Dr Elena Verdú’s lab seeks to understand the complex pathophysiology of gastrointestinal disease, with a focus on microbiota-diet interactions, to identify novel therapeutic targets for these disorders.
1/ What strikes you most in the evolution of research on gut microbiota and why?
One interesting aspect relates to the way we have approached the study of the microbiota. We started off with classical culture techniques. We realized that we were only culturing a fraction of the microbiota, and moved on to heavily rely on high throughput molecular techniques. These have greatly enhanced our capacity to know “who is there”.
Moreover, metagenomic and metabolomic techniques are allowing us to understand what the microbiota “is doing”. These concepts regarding the limitations of culture techniques are undergoing some revisiting, and we are beginning to understand that what was considered unculturable before, is in fact our lack of capacity –or effort!– to culture what is there.
The groups of Dr M Surette and Dr P Bercik at the Farncombe Institute in McMaster University are engaged in a clinical collaborative study that investigates the recovery of microbiota by culture techniques from fecal samples from patients with irritable bowel syndrome, and compares this with state of the art molecular approaches. In a recent study presented at the Canadian Digestive Disease Week (Lau et al. 2014, Characterization of the cultivable human gut microbiota by culture-enriched molecular profiling, CDDW2014 Abstract) Surette’s group has shown that by using more than 50 different culture media and conditions, they are able to culture between 90-100 % of the species detected by advanced pyrosequencing techniques.
We are beginning to realize that old methods will be invaluable for the isolation of species present in the microbiota, if sufficient effort is employed. When used together with molecular and metagenomic approaches and gnotobiotic technology, the renaissance of culture techniques will increase our understanding of the role of the microbiome in health and disease. We have come full circle.
2/ You are our nutrition expert on the platform. What is according to you the health potential of better understanding the gut microbiota in this area?
There is little doubt that diet and nutrition affect the microbiota. Several recent studies have demonstrated that long-term diet is an important determinant of the microbiota (Wu et al., Science 2011). On the other hand, the microbiota may be a disease-promoting factor in food intolerances because of the important role it plays in immune and functional gut homeostasis (Natividad et al., PlosOne 2009; Rodriguez, FEMS Microbiol Ecol. 2011; Noval Rivas, J Allergy Clin Immunol. 2013). The relationship is bi-directional. We are currently conducting studies that aim at understanding how the gut microbiota interacts with specific dietary components. Specifically we are interested in the dietary protein gluten, the trigger in celiac disease, and how the microbiota may modify disease severity and expression.
3/ How do you see the evolution of clinical applications and interventions in the field of gut microbiota?
There is evidence for an association between intestinal dysbiosis and disease states, including food intolerances like celiac disease. However, evidence demonstrating causality and mechanisms of action is lacking. The challenge will be to assign function to the microbial profiles associated with specific dietary components or interventions and how they affect expression of common diseases and their therapies. The continued use of gnotobiotic animal models in combination with clinical research will be necessary to explore this complex relationship. These studies will help develop targeted interventions directed at modulation of the microbiota to prevent or treat diseases, including food intolerance.