Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Observational Study
. 2014 Dec;38(12):1525-31.
doi: 10.1038/ijo.2014.46. Epub 2014 Mar 19.

Evidence for greater production of colonic short-chain fatty acids in overweight than lean humans

S Rahat-Rozenbloom  1 , J Fernandes  1 , G B Gloor  2 , T M S Wolever  3
Affiliations
Observational Study

Evidence for greater production of colonic short-chain fatty acids in overweight than lean humans

S Rahat-Rozenbloom et al. Int J Obes (Lond). 2014 Dec.

Abstract

Background: Short-chain fatty acids (SCFA) are produced by colonic microbiota from dietary carbohydrates and proteins that reach the colon. It has been suggested that SCFA may promote obesity via increased colonic energy availability. Recent studies suggest obese humans have higher faecal SCFA than lean, but it is unclear whether this difference is due to increased SCFA production or reduced absorption.

Objectives: To compare rectal SCFA absorption, dietary intake and faecal microbial profile in lean (LN) versus overweight and obese (OWO) individuals.

Design: Eleven LN and eleven OWO individuals completed a 3-day diet record, provided a fresh faecal sample and had SCFA absorption measured using the rectal dialysis bag method. The procedures were repeated after 2 weeks.

Results: Age-adjusted faecal SCFA concentration was significantly higher in OWO than LN individuals (81.3±7.4 vs 64.1±10.4 mmol kg(-1), P=0.023). SCFA absorption (24.4±0.8% vs 24.7±1.2%, respectively, P=0.787) and dietary intakes were similar between the groups, except for a higher fat intake in OWO individuals. However, fat intake did not correlate with SCFAs or bacterial abundance. OWO individuals had higher relative Firmicutes abundance (83.1±4.1 vs 69.5±5.8%, respectively, P=0.008) and a higher Firmicutes:Bacteriodetes ratio (P=0.023) than LN individuals. There was a positive correlation between Firmicutes and faecal SCFA within the whole group (r=0.507, P=0.044), with a stronger correlation after adjusting for available carbohydrate (r=0.615, P=0.005).

Conclusions: The higher faecal SCFA in OWO individuals is not because of differences in SCFA absorption or diet. Our results are consistent with the hypothesis that OWO individuals produce more colonic SCFA than LN individuals because of differences in colonic microbiota. However, further studies are needed to prove this.

PubMed Disclaimer

Conflict of interest statement

S.R. Rozenbloom, J. Fernandes, G. B. Gloor, and T.M.S. Wolever have no conflicts of interest.

Conflict of interest: The authors declared no conflict of interest.

Figures

Figure 1
Figure 1
Faecal SCFA concentration by Group interaction with SCFA absorption. P value for the interaction calculated by SAS Proc-Mixed model to account for repeated measurements. Each point represents one visit.
Figure 2
Figure 2
Group and dietary components interactions with faecal acetate concentration; Group by Energy intake interaction with faecal acetate concentration (A), Group by fibre intake with faecal acetate concentration (B), Group by fat intake interaction with faecal acetate concentration (C). Low, visit with lower intake; High, visit with higher intake. §adjusted for energy.
See this image and copyright information in PMC

References

    1. Cummings JH. Short chain fatty acids in the human colon. Gut. 1981;22:763–779. - PMC - PubMed
    1. Topping DL, Clifton PM. Short-chain fatty acids and human colonic function: Roles of resistant starch and nonstarch polysaccharides. Physiol Rev. 2001;81:1031–1064. - PubMed
    1. Wong JMW, De Souza R, Kendall CWC, Emam A, Jenkins DJA. Colonic health: Fermentation and short chain fatty acids. J Clin Gastroenterol. 2006;40:235–243. - PubMed
    1. Ley RE, Bäckhed F, Turnbaugh P, Lozupone CA, Knight RD, Gordon JI. Obesity alters gut microbial ecology. Proc Natl Acad Sci U S A. 2005;102:11070–11075. - PMC - PubMed
    1. Turnbaugh PJ, Ley RE, Mahowald MA, Magrini V, Mardis ER, Gordon JI. An obesity-associated gut microbiome with increased capacity for energy harvest. Nature. 2006;444:1027–1031. - PubMed

Publication types