Transition of the probiotic bacteria, Lactobacillus casei strain Shirota, in the gastrointestinal tract of a pig

A prebiotic role of Ecklonia cava improves the mortality of Edwardsiella tarda-infected zebrafish models via regulating the growth of lactic acid bacteria and pathogen bacteria

In this study, the beneficial prebiotic roles of Ecklonia cava (E. cava, EC) were evaluated on the growth of lactic acid bacteria (LAB) and pathogen bacteria and the mortality of pathogen-bacteria infected zebrafish model. The result showed that the original E. cava (EC) led to the highest growth effects on three LABs (Lactobacillus brevis, L. brevis; Lactobacillus pentosus, L. pentosus; Lactobacillus plantarum; L. plantarum) and it was dose-dependent manners. Also, EC, its Celluclast enzymatic (ECC) and 100% ethanol extracts (ECE) showed the anti-bacterial activities on the fish pathogenic bacteria such as (Edwardsiella tarda; E. tarda, Streptococcus iniae; S. iniae, and Vibrio harveyi; V. harveyi). Interestingly, EC induced the higher production of the secondary metabolites from L. plantarum in MRS medium. The secondary metabolites produced by EC significantly inhibited the growth of pathogen bacteria. In further in vivo study, the co-treatment of EC and L. plantarum improved the growth and mortality of E. tarda-infected zebrafish as regulating the expression of inflammatory molecules such as iNOS and COX2. Taken together, our present study suggests that the EC plays an important role as a potential prebiotic and has a protective effect against the infection caused by E. tarda injection in zebrafish. Also, our conclusion from this evidence is that EC can be used and applied as a useful prebiotic.

Health-beneficial effects of probiotics: Its mode of action

It is now widely recognized that probiotics have health-beneficial effects on humans and animals. Probiotics should survive in the intestinal tract to exert beneficial effects on the host's health. To keep a sufficient level of probiotic bacteria in the gastrointestinal tract, a shorter interval between doses may be required. Although adherence to the intestinal epithelial cell and mucus is not a universal property of probiotics, high ability to adhere to the intestinal surface might strongly interfere with infection of pathogenic bacteria and regulate the immune system. The administration of probiotic Lactobacillus stimulated indigenous Lactobacilli and the production of short-chain fatty acids. This alteration of the intestinal environment should contribute to maintain the host's health. The immunomodulatory effects of probiotics are related to important parts of their beneficial effects. Probiotics may modulate the intestinal immune response through the stimulation of certain cytokine and IgA secretion in intestinal mucosa. The health-beneficial effects, in particular the immunomodulation effect, of probiotics depend on the strain used. Differences in indigenous intestinal microflora significantly alter the magnitude of the effects of a probiotic. Specific probiotic strains suitable for each animal species and their life stage as well as each individual should be found.

PCR monitoring of Lactobacillus and Bifidobacterium dynamics in fermentations by piglet intestinal microbiota

A new group-specific primer (Lact71R), targeting the 16S-23S rDNA intergenic spacer region of Lactobacillus, was tested in its specificity to amplify rDNA of lactobacilli from piglet intestinal origin by polymerase chain reaction (PCR). Lact71R and Lab0677F, a Lactobacillus group-specific primer targeting the 16S rDNA, generated a common amplicon by PCR with DNA from Lactobacillus and Pediococcus reference strains, but not from Weissella strains. Sequence analysis of clones obtained by PCR amplification with Lact71R and Lab0677F and total DNA isolated from the ileal, caecal and colonic contents of one piglet resulted in Lactobacillus and Lactobacillus-like sequences mainly retrieved from intestinal environments. The primer pair was further validated in a culture independent PCR-analysis to monitor broad fluctuations of lactobacilli populations in fructo-oligosaccharides (FOS) fermentations by piglet intestinal microbiota. Bifidobacterium genus-specific primers were also used for PCR titre determination throughout FOS fermentations, in parallel with lactate and short chain fatty acids (SCFA) quantification. Increases between PCR titres were correlated with lactate detection in early stages of fermentation. Based on the obtained results, a simple monitoring PCR approach is proposed, foreseeing its application to the study of the dynamics of specific bacterial populations in complex environments.

Effects of inner-phase components of water-in-oil-in-water emulsion on low-pH tolerance of Lactobacillus acidophilus incorporated into inner-water phase

The incorporation of Lactobacillus acidophilus, which has a low acid tolerance, into the inner-water phase of water-in-oil-in-water (W/O/W) emulsion improved the bacterial survival rate in a model gastric juice. The components that enhanced the acid tolerance of the bacterium in W/O/W emulsion were investigated. Although the acid tolerance enhancement induced by the tested components was low at pH 2, some components significantly improved the tolerance at pH 4. In particular, the acid tolerance enhancement induced by yeast extract and sodium caseinate was marked.

Adhesion of Lactobacillus plantarum 423 and Lactobacillus salivarius 241 to the intestinal tract of piglets, as recorded with fluorescent in situ hybridization (FISH), and production of plantaricin 423 by cells colonized to the ileum

AIMS

To determine which intestinal section of pre and postweaned piglets are colonized by Lactobacillus plantarum 423 and Lactobacillus salivarius 241, and follow production of plantaricin 423 in a gastro-intestinal model.

METHODS AND RESULTS

Lactobacillus plantarum 423 and Lact. salivarius 241, single or in combination, were administered to 1-, 14- and 28-day-old (postweaned) piglets. According to results obtained by fluorescent in situ hybridization (FISH), Lact. plantarum 423 adhered strongly to the ileum and posterior colon and Lact. salivarius 241 to the duodenum in preweaned piglets. High numbers of strain 241 were recorded in the duodenum and posterior colon of postweaned piglets, whereas strain 423 remained localized to the ileum. Lowering in Enterococcus faecalis cell numbers were recorded when preweaned piglets were challenged with strain 241. Plantaricin 423 was produced for 96 h in the ileum section of a gastro-intestinal model.

CONCLUSIONS

Lactobacillus plantarum 423 and Lact. salivarius 241 adhere to different sections of the intestinal tract, depending on the piglet's age. Ent. faecalis were inhibited in vivo, probably by plantaricin 423.

SIGNIFICANCE AND IMPACT OF THE STUDY

Fluorescent in situ hybridization proved valuable in the detection of probiotic bacteria adhered to the intestine. This is the first report of bacteriocin production in a model simulating the porcine gastro-intestinal tract.

Nutritional significance of the selective ingestion ofAlbizia zygia gum exudate by wild chimpanzees in Bossou, Guinea

The selective ingestion of plant gum exudates by chimpanzees has been frequently observed at various study sites. At Bossou, Guinea, chimpanzees also frequently ingest Albizia zygia gum exudate. A functional explanation for this behavior is lacking, so we evaluated its possible contribution of energy in the form of short-chain fatty acids (SCFA) as well as minerals. An in vitro fermentation study of A. zygia gum using the fecal bacteria of a Bossou chimpanzee showed that carboxylic acids were produced with a 6-hr lag phase up to 44 mmol/l by 18 hr of incubation. Acetate was the most abundant acid produced, followed by lactate and propionate. The energy supplied from the fermentation of a piece of gum exudate (20-30 g) was negligible in comparison with the estimated daily energy requirements of chimpanzees in the wild. However, A. zygia gum exudate (20-30 g) can supply sufficient amounts of calcium, manganese, magnesium, and potassium to fulfill the daily requirements for these minerals in chimpanzees.