ECE2024 Poster Presentations Diabetes, Obesity, Metabolism and Nutrition (130 abstracts)
1Sorbonne Université, Inserm, Nutrition and Obesities: Systemic Approaches (NutriOmics) Research Unit, Paris, France; 2Sapienza University of Rome, Experimental Medicine, Roma, Italy; 3Université de Paris, Inserm U1016, Team Mucosal microbiota in chronic inflammatory diseases, Cnrs Umr 8104, Paris, France; 4Hôpital privédes Peupliers - Ramsay Générale de Santé, Paris, France; 5Sorbonne Université, Inserm Umrs-938, Centre de Recherche Saint-Antoine, Crsa, AP-HP, Paris, France; Paris Center for Microbiome Medicine, Fédération Hospitalo-Universitaire, Paris, France; INRAE, UMR1319 Micalis & AgroParisTech, Jouy en Josas, France
Introduction: While extensive research on the fecal microbiome (FM) has already underscored the gut microbiomes role in metabolic diseases, it is imperative to recognize its limitations in depicting the entire gastrointestinal tract. Each segment of the tract harbors unique conditions shaping microbial ecosystems, necessitating exploration beyond the FM. The upper small intestine (USI) significantly impacts nutrient digestion and absorption, hinting at its microbiomes potential influence on the regulation of host metabolism. In a recent systematic review of the literature, we pointed out that studies on the C57BL/6 murine strain fed a high-fat diet showed a causal connection between the USI microbiome (USIM) and metabolism. However, research on individuals with obesity remains scarce and conflicting, and comparative studies between different gastrointestinal niches in patients with obesity are lacking.
Materials and Methods: This pilot study employed Shotgun Illumina sequencing to conduct metagenomic analysis of the USI, FM, and oral microbiome (OM) in both candidates for metabolic surgery (n=15) and healthy controls (n=15).
Results: USIM exhibited lower gene richness than OM and FM (P<0.0001). Compositionally, USIM resembled OM more than FM but exhibited significant differences from FM. Multivariate permutational analysis revealed that body composition and corpulence variables accounted for variance in USIM and its associated metabolome composition, showing a negative correlation with metagenomic richness. Comparison between groups with and without obesity within each ecosystem unveiled greater metagenomic richness in the USI of patients with obesity (P=0.037). This group also displayed a lower relative abundance of Proteobacteria (P<0.001), notably Neisseriaceae (P<0.0001), in the USIM.
Conclusion: Our study underscores the significance of studying the proximal gut microbiota to unravel intricate connections between gut microbiota composition and metabolic health. These insights provide a foundation for potential therapeutic interventions targeting the proximal gut microbiome in managing metabolic diseases.