Véronique Demers-Mathieu, Dairy Science and Technology (STELA), Institute of Nutrition and Functional Foods (INAF), Department of Food Sciences and Nutrition, Laval University, Quebec City, Canada
Véronique Demers-‐ Mathieua,b,c*, Sabrine Naïmia, Mélanie Le Barza,c, Noémie Daniela,c, Geneviève Pilonac, André Marettea,c, Julie Audyd, Emilie Laurine, Ismaïl Flissa, Daniel St-‐ Gelaisa,b
a Dairy Science and technology (STELA), Institute of Nutrition and Functional Foods (INAF),
b Agriculture and Food Canada, Food Research and Development, St-‐ Hyacinthe, QC, Canada J2S 8E3,
c Quebec Heart and Lung Institute (CRIUCPQ), Quebec, QC, Canada, G1V 0B8,
d Agropur coopérative, 101 boul. Roland-‐‐Therrien, St-‐ Hubert, QC, Canada J4H 4B9
e Aliments Utima Inc., 2177 boul. Fernand Lafontaine, Longueuil, QC J4G 2V2
Chronic Inflammation can play an important role in the development of the pathogenesis related with obesity. It has been demonstrated that some probiotics (Lactobacillus, Bifidobacterium) can prevent obesity and inflammation by reducing the metabolic endotoxemia, by inhibiting the production of pro-inflammatory cytokines and by shaping the gut microbiota (commensal bacteria). No dairy product containing anti-inflammatory and anti-obesity probiotics are currently available in North America. The viability of probiotic is important during the manufacture and the storage of dairy product since cheese (50 g) and yogurt (100 g) must contain at least 109 colony forming unity (cfu) of the specific probiotic strain with health claims. The objective of this study was to determinate anti-inflammatory (in vitro) & anti-obesity (in vivo) effects of new probiotics and their viability during production and storage of non-fat yogurt and low-fat Cheddar cheese. Five probiotics isolated from faeces and raw milk, Bifidobacterium animalis ssp lactis (Bf141, Bf26), Lactobacillus (Lb.) casei/paracasei (L79), Lb. rhamnosus (Lb102) and Lb. plantarum (Lb38), genetically identified, were used. A cell model of inflammation (macrophages) and a mouse model of diet-induced obesity (obesogenic diet) were used. The heat-killed of probiotic strains induced a significant decrease in NO production and were able to increase cytokine IL-10 production (except L79) in macrophages. The body weight gain and epididymal, inguinal and retroperitoneal white adipose tissue masses in mice were more reduced with probiotics milks than control milk without probiotic. At the beginning of the cheese ripening period, all probiotic candidates were at the targeted count (109 per 50 g portion, based on health claim regulations for probiotic foods). The counts of both bifidobacteria isolates dropped below 109 during cheese ripening, while the lactobacilli counts remained stable or increased. Yogurts were formulated to contain 1.0 × 107 cfu g-1 of probiotic candidate for at least 30 days of storage. After 60 days, this count was maintained in the case of lactobacilli, but not in the case of bifidobacteria. Studies are in process to evaluate the effects of these probiotics on the parameters associated with inflammation (cytokines and LPS levels) and on the composition of gut microbiota. Obesity is associated with chronic lowgrade inflammation. Some probiotics (Lactobacillus, Bifidobacterium) have contributed to prevent obesity and inflammation by improving intestinal barrier function with the decrease of lipopolysaccharides (LPS) circulation, by decreasing the liberation of pro-inflammatory metabolites such as cytokine (IL-6, TNF-α) and nitric oxide (NO), and by increasing the production of anti-inflammatory cytokine (IL‐10). No dairy products containing anti‐inflammatory and anti-obesity probiotics are currently available in North America. The viability of probiotic bacteria is important during the manufacture and storage of dairy products since cheese (30 g) and yogurt (100 g) must contain at least 109 of probiotic strain with health claims, according to the regulation of probiotic foods. The objective of this study was to determinate anti‐inflammatory (in vitro) & anti- obesity (in vivo) effects of new probiotics and their viability during production and storage of low‐fat yogurt and Cheddar cheese. New probiotic strains were isolated from infants or adults feces and dairy products. The use of 16S genetic identification and specific Q-PCR primers allowed confirming two Bifidobacterium animalis ssp lactis (Bf26, Bf141) and the use of RpoB primers three Lactobacillus strains (Lb38, Lb79, Lb102). Model cell of inflammation and model mice obese with milk as vector were used.
The heat-killed of probiotic strains induced a significant decrease in NO production and were able to increase IL-10 production (except L79) in macrophages. The body weight gain of mice fed with high‐fat high‐sucrose (HFHS) diet treated with probiotic milks was significantly reduced comparing to mice fed with HFHS diet and milk without probiotic. Probiotic cells were viable (>109 cfu/g) in dairy products after the production and storage of low‐fat yogurt and Cheddar cheese as recommended FDA. However, results obtained in vitro study suggests that death probiotic cells could play a role in anti‐inflammatory effect.