Assessment of the in vitro inhibitory activity of specific probiotic bacteria against different Escherichia coli strains

Probiotics for managing patients after bowel preparation for colonoscopy: an interventional, double-arm, open, randomized, multi-center, and national study (COLONSTUDY)

BACKGROUND

Bowel preparation (BP) for colonoscopy induces significant changes in gut microbiota, causing dysbiosis that, in turn, elicits intestinal symptoms. Consequently, probiotics may counterbalance the disturbed microbiota after BP. So, probiotics may restore microbiota homeostasis.

METHODS

The current study evaluated the efficacy and safety of Abincol®, an oral nutraceutical containing a probiotic mixture with Lactobacillus plantarum LP01 (1 billion living cells), Lactobacillus lactis subspecies cremoris LLC02 (800 millions living cells), and Lactobacillus delbrueckii LDD01 (200 millions living cells), Patients were randomized in two groups (2:1). Group A took one stick/daily for four weeks after colonoscopy. Group B was considered as control. Patients were evaluated at baseline (T0) and after one (T1), two (T2), and four (T3) weeks. The severity of symptoms was measured by patients using a Visual Analog Scale.

RESULTS

Abincol® significantly diminished the presence and the severity of intestinal symptoms at T2 and even more at T3. All patients well tolerated the probiotic mixture.

CONCLUSIONS

The present study suggests that Abincol® may be considered an effective and safe therapeutic option in managing patients undergoing BP. The course should last one month.

Rhynchophorus ferrugineus larvae: A novel source for combating broad-spectrum bacterial and fungal infections

Antimicrobial resistance is a growing concern due to the growth of antibiotic-resistant microorganisms, which makes it difficult to treat infection. Due to its broad-spectrum antimicrobial properties against a diverse array of bacteria, both Gram-positive and Gram-negative bacteria, and fungi, Rhynchophorus ferrugineus larval antimicrobial peptides (AMPs) have demonstrated potential as antimicrobial agents for the treatment of microbial infections and prevention of antibiotic resistance. This study emphasizes the unexplored mechanisms of action of R. ferrugineus larvae against microorganisms. Among the most widely discussed mechanisms is the effect of AMPs in larvae in response to a threat or infection. Modulation of immune-related genes in the intestine and phagocytic capacity of its hemocytes may also affect the antimicrobial activity of R. ferrugineus larvae, with an increase in phenoloxidase activity possibly correlated with microbial clearance and survival rates of larvae. The safety and toxicity of R. ferrugineus larvae extracts, as well as their long-term efficacy, are also addressed in this paper. The implications of future research are explored in this paper, and it is certain that R. ferrugineus larvae have the potential to be developed as a broad-spectrum antimicrobial agent with proper investigation.

AB5 Enterotoxin-Mediated Pathogenesis: Perspectives Gleaned from Shiga Toxins

Foodborne diseases affect an estimated 600 million people worldwide annually, with the majority of these illnesses caused by Norovirus, Vibrio, Listeria, Campylobacter, Salmonella, and Escherichia coli. To elicit infections in humans, bacterial pathogens express a combination of virulence factors and toxins. AB₅ toxins are an example of such toxins that can cause various clinical manifestations, including dehydration, diarrhea, kidney damage, hemorrhagic colitis, and hemolytic uremic syndrome (HUS). Treatment of most bacterial foodborne illnesses consists of fluid replacement and antibiotics. However, antibiotics are not recommended for infections caused by Shiga toxin-producing E. coli (STEC) because of the increased risk of HUS development, although there are conflicting views and results in this regard. Lack of effective treatment strategies for STEC infections pose a public health threat during outbreaks; therefore, the debate on antibiotic use for STEC infections could be further explored, along with investigations into antibiotic alternatives. The overall goal of this review is to provide a succinct summary on the mechanisms of action and the pathogenesis of AB₅ and related toxins, as expressed by bacterial foodborne pathogens, with a primary focus on Shiga toxins (Stx). The role of Stx in human STEC disease, detection methodologies, and available treatment options are also briefly discussed.

Probiotics and the Treatment of Parkinson's Disease: An Update

Parkinson's disease (PD) is a progressive neurological disorder characterized by motor and non-motor features. Although some progress has been made in conventional PD treatments, these breakthroughs have yet to show high efficacy in treating this neurodegenerative disease. Probiotics are live microorganisms that confer health benefits on the host when administered in adequate amounts. Probiotics have putative anticancer, antioxidative, anti-inflammatory, and neuroprotective effects. Multiple lines of evidence show that probiotics control and improve several motor and non-motor symptoms in patients and experimental animal models of PD. Probiotic supplementation mediates these pharmacological effects by targeting a variety of cellular and molecular processes, i.e., oxidative stress, inflammatory and anti-inflammatory pathways, as well as apoptosis. Herein, we summarize the effects of probiotics on motor and non-motor symptoms as well as various cellular and molecular pathways in PD.

Dietary Modulation of Bacteriophages as an Additional Player in Inflammation and Cancer

Natural compounds such as essential oils and tea have been used successfully in naturopathy and folk medicine for hundreds of years. Current research is unveiling the molecular role of their antibacterial, anti-inflammatory, and anticancer properties. Nevertheless, the effect of these compounds on bacteriophages is still poorly understood. The application of bacteriophages against bacteria has gained a particular interest in recent years due to, e.g., the constant rise of antimicrobial resistance to antibiotics, or an increasing awareness of different types of microbiota and their potential contribution to gastrointestinal diseases, including inflammatory and malignant conditions. Thus, a better knowledge of how dietary products can affect bacteriophages and, in turn, the whole gut microbiome can help maintain healthy homeostasis, reducing the risk of developing diseases such as diverse types of gastroenteritis, inflammatory bowel disease, or even cancer. The present review summarizes the effect of dietary compounds on the physiology of bacteriophages. In a majority of works, the substance class of polyphenols showed a particular activity against bacteriophages, and the primary mechanism of action involved structural damage of the capsid, inhibiting bacteriophage activity and infectivity. Some further dietary compounds such as caffeine, salt or oregano have been shown to induce or suppress prophages, whereas others, such as the natural sweeter stevia, promoted species-specific phage responses. A better understanding of how dietary compounds could selectively, and specifically, modulate the activity of individual phages opens the possibility to reorganize the microbial network as an additional strategy to support in the combat, or in prevention, of gastrointestinal diseases, including inflammation and cancer.

A prospective longitudinal study on the microbiota composition in amyotrophic lateral sclerosis

BACKGROUND

A connection between amyotrophic lateral sclerosis (ALS) and altered gut microbiota composition has previously been reported in animal models. This work is the first prospective longitudinal study addressing the microbiota composition in ALS patients and the impact of a probiotic supplementation on the gut microbiota and disease progression.

METHODS

Fifty patients and 50 matched controls were enrolled. The microbial profile of stool samples from patients and controls was analyzed via PCR-Denaturing Gradient Gel Electrophoresis, and the main microbial groups quantified via qPCR. The whole microbiota was then analyzed via next generation sequencing after amplification of the V3-V4 region of 16S rDNA. Patients were then randomized to receive probiotic treatment or placebo and followed up for 6 months with ALSFRS-R, BMI, and FVC%.

RESULTS

The results demonstrate that the gut microbiota of ALS patients is characterized by some differences with respect to controls, regardless of the disability degree. Moreover, the gut microbiota composition changes during the course of the disease as demonstrated by the significant decrease in the number of observed operational taxonomic unit during the follow-up. Interestingly, an unbalance between potentially protective microbial groups, such as Bacteroidetes, and other with potential neurotoxic or pro-inflammatory activity, such as Cyanobacteria, has been shown. The 6-month probiotic treatment influenced the gut microbial composition; however, it did not bring the biodiversity of intestinal microbiota of patients closer to that of control subjects and no influence on the progression of the disease measured by ALSFRS-R was demonstrated.

CONCLUSIONS

Our study poses the bases for larger clinical studies to characterize the microbiota changes as a novel ALS biomarker and to test new microbial strategy to ameliorate the health status of the gut.

TRIAL REGISTRATION

CE 107/14, approved by the Ethics Committee of the "Maggiore della Carità" University Hospital, Italy.

Treatment Strategies for Infections With Shiga Toxin-Producing Escherichia coli

Infections with Shiga toxin-producing Escherichia coli (STEC) cause outbreaks of severe diarrheal disease in children and the elderly around the world. The severe complications associated with toxin production and release range from bloody diarrhea and hemorrhagic colitis to hemolytic-uremic syndrome, kidney failure, and neurological issues. As the use of antibiotics for treatment of the infection has long been controversial due to reports that antibiotics may increase the production of Shiga toxin, the recommended therapy today is mainly supportive. In recent years, a variety of alternative treatment approaches such as monoclonal antibodies or antisera directed against Shiga toxin, toxin receptor analogs, and several vaccination strategies have been developed and evaluated in vitro and in animal models. A few strategies have progressed to the clinical trial phase. Here, we review the current understanding of and the progress made in the development of treatment options against STEC infections and discuss their potential.

The Biotherapeutic Potential of Lactobacillus reuteri Characterized Using a Target-Specific Selection Process

A growing body of clinical and experimental data supports the view that the efficacy of probiotics is strain-specific and restricted to particular pathological conditions, which means that newly isolated probiotic strains need to be targeted to a specific disease. Following national and international guidelines, we used a conventional in vitro experimental approach to characterize a novel strain of Lactobacillus reuteri, LMG P-27481, for safety (sensitivity to antibiotics and genome analysis) and putative efficacy (resistance to gastro-intestinal transit, adhesiveness, induction of cytokines, and release of antimicrobial metabolites). In vitro assays, which were carried out to examine the probiotic's effect on diarrhea (lactose utilization, inhibition of pathogens such as bacteria and Rotavirus), showed that it was more efficacious with respect to well-known reference strains in antagonizing Clostridioides difficile (CD). Data confirming that the probiotic can effectively treat CD colitis was gained from in vivo trials involving mice conditioned with large spectrum antibiotics before they were subjected to CD challenge. Two out of the three antibiotic-treated groups received daily LMG P-27481 for different time durations in order to simulate a preventive approach (LMG P-27481 administered prior to CD challenge) or an antagonistic one (LMG P-27481 administered after CD challenge). Both approaches significantly reduced, with respect to the untreated controls, CD DNA concentrations in caecum and C. difficile toxin titers in the gut lumen. In addition, LMG P-27481 supplementation significantly mitigated body weight loss and the extent of inflammatory infiltrate and tissue damage. The study results, which need to be confirmed by in vivo clinical trials, have demonstrated that the L. reuteri LMG P-27481 strain is a promising probiotic candidate for the treatment of CD infection.

Minocycline and Its Impact on Microbial Dysbiosis in the Skin and Gastrointestinal Tract of Acne Patients

Background

Associations between acne and gastrointestinal comorbidities suggest that microbial dysbiosis and intestinal permeability may promote inflammatory acne, a condition often managed with oral antibiotics.

Objective

We performed a case-control study to investigate the skin and gut microbiota in 8 acne patients before and after receiving oral minocycline compared to controls matched by age ±5 years, sex, and race.

Methods

DNA was extracted from stool samples and facial skin swabs. Sequencing of the V3V4 region of the bacterial 16S rRNA gene was performed using Illumina MiSeq and analyzed using QIIME/MetaStats 2.0 software.

Results

Acne patients included 7 female and 1 male, ages 20~32. Shannon diversity was not significantly different between the skin (p=0.153) or gut (p<0.999) microbiota of acne patients before and after antibiotics. The gut microbiota in pre-antibiotic acne patients compared to acne-free controls was depleted in probiotics Lactobacillus iners (p=0.001), Lactobacillus zeae (p=0.001), and Bifidobacterium animalis (p=0.026). After antibiotics, the gut microbiota of acne patients was depleted in Lactobacillus salivarius (p=0.001), Bifidobacterium adolescentis (p=0.002), Bifidobacterium pseudolongum (p=0.010), and Bifidobacterium breve (p=0.042), while the skin microbiota was enriched in probiotics Bifidobacterium longum (p=0.028) and Leuconostoc mesenteroides (p=0.029) and depleted in Staphylococcus epidermidis (p=0.009) and Prevotella nigrescens (p=0.028). At the phylum level, significant enrichment of Bacteroidetes in stool of acne patients following antibiotic treatment (p=0.033) led to a decreased Firmicutes to Bacteroidetes ratio.

Conclusion

Minocycline produces significant derangements in the microbiota of the skin and gut, including many probiotic species, highlighting the potential for more targeted antimicrobial treatments for acne.

Probiotic potential of Lactobacillus on the intestinal microflora against Escherichia coli induced mice model through high-throughput sequencing

The aim of this study was to evaluate the antibacterial potential of Lactobacillus screened from Tibetan yaks on clinical symptoms and intestinal microflora in enteroinvasive Escherichia coli (EIEC) induced mice model. In vitro study, Lactobacillus reuteri (LR1) exhibited stronger resistance to acid and bile and inhibited the growth of EIEC than Lactobacillus mucosae (LM1). The mice were randomly divided into four groups i.e. the LR1 group (LR1 1 × 10⁹ CFU/day), LM1 group (LM1 1 × 10⁹ CFU/day), blank control group and control group. Mice in control, LR1, and LM1 groups were challenged with EIEC on day 23. The body weight in the control and LM1 groups were significantly decreased after the infection with EIEC (P < 0.05), whereas the body weight of mice in the LR1 group did not change significantly (P > 0.05). The lowest diarrhea rate was recorded in the LR1 group after infection with EIEC. The results showed that the number of pathogens in the control group was higher than that in the experimental groups. The sequence analysis and OTU classification showed that the duodenum, ileum, and cecum of mice in the LR1 group had the highest number of OTUs compared with other groups. Whereas, the diversity analysis showed that in duodenum, ileum and cecum of mice in the LR1 group had the highest abundance and diversity. The composition of intestinal microbes indicated the presence of high proportions of Firmicutes, Proteobacteria and Bacteroidetes. Heat map analysis indicated high abundance of Bdello vibrio in the duodenum of mice in the LR1 group, while many pathogens were found in the different part of intestines in the control group, such as Streptococcus, Clostridium and Pseudomonas. In conclusion, pre-supplementation of LR1 alleviate the clinical symptoms caused by E. coli, and promote a healthy gut flora.

Single-Scaffold Genome Sequence of Probiotic Strain Bifidobacterium breve BR03 (DSM 16604), Obtained by Combining Hybrid Sequencing and Optical Mapping

Bifidobacterium breve BR03 (DSM 16604) is known for its health-promoting activity. We present a single-scaffold genome obtained by using a hybrid approach combining long- and short-read sequencing techniques integrated by an optical map.

Management of STEC Gastroenteritis: Is There a Role for Probiotics?

Shiga toxin-producing Escherichia Coli (STEC) infections routinely run as a common gastroenteritis, but in many cases they may evolve towards hemolytic uremic syndrome (HUS). HUS is a rare disease characterized by microangiopathic hemolytic anemia, thrombocytopenia, and acute renal failure. Gut microorganisms have a fundamental impact on human physiology, because they modulate normal intestinal functions and play a pivotal role in influencing the local and systemic immune responses. Despite surveillance established in many countries and major progresses in the understanding of STEC-HUS mechanisms, no specific treatment is currently available. Targeting the gut microbiota could represent a new potential therapeutic strategy in STEC infection. In this paper, we reviewed the current knowledge about microbiota characteristics of patients with STEC infections, as well as in vitro and in vivo evidence of probiotic supplementation in managing STEC gastroenteritis and in HUS onset prevention.

Probiotics May Have Beneficial Effects in Parkinson's Disease: In vitro Evidence

Background: Parkinson's disease (PD) is characterized by loss of dopaminergic neurons and intraneuronal accumulation of alpha-synuclein, both in the basal ganglia and in peripheral sites, such as the gut. Peripheral immune activation and reactive oxygen species (ROS) production are important pathogenetic features of PD. In this context, the present study focused on the assessment of in vitro effects of probiotic bacterial strains in PBMCs isolated from PD patients vs. healthy controls.

Methods: 40 PD patients and 40 matched controls have been enrolled. Peripheral blood mononuclear cells (PBMCs) were isolated and co-cultured with a selection of probiotics microorganisms belonging to the lactobacillus and bifidobacterium genus. In vitro release of the major pro- (Tumor Necrosis Factor-alpha and Interleukin-17A and 6) and anti-inflammatory (Interleukin 4 and 10) cytokines by PBMCs, as well as the production of ROS was investigated. Furthermore, we assessed the ability of probiotics to influence membrane integrity, antagonize the growth of potential pathogen bacteria, such as Escherichia coli and Klebsiella pneumoniae and encode tyrosine decarboxylase genes (tdc).

Results: All probiotic strains were able to inhibit inflammatory cytokines and ROS production in both patients and controls. The most striking results were obtained in PD subjects with L. salivarius LS01 and L. acidophilus which significantly reduced pro-inflammatory and increased the anti-inflammatory cytokines (p < 0.05). Furthermore, most strains determined restoration of membrane integrity and inhibition of E. coli and K. pneumoniae. Finally, we also showed that all the strains do not carry tdc gene, which is known to decrease levodopa bioavailability in PD patients under treatment.

Conclusions: Probiotics exert promising in vitro results in decreasing pro-inflammatory cytokines, oxidative stress and potentially pathogenic bacterial overgrowth. In vivo longitudinal data are mandatory to support the use of bacteriotherapy in PD.

Therapeutic Microbiology: The Role of Bifidobacterium breve as Food Supplement for the Prevention/Treatment of Paediatric Diseases

The human intestinal microbiota, establishing a symbiotic relationship with the host, plays a significant role for human health. It is also well known that a disease status is frequently characterized by a dysbiotic condition of the gut microbiota. A probiotic treatment can represent an alternative therapy for enteric disorders and human pathologies not apparently linked to the gastrointestinal tract. Among bifidobacteria, strains of the species Bifidobacterium breve are widely used in paediatrics. B. breve is the dominant species in the gut of breast-fed infants and it has also been isolated from human milk. It has antimicrobial activity against human pathogens, it does not possess transmissible antibiotic resistance traits, it is not cytotoxic and it has immuno-stimulating abilities. This review describes the applications of B. breve strains mainly for the prevention/treatment of paediatric pathologies. The target pathologies range from widespread gut diseases, including diarrhoea and infant colics, to celiac disease, obesity, allergic and neurological disorders. Moreover, B. breve strains are used for the prevention of side infections in preterm newborns and during antibiotic treatments or chemotherapy. With this documentation, we hope to increase knowledge on this species to boost the interest in the emerging discipline known as "therapeutic microbiology".

The 2011 German Enterohemorrhagic Escherichia Coli O104:H4 Outbreak-The Danger Is Still Out There

Enterohemorrhagic Escherichia coli (EHEC) are Shiga toxin (Stx) producing bacteria causing a disease characterized by bloody (or non-bloody) diarrhea, which might progress to hemolytic uremic syndrome (HUS). EHEC O104:H4 caused the largest ever recorded EHEC outbreak in Germany in 2011, which in addition showed the so far highest incidence rate of EHEC-related HUS worldwide. The aggressive outbreak strain carries an unusual combination of virulence traits characteristic to both EHEC-a chromosomally integrated Stx-encoding bacteriophage, and enteroaggregative Escherichia coli-pAA plasmid-encoded aggregative adherence fimbriae mediating its tight adhesion to epithelia cells. There are currently still open questions regarding the 2011 EHEC outbreak, e.g., with respect to the exact molecular mechanisms resulting in the hypervirulence of the strain, the natural reservoir of EHEC O104:H4, and suitable therapeutic strategies. Nevertheless, our knowledge on these issues has substantially expanded since 2011. Here, we present an overview of the epidemiological, clinical, microbiological, and molecular biological data available on the 2011 German EHEC O104:H4 outbreak.

Bifidobacterium adolescentis IM38 ameliorates high-fat diet-induced colitis in mice by inhibiting NF-κB activation and lipopolysaccharide production by gut microbiota

Gut microbiota play essential roles in the regulation of human metabolism via symbiotic interactions with the host. Prolonged consumption of high-fat diet (HFD) elevates the Firmicutes to Bacteroidetes ratio and lipopolysaccharide (LPS) production by gut microbiota, thereby increasing the probability of developing metabolic and immune disorders such as obesity and colitis. The use of probiotics with anti-inflammatory properties has been suggested to counteract this effect. Here, we tested whether Bifidobacterium adolescentis IM38, which inhibited nuclear factor-kappa B (NF-κB) activation in Caco-2 cells and peritoneal macrophages and inhibited Escherichia coli LPS production, exerted an anticolitic effect in mice with HFD-induced obesity. Oral administration of IM38 (2×10⁹CFU/mouse per day) for 6 weeks in mice with HFD-induced obesity inhibited whole-body and epididymal fat weight gain. IM38 also increased HFD-suppressed expression of interleukin (IL)-10 and tight junction proteins but significantly downregulated HFD-induced NF-κB activation and tumor necrosis factor expression in the colon. IM38 inhibited differentiation into helper T17 cells and reduced IL-17 levels in the colon of mice with HFD-induced obesity but increased HFD-suppressed differentiation into regulatory T cells and IL-10 levels. Furthermore, treatment with IM38 lowered the HFD-induced LPS levels in blood and colonic fluid, as well as the Proteobacteria to Bacteroidetes ratio in gut microbiota. Therefore, we suggest that IM38 can inhibit HFD-induced LPS production in gut microbiota through the regulation of Proteobacteria to Bacteroidetes ratio and NF-κB activation in the colon, which ultimately attenuates colitis. Thus, IM38 may be a suitable ingredient of functional foods designed for treating or preventing colitis.

The Association of Bifidobacterium breve BR03 and B632 is Effective to Prevent Colics in Bottle-fed Infants: A Pilot, Controlled, Randomized, and Double-Blind Study

GOALS

To assess the effectiveness of Bifidobacterium breve B632 and BR03 association in the reduction of infants crying over time. The second endpoint was to observe the effect of the same strains on daily evacuations and on the number of regurgitations and vomits.

BACKGROUND

Infant colics represent a clinical condition in childhood, characterized by an uncontrollable crying that occurs without any apparent organic cause. An altered intestinal microbiota composition in the very first months may induce intestinal colics in infants. Thus far, no treatment is really effective for this problem, but recent literature shows an increasing attention toward probiotics.

STUDY

A total of 83 subjects were enrolled, 60 breastfed infants and 23 bottle-fed infants. Sixty of them carried out the study: 29 infants were given probiotics, whereas 31 placebo. During the 90 days of the study, parents were asked to give 5 drops of active product (10 viable cells/strain) or placebo and to daily take note of: minutes of crying, number, color, and consistency of evacuations, and number of regurgitations or vomits.

RESULTS

No significant differences were detected in the infants treated with probiotics, compared with placebo group (P=0.75). The analysis of the 3 months of treatment demonstrated that during the third month, the probiotic group cried 12.14 minutes on average and the placebo cried 46.65 minutes. This difference is statistically significant (P=0.016).

CONCLUSIONS

The evidence of the usefulness of some probiotic strains in the treatment and prevention of infant colics is growing, and therefore their use in clinical practice is spreading.

Can Probiotics Reduce Diarrhea and Infant Mortality in Africa?: The Project of a Pilot Study

BACKGROUND

Diarrhea accounts for 9% of the mortality among children under 5 years of age worldwide, and it is significantly associated with malnutrition. Each year, diarrhea kills around 760,000 children under 5 years of age and most of these are in sub-Saharan Africa.In Uganda, the infant mortality rate of 58 per 1000 is unacceptably high, and the major contributors include malnutrition, diarrhea, pneumonia, malaria, prematurity, sepsis, and newborn illnesses.There is an urgent need for intervention to prevent and control diarrheal diseases.

STUDY DESIGN

Our open-label, randomized controlled study has the primary endpoint of reducing diarrhea and infectious diseases (number of episodes/severity) and the secondary endpoint of decreasing infant mortality. The trial is currently conducted in Luzira, a suburb of Kampala, the capital of Uganda, and in Gulu and Lira, in the north of Uganda.The study is projected to enroll 4000 babies (control=2000 and treatment=2000) who will be followed till 1 year of life. As controls, 2000 babies of the same community are planned to be considered.The probiotic product selected for the trial is composed of 3 designated microorganisms, namely Bifidobacterium breve BR03 (DSM 16604), B. breve B632 (DSM 24706), and Lactobacillus delbrueckii subsp. delbrueckii LDD01 (DSM 22106). The concentration of the 3 bacteria is 10 viable cells/strain/daily dose (5 drops).

PERSPECTIVES

For a total sample of 4000 babies, the study has an 80% power at a 5% significance level.

The Early Intestinal Microbiota of Healthy Korean Newborns

Background:

The microflora hypothesis may be the underlying explanation for the growth of inflammatory disease. In addition to many known affecting factors, knowing the gut microbiota of healthy newborns can help to understand the gut immunity and modulate it.

Objectives:

This study examined the microbiota of healthy newborns from urban regions.

Patients and Methods:

We enrolled 128 full-term newborns, born at Seoul St. Mary and St. Paul hospital from January 2009 to February 2010. All 143 samples of feces were cultivated in six culture plates to determine the amounts of total bacteria, anaerobes, gram-positive bacteria, coliforms, lactobacilli, and bifidobacteria. The samples were evaluated with a bivariate correlation between coliforms and lactobacilli. Terminal restriction fragment length polymorphism (T-RFLP) analysis with HhaI and MspI and a clustering analysis were performed for determination of diversity.

Results:

Bacteria were cultured in 61.5% of feces in the following order: anaerobes, gram-positive bacteria, lactobacilli, coliform, and bifidobacteria. The growth of total bacteria and lactobacilli increased in feces defecated after 24 hours of birth (P < 0.001, P = 0.008) and anaerobes decreased (P = 0.003). A negative correlation between the growth of lactobacilli and coliforms was found (r = -463, P < 0.001).

Conclusions:

This study confirms that bacterial colonization of healthy newborns born in cities is non-sterile, but has early diversification and inter-individuality.

Approaches to treatment of emerging Shiga toxin-producing Escherichia coli infections highlighting the O104:H4 serotype

Shiga toxin-producing Escherichia coli (STEC) are a group of diarrheagenic bacteria associated with foodborne outbreaks. Infection with these agents may result in grave sequelae that include fatality. A large number of STEC serotypes has been identified to date. E. coli serotype O104:H4 is an emerging pathogen responsible for a 2011 outbreak in Europe that resulted in over 4000 infections and 50 deaths. STEC pathogenicity is highly reliant on the production of one or more Shiga toxins that can inhibit protein synthesis in host cells resulting in a cytotoxicity that may affect various organ systems. Antimicrobials are usually avoided in the treatment of STEC infections since they are believed to induce bacterial cell lysis and the release of stored toxins. Some antimicrobials have also been reported to enhance toxin synthesis and production from these organisms. Various groups have attempted alternative treatment approaches including the administration of toxin-directed antibodies, toxin-adsorbing polymers, probiotic agents and natural remedies. The utility of antibiotics in treating STEC infections has also been reconsidered in recent years with certain modalities showing promise.

Lactobacillus pentosus strain LPS16 produces lactic acid, inhibiting multidrug-resistant Helicobacter pylori

BACKGROUND/PURPOSE

Helicobacter pylori is a human gastric pathogen. Antibiotic resistance of H. pylori has become a problem increasing the failure of H. pylori eradication. Therefore alternative approaches are required. The aim of this study was to evaluate the anti-H. pylori activity of Lactobacillus pentosus strain LPS16 and the mechanism of its killing effect.

METHODS

The anti-H. pylori activity of LPS16 was determined by the disc diffusion test and time killing assay. High-performance liquid chromatography analysis was used to analyze the secreted compounds of LPS16. Sixty H. pylori strains isolated from different gastric diseases, having different antibiotic susceptibility were collected to analyze the spectrum of anti-H. pylori activity of LPS16. Adhesion ability of LPS16 to gastric epithelial cell lines was assayed by flow cytometry.

RESULTS

The anti-H. pylori activity of LPS16 depended on the secreted component, and lactic acid mediated bactericidal activity against H. pylori. The bactericidal activity did not vary significantly among the strains isolated from different diseases having different antibiotic susceptibility. Moreover, LPS16 can adhere on gastric epithelial cell lines AKG and MKN45.

CONCLUSION

L. pentosus strain LPS16 had the broad-spectrum anti-H. pylori activity, suggesting that it can be used to prevent H. pylori infection.

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.

The gut microbiota and the liver: implications for clinical practice

While a central role for the microbiota in the precipitation of infectious and non-infectious complications of liver disease has been long established, evidence for a more fundamental role in the etiology of several liver diseases continues to accumulate. However, though progress is rapidly occurring in this area, the definitive delineation of the precise relevance of changes in the microbiota to various forms and stages of liver disease is still far from complete. While high quality clinical evidence supports the use of antibiotic therapy, in the management of hepatic encephalopathy, spontaneous bacterial peritonitis and other infectious complications, how these interventions impact on the microbiota and microbiota-host interactions has not been clearly defined. Although probiotics and even, perhaps, fecal transplantation hold promise in the management of liver disease, and the potential impact of probiotics is supported by a considerable amount of laboratory data, high-quality clinical evidence is scanty.

Recent advances in understanding enteric pathogenic Escherichia coli

Although Escherichia coli can be an innocuous resident of the gastrointestinal tract, it also has the pathogenic capacity to cause significant diarrheal and extraintestinal diseases. Pathogenic variants of E. coli (pathovars or pathotypes) cause much morbidity and mortality worldwide. Consequently, pathogenic E. coli is widely studied in humans, animals, food, and the environment. While there are many common features that these pathotypes employ to colonize the intestinal mucosa and cause disease, the course, onset, and complications vary significantly. Outbreaks are common in developed and developing countries, and they sometimes have fatal consequences. Many of these pathotypes are a major public health concern as they have low infectious doses and are transmitted through ubiquitous mediums, including food and water. The seriousness of pathogenic E. coli is exemplified by dedicated national and international surveillance programs that monitor and track outbreaks; unfortunately, this surveillance is often lacking in developing countries. While not all pathotypes carry the same public health profile, they all carry an enormous potential to cause disease and continue to present challenges to human health. This comprehensive review highlights recent advances in our understanding of the intestinal pathotypes of E. coli.

Review of the inhibition of biological activities of food-related selected toxins by natural compounds

There is a need to develop food-compatible conditions to alter the structures of fungal, bacterial, and plant toxins, thus transforming toxins to nontoxic molecules. The term 'chemical genetics' has been used to describe this approach. This overview attempts to survey and consolidate the widely scattered literature on the inhibition by natural compounds and plant extracts of the biological (toxicological) activity of the following food-related toxins: aflatoxin B1, fumonisins, and ochratoxin A produced by fungi; cholera toxin produced by Vibrio cholerae bacteria; Shiga toxins produced by E. coli bacteria; staphylococcal enterotoxins produced by Staphylococcus aureus bacteria; ricin produced by seeds of the castor plant Ricinus communis; and the glycoalkaloid α-chaconine synthesized in potato tubers and leaves. The reduction of biological activity has been achieved by one or more of the following approaches: inhibition of the release of the toxin into the environment, especially food; an alteration of the structural integrity of the toxin molecules; changes in the optimum microenvironment, especially pH, for toxin activity; and protection against adverse effects of the toxins in cells, animals, and humans (chemoprevention). The results show that food-compatible and safe compounds with anti-toxin properties can be used to reduce the toxic potential of these toxins. Practical applications and research needs are suggested that may further facilitate reducing the toxic burden of the diet. Researchers are challenged to (a) apply the available methods without adversely affecting the nutritional quality, safety, and sensory attributes of animal feed and human food and (b) educate food producers and processors and the public about available approaches to mitigating the undesirable effects of natural toxins that may present in the diet.