Production of Conjugated Linoleic Acid by Intestinal Bacteria in Dogs and Cats.

Abstract

ABSTRACT. Production of conjugated linoleic acid (CLA) by the intestinal bacteria of dogs and cats was demonstrated by incubating their feces with linoleic acid (LA). CLA accumulated once, and then decreased with time. The numbers of LA-hydrogenating bacteria in the intestines appeared to decrease greatly with the ages of dogs and cats. As a major product of LA biohydrogenation, trans-vaccenic acid (t-VA) was identified. Most CLA and t-VA were readily solubilized by shaking the incubation mixture with bovine serum albumin, which strongly supports the presumption that CLA and t-VA are mostly formed on the outer surface of cell membrane, or excreted to the outer cell surface. This result suggests that CLA and t-VA can readily be absorbed through the large intestines. Triacylglycerol and phospholipid were shown to be hydrolyzed to free fatty acids by fecal bacteria, which is critical for biohydrogenation to occur, because esterified LA is not hydrogenated. However, since the ability of intestinal bacteria to produce CLA is probably low, it is desirable to augment CLA production.

A new strain of Butyrivibrio fibrisolvens that has high ability to isomerize linoleic acid to conjugated linoleic acid

“…B. fibrisolvens also resides in the intestines of humans (Wedekind et al, 1988), dogs (Asanuma et al, 2001), and cats (Asanuma et al, 2001). We showed that CLA is produced by the mixed bacteria harvested from dog and cat feces (Fukuda et al, 2002b). Introduction of B. fibrisolvens as a probiotic may enhance CLA supply, and contribute to the health of these animals.…”

“…Cultures were routinely incubated in triplicate at 39°C, maintaining the pH between 6.5 and 7.0 (Miyazaki et al, 1992). Details of culture conditions and procedures were as described previously (Fukuda et al, 2002a). Cell growth was estimated by measuring the optical density at 600 nm (OD 600 ).…”

“…Measurement of LA, CLA, and t-VA. To measure CLA and t-VA, lipids were extracted by shaking the cultures with isopropanol-isooctane-3M H 2 SO 4 (20 : 10 : 1), as described (Fukuda et al, 2002a). Lauric acid (routinely 2.5 mg/culture vial) was added as an internal standard before extraction.…”

“…Lauric acid (routinely 2.5 mg/culture vial) was added as an internal standard before extraction. The extracted lipids were transmethylated with 5% HCl in methanol at 60°C for 1 h under a gas phase of N 2 as described (Fukuda et al, 2002a). The methylated FAs were analyzed by using a gas chromatograph (Shimadzu GC-14B, Japan) equipped with a capillary column (HR-SS-10, 50 m, Shinwa Kako, Japan).…”

“…The methylated FAs were analyzed by using a gas chromatograph (Shimadzu GC-14B, Japan) equipped with a capillary column (HR-SS-10, 50 m, Shinwa Kako, Japan). FAs were identified, based on retention time and also by gas chromatography-mass spectrometry using a Shimadzu GC-17A gas chromatograph connected to a Shimadzu mass spectrometer QP5050, as described (Fukuda et al, 2002a).…”