Isolation and characterization of human colonic bacteria able to hydrolyse chlorogenic acid

Abstract

Aims: Conjugated hydroxycinnamates, such as chlorogenic acid (caffeoyl-quinic acid), are widely consumed in a Western diet, coffee being one of the richest sources. Ingested hydroxycinnamate esters can reach the large intestine essentially unaltered, and may then be hydrolysed by esterases produced by the indigenous micro¯ora. This study is aimed at identifying bacterial species responsible for the release of natural antioxidants, such as hydroxycinnamic acids, in the human large intestine. Methods and Results: Thirty-®ve isolates recovered after anaerobic batch culture incubation of human faecal bacteria in a chlorogenic acid-based medium were screened for cinnamoyl esterase activity. Six isolates released the hydroxycinnamate, ferulic acid, from its ethyl ester in a plate-screening assay, and these were identi®ed through genotypic characterization (16S rRNA sequencing) as Escherichia coli (three isolates), Bi®dobacterium lactis and Lactobacillus gasseri (two strains). Chlorogenic acid hydrolysing activities were essentially intracellular. These cinnamoyl esterase-producing organisms were devoid of other phenolic-degrading activities. Conclusions:The results show that certain gut bacteria, including some already recognized as potentially health-promoting (i.e. species belonging to the genera Bi®dobacterium and Lactobacillus), are involved in the release of bioactive hydroxycinnamic acids in the human colon. Signi®cance and Impact of the Study: Free hydroxycinnamates, including caffeic, ferulic and p-coumaric acids, exhibit antioxidant and anticarcinogenic properties both in vitro and in animal models. Given that the gut¯ora has a major role in human nutrition and health, some of the bene®cial effects of phenolic acids may be ascribed to the micro¯ora involved in metabolism.

Anticancer Properties of Hydroxycinnamic Acids -A Review

“…The CGA not absorbed by small intestine seem to follow until the large intestine, where they would suffer bacterial action. In fact, Couteau et al (2001) reported that a large number of intestinal bacteria expressed esterase activity and are capable of hydrolyzing CGA to form caffeic acid and other metabolites in the intestine. These esterase activity are able to release cinnamic acid of CGA structure, which can then be absorbed and metabolized to its primary metabolites (caffeic acid, ferulic, isoferulic, and p-coumaric) (Couteau et al 2001).…”

“…In fact, Couteau et al (2001) reported that a large number of intestinal bacteria expressed esterase activity and are capable of hydrolyzing CGA to form caffeic acid and other metabolites in the intestine. These esterase activity are able to release cinnamic acid of CGA structure, which can then be absorbed and metabolized to its primary metabolites (caffeic acid, ferulic, isoferulic, and p-coumaric) (Couteau et al 2001). Additionally, Konishi et al (2004) demonstrated that CA liberated from CGA by intestinal mucosa esterase, is not only absorbed via paracellular diffusion but also actively absorbed by the monocarboxylic acid transporter www.ccsenet.org/cco Cancer and Clinical Oncology Vol.…”

Nutritional flavonoids impact on nuclear and extranuclear estrogen receptor activities

“…These substances must be hydrolyzed by intestinal enzymes or by the colonic microflora before they can be absorbed. When microflora is involved, the efficiency of absorption is often reduced because it also degrades the aglycones and produces simple aromatic acid derivatives (Couteau et al, 2001;Gonthier et al, 2003). During the course of absorption, polyphenols are conjugated in the small intestine and later in the liver (Hollman and Katan, 1999;Birt et al, 2001;Manach et al, 2004).…”

Discovery of Quinic Acid Derivatives as Oral Anti-inflammatory Agents

“…73 They found that CGA poorly absorbed through the small intestine, largely reached the cecum of rats where it was hydrolyzed by the microflora, which exhibited esterase activities. 77,78 Caffeic acid (CA) and QA were liberated and further metabolized. 27,79 The proposed CGA metabolism pathway is shown in Figure 1-4.…”

“…Furthermore, they will be hydrolyzed by the microflora, for an example, CGA is hydrolyzed into Caffeic acid and QA. 77,78 Both caffeic acid and QA amide will not be consumed by gut bacteria, and easily be absorbed in animal digestive tract. The synthesis of the lactone 14 was carried out using quinic acid 1 and PTSA in refluxing 2,2-DMP and acetone.…”