Probiotic lactic acid bacteria (Lactobacillus acidophilus HN017, Lactobacillus rhamnosus HN001 and Bifidobacterium lactis HN019) have no adverse effects on the health of mice

Safety assessment of the indigenous probiotic strain Lactiplantibacillus plantarum subsp. plantarum Kita-3 using Sprague-Dawley rats as a model

Lactiplantibacillus plantarum subsp. plantarum Kita-3 is a candidate probiotic from Halloumi cheese produced by Mazaraat Artisan Cheese, Yogyakarta, Indonesia. This study evaluated the safety of consuming a high dose of L. plantarum subsp. plantarum Kita-3 in Sprague-Dawley rats for 28 days. Eighteen male rats were randomly divided into three groups, such as the control group, the skim milk group, and the probiotic group. Feed intake and body weight were monitored, and blood samples, organs (kidneys, spleen, and liver), and the colon were dissected. Organ weight, hematological parameters, serum glutamic oxaloacetic transaminase (SGOT), and serum glutamic pyruvic transaminase (SGPT) concentrations, as well as intestinal morphology of the rats, were measured. Microbial analyses were carried out on the digesta, feces, blood, organs, and colon. The results showed that consumption of L. plantarum did not negatively affect general health, organ weight, hematological parameters, SGOT and SGPT activities, or intestinal morphology. The number of L. plantarum in the feces of rats increased significantly, indicating survival of the bacterium in the gastrointestinal tract. The bacteria in the blood, organs, and colon of all groups were identified using repetitive-polymerase chain reaction with the BOXA1R primers and further by 16S rRNA gene sequencing analysis, which revealed that they were not identical to L. plantarum subsp. plantarum Kita-3. Thus, this strain did not translocate to the blood or organs of rats. Therefore, L. plantarum subsp. plantarum Kita-3 is likely to be safe for human consumption.

Milk Products from Minor Dairy Species: A Review

Milk processing is one of the most ancient food technologies, dating back around 6000 BC. The majority of dairy products are manufactured from cows, buffaloes, goats, and sheep; their production technologies are mostly standardized and have been widely investigated. Milk and dairy products from minor species are less important under the economic point of view, but they play a fundamental social role in many marginal and poor areas. Due to scarce interest of the dairy industry, their technological characteristics and related issues have been investigated less. Recently, the increasing interest toward ethnic foods and food biodiversity is helping these minor products to emerge from the "darkness" in which they have remained for long time. Some of them are increasingly seen as useful for the valorization of marginal areas, while others are recognized as innovative or healthy foods. The present review aims to resume the most recent knowledge about these less-known dairy products. The first part summarizes the main technological properties of equine, camel, and yak milk with a view to processing. The second is a survey on the related dairy products, both the traditional ones that have been manufactured for a long time and those that have been newly developed by food researchers.

Assessment of the functional quality and safety of yoghurts produced with starter cultures obtained from selected commercially sold yoghurts

The study focused on the examination of laboratory prepared yoghurts which were fermented with selected starter cultures from commercially sold yoghurt. The starter cultures were molecularly identified (16s rRNA) as Enterococcus lactis, Lactobacillus plantarum, Lactobacillus pentosus, Pediococcuspentosaceus and Enterococcus durans. The isolates were examined for bile tolerance as an indicator of their ability to survive in the gut. The starter cultures were used to produce different yoghurts in the following order: Enterococcus lactis produced yoghurt, L. plantarum and L. pentosus produced yoghurt, Pediococcuspentosaceus produced yoghurt, E. durans produced yoghurt and yoghurt produced with all starter cultures.  All yoghurts were examined for nutritional quality (vitamin A, B12 and C content, soluble and casein bound magnesium and calcium and proximate nutrient composition). At p ≤0.05, there was statistical significant difference in the nutritional content with P. pentosaceus contained yoghurt, E. durans contained yoghurt and yoghurt produced with a combination of all isolates recording the highest nutritional values and the lowest was observed with the control. Safety tests such as haematology and histology were carried out on wistar rats. After 7 days of feeding the rats in groups with the different yoghurts and a control without yoghurt, there were marked improvements in the red blood cell counts, white blood cell counts but no significant difference in the differentials at p ≤0.05. The isolates were also observed to have no disruptive effect on the morphology and structure of the small intestine. Overall, the use of these lactic acid bacteria strains showed immense benefits in their use as starter cultures and the study demonstrated safety of the final products for consumption.

Effect of Lactobacillus rhamnosus HN001 on carriage of Staphylococcus aureus: results of the impact of probiotics for reducing infections in veterans (IMPROVE) study

BACKGROUND

Infection by Staphylococcus aureus (S. aureus) is a major cause of morbidity and mortality. Colonization by S. aureus increases the risk of infection. Little is known about decolonization strategies for S. aureus beyond antibiotics, however probiotics represent a promising alternative. A randomized controlled trial was conducted to determine the efficacy of Lactobacillus rhamnosus (L. rhamnosus) HN001 in reducing carriage of S. aureus at multiple body sites.

METHODS

One hundred thirteen subjects, positive for S. aureus carriage, were recruited from the William S. Middleton Memorial Medical Center, Madison, WI, USA, and randomized by initial site of colonization, either gastrointestinal (GI) or extra-GI, to 4-weeks of oral L. rhamnosus HN001 probiotic, or placebo. Nasal, oropharyngeal, and axillary/groin swabs were obtained, and serial blood and fecal samples were collected. Differences in prevalence of S. aureus carriage at the end of the 4-weeks of treatment were assessed.

RESULTS

The probiotic and placebo groups were similar in age, gender, and health history at baseline. S. aureus colonization within the stool samples of the extra-GI group was 15% lower in the probiotic than placebo group at the endpoint of the trial. Those in the probiotic group compared to the placebo group had 73% reduced odds (OR 0.27, 95% CI 0.07-0.98) of methicillin-susceptible S. aureus presence, and 83% reduced odds (OR 0.17, 95% CI 0.04-0.73) of any S. aureus presence in the stool sample at endpoint.

CONCLUSION

Use of daily oral L. rhamnosus HN001 reduced odds of carriage of S. aureus in the GI tract, however it did not eradicate S. aureus from other body sites.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01321606 . Registered March 21, 2011.

Integrated Role of Bifidobacterium animalis subsp. lactis Supplementation in Gut Microbiota, Immunity, and Metabolism of Infant Rhesus Monkeys

To investigate the impact of probiotic supplementation of infant formula on immune parameters, intestinal microbiota, and metabolism, five individually housed infant rhesus monkeys exclusively fed standard infant formula supplemented with probiotics (Bifidobacterium animalis subsp. lactis HN019) from birth until 3 months of age were compared with five standard formula-fed and five breast-fed monkeys. Anthropometric measurements, serum insulin, immune parameters, fecal microbiota, and metabolic profiles of serum, urine, and feces were evaluated. Consumption of B. lactis-supplemented formula reduced microbial diversity, restructured the fecal microbial community, and altered the fecal metabolome at the last two time points, in addition to increasing short-chain fatty acids in serum and urine. Circulating CCL22 was lower and threonine, branched-chain amino acids, urea, and allantoin, as well as dimethylglycine in serum and urine, were increased in the group supplemented with B. lactis compared with the standard formula-fed group. These results support a role of probiotics as effectors of gut microbial activity regulating amino acid utilization and nitrogen cycling. Future risk-benefit analyses are still needed to consolidate the existing knowledge on the long-term consequences of probiotic administration during infancy. IMPORTANCE Probiotics are becoming increasingly popular due to their perceived effects on health, despite a lack of mechanistic information on how they impart these benefits. Infant formula and complementary foods are common targets for supplementation with probiotics. However, different probiotic strains have different properties, and there is a lack of data on long-term health effects on the consumer. Given the increasing interest in supplementation with probiotics and the fact that the gastrointestinal tracts of infants are still immature, we sought to determine whether consumption of infant formula containing the probiotic Bifidobacterium animalis subsp. lactis HN019 for 3 months starting at birth would impact gut microbial colonization, as well as infant immunity and metabolism, when compared with consumption of formula alone.

Impact of Probiotics for Reducing Infections in Veterans (IMPROVE): Study protocol for a double-blind, randomized controlled trial to reduce carriage of Staphylococcus aureus

BACKGROUND

Staphylococcus aureus (S. aureus) is an organism of great public health importance, causing 20,000 deaths annually. Decolonization of patients with S. aureus may prevent infections, yet current options are limited to antimicrobials that promote antibiotic resistance and can cause adverse side effects. Probiotics have potential to reduce colonization of pathogenic bacteria, representing a promising alternative for S. aureus decolonization, but thus far lack rigorous evaluation.

METHODS

Potential subjects were recruited from inpatient and outpatient settings within a VA medical center and screened for S. aureus gastrointestinal (GI) or extra-GI colonization using swabs at multiple body sites. Positive, eligible, consenting participants were stratified by colonization site and randomized in a 1:1 ratio to 4-weeks of daily placebo or Lactobacillus rhamnosus (L. rhamnosus) HN001 probiotic treatment. Blood and stool samples, and treatment adherence reports were collected from each subject throughout the study, along with a final set of swabs at study completion to detect S. aureus carriage. The outcomes of this study are GI or extra-GI carriage by S. aureus at the end of 4weeks of therapy, change in phagocytic activity of polymorphonuclear cells from pre-intervention to post-intervention, and symptomatic S. aureus infection at any site during the study period.

CONCLUSION

114 participants have been recruited for this study. Analysis of outcomes is underway. This is the first clinical trial to examine the efficacy of L. rhamnosus HN001 for decolonization of S. aureus, and investigates the mechanism by which L. rhamnosus HN001 mediates its effect on S. aureus colonization. ClinicalTrials.govIdentifier NCT01321606.

Acute and Subacute Oral Toxicity Evaluation of Crude Antifungal Compounds Produced by Lactobacillus plantarum HD1 in Rats

The aim of this study was to investigate the acute and subacute oral toxicity of crude antifungal compounds produced by Lactobacillus plantarum HD1 in Sprague-Dawley rats. In the acute toxicity study, the crude antifungal compounds (0.625, 1.25, 2.5, and 5.0 g/kg) did not produce mortality, significant changes in general behavior, or changes in the gross appearance of the organs. In the subacute toxicity study, the crude antifungal compounds were administered orally to rats at doses of 0, 0.5, 1.0, and 2.0 g/kg daily for 28 days. There were no test article-related deaths, abnormal clinical signs, or body weight changes. The study also showed no significant differences between the control and treated groups in hematological and serum biochemical parameters, histopathological examination, or any other findings. These results suggest that acute or subacute oral administration of crude antifungal compounds from L. plantarum HD1 is not toxic in rats.

High resolution melting analysis (HRM) as a new tool for the identification of species belonging to the Lactobacillus casei group and comparison with species-specific PCRs and multiplex PCR

The correct identification and characterisation of bacteria is essential for several reasons: the classification of lactic acid bacteria (LAB) has changed significantly over the years, and it is important to distinguish and define them correctly, according to the current nomenclature, avoiding problems in the interpretation of literature, as well as mislabelling when probiotic are used in food products. In this study, species-specific PCR and HRM (high-resolution melting) analysis were developed to identify strains belonging to the Lactobacillus casei group and to classify them into L. casei, Lactobacillus paracasei and Lactobacillus rhamnosus. HRM analysis confirmed to be a potent, simple, fast and economic tool for microbial identification. In particular, 201 strains, collected from International collections and attributed to the L. casei group, were examined using these techniques and the results were compared with consolidated molecular methods, already published. Seven of the tested strains don't belong to the L. casei group. Among the remaining 194 strains, 6 showed inconsistent results, leaving identification undetermined. All the applied techniques were congruent for the identification of the vast majority of the tested strains (188). Notably, for 46 of the strains, the identification differed from the previous attribution.

Lactobacillus gasseri K7 modulates the blood cell transcriptome of conventional mice infected with Escherichia coli O157:H7

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.

Lactobacillus reuteri CRL 1098 and Lactobacillus acidophilus CRL 1014 differently reduce in vitro immunotoxic effect induced by Ochratoxin A

Ochratoxin A (OTA) is a widespread mycotoxin contaminating several food products which causes detrimental health effects. The ability of Lactobacillus reuteri CRL 1098 and Lactobacillus acidophilus CRL 1014 to prevent OTA effects on TNF-α and IL-10 production and apoptosis induction in human peripheral blood mononuclear cells (PBMC) was investigated. Membrane rafts participation in these responses was also evaluated. L. reuteri reduced by 29% the OTA inhibition of TNF-α production whereas L. acidophilus increased 8 times the TNF-α production by OTA treated-PBMC. Also, both bacteria reversed apoptosis induced by OTA by 32%. However, neither of the bacteria reversed the OTA inhibition on IL-10 production. On the other hand, the lactobacilli were less effective to reverse OTA effects on disrupted-rafts PBMC. This study shows that two lactobacilli strains can reduce some negative OTA effects, being membrane rafts integrity necessary to obtain better results. Also, the results highlight the potential capacity of some lactobacilli strains usually included in natural dietary components in milk-derived products and cereals feed, to reduce OTA toxicity once ingested by humans or animals.

Probiotics and immunosenescence: cheese as a carrier

Oral intake of specific probiotics has been reported to enhance the immunity of the elderly. Earlier studies have used milk or yoghurt as a probiotic carrier. We chose a commercial probiotic cheese to evaluate its potential as a probiotic food. Thirty-one healthy elderly volunteers (21 female, 10 male) aged from 72 to 103 (median 86) consumed a commercial probiotic cheese containing approximately 10(9) CFU day(-1) of Lactobacillus rhamnosus HN001 and Lactobacillus acidophilus NCFM. The 4-week probiotic intervention was preceded by a 2-week consumption of probiotic-free cheese (run-in) and followed by a 4-week wash-out period with the same control cheese. The cytotoxicity of peripheral blood mononuclear cells (PBMCs), the relative numbers of natural killer (NK) and NKT cells in the total PBMCs, and phagocytic activity were assessed. Consumption of the probiotic cheese significantly increased the cytotoxicity of NK cells. A significant increase in phagocytosis was observed for both the control and the probiotic cheese. Cheese was found to be an effective carrier for the study of probiotics, and daily consumption of the probiotic enhanced parameters of innate immunity in elderly volunteers. It remains to be determined whether this enhancement correlates with a beneficial effect on the health of the elderly population.

In vitro and in vivo safety evaluation of the bacteriocin producer Streptococcus macedonicus ACA-DC 198

Streptococcus macedonicus ACA-DC 198, a bacteriocin producer isolated from Greek Kasseri cheese, was used in a series of in vitro and in vivo experiments in order to evaluate its pathogenic potential. The strain was examined in vitro for haemolytic activity, antibiotic resistance and presence of pathogenicity genes encountered in Streptococcus pyogenes. Subsequently, the strain was orally administered to mice (8.9 log cfu daily), continuously over a period of 12 weeks, in order to ascertain the effects of its long term consumption on animal health and gastric inflammation. S. macedonicus ACA-DC 198 was found to be non-haemolytic and sensitive to ampicillin, chloramphenicol, ciprofloxacin, erythromycin, streptomycin, tetracycline, and vancomycin, with the only resistance observed against kanamycin. PCR amplification and DNA-DNA hybridization did not reveal the presence of any of the S.pyogenes pathogenicity genes examined, namely emm, scpA, hasA, speB, smez2, speJ, sagAB, hylA, ska, speF, speG, slo, hylP2 and mga. In the mouse study, no detrimental effects were observed in the behaviour, general well being, weight gain and water consumption of the animals receiving S. macedonicus ACA-DC 198. Histologic analysis showed no evidence of inflammation in the stomach of the animals receiving S. macedonicus ACA-DC 198, while faecal microbiological analysis revealed that the strain retained its viability passing through the mouse gastrointestinal tract. Finally, no evidence of translocation to the liver, spleen and mesenteric lymph nodes was observed. In conclusion, none of the examined virulence determinants were detected in S. macedonicus ACA-DC 198 and its long term, high dosage oral administration did not appear to induce any pathogenic effect in mice.

Safety of probiotics: translocation and infection

The long history of safety has contributed to the acceptance of probiotics as a safe food adjunct. Consequently, many probiotic products and their applications have been granted GRAS (generally regarded as safe) status. However, this classification has been frequently generalized for all probiotic strains regardless of their application. Cases of probiotics from the genera Lactobacillus, Leuconostoc, Pediococcus, Enterococcus, and Bifidobacterium have been isolated from infection sites, leading to the postulation that these probiotics can translocate. Probiotic translocation is difficult to induce in healthy humans, and even if it does occur, detrimental effects are rare. Despite this, various reports have documented health-damaging effects of probiotic translocation in immunocompromised patients. Due to probiotics' high degree of safety and their morphological confusion with other pathogenic bacteria, they are often overlooked as contaminants and are least suspected as pathogens. However, the antibiotic resistance of some strains has increased the complexity of their eradication. Probiotic translocation and infection deserve further investigation and should become a facet of safety assessment so the negative effects of probiotics do not outweigh the benefits.

Safety evaluation of Bifidobacterium pseudocatenulatum G4 as assessed in BALB/c mice

AIMS

To assess the safety of Bifidobacterium pseudocatenulatum G4 in BALB/c mice that involves examination of bacterial translocation, changes in the internal organs and histology of the intestinal lining.

METHODS AND RESULTS

Forty male BALB/c mice were randomly assigned into five groups (n = 8). Three groups were orally fed with 50 microl of three different concentrations of B. pseudocatenulatum G4 (2 x 10(4), 1 x 10(8) and 1 x 10(11) CFU day(-1)) for 4 weeks. One group was orally administered with 50 microl of 1 x 10(8) CFU B. longum BB536 per day for 4 weeks and last group was used as a nonbifidobacterial treatment control, which received 50 microl of skim milk. The administered strains did not affect the general health of mice and incapable of carrying out translocation to blood or liver. There were no significant differences in the internal organ (liver, heart, kidney and spleen) indices, serum enzymes of liver (aspartate aminotransferase, alkaline phosphate, alanine aminotransferase) and kidney (urea and creatinine) and histology (villi height, crypts height, mucosa thickness and epithelial cell height) of caecum, ileum and colon.

CONCLUSION

Administration of high dose of up to 1 x 10(11) CFU B. pseudocatenulatum G4 per day to mice did not show any health threatening symptoms.

SIGNIFICANCE AND IMPACT OF THE STUDY

Bifidobacterium pseudocatenulatum G4 is none pathogenic to BALB/c mice and could be safe probiotic for human consumption.

Summary of probiotic activities of Bifidobacterium lactis HN019

The bacterium, Bifidobacterium lactis HN019, has been studied for a variety of traits important to its ability to function as a probiotic. Publications documenting identity, safety, antipathogenic effects, immune enhancement, and intestinal colonization are reviewed. Most studies documenting immune effects are short term in duration (< or =6 wk feeding periods), so longer term trials would be useful to determine to what extent effects are sustained. One year-long trial feeding both galacto-oligosaccharides and HN019 in children 1 to 3 years of age provided evidence for improved growth and reduction in infection incidence. HN019 is a well-characterized probiotic strain with documented probiotic effects of meaningful magnitude especially in the area of immune system modulation.

Improvement of the human intestinal flora by ingestion of the probiotic strain Lactobacillus johnsonii La1

To exert beneficial effects for the host, for example, improving the intestinal microflora, a probiotic must reach the intestine as a viable strain. These properties must be demonstrated by in vitro as well as in vivo methods. However, only a few well-designed human clinical studies have shown these properties. Lactobacillus johnsonii La1 has been shown to give many beneficial effects for the host, but it is unclear whether a viable strain of L. johnsonii La1 has the effect of improving host intestinal microflora. In the present study, a randomised double-blind placebo-controlled cross-over trial was conducted to elucidate the effect of L. johnsonii La1 on human intestinal microflora. Twenty-two young healthy Japanese women were randomly divided into two groups, and either received fermented milk with L. johnsonii La1 or a fermented milk without L. johnsonii La1 (placebo) daily for 21 d. Consumption of the fermented milk: (a) increased total Bifidobacterium and Lactobacillus, and decreased lecithinase-positive Clostridium in the faeces; (b) increased the faecal lactic acid concentrations; (c) decreased the faecal pH; (d) increased the defecation frequency. These changes were stronger than those observed with the placebo. L. johnsonii La1 was identified in all subjects only after the consumption of the fermented milk. These results suggest that L. johnsonii La1 can contribute to improve intestinal microflora with probiotic properties.

Phosphatidylinositol-specific phospholipase C activity in Lactobacillus rhamnosus with capacity to translocate

Phosphatidylinositol-specific phospholipase C (PI-PLC) activity was investigated in 25 different lactic acid bacteria (LAB) strains belonging to the genera Lactobacillus, Weisella, and Enterococcus. PI-PLC activity was detected in 44% of the strains studied in culture medium without carbon source. From the PI-PLC positive strains, Lactobacillus rhamnosus ATCC 7469 was selected for translocation studies. Healthy mice were orally administered with a daily dose of 2.0 x 10(9) of viable L. rhamnosus suspension. Viable bacteria were detected in liver and spleen of mice fed with LAB for 7 days. Bacterial colonies isolated from liver were biochemically characterized, and further subjected to randomly amplified polymorphic DNA. Amplification patterns of five strains displayed identical profiles to L. rhamnosus. PI-PLC activity was determined in the strains recovered from liver.