Abundance of the species Clostridium butyricum in the gut microbiota contributes to differences in obesity phenotype in outbred Sprague-Dawley CD rats

ABSTRACT Scope and methods Gut microbiota profiles contribute to differences in obesity phenotype. We examined the abundance of total gut bacteria and the species Clostridium butyricum in relation to the propensity of obesity prone and obesity resistant outbred Sprague-Dawley rats to accumulate abdominal fat. We further examined effects of dietary fat, resistant starch (RS), and a microbiota transplant on obesity phenotype and abundance of C. butyricum. Results Before inclusion of dietary RS, obesity resistant (OR) rats had higher amounts of total bacteria, and C. butyricum compared to obesity prone (OP) rats (P Conclusions While C. butyricum is a known saccharolytic, its proliferation is not enhanced by fermentation of resistant starch. C. butyricum maybe one of the species that constitute a core microbiota involved in energy storage and metabolism through mechanisms that are not yet known.