title: Catabolism of citrus flavanones by the probiotics Bifidobacterium longum and Lactobacillus rhamnosus.
abstract: OBJECTIVE
  Orange juice (OJ) flavanones undergo limited absorption in the upper gastrointestinal tract and reach the colon where they are transformed by the microbiota prior to absorption. This study investigated the ability of two probiotic bacteria, Bifidobacterium longum R0175 and Lactobacillus rhamnosus subsp. Rhamnosus NCTC 10302 to catabolise OJ flavanones.
  
  
  METHODS
  The bacteria were incubated with hesperetin-7-O-rutinoside, naringenin-7-O-rutinoside, hesperetin and naringenin, and the culture medium and intracellular cell extracts were collected at intervals over a 48 h of incubation period. The flavanones and their phenolic acid catabolites were identified and quantified by HPLC-HR-MS.
  
  
  RESULTS
  Both probiotics were able to subject hesperetin to ring fission yielding 3-(3'-hydroxy-4'-methoxyphenyl)propionic acid which was subsequently demethylated producing 3-(3',4'-dihydroxyphenyl)propionic acid and then via successive dehydroxylations converted to 3-(3'-hydroxyphenyl)propionic acid and 3-(phenyl)propionic acid. Incubation of both bacteria with naringenin resulted in its conversion to 3-(4'-hydroxyphenyl)propionic acid which underwent dehydroxylation yielding 3-(phenyl)propionic acid. In addition, only L. rhamnosus exhibited rhamnosidase and glucosidase activity and unlike B. longum, which was able to convert hesperetin-7-O-rutinoside and naringenin-7-O-rutinoside to their respective aglycones. The aglycones were then subjected to ring fission and further catabolised in a similar manner to that described above. The flavanones and their catabolites were found in the culture medium but not accumulated in the bacterial cells.
  
  
  CONCLUSIONS
  These findings demonstrate the enzymatic potential of single strains of bifidobacterium and lactobacillus which may be involved in the colonic catabolism of OJ flavanones in vivo.
authors.affiliation: Postharvest Technology and Agrifood Industry Area, Andalusian Institute of Agricultural and Fishery Research and Training (IFAPA), Alameda del Obispo, Córdoba, Spain. mariag.pereira@juntadeandalucia.es.
authors.forename: Gema
authors.initials: G
authors.lastname: Pereira-Caro
authors.affiliation: Postharvest Technology and Agrifood Industry Area, Andalusian Institute of Agricultural and Fishery Research and Training (IFAPA), Alameda del Obispo, Córdoba, Spain.
authors.forename: Begoña
authors.initials: B
authors.lastname: Fernández-Quirós
authors.affiliation: Department of Food Technology, Universitat de Lleida, Lleida, Spain.
authors.forename: Iziar A
authors.initials: IA
authors.lastname: Ludwig
authors.affiliation: Postharvest Technology and Agrifood Industry Area, Andalusian Institute of Agricultural and Fishery Research and Training (IFAPA), Alameda del Obispo, Córdoba, Spain.
authors.forename: Inmaculada
authors.initials: I
authors.lastname: Pradas
authors.affiliation: Department of Nutrition, University of California, Davis, Davis, CA, USA.
authors.forename: Alan
authors.initials: A
authors.lastname: Crozier
authors.affiliation: Postharvest Technology and Agrifood Industry Area, Andalusian Institute of Agricultural and Fishery Research and Training (IFAPA), Alameda del Obispo, Córdoba, Spain.
authors.forename: José Manuel
authors.initials: JM
authors.lastname: Moreno-Rojas
mesh_terms: D000069978:Bifidobacterium longum / Q000201:enzymology / Q000254:growth & development / Q000378:metabolism*; D032084:Citrus sinensis; D044950:Flavanones / Q000378:metabolism* / Q000493:pharmacokinetics; D005638:Fruit / Q000737:chemistry*; D000067030:Fruit and Vegetable Juices / Q000032:analysis; D005959:Glucosidases / Q000378:metabolism; D006569:Hesperidin / Q000378:metabolism; D007408:Intestinal Absorption; D052201:Lacticaseibacillus rhamnosus / Q000201:enzymology / Q000254:growth & development / Q000378:metabolism*; D019936:Probiotics / Q000378:metabolism*
chemical_list: D044950:Flavanones; D006569:Hesperidin; D005959:Glucosidases; C005273:naringenin; C013015:hesperetin
keywords: Bacterial catabolism; Bifidobacterium longum R0175; Flavanones; In vitro incubation; Lactobacillus rhamnosus subsp. Rhamnosus NCTC 10302; Probiotics