Probiotics: potential pharmaceutical applications

It Is All about Probiotics to Control Cervical Cancer

Cervical cancer (CC) is the fourth most common malignancy in female patients. "Human papillomavirus" (HPV) contamination is a leading cause of all forms of cervical cancer, accounting for an expected 570,000 reported incidents in 2018. Two HPV strains (16 and 18) are responsible for 70% of CC and pre-cancerous cervical abnormalities. CC is one of the foremost reasons for the malignancy death rate in India among women ranging from 30 to 69 years of age in India, responsible for 17% of all cancer deaths. Currently approved cervical cancer treatments are associated with adverse reactions that might harm the lives of women affected by this disease. Consequently, probiotics can play a vital role in the treatment of CC. It is reflected from various studies regarding the role of probiotics in the diagnosis, prevention or treatment of cancer. In this review article, we have discussed the rationale of probiotics for treatment of CC, the role of probiotics as effective adjuvants in anti-cancer therapy and the combined effect of the anti-cancer drug along with probiotics to minimize the side effects due to chemotherapy.

Probiotics Influence Gut Microbiota and Tumor Immune Microenvironment to Enhance Anti-Tumor Efficacy of Doxorubicin

Probiotics have been reported to influence the gut microbiota and immune system in various diseases. Now, the potential impacts of probiotics on tumor treatment still need to be investigated. In this study, three strains of probiotics, Bifidobacterium breve BBr60 (BBr60), Pediococcus pentosaceus PP06 (PP06), and Bifidobacterium longum subsp. longum BL21 (BL21) were investigated for their combination with chemotherapeutic drugs doxorubicin (DOX). Our study showed that PP06 and BL21 have good performance in gastric acid, bile salt, and intestinal fluid tolerance, antimicrobial activity to pathogenic Staphylococcus aureus, and adhesion to Caco-2 cells. Besides, the probiotics all exhibited antioxidant effect, especially BL21. In vitro cytotoxicity and in vivo animal studies revealed that probiotics used alone could not directly induce anti-tumor effects, but the combination of PP06/BL21 and DOX exhibits a higher inhibition rate than DOX alone, via recruitment and infiltration of immune cells in the tumor region. After 16S rRNA analysis of fecal samples from animal models, it was found that BL21 could increase the abundance of Akkermansia, which may also play a role in regulating the tumor microenvironment to improve immune response. In conclusion, BL21 and PP06 in this study could enhance the anti-tumor efficacy by influencing the gut microbiota and tumor immune microenvironment.

Tuning Expectations to Reality: Don't Expect Increased Gut Microbiota Diversity with Dietary Fiber

Dietary approaches, particularly those including fiber supplementation, can be used to promote health benefits by shaping gut microbial communities. Whereas community diversity measures, such as richness and evenness, are often used in microbial ecology to make sense of these complex and vast microbial ecosystems, it is less clear how these concepts apply when dietary fiber supplementation is given. In this perspective, we summarize and demonstrate how factors including experimental approach, number of bacteria sharing a dietary fiber, and initial relative abundances of bacteria that use a fiber can significantly affect diversity outcomes in fiber fermentation studies. We also show that a reduction in alpha diversity is possible, and perhaps expected, for most approaches that use fermentable fibers to beneficially shape the gut microbial community while still achieving health-related improvements.

Neuroprotective Effects of Probiotic Lactobacillus reuteri GMNL-263 in the Hippocampus of Streptozotocin-Induced Diabetic Rats

Diabetes-related brain complications have been reported in clinical patients and experimental models. The objective of the present study was to investigate the neuroprotective mechanisms of Lactobacillus reuteri GMNL-263 in streptozotocin (STZ)-induced diabetic rats. In this study, three different groups, namely control group, STZ-induced (55 mg/kg streptozotocin intraperitoneally) diabetic rats (DM), and DM rats treated with Lactobacillus reuteri GMNL-263 (1 × 109 CFU/rat/day), were utilized to study the protective effect of GMNL-263 in the hippocampus of STZ-induced diabetic rats. The results demonstrated that GMNL-263 attenuated diabetes-induced hippocampal damage by enhancing the cell survival pathways and repressing both inflammatory and apoptotic pathways. Histopathological analysis revealed that GMNL-263 prevented structural changes in the hippocampus in the DM group and decreased the level of inflammation and apoptosis in the hippocampus of DM rats. The IGF1R cell survival signaling pathway also improved after GMNL-263 treatment. These results indicate that probiotic GMNL-263 exerts beneficial effects in the brain of diabetic rats and has potential ability for clinical application.

Chronic kidney disease and gut microbiota

Chronic kidney disease (CKD) refers to a range of various pathophysiological processes correlated with abnormal renal function and a progressive loss in GFR. Just as dysbiosis and altered pathology of the gut are accompanied with hypertension, which is a significant CKD risk factor. Gut dysbiosis in CKD patients is associated with an elevated levels of uremic toxins, which in turn increases the CKD progression. According to research results, the gut-kidney axis has a role in the formation of kidney stones, also in IgAN. A number of researchers have categorized the gut microbiota as enterotypes, and others, skeptical of theory of enterotypes, have suggested biomarkers to describe taxa that related to lifestyle, nutrition, and disease status. Metabolome-microbiome studies have been used to investigate the interactions of host-gut microbiota in terms of the involvement of metabolites in these interactions and are yielded promising results. The correlation between gut microbiota and CKD requires further multi-omic researches. Also, with regard to systems biology, studies on the communication network of proteins and transporters such as SLC and ABC, can help us achieve a deeper understanding of the gut-liver-kidney axis communication and can thus provide promising new horizons in the treatment of CKD patients. Probiotic-based treatment is an approach to reduce uremic poisoning, which is accomplished by swallowing microbes those can catalyze URS in the gut. If further comprehensive studies are carried out, we will know about the probiotics impact in slowing the renal failure progression and reducing inflammatory markers.

Potential of jackfruit inner skin fibre for encapsulation of probiotics on their stability against adverse conditions

The aim of this study was to investigate the impact of jackfruit inner skin fibre (JS) incorporated with whey protein isolate (WPI) and soybean oil (SO) as a wall material for probiotic encapsulation to improve probiotic stability against freeze-drying and gastrointestinal (GI) tract conditions. Bifidobacterium bifidum TISTR2129, Bifidobacterium breve TISTR2130, and Lactobacillus acidophilus TISTR1338 were studied in terms of SCFA production and the antibiotic-resistant profile and in an antagonistic assay to select suitable strains for preparing a probiotic cocktail, which was then encapsulated. The results revealed that B. breve and L. acidophilus can be used effectively as core materials. JS showed the most influential effect on protecting probiotics from freeze-drying. WPI:SO:JS at a ratio of 3.9:2.4:3.7 was the optimized wall material, which provided an ideal formulation with 83.1 ± 6.1% encapsulation efficiency. This formulation presented > 50% probiotic survival after exposure to gastro-intestinal tract conditions. Up to 77.8 ± 0.1% of the encapsulated probiotics survived after 8 weeks of storage at refrigeration temperature. This study highlights a process and formulation to encapsulate probiotics for use as food supplements that could provide benefits to human health as well as an alternative approach to reduce agricultural waste by increasing the value of jackfruit inner skin.

Comprehensive Analysis of the Physiological Characterization of Escherichia coli Nissle 1917

Escherichia coli Nissle 1917 (EcN) is one of the probiotics that has drawn more attention from researchers in recent days as it extends many host beneficial effects. EcN is being used as a treatment regimen especially for gastrointestinal disorders for more than 100 years. Apart from its clinical applications in its original form, EcN is being genetically engineered to meet the therapeutic requirements which ultimately led to the gradual transformation of EcN from being a mere food supplement to a complex therapeutic agent. However, comprehensive analysis of physiological characterization of EcN is inadequate. In this study, we have systematically studied various physiological parameters and found that EcN grows very well at the normal as well as at stressful conditions such as temperature (30, 37 and 42 °C), nutritional (minimal and LB), pH (ranging from 3 to 7) and osmotic stress (0.4 M NaCl, 0.4 M KCl, 0.4 M Sucrose and salt conditions). However, EcN shows nearly onefold reduction in viability at extreme acidic conditions (pH 3 and 4). It produces biofilm and curlin very efficiently compared to the laboratory strain MG1655. Through genetic analysis we have also shown that EcN exhibits high level of transformation efficiency and greater ability to retain heterogenous plasmid. Very interestingly, we have found that EcN is highly resistant to P1 phage infection. Since, EcN is being exploited largely for its clinical and therapeutic applications, the results that we have reported here would add more value and further expand its scope in clinical and biotechnological research.

Anticancer properties of curcumin-treated Lactobacillus plantarum against the HT-29 colorectal adenocarcinoma cells

Probiotic bacteria with functions of importance to the health and well-being of the host exhibit various medicinal properties including anti-proliferative properties against cancer cells. There are observations demonstrating probiotic bacteria and their metabolomics can be different in various populations with different eating habits. Here, Lactobacillus plantarum was treated with curcumin (the major compound of turmeric), and its resistance to the curcumin was determined. After then the cell-free supernatants of untreated bacteria (CFS) and bacteria treated with curcumin (cur-CFS) were isolated and their anti-proliferative properties against HT-29 colon cancer cells were compared. The ability of L. plantarum treated with curcumin to combat a variety of pathogenic bacterial species and its ability to survive in acidic conditions were evidence that the probiotic properties of the bacterium were unaffected by the curcumin treatment. L. plantarum treated with curcumin and intact L. plantarum were both able to live in acidic conditions, according to the results of the resistance to low pH test. The MTT result showed that CFS and cur-CFS dose-dependently decreased the growth of HT29 cells with a half-maximal inhibitory concentration of 181.7 and 116.3 µL/mL at 48 h, respectively. Morphological alteration of DAPI-stained cells also exhibited significant fragmentation in the chromatin within the nucleus of cur-CFS-treated cells compared to CFS-treated HT29 cells. Moreover, flow cytometry analyses of apoptosis and cell cycle confirmed DAPI staining and MTT assay results and stipulated the increased occurrence of programmed cell death (apoptosis) in cur-CFS-treated cells (~ 57.65%) compared to CFS-treated cells (~ 47%). These results were more confirmed with qPCR and exhibited the upregulation of Caspase 9-3 and BAX genes, and downregulation of the BCL-2 gene in cur-CFS- and CFS-treated cells. In conclusion, turmeric spice and curcumin may affect the metabolomics of probiotics in intestinal flora which could subsequently influence their anticancer properties.

Effects of a high-prebiotic diet versus probiotic supplements versus synbiotics on adult mental health: The "Gut Feelings" randomised controlled trial

Background

Preliminary evidence supports the use of dietary interventions and gut microbiota-targeted interventions such as probiotic or prebiotic supplementation for improving mental health. We report on the first randomised controlled trial (RCT) to examine the effects of a high-prebiotic dietary intervention and probiotic supplements on mental health.

Methods

"Gut Feelings" was an 8-week, 2 × 2 factorial RCT of 119 adults with moderate psychological distress and low prebiotic food intake. Treatment arms: (1) probiotic supplement and diet-as-usual (probiotic group); (2) high-prebiotic diet and placebo supplement (prebiotic diet group); (3) probiotic supplement and high-prebiotic diet (synbiotic group); and (4) placebo supplement and diet-as-usual (placebo group). The primary outcome was assessment of total mood disturbance (TMD; Profile of Mood States Short Form) from baseline to 8 weeks. Secondary outcomes included anxiety, depression, stress, sleep, and wellbeing measures.

Results

A modified intention-to-treat analysis using linear mixed effects models revealed that the prebiotic diet reduced TMD relative to placebo at 8 weeks [Cohen's d = -0.60, 95% confidence interval (CI) = -1.18, -0.03; p = 0.039]. There was no evidence of symptom improvement from the probiotic (d = -0.19, 95% CI = -0.75, 0.38; p = 0.51) or synbiotic treatments (d = -0.03, 95% CI = -0.59, 0.53; p = 0.92). Improved anxiety, stress, and sleep were noted in response to the prebiotic diet while the probiotic tentatively improved wellbeing, relative to placebo. No benefit was found in response to the synbiotic intervention. All treatments were well tolerated with few adverse events.

Conclusion

A high-prebiotic dietary intervention may improve mood, anxiety, stress, and sleep in adults with moderate psychological distress and low prebiotic intake. A synbiotic combination of high-prebiotic diet and probiotic supplement does not appear to have a beneficial effect on mental health outcomes, though further evidence is required. Results are limited by the relatively small sample size.

Clinical trial registration

https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=372753, identifier ACTRN12617000795392.

Cholesterol-lowering effects and safety assessment of Lactobacillus spp. in vivo and in vitro testing for human use as probiotic from the dairy product in Egypt

BACKGROUND

The toxicity profile of lactobacilli may be strain dependent, so it should be considered for safe utilization of probiotics. Further, in vivo studies are necessary to evaluate their safety.

RESULT

The ability of various probiotic strains to hydrolyze bile salts has been confirmed without noticeable hemolytic activity. Results revealed the presence of α-glucosidase, β-glucosidase, α-galactosidase, and β-galactosidase activity in all investigated isolates, while none of the isolates produced the carcinogenic enzyme β-glucuronidase. The probiotic strains exhibited remarkable cholesterol-lowering impact. Also, we found no evidence of chronic toxicity under the experimental conditions based on gross pathological examination of the viscera and study of the spleen and liver weight ratios. These findings indicated that the investigated strains, either alone or combined with their metabolites, had no obvious adverse effect on the mice's general health status.

CONCLUSION

There is prove that the investigated probiotic strains are safe to be utilized for enhancing of the growth performance and are free of adverse side effects.

Influence of Probiotic Strains Bifidobacterium, Lactobacillus, and Enterococcus on the Health Status and Weight Gain of Calves, and the Utilization of Nitrogenous Compounds

The aim of this study was to monitor the effect of Bifidobacterium bifidum (BB) and the combination of Lactobacillus sporogenes, Enterococcus faecium, and Bifidobacterium bifidum (LEB) on the health status and weight gain of calves, and the utilisation of nitrogenous substances. The experiment was performed in the period from April 2020 to September 2020. A total of 90 Holstein heifers, which were one to 56 days old, were used as experimental animals. Differences in live weight gain were significant if we compared the LEB vs. BB group and the LEB vs. C, the control group (86.23 ± 5.49 kg vs. 84.72 ± 6.22 kg, p < 0.05; 86.23 ± 5.49 kg vs. 82.86 ± 5.35 kg, p < 0.01). Considering the live weight gain, group BB was heavier than group C only (84.72 ± 6.22 kg vs. 82.86 ± 5.35 kg, p < 0.05). An effect on reducing the incidence and duration of diarrheal diseases was not demonstrated in this study (p = 0.1957). The administration of feed additives had no statistically significant effect on the amount of N excreted in the feces. The values of hematological and biochemical parameters were unaffected except for the first sampling of urea. Other blood parameters were not affected by the addition of probiotic feed additives. The bacterial populations in the feces 5 days and 56 days after birth were not affected by the inclusion of feed additives.

Amino Acid-Derived Quorum Sensing Molecule Alanine on the Gastrointestinal Tract Tolerance of the Lactobacillus Strains in the Cocultured Fermentation Model

More and more people are aware of the importance of intestinal flora to human health, and people are interested in the regulation of intestinal flora and its interaction with the host. The survival status of the probiotics in the gastrointestinal environment and the microbial interactions between the lactic acid bacteria have also received considerable attention. In this study, the gastrointestinal environment tolerance, adhesion ability, and biofilm formation of the Lactobacillus strain in the coculture system were explored through the real-time fluorescence-based quantitative PCR, UPLC-MS/MS metabolic profiling analysis, and Live/Dead BacLight cell staining methods. The results showed that the coculture system could promote the release of signal molecules autoinducer-2 and effectively protect the viability of the Lactobacillus acidophilus in the gastrointestinal environment. Meanwhile, amino acid-derived characteristic metabolite l-alanine (1%) could effectively enhance the communication of the cells in the complex fermentation model, which led to an increase in the tolerance ability of the L. acidophilus by 28% in the gastrointestinal-like environment.

IMPORTANCE It was deduced from the study that amino acid-derived metabolites play an important role in cell communication in the gastrointestinal tract (GIT) environment, thus enhancing the communication of Lactobacillus strains in the complex fermentation model. Meanwhile, the viability of Lactobacillus acidophilus can be increased in the coculture system during the gastrointestinal stress environment treated with the amino acid-derived quorum sensing (QS) molecule l-alanine. It will shed some light on the application of amino acid-derived QS molecules in the fermentation stater industry.

Assessing the drug resistance profiles of oral probiotic lozenges

Background

Probiotic lozenges have been developed to harvest the benefits of probiotics for oral health, but their long-term consumption may encourage the transfer of resistance genes from probiotics to commensals, and eventually to disease-causing bacteria.

Aim

To screen commercial probiotic lozenges for resistance to antibiotics, characterize the resistance determinants, and examine their transferability in vitro.

Results

Probiotics of all lozenges were resistant to glycopeptide, sulfonamide, and penicillin antibiotics, while some were resistant to aminoglycosides and cephalosporins. High minimum inhibitory concentrations (MICs) were detected for streptomycin (>128 µg/mL) and chloramphenicol (> 512 µg/mL) for all probiotics but only one was resistant to piperacillin (MIC = 32 µg/mL). PCR analysis detected erythromycin (erm(T), ermB or mefA) and fluoroquinolone (parC or gyr(A)) resistance genes in some lozenges although there were no resistant phenotypes. The dfrD, cat-TC, vatE, aadE, vanX, and aph(3")-III or ant(2")-I genes conferring resistance to trimethoprim, chloramphenicol, quinupristin/dalfopristin, vancomycin, and streptomycin, respectively, were detected in resistant probiotics. The rifampicin resistance gene rpoB was also present. We found no conjugal transfer of streptomycin resistance genes in our co-incubation experiments.

Conclusion

Our study represents the first antibiotic resistance profiling of probiotics from oral lozenges, thus highlighting the health risk especially in the prevailing threat of drug resistance globally.

A novel probiotic strain of Lactobacillus fermentum TIU19 isolated from Haria beer showing both in vitro antibacterial and antibiofilm properties upon two multi resistant uro-pathogen strains

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L. fermentum TIU19 was isolated from the ethnic traditional rice beverage, Haria.

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L. fermentum TIU19 showed antagonistic activity against uro-pathogens in both planktonic and biofilm conditions.

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L. fermentum TIU19 had potential probiotic traits.

Probiotics with antimicrobial activity are gaining interest as a topic in the research field. Urinary tract infections (UTIs), acquired in the hospital or the community, are among the most prevalent infections. The emergence of multidrug resistance (MDR) uro-pathogens has made the current situation more critical in terms of global public health. To face this situation, in this study, Lactobacillus fermentum TIU19 (L. fermentum TIU19) was isolated and characterized as a new probiotic strain of the rice-based fermented beverage Haria. Subsequently, we also investigated its application as a biological agent that inhibits the growth of multidrug-resistant uro-pathogens, Escherichia coli, and Enterococcus faecalis. The results showed that, the isolated strain L. fermentum TIU19 was sensitive to all antibiotics tested except vancomycin and was devoid of virulence factors, such as haemolytic and gelatinase activities. Therefore, it may be considered safe for public health. It has many probiotic properties, such as survival in simulated gastrointestinal fluid, antioxidant activity, β-galactosidase producing ability, high cell surface hydrophobicity, adhesion ability to epithelial cells, and strong biofilm producer. The growth inhibitory and antibiofilm activities were shown against two uro-pathogens. All these results suggest that L. fermentum TIU19 can be explored as a potential probiotic with antagonistic activity against MDR uro-pathogenic E. coli and E. faecalis.

Survivability of Collagen-Peptide Microencapsulated Lactic Acid Bacteria during Storage and Simulated Gastrointestinal Conditions

The intracellular homeostasis of lyophilized lactic acid bacteria (LAB) is destroyed by extreme cold stress, resulting in decreased stability. This study aimed to verify the validity of collagen as a potential protective agent for improving microbial stability deteriorated by freezing. The collagen types used in this study were low molecular weight collagen (LC) of less than 1000 Da and low molecular weight collagen-peptide (LCP) of less than 300 Da. By the accelerated stability test according to the addition of each collagen type, a 3% LCP displaying a protective effect on the viability of various LAB strains (Lactoplantibacillus plantarum MG989, Lactococcus lactis MG5125, Enterococcus faecium MG5232, Bifidobacterium animalis ssp. lactis MG741, and Streptococcus thermophilus MG5140) was finally selected. It was evaluated whether LCP enhances bacterial stability, survivability in the gastrointestinal (GI) tract, and heat resistance. LCP significantly improved the viability of all strains in the GI tract compared to sucrose and skim milk, which are conventional protective agents. Based on morphological observations, LCP was uniformly coated on the cell surface, resulting in protective effects against multiple external stress stimuli. Such findings indicate the applicability of LCP as an unprecedented protective agent, which can improve the stability of various probiotics with antifreeze effects.

Characterization of Latilactobacillus curvatus MS2 isolated from Korean traditional fermented seafood and cholesterol reduction effect as synbiotics with isomalto-oligosaccharide in BALB/c mice

This study investigated the properties of Latilactobacillus curvatus MS2 isolated from Korean traditional fermented seafood as probiotics and the effect of reducing cholesterol as a synbiotic with isomalto-oligosaccharide (IMO) in BALB/c mice. The isolated strain showed high resistance to acids and bile acids and exhibited a high DPPH scavenging capacity of 72.27 ± 0.38 %. In the intestinal adhesion test using HT-29 cells, the adhesion rate of MS2 was 17.10 ± 1.78 %, which was higher than the adhesion rate of the other investigated probiotics. MS2 showed good antimicrobial activity against food-borne pathogens, especially Staphylococcus aureus, S. epidermidis, Escherichia coli, and Vibrio vulnificus. This strain had high availability for IMO among the prebiotics of fructo-oligosaccharide, inulin and IMO. Oral administration of MS2 and IMO to BALB/c mice for 5 weeks resulted in a significant reduction in blood cholesterol levels by regulating liver lipid metabolism. These results suggest that the combination of MS2 and IMO has potential for application in functional foods.

Genomic and proteomic comparisons of bacteriocins in probiotic species Lactobacillus and Bifidobacterium and inhibitory ability of Escherichia coli MG 1655

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The genomes and proteomes of 12 Bifidobacterium and 46 Lactobacillus were reviewed and then compared for bacteriocin identification.

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NCBI-Genome, UniProt-Proteome, Bactibase, and BAGL4 databases, as well as BLASTP, and Clustal Omega can be used for bacteriocin mining.

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Lactobacillus species have more diversity and abundance of bacteriocin compared to Bifidobacterium species.

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Notably, L. sakei, L. plamtarum, L. reuteri, L. fermentum, and L. casei had the highest pathogen inhibition (E. coli MG 1655); respectively.

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A set of Lactobacillus bacteria including L. sakei, L. reuteri, L. fermentum, and L. casei can be proposed as a biosecure and safe solution to control gastrointestinal pathogens.

Bacteriocins are a large family of bacterial peptides or proteins, ribosomally synthesized with antimicrobial activity against other bacteria. We investigated and compared the genomes and proteomes of 12 Bifidobacterium and 46 Lactobacillus species for bacteriocins using NCBI-Genome, UniProt-Proteome, Bactibase, and BAGL4 databases. Selected Lactobacillus species were examined for bile salt resistance, acid and pH resistance, pepsin and trypsin enzyme resistance, and antibiotic resistance. Also, the antimicrobial activity of selected Lactobacillus species was evaluated against E. coli MG 1655. Results showed that Lactobacillus species have more diversity and abundance of bacteriocin compared to Bifidobacterium species. Notably, L. sakei, L. plamtarum, L. reuteri, L. fermentum, and L. casei had the highest pathogen inhibition; respectively. Therefore, a combination of these Lactobacillus species can be suggested as a biochemical and safe solution to control gastrointestinal pathogens and suitable alternatives to antibiotics and chemicals in food technology.

Comparative Evaluation of Antibacterial Activity of Probiotics SK12 and SM18: An In Vitro Study

Aim

To assess the antimicrobial activity of probiotics SK12 and SM18 on Streptococcus mutans and also to compare the antimicrobial activity of SK12 and SM18.

Materials and methods

Synthetic strains of Streptococcus mutans were used to study the antimicrobial activity of probiotics SK12 and SM18 using various tests such as disk diffusion, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC). In disk diffusion, the zone of inhibition was measured to assess the antimicrobial activity. Chlorhexidine was used as a control for this test. The MIC and MBC were assessed at different dilutions of the probiotic sample (100 mg/mL, 50 mg/mL, 25 mg/mL, 12.5 mg/mL, 6.25 mg/mL, 3.12 mg/mL, 1.6 mg/mL, 0.8 mg/mL, 0.4 mg/mL, and 0.2 mg/mL).

Result

SM18 demonstrated 20 mm of zone of inhibition, whereas SK12 demonstrated 15 mm showing a less antibacterial activity in comparison to SM18. SM18 was found to be bactericidal and effective at a minimum concentration of 0.8 mg/mL, whereas SK12 was bactericidal and effective at a minimum concentration of 1.6 mg/mL.

Conclusion

Probiotics demonstrate antibacterial activity against cariogenic microflora. SM is 18 having a better antibacterial activity at lower concentrations than SK12 in reducing cariogenic microorganisms. Clinical significance: BLIS K12 and M18 both demonstrated an antibacterial effect on Streptococcus mutans, wherein the use of probiotic in caries prevention is found to be limited. Hence, it is suggestive to reap the bacterial effects of BLIS K12 and M18 in caries prevention.

How to cite this article

Chandrasekhar SN, Mallikarjun SB, Salim HP. Comparative Evaluation of Antibacterial Activity of Probiotics SK12 and SM18: An In Vitro Study. Int J Clin Pediatr Dent 2020;13(6):611–616.

Biological Insights of Fluoroaryl-2,2'-Bichalcophene Compounds on Multi-Drug Resistant Staphylococcus aureus

Resistance of bacteria to multiple antibiotics is a significant health problem; hence, to continually respond to this challenge, different antibacterial agents must be constantly discovered. In this work, fluoroaryl-2,2'-bichalcophene derivatives were chemically synthesized and their biological activities were evaluated against Staphylococcus aureus (S. aureus). The impact of the investigated bichalcophene derivatives was studied on the ultrastructural level via scanning electron microscopy (SEM), molecular level via sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) method and on the biofilm inhibition via the electrochemical biosensors. Arylbichalcophenes' antibacterial activity against S. aureus was affected by the presence and location of fluorine atoms. The fluorobithiophene derivative MA-1156 displayed the best minimum inhibitory concentration (MIC) value of 16 µM among the tested fluoroarylbichalcophenes. Over a period of seven days, S. aureus did not develop any resistance against the tested fluoroarylbichalcophenes at higher concentrations. The impact of fluoroarylbichalcophenes was strong on S. aureus protein pattern showing high degrees of polymorphism. SEM micrographs of S. aureus cells treated with fluoroarylbichalcophenes displayed smaller cell-sizes, fewer numbers, arranged in a linear form and some of them were damaged when compared to the untreated cells. The bioelectrochemical measurements demonstrated the strong sensitivity of S. aureus cells to the tested fluoroarylbichalcophenes and an antibiofilm agent. Eventually, these fluoroarylbichalcophene compounds especially the MA-1156 could be recommended as effective antibacterial agents.

Management and Prevention Strategies for Non-communicable Diseases (NCDs) and Their Risk Factors

Non-communicable diseases (NCDs) are of increasing concern for society and national governments, as well as globally due to their high mortality rate. The main risk factors of NCDs can be classified into the categories of self-management, genetic factors, environmental factors, factors of medical conditions, and socio-demographic factors. The main focus is on the elements of self-management and to reach a consensus about the influence of food on risk management and actions toward the prevention of NCDs at all stages of life. Nutrition interventions are essential in managing the risk of NCDs. As they are of the utmost importance, this review highlights NCDs and their risk factors and outlines several common prevention strategies. We foresee that the best prevention management strategy will include individual (lifestyle management), societal (awareness management), national (health policy decisions), and global (health strategy) elements, with target actions, such as multi-sectoral partnership, knowledge and information management, and innovations. The most effective preventative strategy is the one that leads to changes in lifestyle with respect to diet, physical activities, cessation of smoking, and the control of metabolic disorders.

Molecular insights into probiotic mechanisms of action employed against intestinal pathogenic bacteria

Gastrointestinal (GI) diseases, and in particular those caused by bacterial infections, are a major cause of morbidity and mortality worldwide. Treatment is becoming increasingly difficult due to the increase in number of species that have developed resistance to antibiotics. Probiotic lactic acid bacteria (LAB) have considerable potential as alternatives to antibiotics, both in prophylactic and therapeutic applications. Several studies have documented a reduction, or prevention, of GI diseases by probiotic bacteria. Since the activities of probiotic bacteria are closely linked with conditions in the host's GI-tract (GIT) and changes in the population of enteric microorganisms, a deeper understanding of gut-microbial interactions is required in the selection of the most suitable probiotic. This necessitates a deeper understanding of the molecular capabilities of probiotic bacteria. In this review, we explore how probiotic microorganisms interact with enteric pathogens in the GIT. The significance of probiotic colonization and persistence in the GIT is also addressed.

Probiotics at War Against Viruses: What Is Missing From the Picture?

Our world is now facing a multitude of novel infectious diseases. Bacterial infections are treated with antibiotics, albeit with increasing difficulty as many of the more common causes of infection have now developed broad spectrum antimicrobial resistance. However, there is now an even greater challenge from both old and new viruses capable of causing respiratory, enteric, and urogenital infections. Reports of viruses resistant to frontline therapeutic drugs are steadily increasing and there is an urgent need to develop novel antiviral agents. Although this all makes sense, it seems rather strange that relatively little attention has been given to the antiviral capabilities of probiotics. Over the years, beneficial strains of lactic acid bacteria (LAB) have been successfully used to treat gastrointestinal, oral, and vaginal infections, and some can also effect a reduction in serum cholesterol levels. Some probiotics prevent gastrointestinal dysbiosis and, by doing so, reduce the risk of developing secondary infections. Other probiotics exhibit anti-tumor and immunomodulating properties, and in some studies, antiviral activities have been reported for probiotic bacteria and/or their metabolites. Unfortunately, the mechanistic basis of the observed beneficial effects of probiotics in countering viral infections is sometimes unclear. Interestingly, in COVID-19 patients, a clear decrease has been observed in cell numbers of Lactobacillus and Bifidobacterium spp., both of which are common sources of intestinal probiotics. The present review, specifically motivated by the need to implement effective new counters to SARS-CoV-2, focusses attention on viruses capable of co-infecting humans and other animals and specifically explores the potential of probiotic bacteria and their metabolites to intervene with the process of virus infection. The goal is to help to provide a more informed background for the planning of future probiotic-based antiviral research.

Anti-tumor activities of probiotics in cervical cancer

Cervical cancer is considered as an important malignancy among women worldwide. Currently-used treatments of cervical cancer are reported to be cytotoxic for patients. Moreover, these therapies have shown some side effects which can negatively affect the lives of women suffering from this cancer. Therefore, there is need for anti-tumor agents that are less toxic than common therapeutic drugs. Besides, applying agents for preventing or reducing the side effects of cervical cancer therapies can be effective in improving the life quality of cervical cancer patients. Studies have shown that probiotics have several effects on biological processes. One of the most prominent aspects in which probiotics play a role is in the field of cancer. There are multiple studies which have focused on the functions of probiotics in diagnosis, prevention, or treatment of cancer. Besides their direct anti-tumor activities, probiotics can be used as an additional agent for enhancing or modulating other diagnostic and therapeutic methods. Herein, the effects of probiotics on cervical cancer cells are discussed, which may be useful in the prevention and treatment of this cancer. We review the studies concerned with the roles of probiotics in modulating and reducing the gastrointestinal adverse effects caused by cervical cancer therapies. Furthermore, we cover the investigations focusing on the combination of probiotics with other drugs for diagnosis or treatment of cervical cancer.

Potential Probiotic Yeasts Sourced from Natural Environmental and Spontaneous Processed Foods

In the last decades, there has been a growing interest from consumers in their food choices. Organic, natural, less processed, functional, and pre-probiotic products were preferred. Although, Saccharomyces cerevisiae var. boulardii is the most well-characterized probiotic yeast available on the market, improvement in probiotic function using other yeast species is an attractive future direction. In the present study, un-anthropized natural environments and spontaneous processed foods were exploited for wild yeast isolation with the goal of amplifying the knowledge of probiotic aptitudes of different yeast species. For this purpose, 179 yeast species were isolated, identified as belonging to twelve different genera, and characterized for the most important probiotic features. Findings showed interesting probiotic characteristics for some yeast strains belonging to Lachancea thermotolerans, Metschnikowia ziziphicola, Saccharomyces cerevisiae, and Torulaspora delbrueckii species, although these probiotic aptitudes were strictly strain-dependent. These yeast strains could be proposed for different probiotic applications, such as a valid alternative to, or in combination with, the probiotic yeast S. cerevisiae var. boulardii.

Probiotic Supplements: Hope or Hype?

Probiotic bacteria have been associated with various health benefits and included in overwhelming number of foods. Today, probiotic supplements are consumed with increasing regularity and record a rapidly growing economic value. With billions of heterogeneous populations of probiotics per serving, probiotic supplements contain the largest quantity of probiotics across all functional foods. They often carry antibiotic-resistant determinants that can be transferred to and accumulate in resident bacteria of the gastrointestinal tract and risk their acquisitions by opportunistic pathogens. While the health benefits of probiotics have been widely publicized, this health risk, however, is underrepresented in both scientific studies and public awareness. On the other hand, the human gut presents conditions that are unfavorable for bacteria, including probiotics. It remains uncertain if probiotics from supplements can tolerate acids and bile salts that may undermine their effectiveness in conferring health benefits. Here, we put into perspective the perceived health benefits and the long-term safety of consuming probiotic supplements, specifically bringing intolerance to acids and bile salts, and the long-standing issue of antibiotic-resistant gene transfer into sharp focus. We report that probiotics from supplements examined in this study have poor tolerance to acids and bile salts while also displaying resistance to multiple antibiotics. They could also adapt and gain resistance to streptomycin in vitro. In an environment where consuming supplements is considered a norm, our results and that of others will put in perspective the persisting concerns surrounding probiotic supplements so that the current hype does not overpower the hope.

Revealing antibiotic resistance in therapeutic and dietary probiotic supplements

OBJECTIVES

The aim of this study was to evaluate antibiotic susceptibility patterns in commercially available dietary and probiotic supplements.

METHODS

Probiotic strains were isolated from the dietary supplements (designated as sample B, D and V), and multidrug resistance profiles were tested using the Kirby-Bauer test. Minimum inhibitory concentrations and double-disk synergy tests were performed to detect the mechanism of action of the resistance, and the presence of extended spectrum β-lactamase activity (ESBL) was confirmed.

RESULTS

The isolates Streptococcus faecalis and Bacillus mesentericus (both from sample B) were found to be resistant to penicillin G, Lactobacillus acidophilus (sample D) was resistant to ampicillin, and all the isolates from samples B, D and V were resistant to ceftazidime. The isolates Lactobacillus sporogenes, S. faecalis, B. mesentericus from sample B, Lactobacillus. rhamnosus, Saccharomyces boulardii from sample D, and L. sporogenes (sample V) were resistant to erythromycin.

CONCLUSIONS

The findings showed the presence of antibiotic resistance in probiotic bacteria isolated from commercially available dietary supplements. Because multidrug resistance is a serious emerging issue, and the risk of drug-resistant gene transfer to commensals or pathogens of the gut is inevitable, the safety of probiotics has become a major criterion of interest. The findings of this study would serve as a platform for further screening and characterization of the determinants of antibiotic resistance and the genetic mechanisms of resistance.

Stress and the gut microbiota-brain axis

Stress is a nonspecific response of the body to any demand imposed upon it, disrupting the body homoeostasis and manifested with symptoms such as anxiety, depression or even headache. These responses are quite frequent in the present competitive world. The aim of this review is to explore the effect of stress on gut microbiota. First, we summarize evidence of where the microbiota composition has changed as a response to a stressful situation, and thereby the effect of the stress response. Likewise, we review different interventions that can modulate microbiota and could modulate the stress according to the underlying mechanisms whereby the gut-brain axis influences stress. Finally, we review both preclinical and clinical studies that provide evidence of the effect of gut modulation on stress. In conclusion, the influence of stress on gut microbiota and gut microbiota on stress modulation is clear for different stressors, but although the preclinical evidence is so extensive, the clinical evidence is more limited. A better understanding of the mechanism underlying stress modulation through the microbiota may open new avenues for the design of therapeutics that could boost the pursued clinical benefits. These new designs should not only focus on stress but also on stress-related disorders such as anxiety and depression, in both healthy individuals and different populations.

Optimal Criteria for the Selection of Probiotics, Based on their Mode of Action

The objective of this review was to discuss some of the criteria which influence the selection of microorganisms with probiotic properties based on their mode of action. The most common bacteria that belong to the “group” probiotics are the Lactobacillus and Bifidobacterium species/strains. Probiotics have benefits and effects by their mechanism of action in different axial locations such as: producing substances, influencing immune function and response, modification as well as maintenance of a healthy population of microorganisms in the intestinal environment. Probiotics have demonstrated significant potential as therapeutic options for a variety of diseases Potential peripheral pathways that link probiotic ingestion in the brain function are focused on the role of the vagal afferent nerve signalling and changes in the cerebral levels of neuromodulators. The application of probiotic microorganisms represents a way to effectively influence the composition of the intestinal microbiome and the immune system of the host, as well as they can be considered as a suitable alternative to influence a healthy quality of life.

Probiotics in digestive, emotional, and pain-related disorders

In recent years, interest in the relationship between gut microbiota and disease states has grown considerably. Indeed, several strategies have been employed to modify the microbiome through the administration of different diets, by the administration of antibiotics or probiotics, or even by transplantation of feces. In the present manuscript, we focus specifically on the potential application of probiotics, which seem to be a safe strategy, in the management of digestive, pain, and emotional disorders. We present evidence from animal models and human studies, notwithstanding that translation to clinic still deserves further investigation. The microbiome influences gut functions as well as neurological activity by a variety of mechanisms, which are also discussed. The design and performance of larger trials is urgently needed to verify whether these new strategies might be useful not only for the treatment of disorders affecting the gastrointestinal tract but also in the management of emotional and pain disorders not directly related to the gut.

Synbiotic supplementation is not effective on breast milk selenium concentrations and growth of exclusively breast fed infants: a pilot study

In this randomized, double-blind, placebo-controlled trial, 57 lactating mothers were randomly allocated into two groups to receive a daily supplement of synbiotic (n = 30) which contained different probiotic strains (2.0 × 10⁸ CFU) and fructooligosaccharide (394 mg) or a placebo (n = 27) for 30 days. Dietary intake was collected from lactating women by 24-hour recall method. Breast milk selenium contents were determined by atomic absorption spectrometry with graphite furnace. Weight for age Z-score (WAZ) and Height for age Z-score (HAZ) were evaluated for infants. Data analyses were assessed using nutritionist IV, Epi Info and SPSS software and presented as mean ± sd or SEM. The total mean breast milk selenium levels were 50.1 ± 16.1 mcg L^-1. At the baseline, the mean breast milk selenium concentrations in the synbiotic and placebo groups were 51.7 ± 20.2 and 48.5 ± 12.1 mcg L^-1. The mean breast milk selenium levels increased and decreased in the symbiotic and placebo groups respectively, which were not significant (p > 0.05). Also, comparison of the changes in breast milk selenium concentration showed no significant difference between the two study groups after the intervention. At the baseline, the mean WAZ and HAZ of infants whose mothers' milk selenium was more than 60 mcg/l was significantly (P < 0.05) higher than for others. In this pilot study, no significant effect was observed by synbiotic supplementation, however, for concise conclusion, more human studies with higher doses of supplements and longer duration of supplementation are needed to determine the effects of synbiotic supplementation on breast milk selenium contents and infants' growth.

Probiotics: If It Does Not Help It Does Not Do Any Harm. Really?

Probiotics per definition should have beneficial effects on human health, and their consumption has tremendously increased in the last decades. In parallel, the amount of published material and claims for their beneficial efficacy soared continuously. Recently, multiple systemic reviews, meta-analyses, and expert opinions expressed criticism on their claimed effects and safety. The present review describes the dark side of the probiotics, in terms of problematic research design, incomplete reporting, lack of transparency, and under-reported safety. Highlighted are the potential virulent factors and the mode of action in the intestinal lumen, risking the physiological microbiome equilibrium. Finally, regulatory topics are discussed to lighten the heterogeneous guidelines applied worldwide. The shift in the scientific world towards a better understanding of the human microbiome, before consumption of the probiotic cargo, is highly endorsed. It is hoped that better knowledge will extend the probiotic repertoire, re-confirm efficacy or safety, establish their efficacy and substantiate their beneficial effects.

The immunomodulatory role of probiotics in allergy therapy

The increased incidence of allergic disorders may be the result of a relative fall in microbial induction in the intestinal immune system during infancy and early childhood. Probiotics have recently been proposed as viable microorganisms for the prevention and treatment of specific allergic diseases. Different mechanisms have been considered for this probiotic property, such as generation of cytokines from activated pro-T-helper type 1 after bacterial contact. However, the effects of its immunomodulatory potential require validation for clinical applications. This review will focus on the currently available data on the benefits of probiotics in allergy disease.

The role of probiotics in women with recurrent urinary tract infections

Urinary tract infections (UTIs) still represent a significant bother for women and result in high costs to the health system. Increasing antimicrobial resistance has stimulated interest in non-antibiotic prophylaxis of recurrent UTIs. Evidence shows that the microorganisms inhabit many sites of the body, including the urinary tract which has long been assumed to be sterile in healthy individuals, might have a role in maintaining urinary health. Studies of the urinary microbiota (UM) have identified remarkable differences between healthy populations and those with urologic diseases. The depletion of these organisms in women susceptible to UTIs raised the question of whether artificial supplementation of these microorganisms as probiotics could lower infection rates. In the literature, probiotic interventions were shown to have some efficacy in the treatment and prevention of urogenital infections. Despite previous controversy regarding the use of probiotics, as treatment for UTIs, there are increasing signs that it may be possible to use them as a first step in regulating the UM so as to reduce the risk of or as a treatment for certain urinary diseases. However, further future clinical trials, involving large numbers of patients, will be mandatory to achieve definite evidence of the preventive and curative role of probiotics in UTIs. Details about correct formulations in terms of amount of bacteria, viability and associated growth factors, will be required in order to standardize the administration schedule and achieve homogeneous and comparable results on selected patients.

Salmonella infection - prevention and treatment by antibiotics and probiotic yeasts: a review

Global Salmonella infection, especially in developing countries, is a health and economic burden. The use of antibiotic drugs in treating the infection is proving less effective due to the alarming rise of antibiotic-resistant strains of Salmonella, the effects of antibiotics on normal gut microflora and antibiotic-associated diarrhoea, all of which bring a growing need for alternative treatments, including the use of probiotic micro-organisms. However, there are issues with probiotics, including their potential to be opportunistic pathogens and antibiotic-resistant carriers, and their antibiotic susceptibility if used as complementary therapy. Clinical trials, animal trials and in vitro investigations into the prophylactic and therapeutic efficacies of probiotics have demonstrated antagonistic properties against Salmonella and other enteropathogenic bacteria. Nonetheless, there is a need for further studies into the potential mechanisms, efficacy and mode of delivery of yeast probiotics in Salmonella infections. This review discusses Salmonella infections and treatment using antibiotics and probiotics.

The food safety of DP-356Ø43 soybeans on SD rats reflected by physiological variables and fecal microbiota during a 90-day feeding study

Soybean is an important food resource for the eastern countries and herbicide-tolerant genetically modified soybeans (GMS) were widely developed to deal with weeds problems. Unprocessed soybean flour instead of dehulled and defatted soybean meal was used to reflect the safety of soybean food in whole. Rats were given formulated diets containing DP-356Ø43 or non-GM soybean JACK at an incorporation rate of 7.5%, 15%, or 30% (w/w), respectively for 90 days. Targeted traditional toxicological response variables were measured to reflect the holistic health of animals. No treatment-related adverse or toxic effects were observed based on an examination of the daily clinical signs, body weight, food consumption, hematology, serum biochemistry, and organ weight or based on gross and histopathological examination. The results demonstrate that the soybean DP-356Ø43 is as safe for consumption as conventional soybean JACK. In the current study, the effect of a herbicide-tolerant GMS DP-356043 on identified intestinal microbiota was evaluated in a rodent feeding study compared with its conventional control JACK. Feces samples from rats consuming different diets were collected before the start of the experiment (time 0) and at monthly intervals (at the end of the 1st, 2nd and 3rd months) over the course of 90 days. Six types of bacterias shared by humans and rats were detected with Q-PCR. The results of QPCR indicated that the GMS 356Ø43 had a comparable effect on the abundance of Bifidobacterium group, Clostridium perfringens subgroup, Escherichia coli, and Bacteroides-Prevotella group as the non-GMS JACK.

A Pilot Randomized Controlled Trial to Explore Cognitive and Emotional Effects of Probiotics in Fibromyalgia

It has recently been found that microbes in the gut may regulate brain processes through the gut microbiota–brain axis, which modulates affection, motivation and higher cognitive functions. According to this finding, the use of probiotics may be a potential treatment to improve physical, psychological and cognitive status in clinical populations with altered microbiota balance such as those with fibromyalgia (FMS). Thus, the aim of the present pilot study with a double-blind, placebo-controlled, randomised design was to test whether a multispecies probiotic may improve cognition, emotional symptoms and functional state in a sample of patients diagnosed with FMS. Pain, impact of FMS, quality of life, anxiety and depressive symptoms were measured during the pre- and post-intervention phases; participants also completed two computerised cognitive tasks to assess impulsive choice and decision-making. Finally, urinary cortisol concentration was determined. To our knowledge, this is the first study that explore the effect of a multispecies probiotic in FMS patients. Our results indicated that probiotics improved impulsivity and decision-making in these patients. However, more research is needed to further explore the potential effects of probiotics on other cognitive functions affected in FMS as well as in other clinical populations.

Fermentation of non-digestible raffinose family oligosaccharides and galactomannans by probiotics

Due to their prebiotic potential indigestible oligosaccharides became a major focus of research interest. In this study the growth of selected probiotic strains including lactobacilli, bifidobacteria, Lactococcus lactis, Streptococcus salivarius ssp. thermophilus, Pediococcus ssp. and Enterococcus faecium with the, raffinose family oligosaccharides (RFOs) raffinose, stachyose and verbascose and galactomannan from guar bean Cyamopsis tetragonoloba (total guar carbohydrates, oligosaccharides (dp 2-4) and polysaccharides (dp > 5), obtained by size exclusion chromatography) were tested by means of turbidity measurements. RFOs were used by 75% of all strains, with some delay for the trisaccharide raffinose and the tetrasaccharide stachyose and a limited fermentation of the pentasaccharide verbascose. L. reuteri, P. pentosaceus and B. lactis HNO19™ were able to ferment not only raffinose and stachyose but also verbascose. Guar oligosaccharides were fermented by 15 out of 20 strains; P. acidilactici, L. acidophilus, L. rhamnosus GG and B. animalis ssp. lactis BB12 metabolized them comparably well as glucose or galactose. Isolated guar polysaccharides were not fermented whereas total guar carbohydrates were fermented by 7 strains, apparently caused by the oligosaccharide content. The findings of this study may be important for functional food products especially for indigestible oligosaccharides which may cause adverse effects in the gut when not cleaved.

In vitro and in vivo safety analysis of Enterococcus faecium 2C isolated from human breast milk

INTRODUCTION

Safety analysis of probiotic bacteria is an obligatory characteristic to be evaluated prior to application in food or pharmacological products. This study was designed to evaluate in vitro and in vivo safety parameters of Enterococcus faecium 2C strain, a probiotic candidate isolated from human breast milk.

MATERIAL AND METHODS

E.faecium 2C was studied for its hemolytic activity and phenotypic antibiotics resistance profile. In vivo safety of the mentioned Enterococcus strain was studied by determining acute oral toxicity in Wistar Male rats. The animals were randomly divided into two groups of 3 animals each. The test group animals were gavaged daily with bacterial dose of 1 × 10¹¹ CFU/kg of animal body weight for 21 consecutive days. The animals in control group received normal basal diet without any supplementations. Hematological and biochemical parameters, organ weight, body weight and common health features of the animals were recorded.

RESULTS

E.faecium 2C appeared non-hemolytic and sensitive to the majority of the tested antibiotics. The Wistar male rats fed orally with the mentioned bacterial suspensions survived the test period, and showed normal growth and development. No adverse effects on the general health condition, behavior, and growth were seen in the treated animals compared to control group. Additionally, no significant changes in the hematological results, blood biochemistry, organ weights and histopathology of the rats in treatment groups were observed. None of the vital organs of the treated animals showed signs of bacteremia or infectivity.

CONCLUSION

E.faecium 2C strain isolated from human breast milk might be considered safe for use in probiotic formulations intended for man and animals.

Screening and characterization of lactic acid bacterial strains that produce fermented milk and reduce cholesterol levels

OBJECTIVE

To screen for and characterize lactic acid bacteria strains with the ability to produce fermented milk and reduce cholesterol levels.

METHODS

The strains were isolated from traditional fermented milk in China. In vitro and in vivo evaluation of cholesterol-reduction were used to identify and verify strains of interest. Characteristics were analyzed using spectrophotometry and plate counting assays.

RESULTS

The isolate HLX37 consistently produced fermented milk with strong cholesterol-reducing properties was identified as Lactobacillus plantarum (accession number: KR105940) and was thus selected for further study. The cholesterol reduction by strain HLX37 was 45.84%. The isolates were acid-tolerant at pH 2.5 and bile-tolerant at 0.5% (w/v) in simulated gastric juice (pH 2.5) for 2h and in simulated intestinal fluid (pH 8.0) for 3h. The auto-aggregation rate increased to 87.74% after 24h, while the co-aggregation with Escherichia coli DH5 was 27.76%. Strain HLX37 was intrinsically resistant to antibiotics such as penicillin, tobramycin, kanamycin, streptomycin, vancomycin and amikacin. Compared with rats in the model hyperlipidemia group, the total cholesterol content in the serum and the liver as well as the atherogenic index of rats in the viable fermented milk group significantly decreased by 23.33%, 32.37% and 40.23%, respectively. Fewer fat vacuoles and other lesions in liver tissue were present in both the inactivated and viable fermented milk groups compared to the model group.

CONCLUSION

These studies indicate that strain HLX37 of L. plantarum demonstrates probiotic potential, potential for use as a candidate for commercial use for promoting health.

Assessing the Risk of Probiotic Dietary Supplements in the Context of Antibiotic Resistance

Probiotic bacteria are known to harbor intrinsic and mobile genetic elements that confer resistance to a wide variety of antibiotics. Their high amounts in dietary supplements can establish a reservoir of antibiotic resistant genes in the human gut. These resistant genes can be transferred to pathogens that share the same intestinal habitat thus resulting in serious clinical ramifications. While antibiotic resistance of probiotic bacteria from food, human and animal sources have been well-documented, the resistant profiles of probiotics from dietary supplements have only been recently studied. These products are consumed with increasing regularity due to their health claims that include the improvement of intestinal health and immune response as well as prevention of acute and antibiotic-associated diarrhea and cancer; but, a comprehensive risk assessment on the spread of resistant genes to human health is lacking. Here, we highlight recent reports of antibiotic resistance of probiotic bacteria isolated from dietary supplements, and propose complementary strategies that can shed light on the risks of consuming such products in the context of a global widespread of antibiotic resistance. In concomitant with a broader screening of antibiotic resistance in probiotic supplements is the use of computational simulations, live imaging and functional genomics to harvest knowledge on the evolutionary behavior, adaptations and dynamics of probiotics studied in conditions that best represent the human gut including in the presence of antibiotics. The underlying goal is to enable the health benefits of probiotics to be exploited in a responsible manner and with minimal risk to human health.

Lactobacillus paracasei GMNL-32, Lactobacillus reuteri GMNL-89 and L. reuteri GMNL-263 ameliorate hepatic injuries in lupus-prone mice

Probiotics are known to regulate host immunity by interacting with systemic and mucosal immune cells as well as intestinal epithelial cells. Supplementation with certain probiotics has been reported to be effective against various disorders, including immune-related diseases. However, little is known about the effectiveness of Lactobacillus paracasei GMNL-32 (GMNL-32), Lactobacillus reuteri GMNL-89 (GMNL-89) and L. reuteri GMNL-263 (GMNL-263) in the management of autoimmune diseases, especially systemic lupus erythematosus (SLE). NZB/W F1 mice, which are a lupus-prone animal model, were orally gavaged with GMNL-32, GMNL-89 or GMNL-263 to investigate the effects of these Lactobacillus strains on liver injuries in NZB/W F1 mice. The results thus obtained reveal that supplementary GMNL-32, GMNL-89 or GMNL-263 in NZB/W F1 mice ameliorates hepatic apoptosis and inflammatory indicators, such as matrix metalloproteinase-9 activity and C-reactive protein and inducible nitric oxide synthase expressions. In addition, supplementation with GMNL-32, GMNL-89 or GMNL-263 in NZB/W F1 mice reduced the expressions of hepatic IL-1β, IL-6 and TNF-α proteins by suppressing the mitogen-activated protein kinase and NF-κB signalling pathways. These findings, presented here for the first time, reveal that GMNL-32, GMNL-89 and GMNL-263 mitigate hepatic inflammation and apoptosis in lupus-prone mice and may support an alternative remedy for liver disorders in cases of SLE.

Effect of a probiotic beverage consumption (Enterococcus faecium CRL 183 and Bifidobacterium longum ATCC 15707) in rats with chemically induced colitis

Background

Some probiotic strains have the potential to assist in relieving the symptoms of inflammatory bowel disease. The impact of daily ingestion of a soy-based product fermented by Enterococcus faecium CRL 183 and Lactobacillus helveticus 416 with the addition of Bifidobacterium longum ATCC 15707 on chemically induced colitis has been investigated thereof within a period of 30 days.

Methods

Colitis was induced by dextran sulfate sodium. The animals were randomly assigned into five groups: Group C: negative control; Group CL: positive control; Group CLF: DSS with the fermented product; Group CLP: DSS with the non-fermented product (placebo); Group CLS: DSS with sulfasalazine. The following parameters were monitored: disease activity index, fecal microbial analyses, gastrointestinal survival of probiotic microorganisms and short-chain fatty acids concentration in the feces. At the end of the protocol the animals’ colons were removed so as to conduct a macroscopical and histopathological analysis, cytokines and nitrite quantification.

Results

Animals belonging to the CLF group showed fewer symptoms of colitis during the induction period and a lower degree of inflammation and ulceration in their colon compared to the CL, CLS and CLP groups (p<0.05). The colon of the animals in groups CL and CLS presented severe crypt damage, which was absent in CLF and CLP groups. A significant increase in the population of Lactobacillus spp. and Bifidobacterium spp. at the end of the protocol was verified only in the CLF animals (p<0.05). This group also showed an increase in short-chain fatty acids (propionate and acetate). Furthermore, the intestinal survival of E. faecium CRL 183 and B. longum ATCC 15707 in the CLF group has been confirmed by biochemical and molecular analyzes.

Conclusions

The obtained results suggest that a regular intake of the probiotic product, and placebo to a lesser extent, can reduce the severity of DSS-induced colitis on rats.

Probiotics as an adjuvant treatment in Helicobacter pylori eradication therapy

Over 80% of individuals infected with Helicobacter pylori (H. pylori) are asymptomatic. Increased resistance to antibiotics and decreased compliance to the therapeutic regimens have led to the failure of eradication therapy. Probiotics, with direct and indirect inhibitory effects on H. pylori in both animal models and clinical trials, have recently been used as a supplementary treatment in H. pylori eradication therapy. Probiotics have been considered useful because of the improvements in H. pylori eradication rates and therapy-related side effects although treatment outcomes using probiotics are controversial due to the heterogeneity of species, strains, doses and therapeutic duration of probiotics. Thus, despite the positive role of probiotics, several factors need to be further considered during their applications. Moreover, adverse events of probiotic use need to be noted. Further investigations into the safety of adjuvant probiotics to H. pylori eradication therapy are required.

Lactobacillus-derived extracellular vesicles enhance host immune responses against vancomycin-resistant enterococci

Background

Probiotic bacteria are known to modulate host immune responses against various pathogens. Recently, extracellular vesicles (EVs) have emerged as potentially important mediators of host-pathogen interactions. In this study, we explored the role of L. plantarum derived EVs in modulating host responses to vancomycin-resistant Enterococcus faecium (VRE) using both Caenorhabditis elegans and human cells.

Results

Our previous work has shown that probiotic conditioning C. elegans with L. acidophilus NCFM prolongs the survival of nematodes exposed to VRE. Similarly, L. plantarum WCFS1 derived extracellular vesicles (LDEVs) also significantly protected the worms against VRE infection. To dissect the molecular mechanisms of this EV-induced protection, we found that treatment of C. elegans with LDEVs significantly increased the transcription of host defense genes, cpr-1 and clec-60. Both cpr-1 and clec-60 have been previously reported to have protective roles against bacterial infections. Incubating human colon-derived Caco-2 cells with fluorescent dye-labeled LDEVs confirmed that LDEVs could be transported into the mammalian cells. Furthermore, LDEV uptake was associated with significant upregulation of CTSB, a human homologous gene of cpr-1, and REG3G, a human gene that has similar functions to clec-60.

Conclusions

We have found that EVs produced from L. plantarum WCFS1 up-regulate the expression of host defense genes and provide protective effects on hosts. Using probiotic-derived EVs instead of probiotic bacteria themselves, this study provides a new direction to treat antimicrobial resistant pathogens, such as VRE.

Electronic supplementary material

The online version of this article (doi:10.1186/s12866-017-0977-7) contains supplementary material, which is available to authorized users.