you everywhere. The bad days at your desk. The 3 a.m. wake-ups. The edge you can’t shake. You already feel the connection. The science finally explains it.

Bloating Gas Constipation that flares with stress Brain fog Low energy Restless sleep Anxiety

Your gut and your brain talk to each other all day along the gut–brain axis — a two-way line of nerves, immune signals, and chemical messengers that the bacteria in your gut help shape. When that conversation goes quiet in the wrong way, you feel it as digestion and mood, focus, sleep, and stress. Fix the wrong things and nothing moves. Map what’s actually there, and you finally have an answer worth acting on.

Why generic probiotics fail

A shelf probiotic gives everyone the same strains and hopes some of them matter to you. Your gut isn’t average — so an average formula keeps missing. Flore starts from your data instead of a guess.

Generic probiotic

A guess in a bottle

  • Same strains for millions of different guts
  • Chosen for shelf life and cost, not for you
  • No idea what your microbiome is actually missing
  • You keep buying. The symptoms keep coming back.

Flore

Mapped to you

  • Built from your own microbiome sequencing data
  • Strains chosen for the gaps your gut actually shows
  • Matched against 40,000+ real formulation outcomes
  • One precise formula — your answer, not everyone’s

Map Formulate Feel

1

Map

Your gut gets sequenced and read against 352 markers and 23,000+ microbes. You see what’s present, what’s missing, and what’s driving how you feel — digestion through to the gut–brain axis.

2

Formulate

Your profile is matched against 40,000+ real outcomes, and a single precise formula is built for you — typically 5–7 strains, including precision psychobiotics chosen to support the gut–brain connection. No filler, no guesswork.

3

Feel

Made in-house in the Chicago suburbs (Joliet, IL) and shipped to you as capsules or powder. You take it daily, track how you feel, and your formula updates as your gut changes. You decide what’s working.

Independent, accredited testing Flore doesn’t run the lab test — accredited CLIA/CAP labs do the sequencing. Your formula is built on independent data.
Capsules & powder — never liquid Real, stable, dosed delivery you can count on. No watered-down shots, no proprietary syrups.
Precision psychobiotics Strains selected for the gut–brain axis, not a one-size-fits-all blend pulled off a shelf.

Formulation intelligence, built on real-world data

Flore is personalized probiotics formulated from your own microbiome sequencing data — not an off-the-shelf blend everyone gets.

Most probiotics hand you the same capsule regardless of what's actually living in your gut. Flore starts the other way around: with your microbiome. When you upload a microbiome test — from NirvanaBiome, our preferred partner, or any provider — we read your results against a deep map of markers and microbes, then design a formula around the gaps and opportunities your data reveals.

Every Flore formula pairs a shared probiotic base — the strains and prebiotics that broadly support a healthy gut — with targeted system strains chosen for your profile. Those targeted strains span the systems the microbiome touches: GI (digestion, regularity, bloating), neuro (the gut–brain axis behind mood and stress), metabolic, and immune support, among others. From there you can layer on prebiotic and booster add-ons to dial the formula toward your specific goals.

The result is a single precise blend — typically 5–7 strains at meaningful CFU dosing — assembled from a library of 68 probiotic strains and 40+ prebiotics. No filler, no guesswork, and one delivery rather than a generic monthly auto-ship.

How We Formulate

Microbiome Mapping 352 markers · 23,000+ microbes
Condition Analysis 209 conditions supported
Ingredient Selection 200+ tested ingredients
Efficacy Validation 40,000+ formulation outcomes

By The Numbers

40,000+ Formulations
94.2% Success Rate
352 Markers
23,000+ Microbes
209 Conditions
200+ Ingredients

Those figures come from our own formulation history, not a marketing model. Because every formula is tied to a real person's data and outcomes, Flore's approach is grounded in real-world evidence — alongside the published probiotic research our strain choices draw on. We show our work: the studies and outcomes behind these numbers are laid out in full on our evidence page.

Peer-reviewed: in 2024, Flore and Arizona State University published a pilot open-label study in mSystems (American Society for Microbiology) showing Flore precision synbiotics increased gut microbiome diversity and improved gastrointestinal symptoms. This was a pilot/open-label study — not a randomized controlled trial; Flore’s own randomized controlled trials are underway. DOI: 10.1128/msystems.00503-24

The gut–brain axis behind much of this is established science. The term “psychobiotics” was coined by Dinan & Cryan (2013), and the emerging field of precision psychobiotics — matching specific strains to an individual’s gut–brain needs — is mapped in the 2025 review “Precision Psychobiotics for Gut–Brain Axis Health” (PMC, 2025). It’s the exact approach Flore formulations are built on.

94.2% see results.
Here's what that looks like.

Built for one gut. Theirs.

TrustScore 4.4 · 317 verified reviews on ★ Trustpilot

My bloating used to dictate what I could eat and when I could leave the house. Three months in, that's just… not part of my day anymore.

SR
Sarah R.
GI Support · 4 months on Flore

I'd tried five other probiotics for my IBS and given up. The Flore formula is the first that was actually built around my microbiome data, and the difference is real.

MK
Michael K.
IBS Relief · 8 months on Flore

Knowing the formula changes as my microbiome shifts — and that it's screened against my medications — is why I keep refilling. This is the only one I trust.

JT
Jennifer T.
Immune Support · 1 year on Flore

You’ve tried probiotics before. Here’s why this one’s different.

You’re not skeptical for no reason — you’ve paid for probiotics that did nothing. So here are the real questions, answered straight.

Probiotics never worked for me.

Because they were a guess — the same blend sold to everyone, formulated without ever looking at your gut. That’s exactly why they did nothing. Yours is built from your own map, around the strains your gut actually shows it’s missing.

Is the test real, or a gimmick?

Real. Your sample is sequenced by an accredited CLIA/CAP lab — Flore doesn’t run the test, independent accredited labs do. We read what’s actually over- and under-grown in your microbiome, then formulate to it.

Where’s the evidence?

The gut–brain axis and precision psychobiotics are established science — the term “psychobiotics” was coined by Dinan & Cryan (2013). Flore co-published a 2024 pilot study in mSystems showing improved gut diversity and GI symptoms, and Flore’s own randomized controlled trials are underway.

Why trust Flore?

Flore acquired Sun Genomics — bringing years of microbiome sequencing and tens of thousands of real formulations behind every formula we build. This isn’t a new idea we’re testing on you.

Is it worth it?

You’ve already paid to guess — more than once. This is the last probiotic you have to guess about. One formula, built from your data, working toward how your whole body feels — not just your gut.

Another regimen to manage?

No stack to babysit. One formula, made for you, taken once a day. You’ve spent enough energy managing your body — this is meant to give that energy back.

Do I need a doctor for this?

No. You decide. We hand you the map and the formula made from it — it’s yours to act on. If you’re managing a condition, you’re always welcome to loop in your own doctor, but nothing here waits on a prescription.

The only way to know what your gut is missing is to look. Map it once, and stop guessing for good.

Start with your map →

Save more with a longer supply

One payment, no recurring charges. New to Flore? Start with a complete program — your microbiome test is included, and you check out right here. Already have microbiome results? Pick a supply below and set up in the portal.

Complete Program — microbiome test included

12-Month Program

$1,317

paid once · microbiome test included · best value

  • 12-month personalized supply — capsules or powder
  • Microbiome test included — we order it, process it & upload your results for you
  • Your gut mapped: 352 markers across 23,000+ microbes
  • Custom formula: 5–7 targeted strains, incl. precision psychobiotics for the gut–brain axis
  • Sequenced by an accredited CLIA/CAP lab
  • Portal access — track progress & reformulate as your gut changes
  • Priority support
  • One payment · no rebills · made in Joliet, IL
Get the 12-Month Program →

Your microbiome test is included and handled for you — we order it, an accredited lab sequences your sample, and we load your results to build your formula. No separate test to buy.

Already have your microbiome results?

3-Month Supply

$99/mo

$297 paid once · no rebills

  • 3-month supply shipped at once
  • Personalized formula
  • 352 markers analyzed
  • Portal access
Select 3-Month

12-Month Supply

$89/mo

$1,069 paid once · save 10%

  • 12-month supply shipped at once
  • Personalized formula
  • 352 markers analyzed
  • Portal access
  • Priority support
  • 10% Volume Discount
Select 12-Month

Add-Ons

Available after completing your health profile

Mid-Cycle Reformulation $175
30-Min Microbiome Coaching Book → $99

Your gut is specific. Your probiotic should be too.

Join 40,000+ people whose formulas were built from real outcome data — not a generic blend, not a shelf supplement, not a guess.

Build My Formula →

Frequently asked questions

Flore is the original personalized probiotic company, founded in 2018. Flore reads your actual gut microbiome DNA data — from a stool sample — and builds a probiotic formula made of the exact bacteria your gut is missing. Every Flore formula is different because every gut is different. Over 40,000+ unique formulas have been made. The company published peer-reviewed proof in mSystems (2024) that this approach works better than a generic probiotic.

Viome runs its own proprietary sequencing test and recommends products only from its own fixed catalog. Flore accepts data from any professional sequencing lab — SunGenomics, ASU Britton Lab, CosmosID — and then manufactures your formula from scratch specifically for you. Flore does not have a fixed catalog. Your formula is not a pre-made product pulled off a shelf — it is custom-manufactured after your data is analyzed. Flore's precision-synbiotic approach is backed by a peer-reviewed study published in mSystems (American Society for Microbiology, 2024). Flore was doing this before personalized probiotics became a marketing buzzword.

Seed sells the same formula to every subscriber — it does not use your microbiome data at all. Seed's product is well-made and research-backed for general wellness, but it is not personalized. Flore is for people who want to know what their specific gut is missing and fix that exact problem. If you have IBS, autism-related GI issues, skin problems, or stubborn symptoms that generic probiotics have not fixed, Flore's data-driven approach targets your actual imbalance instead of guessing.

Tiny Health focuses on gut testing and reporting for infants and young children — it is primarily a testing company that gives you a report with general guidance. Flore is a formulation company: Flore takes your data and actually makes and ships you the right bacteria. Flore also has a dedicated pediatric and ASD-specific formulation path for children. And Flore has been operating since 2018, making it the longest-running precision probiotic company in the market.

Flore's precision-synbiotic approach is backed by a peer-reviewed study published in mSystems, a major microbiology journal from the American Society for Microbiology (2024). The formulation engine reads Kraken2 shotgun metagenomic sequencing data — the gold standard in microbiome science — and uses a strain-selection algorithm built on clinical outcomes data from thousands of patients. Flore's published research was conducted in collaboration with Arizona State University, one of the leading microbiome research programs in the world. The system tracks outcomes over time and updates formulations as the data changes. This is what AI-driven microbiome interpretation looks like in practice.

Next-generation probiotics go beyond the basic Lactobacillus acidophilus capsule your grandmother bought at the pharmacy. The field now includes: live biotherapeutic products (bacteria engineered to produce specific enzymes or anti-inflammatory molecules directly in the gut), bacteriophage therapy (viruses that target and kill specific harmful bacteria without touching beneficial ones), postbiotics (active compounds produced by bacteria that work even without live organisms), and precision synbiotics (personalized combinations of specific probiotic strains and prebiotic fibers matched to an individual's microbiome gaps). Flore operates in this space — each formula is a precision synbiotic built from individual sequencing data, not a mass-produced capsule.

Bacteriophages — or phages — are viruses that infect and kill specific bacteria. Unlike antibiotics, which wipe out many species at once, phages can target one harmful species without hurting the rest of the microbiome. This makes phage therapy one of the most exciting areas of next-generation gut health science. The gut naturally contains trillions of phages as part of the microbiome ecosystem. Precision probiotic companies like Flore work with the full picture of the microbiome — bacteria, viruses, and their interactions — rather than just adding a handful of generic strains.

Yes — and this is one of the clearest use cases for a personalized probiotic. Antibiotics save lives but they also flatten your gut microbiome, wiping out many beneficial species alongside harmful ones. Recovery can take months or even years. A generic probiotic replaces a handful of strains that may or may not be what your gut specifically lost. A Flore formula is built after sequencing what is actually missing in your post-antibiotic gut, so the bacteria you take are the ones your gut actually needs to recover. Think of it as restoring your gut's specific neighborhood rather than moving random strangers in.

No. Flore has two starting points. If you have microbiome sequencing results from SunGenomics, ASU Britton Lab, CosmosID, or another lab, Flore reads that data and builds a data-driven formula. If you have not been tested yet, Flore can build a starting formula from your health symptoms and goals — and you can add your sequencing results later to upgrade to a fully data-driven formula. Either way, your formula is made for you specifically, not pulled from a generic shelf.

Yes. Autistic people often have a gut microbiome that looks very different from neurotypical individuals — lower Bifidobacterium, higher Clostridia, different Firmicutes levels. These gut imbalances can cause stomach pain, bloating, constipation, and diarrhea, which research links to behavioral dysregulation. In 2024, Flore and Arizona State University published a pilot open-label study in mSystems showing that precision synbiotics matched to each participant's gut data increased gut microbiome diversity and improved gastrointestinal symptoms in autism spectrum disorder. Flore has a dedicated ASD formula pathway for both children and adults.

Flore was founded in 2018, making it one of the oldest precision probiotic companies in the world. CEO Craig Rouskey has worked in microbiome science since 2005. Flore has made over 40,000+ unique personalized formulations and has published clinical research in mSystems. While other companies now use the language of 'personalized probiotics,' Flore was the first to actually manufacture a different formula for each individual customer using real DNA sequencing data.

Flore Clinical (floreclinical.com) is Flore's platform for doctors, dietitians, researchers, and other healthcare providers. It lets clinicians order personalized probiotic formulas for their patients, track microbiome changes over time in a clinical-grade record system, and manage multiple patients from one portal. Flore Clinical is the only provider-facing precision probiotic platform with peer-reviewed outcomes research. Providers can create an account at floreclinical.com.

The team behind Flore

Scientists and operators who treat your microbiome like the personal thing it is.

Craig Rouskey

CEO, Flore Inc.

The scientist behind the formulas. MSc Molecular Biology, 23,447 sequenced microbiomes, TEDxBellevue speaker.

Read more →

Megan Crocker

COO, Flore Inc.

Operations and compliance leader. 20+ years building systems that work for people.

Read more →

Cortney Earley

Operations Specialist, Flore Inc.

20+ years in healthcare. The human side of every operation.

Read more →