MICROBIOME RESEARCH UNIT2020-10-20T11:41:09+00:00


Since 2009, VitroScreen has been focalized in creating and validating pre-clinical models based on 3D reconstructed human tissues colonized with biological relevant bacterial strains. Our proficient expertise has been successfully applied to support pharma, cosmetic, medical devices and nutritional industries during the last decade.

VitroScreen’s microorganism portfolio can count over 50 different ATCC strains, considering both bacteria and yeasts species. Although we work on custom’s clinical isolated microorganisms, very often the complexity of the isolate is not fully reflected when cultivated in vitro. Only 30% of human microbiota is cultivable on media or can colonize 3D tissues.

Therefore, we believe that using ATCC selected strains, alone or in co-culture, represents the most robust and reproducible way to study human host-microbiota response in vitro.

This innovative biological tool is also supported by molecular biology techniques (i.e. specific host physiological pathways quantitative analysis), advanced immunohistology platforms (on tissue vertical sections and 3D whole mount samples) as well as by a dedicated microbiological laboratory involved in tissue-colonizing procedures and downstream microbiological analysis.

Overall, our proficient in vitro expertise has been employed during the years in the development of customized experimental designs that mirrored both basic and specific host-bacterium interactions in short and long term period, thus allowing to understand the mechanism of action of specific ingredients or formulations for both basic microbiological screening or pre-clinical studies.

VitroScreen’s assays can count on a unique and fundamental advantage: the colonization of living bacteria on viable tissue. This feature allows the bacteria to accomodate their proliferative/adaptive/adhesion behaviors to host physiological status with regards to the applied topic treatment.

VitroScreen’s colonized in vitro models can give relevant information on both host response (mRNA, biochemical, morphological, proteins expression and localization) and on bacterial response (growth, adhesion, phenotype, morphology at ultrastructural level and genomic response).

3D colonized human tissue models

  • Easy to handle in optimized experimental conditions

  • Short and long term colonization

  • Single or multiple bacterium colonization (competition model)

  • Customized biological model: pathological, young, old, ethnic

  • Ethical, sustainable, enabling routine testing capabilities

  • Biologically relevant

Bacteria behave differently on the skin according to the host and environmental conditions

Bacterial viable count: dual meaning

The bacterial viable count assays is not only focused on the total viable bacterial burden colonizing the tissue but it also discriminates between:

  • Non-adherent bacteria: bacteria that most likely are not interacting with the tissue
  • Adherent bacteria: bacteria involved in biofilm formation

This technical differentiation is a key element to better understand the mechanism of action of the treatment towards the bacterium and its interaction with host tissue.

Experimental models based on VitroScreen strains portfolio

  • Prebiotic and antibacterial efficacy and screening: microbiological assays with standard and customized designs

  • Disk diffusion test on agar plate for insoluble items

  • Crystal violet assay: bacterial biofilm

  • Bacterial adhesion, boosting or inhibiting bacterial growth and proliferative capacity: customized strain’s specific protocols

  • Microbiome impact on barrier function development and innate immunity, specific pathways modification
  • Competition models: based on 2 strains or on multiple step procedure
  • Mechanism of action and efficacy of prebiotics, probiotics, postbiotics after acute and long-term exposure: multiple host targets
  • Prebiotics, probiotics, postbiotics efficacy and mechanisms on pathogens inhibition and recognition
  • Biofilm models (strain specific): anti-biofilm formation efficacy, influencing of EPS matrix production, biofilm disruption after acute or repeated treatments.
  • Microbiome safe claim: suitable for surfactants based formulations and medical devices.
  • Virucide efficacy (under development)
  • Anti-bacterial/Antibiotic efficacy: on selected bacterial strain at defined exposures for bactericidal and bacteriostatic claims


  • Microbiota acute and long term exposures on injured models: infection customized models
  • Wound healing model in presence of strain specific infection (multiple strains) or bacterial biofilm
  • Immuno-competent models: 3D tissues in co-culture with THP-1 monocytes
  • Atopic Dermatitis (S.aureus), Acne lesions and inflammation (C.acnes)


  • Scalp specific microbiome model (co-culture) and dandruff model
  • Bacterial secretome modulatory efficacy on ECM matrix on  DERMIS
  • Microbiota and aging
  • Microbiota and pigmentation
  • In vitro SNIFF test: suitable for odor inhibition semi-quantification
  • Anti-micotic efficacy: acute and long term fungi cultivation
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Examples of 3D colonized tissue models