Metabolic activity of the enteric microbiota influences the fatty acid composition of murine and porcine liver and adipose tissues.
BACKGROUND
Recent reports suggest that the metabolic activity of the gut microbiota may contribute to the pathogenesis of obesity and hepatic steatosis.


OBJECTIVE
The objective was to determine whether the fat composition of host tissues might be influenced by oral administration of commensal bifidobacteria previously shown by us to produce bioactive isomers of conjugated linoleic acid (CLA).


METHODS
Murine trials were conducted in which linoleic acid-supplemented diets were fed with or without Bifidobacterium breve NCIMB 702258 (daily dose of 10(9) microorganisms) to healthy BALB/c mice and to severe combined immunodeficient mice for 8-10 wk. To ensure that the observations were not peculiar to mice, a similar trial was conducted in weanling pigs over 21 d. Tissue fatty acid composition was assessed by gas-liquid chromatography.


RESULTS
In comparison with controls, there was an increase in cis-9, trans-11 CLA in the livers of the mice and pigs after feeding with linoleic acid in combination with B. breve NCIMB 702258 (P < 0.05). In addition, an altered profile of polyunsaturated fatty acid composition was observed, including higher concentrations of the omega-3 (n-3) fatty acids eicosapentaenoic acid and docosahexaenoic acid in adipose tissue (P < 0.05). These changes were associated with reductions in the proinflammatory cytokines tumor necrosis factor-alpha and interferon-gamma (P < 0.05).


CONCLUSIONS
These results are consistent with the concept that the metabolome is a composite of host and microbe metabolic activity and that the influence of the microbiota on host fatty acid composition can be manipulated by oral administration of CLA-producing microorganisms.
Alimentary Pharmabiotic Centre, Cork, Ireland.
Rebecca
R
Wall
R Paul
RP
Ross
Fergus
F
Shanahan
Liam
L
O'Mahony
Caitlin
C
O'Mahony
Mairead
M
Coakley
Orla
O
Hart
Peadar
P
Lawlor
Eamonn M
EM
Quigley
Barry
B
Kiely
Gerald F
GF
Fitzgerald
Catherine
C
Stanton
D000273:Adipose Tissue / Q000378:metabolism* / Q000382:microbiology*; D000821:Animal Feed; D000818:Animals; D001644:Bifidobacterium / Q000378:metabolism*; D005227:Fatty Acids / Q000378:metabolism*; D005243:Feces / Q000382:microbiology; D008099:Liver / Q000378:metabolism* / Q000382:microbiology*; D008214:Lymphocytes / Q000276:immunology / Q000382:microbiology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D013552:Swine
D005227:Fatty Acids