Evidence & Lineage · For Clinicians

From psychobiotics to neurobiotics.

The scientific through-line behind Flore's neurobiome testing — from an established 2013 term to the emerging category Flore is defining today. Sourced, and honest about what is settled and what is not.

Neurobiome testing for practice → Talk to Flore
Psychobiotics vs. neurobiotics — what's the difference?

Psychobiotics is the established term, defined by Dinan, Stanton and Cryan in 2013 as live organisms that, in adequate amounts, confer a mental-health benefit through the gut–brain axis. It is the peer-reviewed scientific lineage.

Neurobiotics is an emerging concept — introduced in the literature in 2022 for microbiota-targeted strategies acting on the nervous system. Flore extends this lineage into an applied clinical category, neurobiome testing: reading the gut-brain functional capacity of a patient's microbiome and matching a personalized synbiotic to it. Flore is pioneering this category; it is not yet an established standard of care.

Two terms, honestly labelled

Psychobiotics

Coined 2013 (Dinan, Stanton & Cryan, Biological Psychiatry). A decade of peer-reviewed mechanistic and clinical study. The established anchor Flore builds from.[1]

Established · peer-reviewed

Neurobiotics / neurobiome

Introduced 2022 (Herrera-Rincon et al., Neural Regeneration Research). A new, forward concept. Flore operationalizes it as neurobiome testing — and is transparent that the category is emerging.[2]

Emerging · Flore-defined

The evidence, by mechanism and tier

Where the gut–brain signal travels, and how strong the evidence is at each node. We label the tier so you can weigh it clinically.

PathwayWhat the evidence showsEvidence tierKey source
Axis overviewComprehensive synthesis of vagal, endocrine, immune and metabolite routes between microbiome and CNS.Human/preclinical reviewCryan 2019[3]
Stress axisMicrobiome regulation of the HPA / stress response and behaviour.ReviewFoster 2017[4]
Vagal signallingA specific Lactobacillus strain altered central GABA-receptor expression and emotional behaviour via the vagus nerve.Preclinical (mouse)Bravo 2011[5]
SerotoninIndigenous spore-forming gut bacteria regulate host enterochromaffin-cell serotonin biosynthesis.MechanisticYano 2015[6]
GABADefined human gut bacteria produce and consume GABA; abundance linked to brain-signalling measures.Mechanistic / human isolatesStrandwitz 2019[7]
SCFAsMicrobial short-chain fatty acids as a core gut-brain communication channel.Human reviewDalile 2019[8]
Applied (Flore, GI-neuro)3-month precision synbiotic associated with increased microbiome diversity and reduced GI discomfort in ASD.Open-label pilot — not an RCTPhan 2024[9]
Applied (Flore, GI)Altered microbiome composition/function in IBS; measurable probiotic engraftment with daily supplementation.Observational + supplementationPhan 2021[10]

Honest read: the mechanisms are well-described but much of the causal work is preclinical, and human clinical evidence is still maturing. Flore positions neurobiome testing as functional insight to personalize support — not as a diagnostic or a settled therapy.

How Flore extends the lineage

Classical psychobiotics research asks whether a single, fixed strain benefits a population on average. Flore's contribution is to make the approach personalized and measurable: sequence the individual microbiome to strain level with functional-gene detection, stratify its neuroactive-metabolite capacity, compound a matched synbiotic to the specific deficit, and re-sequence to quantify the shift. Strains are disclosed to clinicians as genus, species and a Flore identifier (e.g. Lactobacillus reuteri FLORE-XXXX); the selection logic is proprietary. This personalized, closed-loop model — and the applied dataset behind it — is what Flore means by neurobiome testing.

See the intelligence behind it → Neurobiome testing in practice →

Common questions

Is a psychobiotic the same as an antidepressant or anxiolytic?

No. Psychobiotics and neurobiome-matched synbiotics are microbiome-support supplements, not pharmaceuticals. They are not intended to diagnose, treat, cure or prevent depression, anxiety or any condition, and are not a substitute for medication or standard care.

Why does Flore use "neurobiome" if "psychobiotics" is the accepted term?

Because they describe different scopes. Psychobiotics names the organisms; neurobiome testing names the applied, personalized clinical workflow Flore is pioneering around the gut-brain axis. We keep psychobiotics as the honest scientific lineage and label neurobiome/neurobiotics as emerging.

Is the autism evidence a randomized controlled trial?

No. The 2024 mSystems study (Phan et al.) is an open-label pilot. It reported increased microbiome diversity and reduced GI discomfort with a 3-month precision synbiotic, and the authors explicitly note the open-label design may include placebo effects. Company-run controlled trials are underway.

How much of the gut-brain evidence is human?

Foundational reviews synthesize both human and animal data, but several key causal mechanisms (e.g. vagal GABA signalling) are demonstrated preclinically. We label each source's tier so you can weigh it. Flore positions neurobiome testing accordingly — as functional insight, not diagnosis.

Bring the science into your practice

Book a 15-minute onboarding call to see how Flore's neurobiome testing fits your patients and workflow.

Schedule an onboarding call →

Or email support@flore.com · 415-326-4743

References

  1. Dinan TG, Stanton C, Cryan JF. Psychobiotics: a novel class of psychotropic. Biol Psychiatry. 2013;74(10):720–726. PubMed 23759244
  2. Herrera-Rincon C, Murciano-Brea J, Geuna S. Can we promote neural regeneration through microbiota-targeted strategies? Introducing the new concept of neurobiotics. Neural Regen Res. 2022;17(9):1965–1966. PubMed 35142677
  3. Cryan JF, O'Riordan KJ, Cowan CSM, et al. The Microbiota-Gut-Brain Axis. Physiol Rev. 2019;99(4):1877–2013. PubMed 31460832
  4. Foster JA, Rinaman L, Cryan JF. Stress & the gut-brain axis: Regulation by the microbiome. Neurobiol Stress. 2017;7:124–136. PubMed 29276734
  5. Bravo JA, Forsythe P, Chew MV, et al. Ingestion of Lactobacillus strain regulates emotional behavior and central GABA receptor expression in a mouse via the vagus nerve. Proc Natl Acad Sci USA. 2011;108(38):16050–16055. PubMed 21876150
  6. Yano JM, Yu K, Donaldson GP, et al. Indigenous bacteria from the gut microbiota regulate host serotonin biosynthesis. Cell. 2015;161(2):264–276. PubMed 25860609
  7. Strandwitz P, Kim KH, Terekhova D, et al. GABA-modulating bacteria of the human gut microbiota. Nat Microbiol. 2019;4(3):396–403. PubMed 30531975
  8. Dalile B, Van Oudenhove L, Vervliet B, Verbeke K. The role of short-chain fatty acids in microbiota-gut-brain communication. Nat Rev Gastroenterol Hepatol. 2019;16(8):461–478. PubMed 31123355
  9. Phan J, Calvo DC, Nair D, et al. Precision synbiotics increase gut microbiome diversity and improve gastrointestinal symptoms in a pilot open-label study for autism spectrum disorder. mSystems. 2024;9(5):e00503-24. PubMed 38661344 (open-label pilot — not an RCT)
  10. Phan J, Nair D, Jain S, et al. Alterations in gut microbiome composition and function in irritable bowel syndrome and increased probiotic abundance with daily supplementation. mSystems. 2021;6(6):e01215-21. PubMed 34726487
Structure/function & scope. Content on this page is for licensed clinicians and describes an emerging area of microbiome science. Flore neurobiome testing and personalized synbiotics support the structure and function of the gut microbiome and general wellness; they are not intended to diagnose, treat, cure or prevent any disease and are not a diagnostic for any neurological or psychiatric condition. These statements have not been evaluated by the Food and Drug Administration. Flore Inc., 51 W. Jackson St, Ste 105, Joliet, IL 60432, US · support@flore.com · 415-326-4743.