scholarly journals Metabolism of Linoleic Acid by Human Gut Bacteria: Different Routes for Biosynthesis of Conjugated Linoleic Acid

2007 ◽  
Vol 189 (6) ◽  
pp. 2566-2570 ◽  
Author(s):  
Estelle Devillard ◽  
Freda M. McIntosh ◽  
Sylvia H. Duncan ◽  
R. John Wallace
Keyword(s):  
Linoleic Acid ◽  
Conjugated Linoleic Acid ◽  
Vaccenic Acid ◽  
Intestinal Bacteria ◽  
Gut Bacteria ◽  
Human Tissues ◽  
Human Gut ◽  
Gram Positive ◽  
Health Promoting

ABSTRACT A survey of 30 representative strains of human gram-positive intestinal bacteria indicated that Roseburia species were among the most active in metabolizing linoleic acid (cis-9,cis-12-18:2). Different Roseburia spp. formed either vaccenic acid (trans-11-18:1) or a 10-hydroxy-18:1; these compounds are precursors of the health-promoting conjugated linoleic acid cis-9,trans-11-18:2 in human tissues and the intestine, respectively.

scholarly journals Mechanism of conjugated linoleic acid and vaccenic acid formation in human faecal suspensions and pure cultures of intestinal bacteria

Microbiology ◽  
2009 ◽  
Vol 155 (1) ◽  
pp. 285-294 ◽  
Author(s):  
Freda M. McIntosh ◽  
Kevin J. Shingfield ◽  
Estelle Devillard ◽  
Wendy R. Russell ◽  
R. John Wallace
Keyword(s):  
Linoleic Acid ◽  
Conjugated Linoleic Acid ◽  
Vaccenic Acid ◽  
Deuterium Oxide ◽  
Hydrogen Abstraction ◽  
Intestinal Bacteria ◽  
Butyrivibrio Fibrisolvens ◽  
Human Intestinal Bacteria ◽  
Pure Cultures ◽  
Faecal Bacteria

Faecal bacteria from four human donors and six species of human intestinal bacteria known to metabolize linoleic acid (LA) were incubated with LA in deuterium oxide-enriched medium to investigate the mechanisms of conjugated linoleic acid (CLA) and vaccenic acid (VA) formation. The main CLA products in faecal suspensions, rumenic acid (cis-9,trans-11-CLA; RA) and trans-9,trans-11-CLA, were labelled at C-13, as were other 9,11 geometric isomers. Traces of trans-10,cis-12-CLA formed were labelled to a much lower extent. In pure culture, Bifidobacterium breve NCFB 2258 formed labelled RA and trans-9,trans-11-CLA, while Butyrivibrio fibrisolvens 16.4, Roseburia hominis A2-183T, Roseburia inulinivorans A2-192T and Ruminococcus obeum-like strain A2-162 converted LA to VA, labelled in a manner indicating that VA was formed via C-13-labelled RA. Propionibacterium freudenreichii subsp. shermanii DSM 4902T, a possible probiotic, formed mainly RA with smaller amounts of trans-10,cis-12-CLA and trans-9,trans-11-CLA, labelled the same as in the mixed microbiota. Ricinoleic acid (12-OH-cis-9-18 : 1) did not form CLA in the mixed microbiota, in contrast to CLA formation described for Lactobacillus plantarum. These results were similar to those reported for the mixed microbiota of the rumen. Thus, although the bacterial genera and species responsible for biohydrogenation in the rumen and the human intestine differ, and a second route of RA formation via a 10-OH-18 : 1 is present in the intestine, the overall labelling patterns of different CLA isomers formation are common to both gut ecosystems. A hydrogen-abstraction enzymic mechanism is proposed that may explain the role of a 10-OH-18 : 1 intermediate in 9,11-CLA formation in pure and mixed cultures.

Manipulating lamb conjugated linoleic acid content and stearoyl coenzyme A desaturase mRNA by either a grass or concentrate feeding regime

2002 ◽  
Vol 2002 ◽  
pp. 183-183
Author(s):  
R.J. Wynn ◽  
Z.C.T.R. Daniel ◽  
A.M. Salter ◽  
P.J. Buttery
Keyword(s):  
Adipose Tissue ◽  
Linoleic Acid ◽  
Conjugated Linoleic Acid ◽  
Acid Content ◽  
Coenzyme A ◽  
Vaccenic Acid ◽  
Linoleic Acid Content ◽  
Feeding Regime ◽  
Health Promoting ◽  
Ruminant Animals

Conjugated Linoleic Acid (CLA) is a mixture of isomers of linoleic acid implicated with numerous health promoting properties. These include anti-carcinogenicity (cis-9,trans-11 isomer), anti-atherogenicity and increasing the lean:fat ratio (trans-10,cis-12 isomer). CLA is produced naturally by all ruminant animals through the incomplete biohydrogenation of linoleic acid within the rumen. Alternatively, it can be made endogenously by stearoyl coenzyme A desaturase (SCD) from vaccenic acid (VA) (Griinariet al,2000). It has been well documented that cows fed on a grass diet produce morecis-9,trans-11 in milk than those fed on a concentrate based regime (Kellyet al,1998) but to date, little work would appear to have been undertaken to determine if this is the case with sheep tissues. In the present study, a grass based diet was compared with a concentrate diet in order to determine whether the CLA content of adipose tissue differed and if so, which isomer and what mechanisms may be involved.

scholarly journals Diets Rich in Conjugated Linoleic Acid and Vaccenic Acid Have No Effect on Blood Pressure and Isobaric Arterial Elasticity in Healthy Young Men

2006 ◽  
Vol 136 (4) ◽  
pp. 992-997 ◽  
Author(s):  
Marianne Raff ◽  
Tine Tholstrup ◽  
Kristen Sejrsen ◽  
Ellen M. Straarup ◽  
Niels Wiinberg
Keyword(s):  
Blood Pressure ◽  
Linoleic Acid ◽  
Conjugated Linoleic Acid ◽  
Vaccenic Acid ◽  
Young Men ◽  
Arterial Elasticity

scholarly journals Differences between human subjects in the composition of the faecal bacterial community and faecal metabolism of linoleic acid

Microbiology ◽  
2009 ◽  
Vol 155 (2) ◽  
pp. 513-520 ◽  
Author(s):  
Estelle Devillard ◽  
Freda M. McIntosh ◽  
Delphine Paillard ◽  
Nadine A. Thomas ◽  
Kevin J. Shingfield ◽  
...  
Keyword(s):  
Linoleic Acid ◽  
Vaccenic Acid ◽  
Human Subjects ◽  
Microbial Community Composition ◽  
Intestinal Bacteria ◽  
Short Chain Fatty Acids ◽  
Gut Health ◽  
Metabolic Characteristics ◽  
Faecal Samples ◽  
Cla Isomers

Conjugated linoleic acid (CLA) is formed from linoleic acid (LA; cis-9,cis-12-18 : 2) by intestinal bacteria. Different CLA isomers have different implications for human health. The aim of this study was to investigate LA metabolism and the CLA isomers formed in two individuals (V1 and V2) with different faecal metabolic characteristics, and to compare fatty acid metabolism with the microbial community composition. LA incubated with faecal samples was metabolized at similar rates with both subjects, but the products were different. LA was metabolized extensively to stearic acid (SA; 18 : 0) in V1, with minor accumulation of CLA and more rapid accumulation of vaccenic acid (VA; trans-11-18 : 1). CLA accumulation at 4 h was almost tenfold higher with V2, and little SA was formed. At least 12 different isomers of CLA were produced from LA by the colonic bacteria from the two individuals. The predominant (>75 %) CLA isomer in V1 was rumenic acid (RA; cis-9,trans-11-18 : 2), whereas the concentrations of RA and trans-10,cis-12-18 : 2 were similar with V2. Propionate and butyrate proportions in short-chain fatty acids were higher in V1. A 16S rRNA clone library from V1 contained mainly Bacteroidetes (54 % of clones), whereas Firmicutes (66 % of clones) predominated in V2. Both samples were devoid of bacteria related to Clostridium proteoclasticum, the only gut bacterium known to metabolize VA to SA. Thus, the CLA formed in the intestine of different individuals may differ according to their resident microbiota, with possibly important implications with respect to gut health.

Effect of ewe feeding system (grass v. concentrate) on intramuscular fatty acids of lambs raised exclusively on maternal milk

2005 ◽  
Vol 81 (3) ◽  
pp. 431-436 ◽  
Author(s):  
M. A. Valvo ◽  
M. Lanza ◽  
M. Bella ◽  
V. Fasone ◽  
M. Scerra ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Linoleic Acid ◽  
Conjugated Linoleic Acid ◽  
Linolenic Acid ◽  
Vaccenic Acid ◽  
Saturated Fatty Acids ◽  
Feeding System ◽  
Pasture Grass ◽  
Maternal Milk ◽  
Trans Vaccenic Acid

AbstractTwenty pregnant Comisana ewes were divided into two groups of 10. One group was allowed to graze a vetch pasture (grass). The second group of animals was housed collectively in a pen and was given hay and concentrates (concentrate). After lambing, all the ewes were allowed to stay with the respective lambs between 18:00 h and 07:00 h of the following day in two different pens. Therefore all the lambs were raised exclusively on maternal milk. The lambs were slaughtered at 38 days of age. Milk and lamb meat (longissimus dorsi muscle) fatty acids were analysed. Ewes on grass produced milk with a lower (P < 0·001) proportion of saturated fatty acids and with a higher proportion of both monounsaturated (P < 0·05) and polyunsaturated fatty acids (P < 0·01) than ewes given concentrates. Trans-vaccenic acid was significantly higher (P < 0·001) in milk from grass-fed animals compared with ewes given concentrates. Linoleic acid (C18: 2 n-6) tended to be higher (P = 0·06) in milk from ewes on concentrates while linolenic acid (C18: 3 n-3) was significantly higher (P < 0·001) in milk from animals grazing pasture. Conjugated linoleic acid (cis-9, trans-11 C18: 2) was almost double in milk from grass-fed ewes compared with animals given concentrates (P < 0·001). Regarding lamb tissue, trans-vaccenic acid (C18: 1 trans-11) was higher (P = 0·01) in the fat from lambs raised by grazing ewes. Linoleic acid (C18: 2 n-6) was at higher concentration (P < 0·001) in the fat from lambs raised by ewes given concentrates. Linolenic acid (C18: 3 n-3) was increased three-fold (P < 0·001) in the fat of lambs from the grass group compared with lambs suckled by ewes given concentrates. The isomer cis-9, trans-11 of conjugated linoleic acid was present at double concentration (P < 0·001) in the fat from animals raised by grazing ewes. Eicosapentaenoic (C20: 5 n-3; EPA) and docosaesaenoic (C22: 6 n-3; DHA) acids were higher (respectively P < 0·001 and P = 0·01) in the intramuscular fat from lambs from the grass group compared with animals from the concentrate group. The n-6/n-3 ratio was lower (P < 0·001) in the meat from lambs raised by grazing ewes. Overall this trial showed that ewe feeding system strongly affects intramuscular fatty acids even in lambs raised exclusively on maternal milk.

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