Clostridium ramosum promotes high-fat diet-induced obesity in gnotobiotic mouse models.
Bottom Line: Clostridium ramosum, a member of the Erysipelotrichi, is associated with symptoms of the metabolic syndrome in humans.Clostridium ramosum, a member of the Erysipelotrichi, has been linked to symptoms of the metabolic syndrome.Identification of obesogenic bacteria and understanding their mode of action enable the development of novel strategies for the treatment of this epidemic disease.
Affiliation: Department of Gastrointestinal Microbiology, German Institute of Human Nutrition Potsdam-Rehbruecke, Nuthetal, Germany.Show MeSH
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Mentions: After 4 weeks of dietary intervention, SIHUMI mice fed the low-fat diet (LFD) stayed lean, whereas SIHUMI mice fed the HFD became obese. Accordingly, LFD-fed SIHUMI mice gained less body weight than HFD-fed SIHUMI mice (5.35% ± 3.31% versus 19.94% ± 3.98%, P = 0.014) and had lower body fat percentages than HFD-fed SIHUMI mice (28.78% ± 0.88% versus 32.61% ± 1.10%, P = 0.017). Obesity in HFD-fed SIHUMI mice was accompanied by a higher proportion of C. ramosum in cecal (P = 0.003) (Fig. 1) and colonic (LFD, 5% ± 1%, versus HFD, 16% ± 2%, of total bacteria; P < 0.001) contents. (For absolute cell counts of all bacterial species, see Table S1 in the supplemental material.) Cecal and colonic cell counts of C. ramosum in HFD-fed SIHUMI mice (9.34 ± 0.07 and 9.31 ± 0.06 log10 cells/g dry weight, respectively) were approximately 0.5 log10 cells/g dry weight higher (P < 0.001) than those in LFD-fed SIHUMI mice (8.83 ± 0.04 and 8.77 ± 0.05 log10 cells/g dry weight, respectively). Total bacterial cell counts in cecum (10.24 ± 0.06 versus 10.14 ± 0.04 log10 cells/g dry weight) and colon (10.05 ± 0.02 versus 10.05 ± 0.06 log10 cells/g dry weight) did not differ between LFD-fed and HFD-fed SIHUMI mice. Our finding and the reported associations of C. ramosum with obesity (9, 10, 18) suggest a contribution of this bacterium to obesity development. Therefore, a possible obesogenic effect of C. ramosum was investigated in gnotobiotic mice fed HFD.
Affiliation: Department of Gastrointestinal Microbiology, German Institute of Human Nutrition Potsdam-Rehbruecke, Nuthetal, Germany.