Issue 16 march 2020 Special Report 5 year Special Edition

Bäckhed in 2004¹ and later Gordon in 2006² revealed the connection between the gut microbiota and obesity. In 2007, Amar and Cani³ demonstrated a causal link between the translocation of bacterial fragments in tissues and diabetes. Since these first publications, subsequent research has described the diversity of the microbiotas we host and confirmed the presence of microbiotas in our tissues, and the role of bacterial translocation on our health is now better understood. In the field of cardiovascular and metabolic diseases, the role of intestinal immunity in interaction with the gut microbiota has been revealed for both diabetes and hypertension, paving the way for an aetiological treatment for what Reaven, for want of a better name, called syndrome X⁴ in 1998. In the field of cancer, the role of the gut microbiota in the tolerance and efficacy of immunotherapy has been reported, opening up new possibilities for precision medicine⁵. The role of tumour tissue dysbiosis in the prognosis of cancers like pancreatic cancer has also been established⁶. The physiopathological mechanism of this relationship has now been identified, paving the way for innovative therapies targeting the interaction between the host’s immunity and the bacteria present in the tumour. In a few short years, we have therefore expanded our very narrow and sterile view of the human body to embrace a new paradigm where the dialogue established from birth between our microbiota and our cells has a major influence on our health. Understanding and modulating this dialogue to our advantage is therefore set to be a major challenge for scientific research in the decade to come.

Good reading and good navigation!

1. Bäckhed F, et al. The gut microbiota as an environmental factor that regulates fat storage. Proc Natl Acad
Sci USA. 2004;101:15718-23
2. Turnbaugh PJ, et al. An obesity-associated gut microbiota with increased capacity for energy harvest. Nature.
2006;444:1027-31.
3. Cani PD, et al. Metabolic endotoxemia initiates obesity and insulin resistance. Diabetes. 2007;56:1761-72.
4. Reaven GM. Role of insulin resistance in human disease. Diabetes. 1988;37:1595-607.
5. Routy B, et al. Gut microbiota influences efficacy of PD-1-based immunotherapy against epithelial tumors.
Science. 2018;359:91-7.
6. Riquelme E, et al. Tumor Microbiota Diversity and Composition Influence Pancreatic Cancer Outcomes. Cell.
2019;178:795-806.