The Third International Congress of Translational Research in Human Nutrition took place in Clermont-Ferrand, France, on June 26 & 27, 2015.
In this post, we bring you an overview of three symposia: clinical implication of gut microbiota knowledge, microbiota and non-intestinal diseases, and microbiota and intestinal integrity.
Follow this link to read the first part of this report.
Prof. Robin Spiller, University of Nottingham, UK – Shifting interfaces between irritable bowel syndrome and in inflammatory bowel diseases: Role of gut microbiota
Inflammatory bowel diseases (IBD) and irritable bowel syndrome (IBS) are two different issues but some symptoms may overlap. IBD patients in remission may experiment IBS symptoms, whereas IBS patients rarely develop IBD. Prof. Spiller explained how IBD patients during remission may develop post inflammatory IBS symptoms. This includes inflammatory damage to the enteric nervous system, an increase in serotonin, and an increase in gut permeability, but also changes to the gut microbiota. Moreover, he discussed the importance of intestinal transit on gut microbiota composition in this context.
Prof. Lena Öhman, University of Gothenburg, Sweden – Microbiota and irritable bowel syndrome
Prof. Öhman explained how gut microbes are potent orchestrators of symptoms related to IBS. She explained that even if alterations in gut microbiota composition and functions exist during IBS, there are to date no uniform patterns detected and no clear associations with symptoms. She also discussed gut microbiota-based therapeutic interventions for IBS.
Prof. Colleen Kelly, Brown Alpert Medical School, Providence, USA – Fecal microbiota transplantation: Evidence, methodology and future direction.
Prof. Kelly presented fecal microbiota transplantation (FMT) as an interesting therapeutic tool to restore the diversity of gut microbial community. She showed evidence supporting the use of FMT for treatment of Clostridium difficile infections. She also discussed mechanisms for the beneficial effects of FMT, including the inhibition of bacterial growth and the competition for a niche. Prof. Kelly reviewed and discussed the methods for safe use of FMT: identification and screening of a healthy donor (she discussed important characteristics to be analyzed in a donor), collection and preparation of the material, and administration to the receiver by nasogastric or endoscopic pathway. Finally she addressed challenges and novel technologies for FMT.
Dr. Valentina Tremaroli, University of Gothenburg, Sweden – The gut microbiota in obesity and diabetes
Dr. Tremaroli addressed gut microbiota dysbiosis associated with type 2 diabetes in human patients. She talked about the key role of gut microbiota modifications in the beneficial effects of bariatric surgery, which is currently the best treatment for weight loss and reduction of type 2 diabetes during obesity. She also discussed the major role of bile acids and FXR signaling in the beneficial effects of this weight loss surgery on glucose metabolism.
Prof Paul O’Toole, University College Cork, Ireland – Microbiota, health and aging
Prof O’Toole talked about the effects of aging on the gut microbiota, considering different parameters such as diet. The diet seems to be one of the drivers of gut microbiota in older adults. Interestingly, gut microbiota composition correlates with health measures. He also showed that a less diverse microbiota appears to be less stable over time.
Dr. Amandine Everard, University catholique de Louvain, Brussels, Belgium – Microbiota, inflammation and adipose tissue development
Considering the importance of the gut microbiota in the onset of fat mass accumulation and inflammation during obesity, I talked about mechanisms linking gut microbes to inflammation, fat mass development and glucose intolerance.
Dr. Guillaume Fond, Henri Mondor Hospital Créteil, France – The “psychomicrobiotic”: Targeting microbiota in major psychiatric disorders
Dr. Fond made a systemic review of the literature regarding the link between gut microbiota and different brain-related disorders such as schizophrenia and autism. He also discussed the role of gut permeability, inflammation and the gut-brain axis through the vagus nerve in that context. He concluded that there is accumulating evidence for a role for the gut microbiota in mental health.
Prof. Andrew Gewirtz, Georgia State University, Atlanta, USA – Microbiota and Toll-like receptor interactions
Prof. Gewirtz focused his talk on interactions between microbes and the host through TLR5. He showed that chronic inflammation associated with TLR5 deficiency leads to obesity and metabolic disorders, or to colitis. Interestingly, the gut microbiota play a key role in that context and are sufficient to transfer the phenotype. He also discussed the importance of the gut barrier function and the importance of the maintenance of an adequate distance between the gut microbiota and intestinal epithelium. Finally, Prof. Gewirtz discussed the deleterious impact of dietary emulsifiers on gut homeostasis, thereby promoting colitis and metabolic syndrome in mice.
Dr. Frédéric Carvalho, University of Clermont-Ferrand, France – Microbiota and colon sensitivity
Dr. Carvalho discussed colonic hypersensitivity (CHS) occurring in irritable bowel syndrome and the implications of intestinal colonization by opportunistic bacteria in CHS. Colonization of the intestine by adherent-invasive Escherichia coli due to overexpression of CEACAM6 is associated with an increase in colon sensitivity. In parallel to humans, not all mice were sensitized post infection. Dr. Carvalho also discussed the role of gut permeability in that context. He suggested that targeting the gut microbiota could be an interesting therapeutic tool to influence colon sensitivity.
Dr. Nathalie Vergnolle, INSERM, University of Toulouse, France – Microbiota and epithelium integrity
After reviewing the main roles of the gut epithelium (including the control of bacterial overgrowth, mucus production, innate and adaptive immune function, IgA transport, and gut barrier function), Dr. Vergnolle discussed the loss of epithelium integrity and function occurring in IBD and IBS. She emphasized that multiple alterations of the intestinal epithelium may be controlled by activity of proteases such as elastase in the intestine. Moreover, IBD is associated with an increase in elastase activity in the inflamed part of the intestine. Interestingly, she showed that gut microbiota components such as LPS may impact on proteolytic homeostasis of intestinal mucosa. Dr. Vergnolle proposed the use of food-grade bacteria expressing elafin (elastase inhibitor and antimicrobial peptide) for their therapeutic effects on gastrointestinal diseases.
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