Bioproduction of Conjugated Linoleic Acid by Probiotic Bacteria Occurs In Vitro and In Vivo in Mice

Abstract

Probiotics have been shown to reduce the incidence of colon cancer in animal models. The mechanisms responsible for this activity are poorly defined. Conjugated linoleic acids (CLA) are a group of isomers of linoleic acid (LA) possessing anti-inflammatory and anticarcinogenic properties, which can be produced from LA by certain bacterial strains. In this study, the ability of probiotic bacteria to exert anticarcinogenic effects through the production of CLA was assessed. Incubation of probiotic bacteria (VSL3, Lactobacillus acidophilus, L. bulgaricus, L. casei, L. plantarum, Bifidobacterium breve, B. infantis, B. longum, and Streptococcus thermophilus) in the presence of LA yielded CLA production as measured by gas chromatography. Conditioned medium, containing probiotic-produced CLA, reduced viability and induced apoptosis of HT-29 and Caco-2 cells, as assessed by MTT assay and DNA laddering, respectively. Western blotting demonstrated an increased expression of PPARgamma in cells treated with conditioned medium compared with LA alone. Incubation of murine feces with LA after administering VSL3 yielded 100-fold more CLA than feces collected prior to VSL3 feeding. This study supports a role for supplemental probiotics as a strategy both for attenuating inflammation and for preventing colon cancer.

Conjugated linoleic acids produced by Lactobacillus dissociates IKK-γ and Hsp90 complex in Helicobacter pylori-infected gastric epithelial cells

“…20,21 L. acidophilus was incubated for 18 h at 371C in 10 ml of RPMI-1640 or Mann-Rogosa-Sharpe broth in the presence or absence of 0.5 g/l of linoleic acid suspended in 0.05% Tween-80. Samples were centrifuged at 3500 Â g for 15 min, from which process supernatants were obtained.…”

“…Briefly, b-galactosidase activity was determined using the chemiluminescent substrate AMPGD (3-(4-methoxyspiro[1,2-dioxetane-3,2 0 -tricylo[3.3.1.1]decan]-4-yl)phenyl-b-D-galactopyranoside; Tropix Inc.) as described before. 18,20 Luminescence was induced by the addition of 50 ml 0.2 N NaOH containing 10% Emerald enhancer (Tropix Inc.) and quantitated for 10 s in a luminometer. Increased activity from pIL-8, p2x NF-kB, and pb-actin promoters was calculated by comparing ratios of luciferase to b-galactosidase activities in the cells co-transfected with pIL8-luciferase and pRSV-b-galactosidase, p2x NF-kBluciferase and pRSV-b-galactosidase, or pb-actin-luciferase and pRSV-b-galactosidase, respectively.…”

“…Non-transfected cells were used as a background control. 18,20,26 RNA oligonucleotides for silencing IKK-a (5 0 -GCA GGCU CUUUCAGGGACA-3 0 ), IKK-b (5 0 -GUGAAGAGGUGGUGG UGAGC-3 0 ), and the nonsilencing control (5 0 -UUCUCCGAA CGUGUCACGU-3 0 ) with two thymidine residues (dTdT) at the 3 0 end were synthesized together with their corresponding antisense RNAs and then annealed (QIAGEN, Hilden, Germany), as described previously. 27 For knockdown of human hsp90 mRNA, siRNA for Hsp90 purchased the predesigned siRNA (siGENOME SMARTpool reagent) from Dharmacon (Lafayette, CO, USA).…”

Conjugated Linoleic and Linolenic Acid Production by Bacteria: Development of Functional Foods

“…The administration of a mix of bacteria able to form CLA as c9, t11 and t10, c12, called VSL3 was used as probiotic for mice administration [102]. Probiotic was prepared as lyophilized form and mice were fed 30 μL of probiotic (0.03 g VSL3 in 10 ml water) for 3 days.…”

Inhibition of VSV by Extracellular RNA from Culture Filtrate of Lactobacillus DM8909 in Vitro

“…shown that the bacterial cell wall (lipopolysaccharide, lipoteichoicacid, peptidoglycan) and metabolites (such as short chain fatty acid, secreted proteins and so on) of viable lactobacilli play a pivotal role in the maintenance of gastrointestinal immune homeostasis and prevention of inflammation 3,[5][6][7][8] The most common cause of gastroenteritis in people of all ages is enteric caliciviruses (SRSVs) and rotaviruses followed by other enteric viruses like hepatitis A and E virus and human cytomegalovirus (CMV). In developing countries, diarrhea caused by rotavirus in children is often a significant cause of infant morbidity and mortality 3) .…”