Composition and energy harvesting capacity of the gut microbiota: relationship to diet, obesity and time in mouse modelsShow others and affiliations
2010 (English)In: Gut, ISSN 0017-5749, E-ISSN 1468-3288, Vol. 59, no 12, p. 1635-42Article in journal (Refereed) Published
Abstract [en]
BACKGROUND AND AIMS: Increased efficiency of energy harvest, due to alterations in the gut microbiota (increased Firmicutes and decreased Bacteroidetes), has been implicated in obesity in mice and humans. However, a causal relationship is unproven and contributory variables include diet, genetics and age. Therefore, we explored the effect of a high-fat (HF) diet and genetically determined obesity (ob/ob) for changes in microbiota and energy harvesting capacity over time.
METHODS: Seven-week-old male ob/ob mice were fed a low-fat diet and wild-type mice were fed either a low-fat diet or a HF-diet for 8 weeks (n=8/group). They were assessed at 7, 11 and 15 weeks of age for: fat and lean body mass (by NMR); faecal and caecal short-chain fatty acids (SCFA, by gas chromatography); faecal energy content (by bomb calorimetry) and microbial composition (by metagenomic pyrosequencing).
RESULTS: A progressive increase in Firmicutes was confirmed in both HF-fed and ob/ob mice reaching statistical significance in the former, but this phylum was unchanged over time in the lean controls. Reductions in Bacteroidetes were also found in ob/ob mice. However, changes in the microbiota were dissociated from markers of energy harvest. Thus, although the faecal energy in the ob/ob mice was significantly decreased at 7 weeks, and caecal SCFA increased, these did not persist and faecal acetate diminished over time in both ob/ob and HF-fed mice, but not in lean controls. Furthermore, the proportion of the major phyla did not correlate with energy harvest markers.
CONCLUSION: The relationship between the microbial composition and energy harvesting capacity is more complex than previously considered. While compositional changes in the faecal microbiota were confirmed, this was primarily a feature of high-fat feeding rather than genetically induced obesity. In addition, changes in the proportions of the major phyla were unrelated to markers of energy harvest which changed over time. The possibility of microbial adaptation to diet and time should be considered in future studies.
Place, publisher, year, edition, pages
BMJ Publishing Group Ltd, 2010. Vol. 59, no 12, p. 1635-42
National Category
Medical and Health Sciences Gastroenterology and Hepatology
Identifiers
URN: urn:nbn:se:oru:diva-65934DOI: 10.1136/gut.2010.215665ISI: 000284109200009PubMedID: 20926643Scopus ID: 2-s2.0-78649887273OAI: oai:DiVA.org:oru-65934DiVA, id: diva2:1192018
Funder
NIH (National Institute of Health), RO1 DK058855
Note
Funding Agencies:
Teagasc (an Agency of the Irish Government Department of Agriculture, Fisheries and Food)
Science Foundation Ireland
Alimentary Health Ltd
2018-03-212018-03-212025-02-11Bibliographically approved