Lactobacillus gasseriK7 modulates the blood cell transcriptome of conventional mice infected withEscherichia coliO157:H7

Abstract

Aims: As the immune cells underlying the intestinal barrier sense luminal microbial signals, blood cell transcriptomics may identify subclinical changes triggered by gut bacteria that may otherwise not be detected. We have therefore investigated how Lactobacillus gasseri K7 and enterohemorrhagic Escherichia coli O157:H7 modulate the blood cell transcriptome of mice possessing an intact microbiota. Methods and Results:We have analysed the transcriptome of five groups of C57BL/6J mice: (i) control, (ii) inoculated with a single dose of E. coli, (iii) inoculated during 2 weeks with Lact. gasseri, (iv) co-inoculated with E. coli and Lact. gasseri, (v) inoculated with Lact. gasseri prior to E. coli infection. The transcriptome could distinguish between the five treatment groups. Gene characteristics of bacterial infection, in particular inflammation, were upregulated in the mice inoculated with E. coli. Lact. gasseri had only mild effects on the transcriptome but modified the gene expression induced by E. coli. Conclusions: The transcriptome differentiates mice inoculated orally with E. coli, Lact. gasseri and combinations of these two strains. Significance and Impact of the Study: These results suggest that the blood cell transcriptome can be used as a source of biomarkers to monitor the impact of probiotics in subclinical models of infectious disease.

Administration of probiotics Lactobacillus rhamnosus GG and Lactobacillus gasseri K7 during pregnancy and lactation changes mouse mesenteric lymph nodes and mammary gland microbiota

“…It was shown previously that both probiotic strains (LGG and LK7) can survive passage through the intestinal tract of mice after oral administration of probiotics (Blümer et al, 2007;Sagaya et al, 2014). In our study, we confirmed the presence of viable LGG and LK7 strains (>1 × 10 3 cfu/g) by strain-specific PCR in all samples from d 3 PP and in one sample from d 8 PP (Table 1).…”

“…Several studies have shown that different LAB and potential probiotics can stimulate the immune system and translocate to MLN of healthy adult mice without causing systemic infection (Zhou et al, 2000;Maragkoudakis et al, 2009;Kandasamy et al, 2011). Most likely, the application of probiotics resulted in an increased activation of the immune system (Gorbach, 2000;Sagaya et al, 2014) and increased sampling of beneficial commensal bacteria from the intestinal lu- men. Moreover, in pregnancy and lactation there could be an increased frequency of translocation of bacteria to MLN and migration of bacterial cells to MG via the entero-mammary pathway (Perez et al, 2007).…”

Improved Draft Genome Sequence of Probiotic Strain Lactobacillus gasseri K7

“…Strains of L. gasseri species are frequently declared to be probiotics (1). L. gasseri K7 is an isolate from infant feces and has established probiotic properties in vitro and in vivo (2–4). The gassericins K7 A (GenBank accession no.…”