Microbiome from gut to other tissues: the importance of bacterial translocation

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How to define microbiota and microbiome?

Microbiome or microbiota? First seen as pathogens, naturally occurring microbes are now recognized as complex and highly diverse assemblages, often associated with a host with whom they interact in a dynamic and beneficial fashion. Microbial communities are commonly defined as the collection of microorganisms living together within a defined environment such as a body part and referred to as the microbiota.

The term microbiome includes the living microbes, their environment but also all the molecules (e.g. nucleic acids, lipids, proteins and metabolites) they and their host produce. Microbiome can also be defined as the collection of genomes and genes from the microbiota members although the term metagenome is preferentially used in this context. Regardless of the term used to define it, the microbiome is essential for health and decisive in human diseases.

Translational research: from animal models to treating patients

Animal models are essential in understanding the role of microbiomes in health and diseases whether the endpoint is to improve human or animal health. In basic research and preclinical studies, animal models such as mice, rats, hamsters or others, enable interventions and easy access to organs that would not be possible in humans. The experimental conditions are also more controlled with homogenous genetic backgrounds and by limiting sources of variations (e.g. diet and environmental conditions) affecting microbiota composition.

Despite the great usefulness of animal models, the need for translational research has become critically important in contemporary biomedical research. How to translate findings from basic research and preclinical studies into practical applications and improvements to general public health? Moving from the bench to the bedside requires collaboration among experts from multiple disciplines and also studying different targets. For example, blood sampling is commonly more acceptable for the patient and profiling the circulating microbiome can be as informative as the analysis of biopsies.

V de Voimer

Bacterial translocation: the missing link between intestinal microbiome and human complex non-communicable diseases

Atlas of Microbiomes:

What are the levels of bacterial biomass of the different tissues?

The gut microbiome affects virtually all aspects of human health

Traditional areas of investigation with the microbiome are gastrointestinal diseases (IBD, IBS, CD) and metabolic diseases (obesity and diabetes). In more recent years, new application areas are emerging such as the central nervous system, infectious diseases or cancer. The study of microbiomes beyond the gut is widening the potential for discoveries.

Interrogate the microbial signature in a wide variety of tissues with Vaiomer outstanding expertise

Travel through the fascinating history of microbiome!

Although gut microbiota is by far the most investigated, the concepts of gut and blood microbiomes have grown in parallel since the early stages of the field.

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VAIOMER Experts’ Highlights

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Several studies have shown the importance of the gut microbiota in cancer progression and treatment response. More

The human tumor microenvironment is colonized by cancer type–specific bacteria and fungi

> The human tumor microbiome is composed of tumor type-specific intracellular bacteria. Nejman et al., 2020, Science.
> Pan-cancer analyses reveal cancer-type-specific fungal ecologies and bacteriome interactions. Narunsky-Haziza et al., 2022, Cell.

Microbiomes modulate the local immune response, influencing immunotherapy response and toxicity
Immunotherapy has revolutionized the treatment of several cancers. However, it remains elusive why only some patients benefit from these treatments and why some patients experience immune-related adverse events (irAEs). More

Microbiomes modulate the local immune response, influencing immunotherapy response and toxicity

> The role of gut microbiome in modulating response to immune checkpoint inhibitor therapy in cancer. Naqash et al., 2021, Ann Transl Med.

Microbiomes beyond the gut


Learn about the gut, blood and tissue microbiota , the link between gut dysbiosis and tissue inflammation, and discover how these microbiota positively or negatively influence our physiology and can cause disease


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Microbiome Scientist