Carbon metabolism of a novel isolate from Lacticaseibacillus rhamnosus Probio-M9 derived through space mutant.

AIMS: Carbon source is a necessary nutrient for bacterial strain growth. In industrial production, the cost of using different carbon sources varies greatly. Moreover, the complex environment in space may cause metabolic a series of changes in the strain, and this method has been successfully applied in some basic research. To date, space mutagenesis is still limited number of studies, particularly in carbon metabolism of probiotics. METHODS AND RESULTS: HG-R7970-41 was isolated from bacterium suspension (Probio-M9) after space flight, which can produce capsular polysaccharide after space mutagenesis. Phenotype Microarray (PM) was used to evaluated the metabolism of HG-R7970-41 in 190 single carbon sources. RNA sequencing and total protein identification of two strains revealed their different carbon metabolism mechanisms. PM results demonstrated the metabolism of 10 carbon sources were different between Probio-M9 and HG-R7970-41. Transcriptomic and proteomic analyses revealed that this change in carbon metabolism of HG-R7970-41 mainly related to changes in phosphorylation and the glycolysis pathway. Based on the metabolic mechanism of different carbon sources and related gene cluster analysis, we found that the final metabolic activities of HG-R7970-41 and Probio-M9 were mainly regulated by PTS-specific membrane embedded permease, carbohydrate kinase and two rate-limiting enzymes (phosphofructokinase and pyruvate kinase) in the glycolysis pathway. The expanded culture test also confirmed that HG-R7970-41 had different metabolic characteristics from original strain. CONCLUSIONS: These results suggested that space environment could change carbon metabolism of Probio-M9. The new isolate (HG-R7970-41) showed a different carbon metabolism pattern from the original strain mainly by the regulation of two rate-limiting enzymes.

The global population stru cture of Lacticaseibacillus rhamnosus and its application to an investigation of a rare case of infective endocarditis.

BACKGROUND: Lacticaseibacillus (formerly Lactobacillus) rhamnosus is widely used in probiotics or food supplements to promote microbiome health and may also be part of the normal microbiota of the human gastrointestinal tract. However, it rarely also causes invasive or severe infections in patients. It has been postulated that these infections may originate from probiotics or from endogenous commensal reservoirs. In this report, we examine the population structure of Lacticaseibacillus rhamnosus and investigate the utility of using bacterial genomics to identify the source of invasive Lacticaseibacillus infections. METHODS: Core genome phylogenetic analysis was performed on 602 L. rhamnosus genome sequences from the National Center for Biotechnology public database. This information was then used along with newly generated sequences of L. rhamnosus isolates from yogurt to investigate a fatal case of L. rhamnosus endocarditis. RESULTS: Phylogenetic analysis demonstrated substantial genetic overlap of L. rhamnosus isolates cultured from food, probiotics, infected patients, and colonized individuals. This was applied to a patient who had both consumed yogurt and developed L. rhamnosus endocarditis to attempt to identify the source of his infection. The sequence of the isolate from the patient's bloodstream differed at only one nucleotide position from one of the yogurt isolates. Both isolates belonged to a clade, identified here as clade YC, composed of mostly gastrointestinal isolates from healthy individuals, some of which also differed by only a single nucleotide change from the patient's isolate. CONCLUSIONS: As illustrated by this case, whole genome sequencing may be insufficient to reliably determine the source of invasive infections caused by L. rhamnosus.

Probiotic bacterial adsorption coupled with CRISPR/Cas12a system for mercury (II) ions detection.

The complex sample matrix poses significant challenges in accurately detecting heavy metals. In view of its superior performance for the biological adsorption of heavy metals, probiotic bacteria can be explored for functional unit to eliminate matrix interference. Herein, Lactobacillus rhamnosus (LGG) demonstrates a remarkable tolerance and can adsorb up to 300 µM of Hg2+, following the Freundlich isotherm model with the correlation coefficient (R2) value of 0.9881. Subsequently, by integrating the CRISPR/Cas12a system, a sensitive and specific fluorescent biosensor, "Cas12a-MB," has been developed for Hg2+ detection. Specifically, Hg2+ adsorbed onto LGG can specifically bind to the nucleic acid probe, thereby inhibiting the binding of the probe to LGG and the subsequent activation of the CRISPR/Cas12a system. Under optimal experimental conditions, with the detection time of 90 min and the detection limit of 0.44 nM, the "Cas12a-MB" biosensor offers a novel, eco-friendly approach for Hg2+ detection, showcasing the innovative application of probiotics in biosensor.

N, O-codoped hierarchical porous graphitic carbon for electrochemical immunosensing of Lactobacillus rhamnosus GG.

An ultrasensitive label-free electrochemical immunosensor was fabricated for quantitative detection of Lactobacillus rhamnosus GG (LGG). The N/O co-doped three-dimensional hierarchical porous graphitic (THPG) carbon was synthesized by a one-step synthesis of polyaniline hydrogel, and followed by simple carbonization and chemical activation procedures. Because of the unique structure design, the obtained THPG carbon networks possess an ultra-large specific surface area of 4859 m2 g-1 along with a class of highly graphitic carbons. The results offer an enormous surface area and excellent electrical conductivity for label-free electrochemical immunosensing of probiotic L. rhamnosus strain. Under optimal conditions, the immunosensor showed a good linear relationship between peak current and concentration of LGG (R2 = 0.9976), with a detection limit of 2 CFU mL-1. Furthermore, this label-free immunosensor also shows good specificity, long-term stability, and reliability, and could be applied to detect probiotic LGG in dairy products and drinks with satisfactory results. The present protocol was shown to be quite promising for practical screening and functional evaluation of probiotic products containing LGG. A ultrasensitive label-free electrochemical immunosensor based on THPG carbon was fabricated for detection of Lactobacillus rhamnosus GG.

Enumeration of Probiotic Strain Lacticaseibacillus rhamnosus GG (ATCC 53103) Using Viability Real-time PCR.

Probiotic health benefits are strain specific and are dose dependent. Hence, administering the correct strains, at the recommended doses is essential to achieve probiotic health benefits. Reliable methods are needed to facilitate probiotic strain identification and enumeration. Plate count methods are the most commonly used methods for probiotic enumeration. However, these methods are time-consuming, laborious, highly variable, and non-specific. Here, we developed a real-time PCR method for enumeration of a commonly used strain, Lacticaseibacillus rhamnosus GG. The method utilizes PMAxx as a viability dye to enumerate viable cells only. Optimization of viability treatment showed that PMAxx at a final concentration of 50 µM was effective in inactivating DNA from dead cells, and that bead beating for 5 min at 3000 rpm was effective in liberating DNA. The assay demonstrated high efficiency between 93 and 102%, with R2 values > 0.99. The assay showed high precision with relative standard deviation (RSD%) below 2.3%. Assay performance was compared to a plate count method in which there was a strong correlation between both methods (Pearson r = 0.8443). This method offers a 10 × shorter time for results and a higher precision compared to plate count methods. Furthermore, this method enables specific enumeration of L. rhamnosus GG in multi-strain products, which is not possible to achieve using plate count methods. This novel method facilitates faster and more accurate enumeration of L. rhamnosus GG as a raw ingredient as well as in finished products which enables better quality assurance and efficacy of probiotics for consumers.

Lactobacillus rhamnosus AD3 as a Promising Alternative for Probiotic Products.

Lactobacillus strains dominate the vaginal habitat and they are associated with a lower risk of genital infections. In addition, they contribute to the conservation of the vaginal microbiota by producing postbiotic agents. Previous studies have shown that their predominance involves antimicrobial activity against urogenital pathologies. In this context, probiotics may improve treatment outcomes. The aim of this study was to evaluate the probiotic properties of lactobacilli strains of vaginal origin using a multidisciplinary approach. For this purpose, safety criteria, ability to resist at low pH and bile salts, antimicrobial activity, ability to produce biofilm, capacity to produce hydrogen peroxide and more importantly, auto-aggregation, co-aggregation (with Candida spp.) and adhesion to human cells were evaluated. The strains belonged to the species of L. crispatus, L. gasseri, L. rhamnosus and L. delbruckii. Among these, a strain of L. rhamnosus named AD3 showed the best probiotic properties. As probiotics are already in use in many clinical practice and there are no major safety concerns, L. rhamnosus AD3 showed promise in becoming a prevention and complementary treatment option for urogenital diseases. Indeed, these results suggest that strain L. rhamnosus AD3 is non-pathogenic and likely to be safe for human consumption. This study revealed the great amensalistic properties of a new L. rhamnosus strain which can aim to be used as probiotic in pharmaceutical applications.

Probiotic Lactobacillus rhamnosus GG (LGG) restores intestinal dysbacteriosis to alleviate upregulated inflammatory cytokines triggered by femoral diaphyseal fracture in adolescent rodent model.

OBJECTIVE: The aim of the study was to examine the influence of femoral shaft fracture on systemic inflammation and gut microbiome in adolescent rats and evaluate the anti-inflammatory effect of Lactobacillus rhamnosus GG (LGG) and its regulation of intestinal flora, as well as illustrate the mechanism by which LGG ameliorates the inflammatory response and restores intestinal dysbacteriosis. MATERIALS AND METHODS: Twenty-four male Sprague Dawley rats of 5 to 6 weeks of age were subjected to a standard femoral shaft fracture and internally fixed with LGG supplementation in advance or on the same day of injury or with saline solution for 1 week. The levels of TNF-α, IL-6, IL-10, and CRP were assessed using standard protocols. Furthermore, gut microbiota composition was analyzed in the fecal samples using 16S rDNA gene sequencing, and the relationship between gut microbiota variation and inflammatory response was tested. RESULTS: The serum indices of the above-mentioned inflammatory cytokines were significantly increased, and the gut microbial balance was significantly disturbed in adolescent rats by diaphyseal fractures of the femur and surgery. Moreover, L. rhamnosus strains manipulated the gut microbiota by decreasing the relative abundance of Proteobacteria and increasing that of Firmicutes, Actinobacteria and Bacteroidetes, which in turn increased the levels of IL-10 and alleviated the levels of IL-6, CRP, and TNF-α. CONCLUSIONS: LGG exhibited anti-inflammatory effects by alleviating the inflammatory response and regulating the gut microbiota in adolescent rats who underwent skeletal fracture and surgery. Our results suggested that the L. rhamnosus strains could be considered as an alternative dietary supplement for the prevention or treatment of skeletal injury and its associated complications.

Effects of Lactobacillus rhamnosus GG on early postoperative outcome after pylorus-preserving pancreatoduodenectomy: a randomized trial.

OBJECTIVE: Pancreatoduodenectomy (PPPD) remains one of the most complex surgical procedures with high complication rates. Infectious complications, postoperative ileus and delayed gastric emptying in the perioperative period have a significant impact on the recovery from the treatment. Probiotics (PB) are known to have a beneficial effect as supportive therapy in major abdominal surgery but the evidence in pancreatic surgery is still limited. The aim of the study was to assess the influence of postoperative administration of PB on the early outcomes after PPPD. PATIENTS AND METHODS: Forty patients undergoing pylorus-preserving PPPD were enrolled to prospective trial and randomized in two groups: A - control group (n=20) receiving standard nutrition and B - probiotic group (n=20) treated additionally with Lactobacillus rahmnosus GG (L. rhamnosus GG) in the postoperative period from the day of the surgery for 30 days. Gastrointestinal motility, infection complications, length of hospital stay, and mortality were compared in the perioperative period and during 2 follow-up (i.e., after 14 and 30 days). RESULTS: There were no significant differences in mortality and infectious complications between groups. The length of hospital stay was shorter in the probiotic group compared to control (10 days vs. 8, respectively). The positive effect of L. rhamnosus GG on gastrointestinal tract's motility was observed, including earlier recurrence of postoperative bowel movements (group B: after 3.75 days vs. group A: 2.15 days), passing gasses (group B after 4 days vs. group A 2.9 days) and the first postoperative stool (group B after 5.84 days vs. group A 3.85 days). L. rhamnosus GG improved the appetite in postoperative day 1, 3, 5, 7 and 30 days after the surgery. CONCLUSIONS: L. rhamnosus GG improves the function of the gastrointestinal tract after major pancreatic surgery and may reduce the length of hospital stay.

In vivo assessment and characterization of lactic acid bacteria with probiotic profile isolated from human milk powder.

INTRODUCTION: Introduction: breast milk (MH) contains nutrients and bioactive compounds for child development, including probiotic bacteria, which contribute to intestinal maturation. This benefit accompanies the individual until adulthood. There are new methods such as spray drying that give this compound a good conservation without loss of microbiota. Objective: the aim of this study was to analyze the viability of lactic acid bacteria isolated from human milk with probiotic potential after the spray drying process, as well as to evaluate the possible adhesion in the colon of mice of the Balb/C strain after feeding them powdered human milk and a commercial formula milk. Method: we isolated and identified the presence of lactic acid bacteria with possible probiotic potential in powdered human milk using the MALDI-TOF MS technique. Powdered human milk and a commercial formula milk were fed to mice of the Bald/C strain for 14 weeks. Glucose level and weight were measured in the mice. The feces were collected to verify the presence of lactic bacteria. The mice were sacrificed and their intestines were weighed, isolating the lactic acid bacteria both from the intestines and from the feces. The strains isolated from mice fed human milk were evaluated for their probiotic potential, analyzing their ability to inhibit pathogens, resistance to pH, temperature, adhesion, and hydrophobicity. Results: the presence of Lactobacillus fermentum LH01, Lactobacillus rhamnosus LH02, Lactobacullis reuteri LH03, and Lactobacillus plantarum LH05 in powdered human milk was identified. All strains showed a possible probiotic profile due to the ability of bacteria to resist low pH, bile salts, and exposure to gastric enzymes, as well as their hydrophobicity and self-aggregation capacity, and their failure to show hemagglutination or hemolysis activity in a culture medium rich in erythrocytes. We observed that the consumption of powdered human milk prevented weight gain and constipation in mice. Conclusions: after spray drying, strains with possible probiotic potential may be preserved in human milk. The consumption of powdered human milk with probiotic bacteria prevents constipation and weight gain in mice, when compared to those fed a commercial formula milk.

INTRODUCCIÓN: Introducción: la leche materna (HM) contiene los nutrientes y compuestos bioactivos necesarios para el desarrollo infantil, incluidas bacterias probióticas, que contribuyen a la maduración intestinal. Objetivo: el objetivo de este estudio fue analizar la viabilidad de las bacterias acidolácticas aisladas de la leche humana con potencial probiótico, después del proceso de secado, así como evaluar su posible adhesión en el colón de ratones (BAlb/C) alimentados con leche humana en polvo y leche de una fórmula comercial. Método: se aislaron e identificaron mediante la técnica de Maldi-Tof-MS las bacterias acidolácticas con posible potencial probiótico en la leche humana en polvo. Se alimentó con leche humana en polvo y leche de una fórmula comercial a ratones de la cepa Bald/C durante 14 semanas. Se midieron el nivel de glucosa y el peso. Las heces se recolectaron para verificar la presencia de bacterias lácticas. Los ratones se sacrificaron y se pesaron los intestinos, aislando las bacterias lácticas tanto de los intestinos como de las heces. En las cepas aisladas de la leche humana se evaluó el potencial probiótico analizando su capacidad para inhibir patógenos, resistir distintos pH y temperaturas, adherirse y mostrar hidrofobicidad. Resultados: se identificó la presencia de Lactobacillus fermentum LH01, Lactobacillus rhamnosus LH02, Lactobacullis reuteri LH03 y L. plantarum LH05 en la leche humana en polvo. Todas las cepas mostraron resistencia a los pH bajos, a las sales biliares y a la exposición a enzimas gástricas, así como una buena hidrofobicidad y capacidad de autoagregación. Además, no presentaron actividad de hemaglutinación o hemólisis en un medio de cultivo rico en eritrocitos. Observamos que el consumo de leche humana en polvo evita en los ratones el aumento de peso y el estreñimiento. Conclusiones: después del secado por aspersión, las cepas con posible potencial probiótico pueden conservarse en la leche materna. El consumo de leche humana en polvo con bacterias probióticas evita el estreñimiento y el aumento de peso en los ratones, en comparación con los alimentados con leche de una formula comercial.

Lactobacillus rhamnosus sepsis associated with probiotic therapy in an extremely preterm infant: Pathogenesis and a review for clinicians.

BACKGROUND: Necrotizing enterocolitis (NEC) is one of the most serious complications in preterm infants. Probiotics have been used to prevent NEC. Safety is a major concern for this practice. METHODS: We reported a female preterm infant who received oral Lactobacillus rhamnosus GG but developed sepsis 12 days after the treatment. Cultures of blood and the catheter tip yielded L. rhamnosus. Next-generation sequencing was performed to analyze isolates from blood, stool, catheter, and product capsules. We also determined the capacities of these isolates to form biofilms. A literature review was performed. RESULTS: The patient was treated with ampicillin and piperacillin/tazobactam, and she subsequently recovered without complications. The analysis of genome sequences indicated that all the isolates belonged to the clone of L. rhamnosus GG (ATCC 53103), suggesting that sepsis was a catheter-related infection caused by the oral probiotic. L. rhamnosus GG (ATCC 53103) and the probiotic strain tested formed biofilms under all growth conditions. Isolates from the blood and catheter tip also formed biofilms, but the stool isolate did not. The capacity of intrinsic biofilm formation in L. rhamnosus GG depended on environmental factors and the type of culture medium. Literature review of L. rhamnosus GG sepsis in preterm and young infants found that nearly 60% of the patients had a suspected or confirmed infected catheter. CONCLUSION: The study showed that the capacity of L. rhamnosus GG to form biofilms, especially in the presence of glucose, is a critical factor leading to the probiotic-related sepsis in preterm infants.

Isolation and characterization of lactic acid bacteria from human milk.

Human milk is the main source of nutrition for infants and the transmission of various microorganisms. The lactic acid bacteria (LAB) in breast milk allow for the establishment of the gut microflora of infants. In this study, we aimed to assess the probiotic potential of LAB strains isolated from breast milk of healthy Chinese women. Two strains, Lacticaseibacillus rhamnosus (formerly Lactobacillus rhamnosus) LHL6 and LHL7, were selected and identified through morphology observation, Gram staining, and 16S rDNA phylogenetic analysis. Using Limosilactobacillus fermentum (formerly Lactobacillus fermentum) CECT5716 as the standard reference strain, the screened strains were characterized for aspects of growth, production of lactic acid and H2O2, antibiotic susceptibility, survival under simulated gastrointestinal conditions, and tolerance to cadmium (Cd). In de Man, Rogosa, and Sharpe (MRS) broth, LHL6 and LHL7 showed longer lag phases than CECT5716 but higher specific growth rates. For the production of lactic acid and H2O2, LHL7 performed better than LHL6 and CECT5716, indicating better antimicrobial ability. Strain LHL7 generated 9.99 mg/L H2O2, considerably higher than 1.25 mg/L for LHL6 and 2.33 mg/L for CECT5716. According to European Food Safety Authority minimum inhibitory concentrations, all of the investigated strains were resistant to chloramphenicol, streptomycin, and kanamycin. However, unlike LHL6 and CECT5716, LHL7 was susceptible to ampicillin and resistant to tetracycline. Resistance to azithromycin, cephalexin, and penicillin G were similar for all 3 strains, whereas CECT5716 was resistant to a higher concentration of roxithromycin. All 3 strains were able to survive in a simulated gastric-like solution, but a low percentage survived in the presence of 0.4% bile salt and 7% pancreatin. Encapsulation with protectants may enhance the survival rate. All 3 strains were tolerant to 500 mg/L Cd in MRS broth and to 1,000 mg/L Cd on MRS agar medium. In summary, 2 novel strains of LAB were obtained that have similar characteristics to the reference strain CECT5716. This work identified potential probiotic candidates for application in the food and pharmaceutical industries and facilitated identification of further probiotics.

Effect of Probiotic Use on Antibiotic Administration Among Care Home Residents: A Randomized Clinical Trial.

Importance: Probiotics are frequently used by residents in care homes (residential homes or nursing homes that provide residents with 24-hour support for personal care or nursing care), although the evidence on whether probiotics prevent infections and reduce antibiotic use in these settings is limited. Objective: To determine whether a daily oral probiotic combination of Lactobacillus rhamnosus GG and Bifidobacterium animalis subsp lactis BB-12 compared with placebo reduces antibiotic administration in care home residents. Design, Setting, and Participants: Placebo-controlled randomized clinical trial of 310 care home residents, aged 65 years and older, recruited from 23 care homes in the United Kingdom between December 2016 and May 2018, with last follow-up on October 31, 2018. Interventions: Study participants were randomized to receive a daily capsule containing a probiotic combination of Lactobacillus rhamnosus GG and Bifidobacterium animalis subsp lactis BB-12 (total cell count per capsule, 1.3 × 1010 to 1.6 × 1010) (n = 155), or daily matched placebo (n = 155), for up to 1 year. Main Outcomes and Measures: The primary outcome was cumulative antibiotic administration days for all-cause infections measured from randomization for up to 1 year. Results: Among 310 randomized care home residents (mean age, 85.3 years; 66.8% women), 195 (62.9%) remained alive and completed the trial. Participant diary data (daily data including study product use, antibiotic administration, and signs of infection) were available for 98.7% randomized to the probiotic group and 97.4% randomized to placebo. Care home residents randomized to the probiotic group had a mean of 12.9 cumulative systemic antibiotic administration days (95% CI, 0 to 18.05), and residents randomized to placebo had a mean of 12.0 days (95% CI, 0 to 16.95) (absolute difference, 0.9 days [95% CI, -3.25 to 5.05]; adjusted incidence rate ratio, 1.13 [95% CI, 0.79 to 1.63]; P = .50). A total of 120 care home residents experienced 283 adverse events (150 adverse events in the probiotic group and 133 in the placebo group). Hospitalizations accounted for 94 of the events in probiotic group and 78 events in the placebo group, and deaths accounted for 33 of the events in the probiotic group and 32 of the events in the placebo group. Conclusions and Relevance: Among care home residents in the United Kingdom, a daily dose of a probiotic combination of Lactobacillus rhamnosus GG and Bifidobacterium animalis subsp lactis BB-12 did not significantly reduce antibiotic administration for all-cause infections. These findings do not support the use of probiotics in this setting. Trial Registration: ISRCTN Identifier:16392920.

Therapeutic effect of Lactobacillus rhamnosus SHA113 on intestinal infection by multi-drug-resistant Staphylococcus aureus and its underlying mechanisms.

Staphylococcus aureus, especially multi-drug-resistant (MDR) pathogenic S. aureus, poses a severe threat to food safety and human health. Probiotics offer promising potential for the control of MDR pathogens because of their safe and biofunctional properties. This study shows that Lactobacillus rhamnosus SHA113, a strain isolated from the milk of healthy women, could efficiently inhibit MDR S. aureus both in vitro and in vivo. In vitro, L. rhamnosus efficiently inhibited and even killed drug resistant and drug sensitive S. aureus strains. In vivo experiments showed that SHA113 could efficiently decrease the number of S. aureus cells, inhibit the expression of inflammatory factors TNF-α and IL-6, and restore the level of white cells and neutrophils in the blood. SHA113 could also efficiently repair damage of the intestinal barrier and other functions impaired by S. aureus infection. This was indicated by a change of intestinal villi length and structure, and an up-regulated expression of tight junction proteins ZO-1 and occludin. SHA113 also restored the structural damage of immune organs, such as the enlargement of the spleen and the increased level of inflammatory cytokines caused by S. aureus infection. More importantly, L. rhamnosus SHA113 showed more effective inhibitory and therapeutic effects on MDR S. aureus strain ZBQ006 than on drug sensitive S. aureus strain 29213. These results illustrated that L. rhamnosus SHA113 has great potential for the treatment of MDR S. aureus contamination as food control and for therapeutic treatment.

A Randomized Controlled Open Label Crossover Trial to Study Vaginal Colonization of Orally Administered Lactobacillus Reuteri RC-14 and Rhamnosus GR-1 in Pregnant Women at High Risk for Preterm Labor.

Lactobacilli administration has been suggested for the treatment and prevention of bacterial vaginosis, which increases the risk for preterm birth. We aimed to evaluate the vaginal colonization of lactobacilli orally administered to pregnant women at risk for preterm birth. We performed a randomized and controlled crossover study between January 2016 and May 2017. Forty pregnant women at high risk for preterm birth with normal vaginal flora (Nugent score ≤ 3) were randomized to either receive two oral capsules/day each containing 5 × 109 Lactobacilli (L.) rhamnosus GR-1 and L. reuteri RC-14 (n = 20) or no treatment (n = 20) for 2 months. Treatments were then crossed over for an additional two months. A vaginal examination and swabbing were performed for assessment of bacterial vaginosis at baseline and every month until study completion. At the same time points, vaginal samples were cultured and subjected to matrix-assisted-laser-desorption/ionization-time-of-flight-mass-spectrometry (MALDI TOF-MS) for the detection of the specific bacterial strains contained in the capsules. The primary endpoint was the presence of the administered lactobacilli strains in the vagina during the first two months of follow-up. Thirty-eight women completed the study. During the first two months of treatment, L. rhamnosus GR-1 was detected in one (5%) woman on the probiotic treatment and 2 (11%) women receiving no treatment (p = 0.6). L. rhamnosus GR-1 was detected in vaginal samples of 4 (11%) women during probiotic treatment (of both groups) and L. reuteri RC-14 was not detected in any samples. The rest of the endpoints were not different between the groups. Altogether, vaginal colonization of lactobacilli following oral administration is low during pregnancy.

Antifungal activity of fermented dairy ingredients: Identification of antifungal compounds.

Fungi are commonly identified as the cause for dairy food spoilage. This can lead to substantial economic losses for the dairy industry as well as consumer dissatisfaction. In this context, biopreservation of fermented dairy products using lactic acid bacteria, propionibacteria and fungi capable of producing a large range of antifungal metabolites is of major interest. In a previous study, extensive screening was performed in vitro and in situ to select 3 dairy fermentates (derived from Acidipropionibacterium jensenii CIRM-BIA1774, Lactobacillus rhamnosus CIRM-BIA1952 and Mucor lanceolatus UBOCC-A-109193, respectively) with antifungal activity. The aim of the present study was to determine the main compounds responsible for this antifungal activity. Fifty-six known antifungal compounds as well as volatiles were targeted using different analytical methods (conventional LC and GC, GC-MS, LC-QToF). The most abundant antifungal compounds in P. jensenii-, L. rhamnosus- and M. lanceolatus-derived fermentates corresponded to propionic and acetic acids, lactic and acetic acids, and butyric acid, respectively. Many other antifungal compounds (organic acids, free fatty acids, volatile compounds) were identified but at lower levels. In addition, an untargeted approach using nano LC-MS/MS identified a 9-amino acid peptide derived from αs2-casein in the L. rhamnosus-derived fermentate. This peptide inhibited M. racemosus and R. mucilaginosa in vitro. This study provides new insights on the molecules involved in antifungal activities of food-grade microorganism fermentates which could be used as antifungal ingredients in the dairy industry.

Enhanced bioactivity of Zanthoxylum schinifolium fermented extract: Anti-inflammatory, anti-bacterial, and anti-melanogenic activity.

Fermented extracts have evolved to be a potential alternative to synthetic chemicals, owing to their anti-inflammatory and anti-bacterial properties. This study intends to assess the potential of fermented Zanthoxylum schinifolium extract for use in biomedical applications. Probiotic bacteria, Lactobacillus rhamnosus A6-5, were deployed as a seed culture for fermentation. The fermented extract showed greater tyrosinase inhibitory activity and reduced melanin production (58.3%) compared with the raw extract. Cytotoxicity assay inferred that 500 µg/mL is the ideal non-toxic concentration with maximum cell viability. In addition, DAPI staining did not show any damage to the chromatin structure of the cells. The anti-aging property of the fermented extract was confirmed by a decrease in IL-6 content. The fermented extract showed lower MIC (40 mg/mL) and MBC (60 mg/mL), indicating greater anti-bacterial activity than the raw extract. The results confirmed that the fermented Z. schinifolium extract has high biomedical properties compared with the raw extract and can be used as an ideal skin whitening agent.

Characteristic of Bacteriocins of Lactobacillus rhamnosus BTK 20-12 Potential Probiotic Strain.

Multidrug resistance (MDR) is a serious health threat throughout the world resulting in reduced efficacy of antibacterial, antiparasitic, antiviral, and antifungal drugs. One of the most promising concepts that may represent a good alternative to antibiotics can be the use of bacteriocins obtained from lactic acid bacteria. The L. rhamnosus BTK 20-12 strain was isolated from traditional Armenian naturally fermented salted cheese. The probiotic potential of the strain was approved. It was shown that strain produced at less two bacteriocins (BCN 1 and BCN 2) with different molecular weight (1427 Da and 602.6 Da, respectively). Bacteriocins inhibited the growth of multidrug-resistant bacteria of different etiologies and belong to different taxonomic groups with diverse efficiency and it depends on properties of bacteriocins, as well as from isolation sources of pathogens. Thus, bacteriocins of L. rhamnosus BTK 20-12 have protein-like nature and a broad range of activity and are excellent candidates for the development of new prophylactic and therapeutic substances to complement or replace conventional antibiotics.

Lactobacillus rhamnosus from human breast milk shows therapeutic function against foodborne infection by multi-drug resistant Escherichia coli in mice.

The emergence of multi-drug resistant (MDR) pathogens greatly challenges the development of new drugs. Probiotics with the ability to inhibit MDR pathogens offer advantages over chemical antibiotics and drugs due to increased safety and fewer side effects. This study reports that Lactobacillus rhamnosus SHA113 (isolated from breast milk) significantly inhibited MDR Escherichia coli both in vitro and in vivo. MDR E. coli caused more severe inflammatory effects. TNF-α and IL-6 levels increased, while the IL-10 content decreased in serum. MDR E. coli caused disturbance in the gut microbial balance, increased the total coliform, decreased lactic acid bacteria in feces, decreased Firmicutes, and increased both Bacteroidetes and Proteobacteria. At the end of the curing treatment, ampicillin (AMP) treatment significantly reduced lactic acid bacteria compared to total coliform in feces and exacerbated the increase of Proteobacteria caused by MDR E. coli. L. rhamnosus SHA113 treatment resulted in a more significant and faster decrease of total coliform in feces and a significant decrease of Proteobacteria in the gut microbiota. The increase of total coliform in feces (caused by MDR E. coli infection) was positively correlated with IL-6 and TNF-α and negatively correlated with IL-10 in serum. However, the increase of lactic acid bacteria in feces (caused by L. rhamnosus SHA113 treatment) was negatively correlated with serum TNF-α, indicating that SHA113 exerted anti-inflammatory effects. These results suggest that L. rhamnosus SHA113 has great potential for inhibiting infections by MDR E. coli and for regulating the gut flora balance.

Characterization of the immunomodulatory and anti-Helicobacter pylori properties of the human gastric isolate Lactobacillus rhamnosus UCO-25A.

The ability to form biofilms and the potential immunomodulatory properties of the human gastric isolate Lactobacillus rhamnosus UCO-25A were characterized in vitro. It was demonstrated that L. rhamnosus UCO-25A is able to form biofilms on abiotic and cell surfaces, and to modulate the inflammatory response triggered by Helicobacter pylori infection in gastric epithelial cells and THP-1 macrophages. L. rhamnosus UCO-25A exhibited a substantial anti-inflammatory effect in both cell lines and improved IL-10 levels produced by challenged macrophages. Additionally, UCO-25A protected AGS cells against H. pylori infection with a higher pathogen inhibition when a biofilm was formed. Given the importance of inflammation in H. pylori-mediated diseases, the differential modulation of the inflammatory response in the gastric mucosa by an autochthonous strain is an attractive alternative for improving H. pylori eradication and reducing the severity of the diseases that arise from the resulting chronic inflammation.