Study suggests designer probiotics could help cut obesity
Recently published in Microbiology, the study from scientists at Teagasc (the Irish Agriculture and Food Development Authority), University College Cork and the Alimentary Pharmabiotic Centre examined whether a lactobacillus strain with CLA (conjugated linoleic acid) influenced fat tissue composition in mice.
Previous research from Racine et al. (2010) and Thom et al. (2001) has linked fatty acid t10, c12 CLA consumption with decreased body fat in humans, while other studies suggest that this type of fatty acid inhibits colon cancer cell growth.
Probiotics assists CLA metabolism
In this study, scientists transferred an enzyme-encoding gene from skin bacterium P.acnes to Lactobacillus paracasei and induced it to produce CLA t10, c12, which fed to mice resulted in a fourfold increase of CLA in mouse fat tissue composition (against a second probiotic control strain) showing that live bacteria intake affects metabolism at remote body sites.
The researchers wrote: “t10, c12 CLA has been shown to be beneficial to host health…and has been demonstrated to alter body composition by reducing the fat content and increasing the lean body mass in animal studies, and also in some human studies.”
Since one well-known side-effect of higher doses of CLA is liver steatosis (abnormal fatty lipid retention in human cells), they added: “The lower dose of CLA produced by a probiotic strain may be a reliable solution to control these adverse dietary effects.”
Fat is not inert
Study leader Dr. Catherine Stanton said: “CLA has already been shown to alleviate non-alcoholic fatty liver disease that often accompanies obesity. Therefore, increasing levels of CLA in the liver by ingestion of a probiotic strain is of therapeutic relevance.”
“Furthermore, fat is not an inert layer around our bodies, it is active and pro-inflammatory and is a risk factor for many diseases, including cancers. The work shows that there is potential to influence this through diet-microbe-host interactions in the gut.”
Two groups of eight-week old mice were fed CLA-supplemented diets (2% of weight) for 8 weeks: in combination with either recombinant t10, c12 CLA-producing Lactobacillus paracasei (8 mice) or a non-producing CLA control strain of the probiotic (8 mice).
A third group (5 mice) was fed CLA alone, while tissue fatty acid composition was assessed by gas liquid chromatography at the end of the trial, after the mice had been humanely killed and their organs removed.
Source: Microbiology, (published online ahead of print, December 22 2010) DOI: 10.1099/mic.0.043406-0
'Recombinant lactobacilli expressing linoleic acid isomerase can modulate the fatty acid composition of host adipose tissue in mice’
Authors: Cody, R-C; Stanton, C.; O’Mahony, L.; Wall, R. ; Shanahan, F. ; Quigley, E.M; Fitzgerald, G.F; Paul Ross, R.
