Scientific Opinion on the substantiation of a health claim related to Lactobacillus casei strain Shirota and maintenance of the upper respiratory tract defence against pathogens by maintaining immune defences pursuant to Article 13(5) of Regulation (EC) N

ABSTRACT The closely related species of the Lactobacillus casei group are extensively studied because of their applications in food fermentations and as probiotics. Our results show that many strains in this group are incorrectly classified and that reclassifying them to their most closely related species type strain improves the functional predictive power of their taxonomy. In addition, our findings may spark increased interest in the L. casei species. We find that after reclassification, only 10 genomes remain classified as L. casei. These strains show some interesting properties. First, they all appear to be catalase positive. This suggests that they have increased oxidative stress resistance. Second, we isolated an L. casei strain from the human upper respiratory tract and discovered that it and multiple other L. casei strains harbor one or even two large, glycosylated putative surface adhesins. This might inspire further exploration of this species as a potential probiotic organism. Although the genotypic and phenotypic properties of the Lactobacillus casei group have been studied extensively, the taxonomic structure has been the subject of debate for a long time. Here, we performed a large-scale comparative analysis by using 183 publicly available genomes supplemented with a Lactobacillus strain isolated from the human upper respiratory tract. On the basis of this analysis, we identified inconsistencies in the taxonomy and reclassified all of the genomes according to their most closely related type strains. This led to the identification of a catalase-encoding gene in all 10 L. casei sensu stricto strains, making it the first described catalase-positive species in the Lactobacillus genus. Moreover, we found that 6 of 10 L. casei genomes contained a SecA2/SecY2 gene cluster with two putative glycosylated surface adhesin proteins. Altogether, our results highlight current inconsistencies in the taxonomy of the L. casei group and reveal new clade-associated functional features. IMPORTANCE The closely related species of the Lactobacillus casei group are extensively studied because of their applications in food fermentations and as probiotics. Our results show that many strains in this group are incorrectly classified and that reclassifying them to their most closely related species type strain improves the functional predictive power of their taxonomy. In addition, our findings may spark increased interest in the L. casei species. We find that after reclassification, only 10 genomes remain classified as L. casei. These strains show some interesting properties. First, they all appear to be catalase positive. This suggests that they have increased oxidative stress resistance. Second, we isolated an L. casei strain from the human upper respiratory tract and discovered that it and multiple other L. casei strains harbor one or even two large, glycosylated putative surface adhesins. This might inspire further exploration of this species as a potential probiotic organism.

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Scientific Opinion on the substantiation of health claims related to Fagopyrum esculentum Moench. and function of the upper respiratory tract (ID 2442) pursuant to Article 13(1) of Regulation (EC) No 1924/2006

EFSA Journal ◽

10.2903/j.efsa.2009.1290 ◽

2009 ◽

Vol 7 (10) ◽

pp. 1290

Author(s):

Keyword(s):

Respiratory Tract ◽

Fagopyrum Esculentum ◽

Health Claims ◽

Upper Respiratory Tract ◽

Scientific Opinion ◽

Upper Respiratory ◽

Fagopyrum Esculentum Moench ◽

And Function

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Reduction of Influenza Virus Titer and Protection against Influenza Virus Infection in Infant Mice Fed Lactobacillus casei Shirota

Clinical and Diagnostic Laboratory Immunology ◽

10.1128/cdli.11.4.675-679.2004 ◽

2004 ◽

Vol 11 (4) ◽

pp. 675-679 ◽

Cited By ~ 113

Author(s):

Hisako Yasui ◽

Junko Kiyoshima ◽

Tetsuji Hori

Keyword(s):

Influenza Virus ◽

Respiratory Tract ◽

Oral Administration ◽

Lactobacillus Casei ◽

Influenza Virus Infection ◽

Interleukin 12 ◽

Saline Control ◽

Control Group ◽

Upper Respiratory Tract ◽

Upper Respiratory

ABSTRACT We investigated whether oral administration of Lactobacillus casei strain Shirota to neonatal and infant mice ameliorates influenza virus (IFV) infection in the upper respiratory tract and protects against influenza infection. In a model of upper respiratory IFV infection, the titer of virus in the nasal washings of infant mice administered L. casei Shirota (L. casei Shirota group) was significantly (P < 0.05) lower than that in infant mice administered saline (control group) (102.48 ± 100.31 and 102.78 ± 100.4, respectively). Further, the survival rate of the L. casei Shirota group was significantly (P < 0.05) higher than that of the control group (14.3 versus 40.0%). One day after infection, pulmonary NK cell activity and interleukin-12 production by mediastinal lymph node cells of mice in the L. casei Shirota group were significantly greater than those of mice in the control group. These findings suggest that oral administration of L. casei Shirota activates the immature immune system of neonatal and infant mice and protects against IFV infection. Therefore, oral administration of L. casei Shirota may accelerate the innate immune response of the respiratory tract and protect against various respiratory infections in neonates, infants, and children, a high risk group for viral and bacterial infections.

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