Effect of intestinal colonisation by two Lactobacillus strains on the immune response of gnotobiotic mice

Abstract

The effect of intestinal colonisation on the immune system was investigated in germ-free mice monoassociated with Lactobacillus strains isolated from calf faeces. Single doses of Lactobacillus acidophilus L36 or Lactobacillus salivarius L38 were administered to germ-free mice by intragastric gavage. Ten days later, the mice were euthanised. Gene expression levels of interleukin 5 (IL-5), IL-6, IL-10, IL-12b, IL-17a, gamma interferon (IFN-γ), transforming growth factor beta 1 (TGF-β1), and tumour necrosis factor alpha (TNF-α) were quantified in segments of the small and large intestines by real time quantitative polymerase chain reaction. All the mice were colonised rapidly after Lactobacillus administration with intestinal counts ranging from 6.53 to 8.26 log cfu/g. L. acidophilus L36 administration increased the expression of cytokines involved with the Th2 (IL-5, IL-6 and TGF-β1) and Th17 (IL-17a, TNF-α and IL-6) inflammatory response, whereas L. salivarius L38 appeared to stimulate a pattern of less diversified cytokines in the intestine. Intragastric gavage of L. acidophilus L36 and L. salivarius L38 induced similar levels of colonisation in the digestive tracts of germ-free mice but stimulated different immune responses in the intestinal mucosa. The different immunomodulation patterns might facilitate the potential use of these lactobacilli as probiotics to treat distinct pathological conditions, for example protection against Citrobacter rodentium infection by stimulating IL-17 production.

Safety and Protective Effectiveness of Two Strains of Lactobacillus with Probiotic Features in an Experimental Model of Salmonellosis

“…L. salivarius (L38) and L acidophilus (L36) strains were previously isolated from bovine stool samples (unpublished data) and in in vivo experiments with germ-free mice they successfully colonized and changed the expression of cytokines in the gastrointestinal tract of gnotobiotic animals [ 28 ]. Herein, L38 and L36 bacteria were supplied as live suspensions to mice challenged with Salmonella enterica serovar Typhimurium to evaluate, on the 9th day post-infection, their effects on animal weight, spleen and liver size indexes, and small intestine architecture and histological aspects.…”

“…Gene-specific primers for the cytokines and reference genes ACTB and GAPDH were used according to [ 33 ]. The reactions were performed according to the optimized parameters described in [ 28 ] using an ABI Prism 7900 HT sequence detection system and the analysis was conducted using Sequence Detection software Version 2.4 (Applied Biosystems). The expression levels in the saline control group and Salmonella control group were used as the calibration data in challenged and no-challenged groups, respectively.…”

“…Side effects of using probiotics to increase livestock production are improved quality and biological value of the final commercialized products, and thus have a positive impact on human health. L. salivarius L38 and L. acidophilus L36 were recently isolated from bovine feces, successfully colonized the gastrointestinal tract of germ-free animals, and stimulated expression of different cytokine profiles in the intestinal mucosa [ 28 ]. Herein, we characterize the induced immune responses of these two isolated bovine-based microbials in a mouse model of salmonellosis.…”

The Microbiome in Mental Health: Potential Contribution of Gut Microbiota in Disease and Pharmacotherapy Management

“…Biologic validation of these methods on large human cohorts will be necessary to demonstrate the strength and clinical utility of these types of predictors and therapeutic management of disease. 56 Comparison of germ-free vs SPF mice Basal behavior for germ-free mice vs SPF mice was interpreted as anxiolytic; increased BDNF mRNA in hippocampus of germ-free animals Mouse 57 Campylobacter jejuni Increased anxiety-like behavior and increased markers of activation within the limbic structures in the brain Mouse 41 Lactobacillus rhamnosus Induced region-dependent alterations in GABA mRNA in the brain and reduced stress-induced corticosterone level and anxiety-and depression-related behavior that was not seen in vagotimized mice Mouse 58 Lactobacillus acidophilus L36 or Lactobacillus salivarius L38 L36 increased the expression of Th2 cytokines (IL-5, IL-6 and TGF-b1) and Th17 (IL-17a, TNF-a and IL-6) inflammatory response Conventional…”

Analyses of the probiotic property and stress resistance-related genes of Lactococcus lactis subsp. lactis NCDO 2118 through comparative genomics and in vitro assays

“…The application of MATS experiments facilitates a qualitative assessment of the polarity or non-polarity of the bacterial surface, which is important because it indicates the potential for probiotic adhesion to apolar surfaces in the intestinal and vaginal epithelia. However, this test is only a primary indicator of the adherence of microorganisms [81; 82]. …”