Diversity Of Lactobacilli Research Articles

State of the vaginal biocenosis depending on the species diversity of lactobacilli

Bacterial vaginosis is one of the most common reproductive health problems in women. Lactobacillus spp. play a leading role in the vaginal biocenosis and provide local antimicrobial defense, but not all species are equally capable of protecting the vaginal ecosystem from pathogens. Diagnostic methods in practical healthcare do not allow identification of Lactobacillus spp. species, which limits the ability to comprehensively assess the status of the vaginal biocenosis. We conducted a study in which we compared microscopy data of the examined smear with the detection of Lactobacillus spp. and other microorganisms. The aim of the study was to evaluate the species composition of Lactobacillus spp. from the vagina depending on morphologic characteristics and composition of associated flora. The study included 64 conditionally healthy women of reproductive age from 18 to 35 years old. The study of species composition of the vaginal biocenosis and typing of lactobacilli was carried out by real-time PCR methods. The obtained results were processed using generally accepted methods of descriptive and ordinal statistics. During the study, it was found that the vaginal biocenosis was dominated by species of Lactobacillus spp. L. crispatus, L. vaginalis, L. iners and L. jensenii. L. johnsonii was rarely found, and L. acidophilus was not detected. Typing results showed that the vagina was more frequently colonized by more than one species of Lactobacillus spp. while a single species of Lactobacillus spp. was detected less frequently. A correlation was found between Lactobacillus spp. species and bacilli thickness. If thick bacilli are detected in gynecological smear microscopy, they belong to the species L. crispatus, which has high colonization resistance and is a factor in the stability of the vaginal biocenosis. If smear microscopy reveals thin bacilli, then these are species of L. iners and L. jensenii. These representatives of Lactobacillus spp. are not directly related to the dysbiotic state of the vagina, but may indicate the possible development of dysbiosis in the future.

The double-layer emulsions loaded with bitter melon (Momordica charantia L.) seed oil protect against dextran sulfate sodium-induced ulcerative colitis in mice

In this study, a whey protein isolate (WPI)-chitooligosaccharide (COS) stabilized bitter melon (Momordica charantia L.) seed oil emulsions (WC-BSOE) were prepared using the electrostatic layer-by-layer self-assembly technique, and their modulating effects on ulcerative colitis (UC) were investigated in dextran sulfate sodium (DSS)-induced UC mice model. The stability and releasing ability of WC-BSOE under simulated gastrointestinal digestion condition and their acute toxicity were also investigated. The results showed that WC-BSOE was stable to droplet aggregation in the simulated gastric and intestinal fluids and exhibited sustained release profile during gastrointestinal transit, evidenced by the measurement of particle size, polydispersity index, zeta-potential and released free fatty acids contents. Moreover, WC-BSOE had no toxic effects on BALB/c mice within the dose range of 40,000 mg/kg body weight (BW), and treatment with WC-BSOE at a dosage of 15 mg/kg BW effectively relieved DSS-induced UC symptoms in mice. Furthermore, WC-BSOE could improve the IL-4 and IgA contents in serum, as well as up-regulate the occludin and ZO-1 expressions and down-regulate MPO, MDA and ROS levels in colon tissues of colitis mice, and it also elevated the diversity and relative abundances of Firmicutes, Bacteroides, and Lactobacillus in the intestinal microbiota. These findings indicated that WC-BSOE exerted protective effects in UC through decreasing proinflammatory cytokines, increasing tight junction proteins, suppressing oxidative stress, and regulating intestinal microbiota. Collectively, this study suggested WC-BSOE might be developed as a promising dietary supplement for UC protection.

Biodiversity of intestinal Lactobacillus in relation to dietary habits and health status in Mongolians of China

Diet and health status directly or indirectly affect the gut microbiota. Mongolians have a varied intestinal Lactobacillus. However, how the diet regulates intestinal Lactobacillus and affects health has not been fully discussed. In this research, we engaged 72 adult Mongolian participants. Conducting a physical examination and Dietary assessments to understood their dietary habits and health status. Then, Designed a pair of Lactobacillus-specific primers to seeking correlations between their diet, health, and intestinal Lactobacillus. The results show that the Lactobacillus-specific primer (Lac16s) used was highly effective in amplifying Lactobacillus sequences. The amplified fragment effectively differentiated various Lactobacillus species.We deciphered the Lactobacillus diversity in Mongolian participants, discovering notable differences between the normal and overweight individuals. Specifically, the overweight group exhibited higher abundances of Ligilactobacillus salivarius, Limosilactobacillus mucosae, Ligilactobacillus ruminis, and Limosilactobacillus reuteri, whereas the normal weight group had a pronounced presence of Lacticaseibacillus paracasei. A deeper analysis established that vitamin intake profoundly influences the Lactobacillus composition in Mongolian intestines. Additionally, the health of the participants was closely tied to the presence of Lacticaseibacillus paracasei and Limosilactobacillus mucosae. Scrutinizing the relationships between Lactobacillus strains and metabolic function revealed a significant link between most metabolic pathways, such as ascorbate and aldarate metabolism, fructose and mannose metabolism, and histidine metabolism, especially with Lacticaseibacillus paracasei. This strain may be influenced by dietary habits. In conclusion, we infer that the Lactobacillus composition in Mongolian intestines is intertwined with their diet and health.

Species characteristics of bacteria of the genus <i>Lactobacillus</i> identified in different loci of the human body (literature review)

Bacteria of the genus Lactobacillus are inhabitants of the surfaces of human mucous membranes, such as the oral cavity, digestive and urogenital tracts. Moreover, there is evidence that they are found in breast milk and sputum. In view of the many genetic differences, metabolic abilities and other functions of the species included in this genus, a revision of the classification of the genus Lactobacillus is proposed in 2020. Recently, in the scientific medical literature, the issues related to the influence of lactobacilli on the human microbiome, maintaining health and preventing pathological conditions of the body have been actively discussed. This review is devoted to the functional characteristics and analysis of the species diversity of Lactobacillus spp. circulating in various body systems, their participation in the formation and regulation of defense mechanisms. However, negative impacts are also noted, most often associated with the transfer of genetic determinants of resistance to antimicrobial drugs from lactobacilli to gram-negative microbiota.

P-365 The composition of the endometrial microbiota, as determined by MicroBioMap®, significantly affects clinical outcomes in assisted reproduction treatments

Abstract Study question How does the presence of specific pathogenic or health-promoting microbial species in the endometrium relate to female fertility in assisted reproduction treatments (ART)? Summary answer Detection of endometrial pathogens using MicroBioMap® is associated with poor ART outcomes, whereas sterile endometria show the highest pregnancy and live birth rates. What is known already Vaginal eubiosis is characterised by low microbial diversity and dominance of Lactobacillus, which displays bioregulatory functions and prevents the growth of pathogenic microorganisms. Vaginal dysbiosis is directly linked to infertility and poor pregnancy outcomes. However, the endometrial microbiota composition and its role in fertility are more controversial. Robust reports show that chronic endometritis (CE) is highly prevalent among infertile patients, whose outcomes improve after antibiotic treatment. However, the role of Lactobacillus in this compartment, whether it also displays bioregulatory functions, or if it is essential and beneficial for women undergoing ART, is still unclear. Study design, size, duration This is a case-control retrospective study analysing the endometrial microbiota in the window of implantation (WOI) and the ART outcomes of 456 women undergoing IVF cycles in egg donation regimes with/without PGT-A (177 and 163 respectively), or using their own eggs in cycles with/without PGT-A (91 and 25 respectively), between March 2016 and April 2021 in IVF-Life Alicante (Spain). ART results after single embryo transfer (sET) of patients with different endometrial microbiota profiles were compared. Participants/materials, setting, methods Presence of 18 microbial CE pathogens and 4 Lactobacillus species was determined by high-throughput qPCR (MicroBioMap®) in 456 endometrial samples obtained during the WOI (determined by ER Map® receptivity test) of a hormone replacement therapy cycle. Clinical outcomes (clinical pregnancy, CP; live birth, LB) of sETs performed during the WOI (guided by ER Map®) were compared in relation to the endometrial microbiota profile. In PGT-A cycles, embryo ploidy was determined by NGS (VeriSeq-MiSeq) before sET. Main results and the role of chance According to the microbial profile detected by MicroBioMap®, patients were categorised as i) Lactobacillus only (L, n = 199), ii) Pathogens only (P, n = 56), iii) Lactobacillus + pathogens (L+P, n = 59) or iv) Undetected (U, n = 142). Absence of endometrial microorganisms was significantly associated to ART success. U-patients showed significantly higher CP (64.2% vs 50.8%, Fisheŕs exact p=0.046) and LB rates (52.9% vs 37.2%, p=0.03) after euploid sET than patients with microorganisms. These differences were more pronounced in patients receiving donor eggs (CP 70.2% vs 50.8%, p=0.026; LB 59.5% vs 40.2%, p=0.046). Presence of Lactobacillus in isolation in the endometrium showed a detrimental effect compared to U-environments. A trend towards statistical significance was detected, with L-patients showing lower LB rates compared to U-patients after euploid sET (38.8% vs 52.9%; p = 0.084). Detection of endometrial pathogens significantly reduced ART success rates. P-patients had significantly lower CP rates (64.2% vs 41.2%, p=0.038) after euploid sET than U-patients, and significantly lower CP (70.2% vs 36%, p=0.006) and LB rates (59.5% vs 21.7%, p=0.004) if receiving donor eggs. Interestingly, Lactobacillus dominance in pathogen-positive patients seemed to improve outcomes after euploid sET compared to pathogen-dominated patients (CP 56.7% vs 42.2%; LB 41.7% vs 31%). Limitations, reasons for caution This is a retrospective study. Randomised-control trials, non-selection studies and/or other investigations including antimicrobial treatments are needed to confirm these results and the extent of any clinical benefits. Endometrial biopsies were obtained transcervically. Although utmost care was taken, risk of contamination from the lower genital tract cannot be completely excluded. Wider implications of the findings Our results suggest that sterile endometria provide the best conditions for embryo implantation and pregnancy. Lactobacillus presence in endometrium might not be essential for pregnancy, and could even be detrimental if found in isolation. Presence of Lactobacillus as a bioregulator might only be beneficial if other pathogens co-colonise the tissue. Trial registration number Not applicable

Vaginal Microbiome Dysbiosis is Associated with the Different Cervical Disease Status

Vaginal microbiome composition was demonstrated to be associated with cervical disease. The colonization characteristics of vaginal microbes and their association with the different cervical disease status, especially cervical cancer (CC), are rarely investigated. In this cross-sectional study, we characterized the vaginal microbiome of women with different status of cervical diseases, including 22 NV + (normal tissue with HPV infection), low-grade squamous intraepithelial lesion (LSIL, n = 45), high-grade squamous intraepithelial lesion (HSIL, n = 36) and CC (n = 27) using bacterial 16S DNA sequencing. Thirty HPV-negative women with normal tissue were used as the control group. We found that higher diversity of microbiome with gradual depletion of Lactobacillus, especially L. crispatus, was associated with the severity of cervical disease. High-risk HPV16 infection was associated with higher microbiome diversity and depletion of Lactobacillus in high-grade cervical diseases (i.e. HSIL and CC). The CC group was characterized by higher levels of Fannyhessea vaginae, Prevotella, Bacteroides, Finegoldia, Vibrio, Veillonella, Peptostreptococcus, and Dialister. Co-occurrence network analyses showed that negative correlations were exclusively observed between Lactobacillus and other bacteria, and almost all non-Lactobacillus bacteria were positively correlated with each other. In particular, the most diverse and complex co-occurrence network of vaginal bacteria, as well as a complete loss of L. crispatus, was observed in women with CC. Logistic regression model identified HPV16 and Lactobacillus as significant risk and protective factors for CC, respectively. These results suggest that specific Lactobacillus species (e.g. L. crispatus and L. iners) can be used as important markers to target prevention measures prioritizing HPV16-infected women and other hrHPV-infected women for test, vaccination and treat initiatives.

Fecal Microbiota in Inflammatory Bowel Disease

Background: Diversity of microbial species is a hallmark of dysbiosis in inflammatory bowel disease (IBD). This study was undertaken to determine whether the diversity of lactobacilli and bifidobacteria, two regulatory microbial genera, is altered in patients with IBD. Methods: DNA from fecal samples of 20 healthy volunteers, 20 patients with ulcerative colitis (UC), and 25 patients with Crohn's disease (CD) was amplified by the polymerase chain reaction (PCR) for 16S ribosomal RNA gene sequences specific to genus Lactobacillus and Bifidobacterium. Real-time PCR was done to quantitate bacterial abundance. Amplified DNA was also bar coded and sequenced on the Roche 454 platform. Individual operational taxonomic units (OTUs) were taken as sequences with at least 97% similarity. Results: Abundance of Lactobacillus was significantly increased in UC compared to controls; no other difference in Lactobacillus or Bifidobacterium abundance was found between the three groups. Median reads for genus Lactobacillus was similar between control (940), UC (994), and CD (960) groups. The median number of OTUs per sample was not significantly different between controls (6), UC (5.5) and CD (7). The Shannon index of community diversity was similar between controls (median 1.12), UC (median 1.13) and CD (median 1.11). The Simpson D index was also similar between controls (median 0.393), UC (median 0.439) and CD (median 0.409). Median reads for genus Bifidobacterium was similar between control (846), UC (1052), and CD (964) groups. The median number of Bifidobacteria OTUs per sample was similar for controls (6), UC (7) and CD (8.5). The Shannon index of community diversity was similar between controls (median 0.75), UC (median 1.0) and CD (median 1.14). The Simpson D index was also similar between controls (median 0.570), UC (median 0.422) and CD (median 0.409). Conclusion: The abundance of Lactobacillus was increased in UC. Diversity of genus Lactobacillus and Bifidobacterium was not altered in either UC or CD.

Comparison of polysaccharides in ginseng root cultures and cultivated ginseng and establishment of high-content uronic acid plant synthesis system

Panax ginseng is a rare and traditional herbal medicine with many pharmacological activities. After ginseng was approved as a new resource food by the Ministry of Health, ginseng food was vigorously researched and developed. As an alternative resource for cultivated ginseng, ginseng tissue cultures has good development potential, but there are few studies on its component and pharmacological activity. In this study, we analyzed the compositional characteristics of polysaccharides in ginseng root cultures. Compared with cultivated ginseng, the relative molecular weight of ginseng polysaccharides in ginseng root cultures was smaller, and the proportion of acidic polysaccharides such as galacturonic acid was higher. Correspondingly, compared with cultivated ginseng, polysaccharide of ginseng root cultures has higher intestinal microbial diversity and abundance of Lactobacillus. On this basis, we constructed a genetic transformation system for ginseng root cultures through gene editing of galacturonic acid which significantly increased the content of uronic acid. This research laid the foundation for the development of ginseng polysaccharide medicines and health products.

Postmenopausal Vaginal Microbiome and Microbiota.

The ovulatory cycle has a significant influence on the microbial composition, according to the action of estrogen and progesterone on the stratified squamous epithelium, due to an increase in epithelial thickness, glycogen deposition, and influence on local immunology. The 16S rRNA gene amplification and pyrosequencing study demonstrated that healthy women have community state types (CST), classified as; type “L,” with a predominance of Lactobacillus crispatus, type II, with a predominance of Lactobacillus gasseri, type III, where Lactobacillus iners predominates, and type V with a predominance of Lactobacillus jensenii. Type IV does not identify lactobacilli but a heterogeneous population of bacteria. There seems to be a relationship between increased vaginal bacterial diversity and poverty of lactobacilli with the complaining of vaginal dryness. With menopause, there appears to be a reduction in lactobacilli associated with higher serum levels of follicle-stimulating hormone (FSH) and lower estrogen levels. The evaluation of Gram-stained vaginal smears in postmenopause women must take into account the clinical-laboratory correlation. We should observe two meanly possibilities, atrophy with few bacterial morphotypes, without inflammatory, infiltrate (atrophy without inflammation), and atrophy with evident inflammatory infiltrate (atrophy with inflammation or atrophic vaginitis). The relationship between the microbiome and postmenopausal vulvovaginal symptoms seems to be related to the bacterial vaginal population. However, more robust studies are needed to confirm this impression.

Distinct Bile Acid Profiles in Patients With Chronic Hepatitis B Virus Infection Reveal Metabolic Interplay Between Host, Virus and Gut Microbiome.

Hepatitis B virus (HBV) can hijack the host bile acids (BAs) metabolic pathway during infection in cell and animal models. Additionally, microbiome was known to play critical role in the enterohepatic cycle of BAs. However, the impact of HBV infection and associated gut microbiota on the BA metabolism in chronic hepatitis B (CHB) patients is unknown. This study aimed to unveil the distinct BA profiles in chronic HBV infection (CHB) patients with no or mild hepatic injury, and to explore the relationship between HBV, microbiome and BA metabolism with clinical implications.Methods: Serum BA profiles were compared between CHB patients with normal ALT (CHB-NALT, n = 92), with abnormal ALT (CHB-AALT, n = 34) and healthy controls (HCs, n = 28) using UPLC-MS measurement. Hepatic gene expression in CHB patients were explored using previously published transcriptomic data. Fecal microbiome was compared between 30 CHB-NALT and 30 HCs using 16S rRNA sequencing, and key microbial function was predicted by PICRUSt analysis.Results: Significant higher percentage of conjugated BAs and primary BAs was found in CHB patients even without apparent liver injury. Combinatory BA features can discriminate CHB patients and HCs with high accuracy (AUC = 0.838). Up-regulation of BA importer Na+ taurocholate co-transporting peptide (NTCP) and down-regulation of bile salt export pump (BSEP) was found in CHB-NALT patients. The microbial diversity and abundance of Lactobacillus, Clostridium, Bifidobacterium were lower in CHB-NALT patients compared to healthy controls. Suppressed microbial bile salt hydrolases (BSH), 7-alpha-hydroxysteroid dehydrogenase (hdhA) and 3-dehydro-bile acid Delta 4, 6-reductase (BaiN) activity were found in CHB-NALT patients.Conclusion: This study provides new insight into the BA metabolism influenced both by HBV infection and associated gut microbiome modulations, and may lead to novel strategy for clinical management for chronic HBV infection.

Vaginal microbiome topic modeling of laboring Ugandan women with and without fever

The composition of the maternal vaginal microbiome influences the duration of pregnancy, onset of labor, and even neonatal outcomes. Maternal microbiome research in sub-Saharan Africa has focused on non-pregnant and postpartum composition of the vaginal microbiome. Here we aimed to illustrate the relationship between the vaginal microbiome of 99 laboring Ugandan women and intrapartum fever using routine microbiology and 16S ribosomal RNA gene sequencing from two hypervariable regions (V1–V2 and V3–V4). To describe the vaginal microbes associated with vaginal microbial communities, we pursued two approaches: hierarchical clustering methods and a novel Grades of Membership (GoM) modeling approach for vaginal microbiome characterization. Leveraging GoM models, we created a basis composed of a preassigned number of microbial topics whose linear combination optimally represents each patient yielding more comprehensive associations and characterization between maternal clinical features and the microbial communities. Using a random forest model, we showed that by including microbial topic models we improved upon clinical variables to predict maternal fever. Overall, we found a higher prevalence of Granulicatella, Streptococcus, Fusobacterium, Anaerococcus, Sneathia, Clostridium, Gemella, Mobiluncus, and Veillonella genera in febrile mothers, and higher prevalence of Lactobacillus genera (in particular L. crispatus and L. jensenii), Acinobacter, Aerococcus, and Prevotella species in afebrile mothers. By including clinical variables with microbial topics in this model, we observed young maternal age, fever reported earlier in the pregnancy, longer labor duration, and microbial communities with reduced Lactobacillus diversity were associated with intrapartum fever. These results better defined relationships between the presence or absence of intrapartum fever, demographics, peripartum course, and vaginal microbial topics, and expanded our understanding of the impact of the microbiome on maternal and potentially neonatal outcome risk.

Non-Lactobacillus-Dominated Vaginal Microbiota Is Associated With a Tubal Pregnancy in Symptomatic Chinese Women in the Early Stage of Pregnancy: A Nested Case-Control Study.

The features of the vaginal microbiota (VM) community can reflect health status, and they could become new biomarkers for disease diagnosis. During pregnancy, domination of bacteria of the genus Lactobacillus in the VM community is regarded as a keystone because they stabilize the VM by producing antimicrobial compounds and competing adhesion. An altered VM composition provides a marker for adverse pregnancy outcomes. This nested case–control study aimed to characterize the VM in women with a tubal pregnancy (TP) presenting with pain and/or uterine bleeding in early pregnancy. Chinese women with a symptomatic early pregnancy of unknown location were the study cohort. 16S rDNA gene-sequencing of V3–V4 variable regions was done to assess the diversity, structures, taxonomic biomarkers, and classification of the VM community. The primary outcome was the location of the early pregnancy. The VM community in women with a TP showed higher diversity (PD-whole-tree, median: 8.26 vs. 7.08, P = 0.047; Shannon Diversity Index, median: 1.43 vs 0.99, P = 0.03) and showed different structures to those in women with an intrauterine pregnancy (IUP) (R = 0.23, P < 0.01). Bacteria of the genus Lactobacillus were significantly enriched in the IUP group, whereas bacteria of the genera Gardnerella and Prevotella were significantly enriched in the TP group. Lactobacillus abundance could be used to classify the pregnancy location (AUC = 0.81). Non-Lactobacillus-dominated microbiota (≤ 0.85% Lactobacillus) was significantly associated with a TP (adjusted odds ratio: 4.42, 95% confidence interval: 1.33 to 14.71, P = 0.02). In conclusion, among women with a symptomatic early pregnancy, a higher diversity and lower abundance of Lactobacillus in the VM is associated with a TP.

The cervical microbiota characteristics in patients with human papillomavirus infection

Objective: To investigate the characteristics of cervical microbiota in patients with HPV (Human Papillomavirus) infection, and to analyze the associations of cervical microbiota and HPV infection or cervicitis. Methods: 300 samples underwent HPV nucleic acid testing was collected in this case-control study from June 2019 to April 2020 in the Zhujiang Hospital of Southern Medical University, there were 150 cases allocated in HPV infection group (HPV+), and 150 cases of negative nucleic acid test were non-infectious Group (HPV-). Next-generation sequencing was used to sequence the V4 region of the bacterial 16S rRNA gene, and QIIME pipeline was used to analysis the microbiota composition of the two groups. Wilcoxon rank sum test and Kruskal-Wallis test were used to statistically analysis the differences of the microbiota between groups; and the α diversity and β diversity of the flora between groups were statistically analyzed by Adonis multivariate analysis of variance and Wilcoxon rank sum test. Results: A total of 300 samples were analyzed in this study, of which 150 samples were HPV-positive and 150 samples were HPV-negative; among HPV-positive cases, 132 were infected by high-risk HPV (88.0%), and 18 were low-risk HPV infections (12.0%). The composition of the cervical microbiota were significantly different between the HPV+group and the HPV-group, which in the HPV+group, the α diversity of the cervical microbiota were significantly increased (Shannon index, W=8 174, P<0.000 1; PD whole tree, W=8 887, P=0.001 7). The β diversity of the two groups was significantly different (Binary Jaccard, F=2.325 4, P=0.042 0; Bray Curtis, F=2.136 44, P=0.044 0). The relative abundance of Lactobacillus spp. and L.iners in the HPV+group sample decreased significantly (W=7 730, P<0.000 1; W=8 979, P=0.002 5), accompanied by enriched Achromobacter, Stenotrophomonas, Methylobacterium, Sneathia and Dialister. There was no significant difference in the composition of the cervical microbiota between high-risk HPV infection and low-risk HPV infection (F=4.100 4, P>0.05). In addition, cervicitis is significantly related to HPV infection (χ²=19.78, P<0.000 1), the composition of cervical flora has similarity features in cervicitis and HPV infection samples. Compared with the normal group, the cervical microbiota of cervicitis with HPV infection is mainly enriched in Achromobacter, Aerococcaceae, Streptococcus, Fusobacteria, and Xanthomonadaceae. Conclusion: The cervical microbiota of patients with HPV infection has a significant dysbiosis, with increased diversity and significant depletion of lactobacillus, accompanied by an increase in the abundance of pathogenic bacteria such as Achromobacter.

English

Breast feeding has critical effects on the newborns and either mother&rsquo;s health. Some of such health-improving effects of the mother&rsquo;s milk is associated with the beneficial microbes, lactic acid bacteria (LAB), which are normally present in the mother&rsquo;s milk. Thus, human milk-associated lactobacilli were isolated in this study and some of their probiotic properties was investigated. Afterwards, Lactobacillus strains were screened for low pH and bile acids tolerance. Molecular identification was carried out using 16SrDNA and polymerase chain reaction (PCR). Antibiotic resistance was evaluated with disk diffusion assay and the inhibitory effect of isolates on pathogenic bacteria was examined with well assay and zone inhibition. Isolation experiments resulted in 122 human milk- associated lactobacilli belonging to 12 species. The most dominant species was Lactobacillus casei followed by Lactobacillus fermentum, Lactobacillus plantarum and Lactobacillus gasser, respectively. Screening for probiotic properties showed that 19 isolates, belonging to, Lactobacillus, have interesting probiotic characteristics. The most prevalent antibiotic resistance was observed in case of vancomycin (63.15%) and no drug resistance was detected for chloramphenicol, penicillin, rifampin (0%). Three Lactobacillus strains, designated as L4, L14 and L16, were found as potential probiotic strains since they have indicated promising inhibitory effects against the studied pathogenic bacterial strains. Our results shed light on the considerable diversity of lactobacilli in human breast milk. Furthermore, the candidate probiotic strains detected in this research might be used as potential probiotic strains. &nbsp; Key words: Breast milk, Lactobacillus, probiotics, inhibitory effect, polymerase chain reaction.

Genetic diversity of Lactobacillus spp. isolates from oral cavity and their probiotic and antimicrobial properties

The kind of used food is effective on diversity of Lactobacillus biota in the oral cavity. Dairy products are major sources of probiotics including lactobacillus. Probably, these lactobacillus species have probiotics properties and they could benefit human health. In this study, consumers of domestic dairy products were selected and Lactobacillus spp. from their oral cavity were isolated and probiotic potential of these bacteria were investigated. Saliva samples were collected from one hundred people and cultured on MRS agar. Samples were incubated in anaerobic condition. Thirty predominant species from 100 persons were isolated and selected for probiotics properties assay by growth at gastric and gastrointestinal conditions (acid pH 3 and bile 0.3 w/v conditions respectively). Antibiotic susceptibility profile and antimicrobial activity of the isolates were defined. Predominant species were L. gasseri (53%) followed by L. fermentum and L. salivarius. All isolates were susceptible to Tigecycline, Penicillin, Tetracyclin and Ticaracillin. In addition, all isolates were resistance to Co-trimoxazole and Tobramycin. Acid resistance rate was higher than bile resistance. In addition, 26% of the isolates were resistant to acid and bile salt, which indicates good probiotic potential. Eight isolates had inhibitory activity against bacterial growth including L. gasseri, L. salivarius, L. crispatus and L. curvatus. The higher antimicrobial activity was showed by L. gasseri (five isolates) against Bacillus cereus. Therefore, some of these Lactobacillus species like of L. gasseri can be good candidate to inhibit of B. cereus growth in foods.

The assessment of microbiome changes and fecal volatile organic compounds during experimental necrotizing enterocolitis

IntroductionNecrotizing enterocolitis (NEC) remains a devastating disease that affects the gastrointestinal tract of the preterm infant. Volatile organic compounds (VOCs) have emerged as a non-invasive biomarker in many diseases. We hypothesized that fecal VOC profiles would be significantly different between control and NEC pups in a NEC mouse model. MethodsExperimental NEC was induced in five-day-old mice. Breastfed and formula-fed control groups were also studied. After four days, pups were euthanized and intestines were H&E stained and blindly scored. Stool microbiome analysis was performed via 16S rRNA sequencing. VOC analysis was assessed by the CyranoseⓇ 320 eNose device and p<0.05 was significant. ResultsNEC pups had severe intestinal injury when compared to controls. Microbiome analysis showed that both control groups had significantly higher microbial diversity and relative abundance of Lactobacillus than NEC, and lower relative abundance of Escherichia. Fecal VOC profile for NEC pups was significantly different from controls. ConclusionsExperimental NEC was associated with intestinal dysbiosis. Fecal VOC analysis by the CyranoseⓇ 320 eNose device can discriminate NEC pups from both breastfed and formula-fed controls. Further research is warranted to establish whether fecal VOCs can be used as a biomarker or predictive algorithm to diagnose NEC.

Phylotype-Level Characterization of Complex Communities of Lactobacilli Using a High-Throughput, High-Resolution Phenylalanyl-tRNA Synthetase (pheS) Gene Amplicon Sequencing Approach.

The lactobacilli identified to date encompass more than 270 closely related species that were recently reclassified into 26 genera. Because of their relevance to industry, there is a need to distinguish between closely related and yet metabolically and regulatory distinct species, e.g., during monitoring of biotechnological processes or screening of samples of unknown composition. Current available methods, such as shotgun metagenomics or rRNA gene-based amplicon sequencing, have significant limitations (high cost, low resolution, etc.). Here, we generated a phylogeny of lactobacilli based on phenylalanyl-tRNA synthetase (pheS) genes and, from it, developed a high-resolution taxonomic framework which allows for comprehensive and confident characterization of the community diversity and structure of lactobacilli at the species level. This framework is based on a total of 445 pheS gene sequences, including sequences of 276 validly described species and subspecies (of a total of 282, including the proposed L. timonensis species and the reproposed L. zeae species; coverage of 98%), and allows differentiation between 265 species-level clades of lactobacilli and the subspecies of L. sakei The methodology was validated through next-generation sequencing of mock communities. At a sequencing depth of ∼30,000 sequences, the minimum level of detection was approximately 0.02 pg per μl DNA (equaling approximately 10 genome copies per μl template DNA). The pheS approach, along with parallel sequencing of partial 16S rRNA genes, revealed considerable diversity of lactobacilli and distinct community structures across a broad range of samples from different environmental niches. This novel complementary approach may be applicable to industry and academia alike.IMPORTANCE Species formerly classified within the genera Lactobacillus and Pediococcus have been studied extensively at the genomic level. To accommodate their exceptional functional diversity, the over 270 species were recently reclassified into 26 distinct genera. Despite their relevance to both academia and industry, methods that allow detailed exploration of their ecology are still limited by low resolution, high cost, or copy number variations. The approach described here makes use of a single-copy marker gene which outperforms other markers with regard to species-level resolution and availability of reference sequences (98% coverage). The tool was validated against a mock community and used to address diversity of lactobacilli and community structure in various environmental matrices. Such analyses can now be performed at a broader scale to assess and monitor the assembly, structure, and function of communities of lactobacilli at the species level (and, in some cases, even at the subspecies level) across a wide range of academic and commercial applications.

Growth Performance and Intestinal Microbiota Diversity in Pacific White Shrimp Litopenaeus vannamei Fed with a Probiotic Bacterium, Honey Prebiotic, and Synbiotic

This study aimed to evaluate the growth performance and intestinal microbiota composition in Pacific white shrimp after probiotic, honey prebiotic, or synbiotic treatment. Pacific white shrimp were treated for 45days with probiotic (1% (v/w) of Bacillus sp. NP5 RfR probiotic), prebiotic (0.5% (v/w) of honey prebiotic), synbiotic (1% (v/w) of probiotic and 0.5% (v/w) prebiotic), or control (without addition of probiotic and prebiotic). Next-generation sequencing (NGS) was used to assess the effects of these treatments on growth performance and intestinal microbial diversity. The administration of a probiotic, prebiotic, or synbiotic led to increases in specific growth rate, feed conversion ratio, and digestive enzyme activities of amylase, protease, and lipase in Pacific white shrimp. The prebiotic treatment demonstrated the greatest effect, with values of growth rate of 3.09 ± 0.02 (% day-1), feed conversion ratio of 1.45 ± 0.00, and enzyme activities of 1.388 ± 0.0211IUmg-1 protein for amylase, 0.055 ± 0.0004IUmg-1 protein for protease, and 0.152 ± 0.0025IUmg-1 protein for lipase. Analysis of the intestinal microbiota diversity revealed that prebiotic administration caused dominance of the phylum Bacteroidetes, whereas the probiotic and synbiotic treatments caused dominance of the phylum Proteobacteria. Moreover, prebiotic treatment was able to increase the diversity of Microbacterium, Lactobacillus, and Neptunomonas, which are established probiotic candidates in aquaculture. The probiotic, prebiotic, and synbiotic treatments induced a number of operational taxonomic units (OTUs) significantly higher than control treatment, that is, 470, 480, 451, and 344 OTU, respectively.

Polyamines of human strain Lactobacillus plantarum Inducia induce modulation of innate immune markers

• Polyamines of L. plantarum Inducia strain and Inducia cheese enhance the intestinal barrier function and the innate immune markers of blood. • The putrescine of Inducia cause the increase of lactobacilli and lymphocytes in the ileal and colonic mucosa of NIH line mice. • In volunteers the increase of ac- putrescine, IL-6 and monocytes amount take place after Inducia cheese consumption. • N-acetylated putrescine in the urine of volunteers followed by a moderate increase of the number of blood monocytes and IL-6. The role of polyamines of the human Lactobacillus plantarum strain Inducia (DSM 21379) for modulation of innate immune markers was explored. The strains’ genes for polyamines, and amino acid metabolites were tested. Edam-type cheese comprised with putrescine producing strain Inducia, and control cheese were administered to n = 20 NIH-line mice and tested in 12 healthy Estonian volunteers (ISRCTN38739209) consuming 50 g Inducia cheese (3 × 109 CFU/daily) and control cheese in blinded placebo-controlled 3-week cross-over trial In experimental mice the amount of ileal and colonic lymphatic tissue, the count and diversity of lactobacilli increased. In volunteers' urine acetylated putrescine (p = 0.021); monocytes (p = 0.032), and cytokine IL-6 (p = 0.020) content in blood increased moderately. The amount of putrescine with IL-6 (r = 0.892, p = 0.003); acetylated spermidine with monocytes (r = 0.657, p = 0.039) and high-sensitive C-reactive protein (r = 0.848, p = 0.004) were correlated. Polyamines of L. plantarum Inducia and its food products can enhance the innate immune markers.

Biodiversity and technological-functional potential of lactic acid bacteria isolated from spontaneously fermented chia sourdough

Chia, is a gluten-free, rich in proteins, oilseed that is “on trend” as an alternative ingredient in food production, adding nutritional value. As a reservoir of natural biodiversity, lactic acid bacteria development, during spontaneous chia flour fermentation (sourdough) for 10 days, were investigated by culturing and high throughput sequencing (HTS). Culture-dependent analysis showed a rapid increase in total LAB numbers from the second day of sourdough refreshment. Taxonomical identification of LAB isolates by rep-PCR and further 16S rRNA sequencing was performed. Besides Among identified LAB by culture-dependent approach, species from genus Enterococcus were the most abundant; Lactococcus (Lc. lactis), Lactobacillus (L. rhamnosus) and Weissella (W. cibaria) species were also isolated. By HTS, twelve OTUs belonging to LAB genera were identified during chia sourdough fermentation with an increased Lactobacillus diversity. Enterococcus (E.) faecium, E. mundtii, W. cibaria and L. rhamnosus were detected as dominant species in the final propagation stages while Bacillus and Clostridium were mostly present during first fermentation stages. The investigation of biotechnological and safety traits (acidification ability, protein hydrolysis, exopolysaccharides production, antimicrobial activity and antibiotic resistance) of 15 representative LAB strains was performed. Strains characterization led to the selection of Lc. lactis CH179, L. rhamnosus CH34 and W. cibaria CH28 as candidates to be used as novel functional starter culture for gluten-free chia fermented products. As far as we know, this is the first study providing information on the molecular inventory of LAB population during spontaneous fermentation of chia sourdough.