Lactobacilli Cell-Free Supernatants Modulate Inflammation and Oxidative Stress in Human Microglia via NRF2-SOD1 Signaling.

Microglia are macrophage cells residing in the brain, where they exert a key role in neuronal protection. Through the gut-brain axis, metabolites produced by gut commensal microbes can influence brain functions, including microglial activity. The nuclear factor erythroid 2-related factor 2 (NRF2) is a key regulator of the oxidative stress response in microglia, controlling the expression of cytoprotective genes. Lactobacilli-derived cell-free supernatants (CFSs) are postbiotics that have shown antioxidant and immunomodulatory effects in several in vitro and in vivo studies. This study aimed to explore the effects of lactobacilli CFSs on modulating microglial responses against oxidative stress and inflammation. HMC3 microglia were exposed to lipopolysaccaride (LPS), as an inflammatory trigger, before and after administration of CFSs from three human gut probiotic species. The NRF2 nuclear protein activation and the expression of NRF2-controlled antioxidant genes were investigated by immunoassay and quantitative RT-PCR, respectively. Furthermore, the level of pro- and anti-inflammatory cytokines was evaluated by immunoassay. All CFSs induced a significant increase of NRF2 nuclear activity in basal conditions and upon inflammation. The transcription of antioxidant genes, namely heme oxygenase 1, superoxide dismutase (SOD), glutathione-S transferase, glutathione peroxidase, and catalase also increased, especially after inflammatory stimulus. Besides, higher SOD1 activity was detected relative to inflamed microglia. In addition, CFSs pre-treatment of microglia attenuated pro-inflammatory TNF-α levels while increasing anti-inflammatory IL-10 levels. These findings confirmed that gut microorganisms' metabolites can play a relevant role in adjuvating the microglia cellular response against neuroinflammation and oxidative stress, which are known to cause neurodegenerative diseases.

Antioxidant Peptides Derived from Cheese Products via Single and Mixed Lactobacillus Strain Fermentation.

Probiotics are used in cheese fermentation to endow the product with unique functional properties, such as enhanced flavor and aroma development through proteolysis and lipolysis. In this study, two probiotic Lactobacillus strains, Lactobacillus plantarum A3 and Lactobacillus reuteri WQY-1, were selected to develop new probiotic cheeses in the form of single- and mixed-strain starters. The results demonstrated that the L. plantarum A3 single-strain group and the L. plantarum A3/L. reuteri WQY-1 mixed fermentation group exhibited superior product performance, particularly the release of functional hydrolysates during cheese ripening. Furthermore, Label-free quantitative proteomic analysis revealed 26 unique antioxidant peptides in the L. plantarum A3 single-strain group and 53 in the L. plantarum A3/L. reuteri WQY-1 mixed fermentation group. Among these, CMENSAEPEQSLACQCL (ß-lactoglobulin), CMENSAEPEQSLVCQCL (ß-lactoglobulin), and IQYVLSR (κ-casein) have been found to possess potential antioxidant properties both in vitro and in vivo. This confirmed that milk-derived protein peptides in cheese products exhibit potential antioxidant functions through the hydrolysis of probiotic strains.

Bacteroides uniformis degrades ß-glucan to promote Lactobacillus johnsonii improving indole-3-lactic acid levels in alleviating colitis.

BACKGROUND: Intake of dietary fiber is associated with a reduced risk of inflammatory bowel disease. ß-Glucan (BG), a bioactive dietary fiber, has potential health-promoting effects on intestinal functions; however, the underlying mechanism remains unclear. Here, we explore the role of BG in ameliorating colitis by modulating key bacteria and metabolites, confirmed by multiple validation experiments and loss-of-function studies, and reveal a novel bacterial cross-feeding interaction. RESULTS: BG intervention ameliorates colitis and reverses Lactobacillus reduction in colitic mice, and Lactobacillus abundance was significantly negatively correlated with the severity of colitis. It was confirmed by further studies that Lactobacillus johnsonii was the most significantly enriched Lactobacillus spp. Multi-omics analysis revealed that L. johnsonii produced abundant indole-3-lactic acid (ILA) leading to the activation of aryl hydrocarbon receptor (AhR) responsible for the mitigation of colitis. Interestingly, L. johnsonii cannot utilize BG but requires a cross-feeding with Bacteroides uniformis, which degrades BG and produces nicotinamide (NAM) to promote the growth of L. johnsonii. A proof-of-concept study confirmed that BG increases L. johnsonii and B. uniformis abundance and ILA levels in healthy individuals. CONCLUSIONS: These findings demonstrate the mechanism by which BG ameliorates colitis via L. johnsonii-ILA-AhR axis and reveal the important cross-feeding interaction between L. johnsonii and B. uniformis. Video Abstract.

Mechanisms of action of Lactobacillus spp. in the treatment of oral candidiasis.

Candida albicans is often associated with oral candidiasis, and drug-resistance profiles have contributed to an increase in morbidity and mortality. It is known that Lactobacillus spp. acts by competing for adhesion to the epithelium, absorption of nutrients and modulation of the human microbiota. Therefore, they are important to assist in the host's microbiological balance and reduce the growth of Candida spp. Until now, there have been no reports in the literature of reviews correlating to the use of Lactobacillus spp. in the treatment of oral candidiasis. Thus, this review aims to highlight the mechanisms of action of Lactobacillus spp. and methods that can be used in the treatment of oral candidiasis. This is a study carried out through the databases PubMed Central and Scientific Electronic Library Online, using the following keywords: Oral Candidiasis and Lactobacillus. Original articles about oral candidiasis were included, with both in vitro and in vivo analyses, and published from 2012 to 2022. Lactobacillus rhamnosus was the most common microorganism used in the experiments against Candida, acting mainly in the reduction of biofilm, filamentation, and competing for adhesion sites of Candida spp. Among in vivo studies, most researchers used immunosuppressed mouse modelsof Candida infection. The studies showed that Lactobacillus has a great potential as a probiotic, acting mainly in the prevention and treatment of mucosal diseases. Thus, the use of Lactobacillus may be a good strategy for the treatment of oral candidiasis.

Biofilm Formation by Lactobacillus Strains of Modern Probiotics and Their Antagonistic Activity against Opportunistic Bacteria.

The species identity of the studied lactobacillus strains was confirmed by matrix-activated laser desorption/ionization with time-of-flight ion separation (MALDI-TOF mass spectrometry). Lactobacillus strains differed in the dynamics of lactic acid accumulation and changes in the pH of the culture medium. The culture medium affected adhesion ability of lactobacilli. The ability to adhere does not affect the formation of biofilms by lactobacillus strains except for the L. acidophilus La5 strain, which has low adhesion ability and fewer microbial cells detected after mechanical destruction of the biofilm. The metabiotics of the lactobacillus culture medium have an antagonistic effect on conditionally pathogenic microorganisms. Adhesion, biofilm formation, and antagonistic activity of probiotic lactobacillus strains are strain-specific properties.

Unveiling the Brazilian kefir microbiome: discovery of a novel Lactobacillus kefiranofaciens (LkefirU) genome and in silico prospection of bioactive peptides with potential anti-Alzheimer properties.

BACKGROUND: Kefir is a complex microbial community that plays a critical role in the fermentation and production of bioactive peptides, and has health-improving properties. The composition of kefir can vary by geographic localization and weather, and this paper focuses on a Brazilian sample and continues previous work that has successful anti-Alzheimer properties. In this study, we employed shotgun metagenomics and peptidomics approaches to characterize Brazilian kefir further. RESULTS: We successfully assembled the novel genome of Lactobacillus kefiranofaciens (LkefirU) and conducted a comprehensive pangenome analysis to compare it with other strains. Furthermore, we performed a peptidome analysis, revealing the presence of bioactive peptides encrypted by L. kefiranofaciens in the Brazilian kefir sample, and utilized in silico prospecting and molecular docking techniques to identify potential anti-Alzheimer peptides, targeting ß-amyloid (fibril and plaque), BACE, and acetylcholinesterase. Through this analysis, we identified two peptides that show promise as compounds with anti-Alzheimer properties. CONCLUSIONS: These findings not only provide insights into the genome of L. kefiranofaciens but also serve as a promising prototype for the development of novel anti-Alzheimer compounds derived from Brazilian kefir.

Heterofermentative Lentilactobacillus buchneri and low dry matter reduce high-risk antibiotic resistance genes in corn silage by regulating pathogens and mobile genetic element.

The study of antibiotic resistance in the silage microbiome has attracted initial attention. However, the influences of lactic acid bacteria inoculants and dry matter (DM) content on antibiotic resistance genes (ARGs) reduction in whole-plant corn silage remain poorly studied. This study accessed the ARGs' risk and transmission mechanism in whole-plant corn silage with different DM levels and treated with Lactiplantibacillus plantarum or Lentilactobacillus buchneri. The macrolide and tetracycline were the main ARGs in corn silage. The dominant species (Lent. buchneri and Lactobacillus acetotolerans) were the main ARGs carriers in whole-plant corn silage. The application of Lent. buchneri increased total ARGs abundance regardless of corn DM. Whole-plant corn silage with 30 % DM reduced the abundances of integrase and plasmid compared with 40 % DM. The correlation and structural equation model analysis demonstrated that bacterial community succession, resulting from changes in DM content, was the primary driving factor influencing the ARGs distribution in whole-plant corn silage. Interestingly, whole-plant corn silage inoculated with Lent. buchneri reduced abundances of high-risk ARGs (mdtG, mepA, tetM, mecA, vatE and tetW) by regulating pathogens (Escherichia coli), mobile genetic elements (MGEs) genes (IS3 and IS1182), and this effect was more pronounced at 30 % DM level. In summary, although whole-plant corn silage inoculated with Lent. buchneri increased the total ARGs abundance at both DM levels, it decreased the abundance of high-risk ARGs by reducing the abundances of the pathogens and MGEs, and this effect was more noticeable at 30 % DM level.

Dental plaque caries related microorganism in relation to demographic factors among a group of Iraqi children.

INTRODUCTION: Streptococcusmutans and lactobacilli are most important bacteria in the pathogenesis of dental caries. Cariogenic microflora has been associated to the primary caregiver transmission and sugary diets.

Role of Native Probiotic Lactobacillus Species via TGF-ß Signaling Pathway Modulation in CRC

Background: Colon microbiome composition in colorectal cancer (CRC) patients undergoes remarkable changes. The present study was designed to assess the impact of Lactobacillus mixture on the regulating the CRC by influencing the transforming growth factor beta (TGF-ß) signaling pathway in both in vitro (HT-29 cancer cells) and in vivo (BALB/c mice) models. Methods: In this study, the antiproliferative effect of a native potential probiotic Lactobacillus mixture on HT-29 cancer cells was evaluated using the MTT assay method. Also, qRT-PCR was performed to assess the RNA expression level of genes associated with the TGF-ß signaling pathway at three levels: receptor, regulatory, and inhibitory SMADs. Finally, the in vivo assays were investigated by three groups of mice: a naive group (PBS), a disease group (azoxymethane [AOM]/ dextran sulfate sodium [DSS] + PBS), and a treatment group (AOM/DSS + Lactobacillus mixture in PBS). Results: The MTT results showed a significant decrease in proliferation of HT-29 cancer cells after 120 h of treatment. Furthermore, qRT-PCR demonstrated the downregulation of the smad2/3 gene expression in HT-29-treated cells and also reduction in the level of smad4 gene expression. In addition, in the mouse model, the tgf-ßR1 gene was downregulated in the group treated with AOM/DSS/Lactobacillus, but not the AOM/DSS group. A downregulation of smad4 gene expression was also observed in in vivo models. Conclusion: The obtained results suggest that our novel probiotic Lactobacillus mixture could have a positive impact on the inhibition of the CRC progression by downregulating the TGF-ß signaling pathway.

Multiple Lactobacillus Infections Caused by Probiotics at Pediatric and Adult Academic Medical Centers.

BACKGROUND: Probiotics are synthetic oral supplements containing live bacterial and fungal species hypothesized to help with various gastrointestinal conditions. However, they can cause infection if the organism spreads outside of the gastrointestinal tract. The aim of this study was to identify and describe patients who experienced systemic infections caused by probiotic use. METHODS: This study was a retrospective chart review of pediatric and adult patients at academic medical centers who received probiotics and subsequently developed positive cultures from a sterile site for probiotic-related species. Two individuals completed the chart reviews to determine if the probiotic was the true cause of the infection. RESULTS: Lactobacillus, Bifidobacterium, and Saccharomyces cultures were reviewed, with a total of 71, 8, and 2 cultures isolated from sterile sites for each organism, respectively. Further review revealed 23 Lactobacillus cultures from 13 unique patients who were taking Lactobacillus-containing probiotics. Four patients without gastrointestinal tract compromise were included in the final analysis, including 1 patient whose culture was confirmed as identical to the probiotic. Types of infections included meningitis and bacteremia. Targeted antimicrobial therapy included ampicillin, ampicillin-sulbactam, and piperacillin-tazobactam, with total durations of therapy ranging from 10 to 22 days. No patients had mortality attributed to Lactobacillus infection. CONCLUSIONS: Probiotics are not harmless supplements as they come with risk of serious infection as demonstrated in this review. Before use, the risks of probiotics should be considered carefully for each individual patient. Clinicians should consider avoiding probiotics in hospitalized patients, especially those with vascular or extra-ventricular access devices.

Protection against DSS-induced colitis in mice through FcεRIα deficiency: the role of altered Lactobacillus.

The role of mast cells (MCs) in ulcerative colitis (UC) development is controversial. FcεRI, the IgE high-affinity receptor, is known to activate MCs. However, its role in UC remains unclear. In our study, Anti-FcεRI showed highly diagnostic value for UC. FcεRIα knockout in mice ameliorated DSS-induced colitis in a gut microbiota-dependent manner. Increased Lactobacillus abundance in FcεRIα deficient mice showed strongly correlation with the remission of colitis. RNA sequencing indicated activation of the NLRP6 inflammasome pathway in FcεRIα knockout mice. Additionally, Lactobacillus plantarum supplementation protected against inflammatory injury and goblet cell loss, with activation of the NLRP6 inflammasome during colitis. Notably, this effect was absent when the strain is unable to produce lactic acid. In summary, colitis was mitigated in FcεRIα deficient mice, which may be attributed to the increased abundance of Lactobacillus. These findings contribute to a better understanding of the relationship between allergic reactions, microbiota, and colitis.

Effects of probiotics on productive performances and serum lipid profile of broiler as substitute of antibiotics.

OBJECTIVES: The present research was accomplished to characterize probiotics from broiler gastrointestinal tract (GIT) by profiling biochemical, antimicrobial, and antibiotic sensitivity properties. Eventually, probiotic potentiality was evaluated as a substitute for antibiotic supplements in broiler focusing growth performance, carcass characteristics, and serum lipid profile. METHODS: Probiotic bacteria were characterized based on morphological, physiological, and several biochemical tests. Antibacterial activity against a broad spectrum of antibiotics and bacterial pathogens was detected. An in vivo trial was conducted on 40-day-old Ross 308 broiler strains during 21 days in an in vivo trial. The chicks were divided into total of five groups, a control group and four experimental groups (Antibiotic1, Antibiotic2, Probiotic1, and Probiotic2) in a completely randomized design. Probiotic was supplemented in broiler feed (2× 109 CFU/g feed) or by direct oral gavage (1× 109 CFU/chick). The variables of production performance like body weight (BW), average daily gain (ADG), feed intake (FI), and feed conversion ratio (FCR), carcass characteristics and serum lipid profile were measured. RESULTS: 10 probiotic bacteria were presumptively identified as Lactobacillus sp. based on the morphological, physiological, and strong resistance properties in several biochemical tests. The mixture of Lactobacillus had favorable effects on productive performance of broilers regarding BW, ADG, and FCR (p < .05) compared with chickens that had no additive or had antibiotic during overall period of in vivo trial. Additionally, noteworthy efficacy on carcass characteristics and serum lipid profile were found (p < .05) in Lactobacillus mixture fed chicken groups of in vivo trial. CONCLUSION: Mixed Lactobacillus sp. can be considered as a potential additive for broiler diet attributable to noteworthy efficacy on growth performance, carcass characteristics, and serum lipid profile. Accordingly, the research highlights the need for suitable alteration of antibiotics through probiotic characterization and proper inclusion in broiler diet.

Protective Mechanisms of Vaginal Lactobacilli against Sexually Transmitted Viral Infections.

The healthy cervicovaginal microbiota is dominated by various Lactobacillus species, which support a condition of eubiosis. Among their many functions, vaginal lactobacilli contribute to the maintenance of an acidic pH, produce antimicrobial compounds, and modulate the host immune response to protect against vaginal bacterial and fungal infections. Increasing evidence suggests that these beneficial bacteria may also confer protection against sexually transmitted infections (STIs) caused by viruses such as human papillomavirus (HPV), human immunodeficiency virus (HIV) and herpes simplex virus (HSV). Viral STIs pose a substantial public health burden globally, causing a range of infectious diseases with potentially severe consequences. Understanding the molecular mechanisms by which lactobacilli exert their protective effects against viral STIs is paramount for the development of novel preventive and therapeutic strategies. This review aims to provide more recent insights into the intricate interactions between lactobacilli and viral STIs, exploring their impact on the vaginal microenvironment, host immune response, viral infectivity and pathogenesis, and highlighting their potential implications for public health interventions and clinical management strategies.

Proposal of Lactobacillus amylovorus subsp. animalis subsp. nov. and an emended description of Lactobacillus amylovorus.

Seven novel lactic acid bacterial strains (BF125T, BF186, TKL145, YK3, YK6, YK10 and NSK) were isolated from the fresh faeces of Japanese black beef cattle and weanling piglets, spent mushroom substrates, or steeping water of a corn starch production plant. These strains are rod-shaped, Gram-stain-positive, non-motile, non-spore-forming, catalase-negative, cytochrome oxidase-negative, facultatively anaerobic, and homofermentative. Strain BF125T did not produce any gas from glucose; both d- and l-lactate were produced as end-products of glucose (D/L, 40 : 60). Growth occurred at 30-45 °C (optimum, 37 °C), pH 5.0-8.0 (optimum, pH 6.0), and with NaCl concentration of 1.0-3.0% (w/v). The G+C content of genomic DNA of strain BF125T was 37.8 mol% (whole-genome analysis). The major fatty acids were C16 : 0, C18 : 1 ω9c, C19 cyclopropane 9, 10, and summed feature 10. The 16S rRNA gene in strain BF125T showed high similarity to that of the type strain of Lactobacillus amylovorus (99.93%), and the other isolates were also identified as L. amylovorus based on these similarities. A phylogenetic tree based on the core genomes of L. amylovorus strains (n=54), including the seven isolates, showed that they could be divided into two clusters. Strains YK3, YK6, YK10, and NSK were in the first cluster, along with the type strain DSM 20531T, while the second cluster included isolates BF125T, BF186, TKL145, and other strains isolated from various animal origins. Phenotypic differences in fermentability were observed for lactose, salicin, and gentiobiose between these two groups. The intergroup digital DNA-DNA hybridization values (72.9-78.6%) and intergroup average nucleotide identity values (95.64-96.92%) were comparable to values calculated using datasets of other valid subspecies of the genus (ex-) Lactobacillus. In light of the physiological, genotypic, and phylogenetic evidence, we propose a novel subspecies of L. amylovorus, named Lactobacillus amylovorus subsp. animalis subsp. nov. (type strain BF125T=MAFF 212522T=DSM 115528T). Our findings also led to the automatic creation of Lactobacillus amylovorus subsp. amylovorus subsp. nov. and an emended description of the species L. amylovorus.

L. acidophilus/L. johnsonii ratio affects slow transit constipation in rats.

Slow Transit Constipation (STC) is characterized by impaired colonic motility, but its relationship with gut microbiota remains unclear. This study investigated the correlation between specific gut microbial populations and STC, focusing on the Lactobacillus acidophilus to Lactobacillus johnsonii (A/J) ratio. We used four rat groups: Control (CON), Loperamide-induced STC (LOP), antibiotic-treated (ABX), and antibiotic plus Loperamide (ABX + LOP). Fecal samples were analyzed using 16S rRNA gene sequencing, and serum metabolites were examined through LC-MS. The LOP group showed an increased A/J ratio, while ABX and ABX + LOP groups had decreased ratios. Notably, the ABX + LOP group did not develop STC symptoms. Metabolomic analysis revealed alterations in key metabolites across groups, including changes in levels of guanidinoacetate, glycine, L-glutamine, nicotine, and nicotinate D-ribonucleotide in the LOP group, and variations in L-glutamine, L-phenylalanine, L-tyrosine, histamine, D-ornithine, and lecithin in the ABX and ABX + LOP groups. Our findings suggest a correlation between the A/J ratio and STC development, offering insights into STC pathophysiology and potential microbiome-targeted therapies.

Isolation, identification, and antibiotic susceptibility profile of bacterial isolates from unused diapers sold in major markets in Enugu Metropolis: Clinical and policy perspectives.

Diapers, being one of the most used items for infant care, it is imperative that they are always free of contamination from microorganisms. The objective of this study is to determine the rate of bacterial contamination and the antibiotics profile of isolated bacteria from unused diapers sold in markets in Enugu Metropolis, southeast Nigeria. The study also investigated the effectiveness of the Nigerian Consumer protection laws towards maintaining the standard of care for infants and toddlers. Fifty pieces of different brands of diapers were sampled for bacterial contamination using standard bacteriological procedures. The results show that out of 50 samples analyzed, bacterial growths were identified in 9 (18%), of which five different bacterial species were isolated. The most prevalent being Escherichia coli and Staphylococcus aureus 3 (33.3%). Other bacteria isolated were Lactobacillus spp, Klebsiella spp, and Streptococcus spp 1 (11.1%). There was no statistically significant difference in the distribution of the bacterial contamination of diapers across the different brands(p>0.05). We conclude that baby diapers sold in markets in Enugu metropolis are prone to contamination with bacteria.We recommend that appropriate measures should be taken during the manufacturing process to reduce or prevent the incidence of bacterial contamination of diapers.

Les couches étant l'un des articles les plus utilisés pour les soins des nourrissons, il est impératif qu'elles soient toujours exemptes de contamination par des micro-organismes. L'objectif de cette étude est de déterminer le taux de contamination bactérienne et le profil antibiotique des bactéries isolées provenant de couches inutilisées vendues sur les marchés de la métropole d'Enugu, dans le sud-est du Nigeria. L'étude a également examiné l'efficacité des lois nigérianes sur la protection des consommateurs pour maintenir le niveau de soins pour les nourrissons et les jeunes enfants. Cinquante morceaux de couches de différentes marques ont été échantillonnés pour détecter toute contamination bactérienne en utilisant des procédures bactériologiques standard. Les résultats montrent que sur 50 échantillons analysés, des croissances bactériennes ont été identifiées dans 9 (18 %), parmi lesquels cinq espèces bactériennes différentes ont été isolées. Les plus répandus sont Escherichia coli et Staphylococcus aureus 3 (33,3 %). Les autres bactéries isolées étaient Lactobacillus spp, Klebsiella spp et Streptococcus spp 1 (11,1 %). Il n'y avait pas de différence statistiquement significative dans la répartition de la contamination bactérienne des couches entre les différentes marques (p>0,05). Nous concluons que les couches pour bébés vendues sur les marchés de la métropole d'Enugu sont sujettes à la contamination bactérienne. Nous recommandons que des mesures appropriées soient prises pendant le processus de fabrication pour réduire ou prévenir l'incidence de la contamination bactérienne des couches.

Human papillomavirus molecular prevalence in south China and the impact on vaginal microbiome of unvaccinated women.

The vaginal microbiome (VM) is associated with human papillomavirus (HPV) infection and progression, but a thorough understanding of the relation between HPV infection, and VM needs to be elucidated. From August to December 2022, women who underwent routine gynecological examinations were screened for HPV infection. The distribution of HPV variants and clinical characteristics were collected. Then, a total of 185 participants were enrolled and divided into HPV-negative (HC), high-risk HPV (H), low-risk HPV (L), multiple high-risk HPV (HH), and mixed high-low risk HPV (HL) groups. Samples were collected from the mid-vagina of these 185 participants and sent for 16S rDNA sequencing (V3-V4 region). Among 712 HPV-positive women, the top 3 most frequently detected genotypes were HPV52, HPV58, and HPV16. Among 185 participants in the microbiology study, the ß diversity of the HC group was significantly different from HPV-positive groups (P < 0.001). LEfSe analysis showed that Lactobacillus iners was a potential biomarker for H group, while Lactobacillus crispatus was for L group. Regarding HPV-positive patients, the α diversity of cervical lesion patients was remarkably lower than those with normal cervix (P < 0.05). Differential abundance analysis showed that Lactobacillus jensenii significantly reduced in cervical lesion patients (P < 0.001). Further community state type (CST) clustering displayed that CST IV was more common than other types in HC group (P < 0.05), while CST I was higher than CST IV in H group (P < 0.05). Different HPV infections had distinct vaginal microbiome features. HPV infection might lead to the imbalance of Lactobacillus spp. and cause cervical lesions. IMPORTANCE: In this study, we first investigated the prevalence of different HPV genotypes in south China, which could provide more information for HPV vaccinations. Then, a total of 185 subjects were selected from HPV-negative, high-risk, low-risk, multiple hr-hr HPV infection, and mixed hr-lr HPV infection populations to explore the vaginal microbiome changes. This study displayed that HPV52, HPV58, and HPV16 were the most prevalent high-risk variants in south China. In addition, high-risk HPV infection was featured by Lactobacillus iners, while low-risk HPV infection was by Lactobacillus crispatus. Further sub-group analysis showed that Lactobacillus jensenii was significantly reduced in patients with cervical lesions. Finally, CST clustering showed that CST IV was the most common type in HC group, while CST I accounted the most in H group. In a word, this study for the first time systemically profiled vaginal microbiome of different HPV infections, which may add bricks to current knowledge on HPV infection and lay the foundation for novel treatment/prevention development.

Vaginal Lactobacillus fatty acid response mechanisms reveal a metabolite-targeted strategy for bacterial vaginosis treatment.

Bacterial vaginosis (BV), a common syndrome characterized by Lactobacillus-deficient vaginal microbiota, is associated with adverse health outcomes. BV often recurs after standard antibiotic therapy in part because antibiotics promote microbiota dominance by Lactobacillus iners instead of Lactobacillus crispatus, which has more beneficial health associations. Strategies to promote L. crispatus and inhibit L. iners are thus needed. We show that oleic acid (OA) and similar long-chain fatty acids simultaneously inhibit L. iners and enhance L. crispatus growth. These phenotypes require OA-inducible genes conserved in L. crispatus and related lactobacilli, including an oleate hydratase (ohyA) and putative fatty acid efflux pump (farE). FarE mediates OA resistance, while OhyA is robustly active in the vaginal microbiota and enhances bacterial fitness by biochemically sequestering OA in a derivative form only ohyA-harboring organisms can exploit. OA promotes L. crispatus dominance more effectively than antibiotics in an in vitro BV model, suggesting a metabolite-based treatment approach.

Stress-sensitive neural circuits change the gut microbiome via duodenal glands.

Negative psychological states impact immunity by altering the gut microbiome. However, the relationship between brain states and microbiome composition remains unclear. We show that Brunner's glands in the duodenum couple stress-sensitive brain circuits to bacterial homeostasis. Brunner's glands mediated the enrichment of gut Lactobacillus species in response to vagus nerve stimulation. Cell-specific ablation of the glands markedly suppressed Lactobacilli counts and heightened vulnerability to infection. In the forebrain, we mapped a vagally mediated, polysynaptic circuit connecting the central nucleus of the amygdala to Brunner's glands. Chronic stress suppressed central amygdala activity and phenocopied the effects of gland lesions. Conversely, excitation of either the central amygdala or parasympathetic vagal neurons activated Brunner's glands and reversed the effects of stress on the gut microbiome and immunity. The findings revealed a tractable brain-body mechanism linking psychological states to host defense.

Characterization of vaginal Lactobacillus in biologically relevant fluid using surface-enhanced Raman spectroscopy.

The native vaginal microbiome plays a crucial role in maintaining vaginal health and disruption can have significant consequences for women during their lifetime. While the composition of the vaginal microbiome is important, current methods for monitoring this community are lacking. Clinically used techniques routinely rely on subjective analysis of vaginal fluid characteristics or time-consuming microorganism culturing. Surface-enhanced Raman spectroscopy (SERS) can aid in filling this gap in timely detection of alterations in the vaginal microbiome as it can discriminate between bacterial species in complex solutions including bacterial mixtures and biofluids. SERS has not previously been applied to study variations in vaginal Lactobacillus, the most common species found in the vaginal microbiome, in complex solutions. Herein, the SERS spectra of Lactobacillus crispatus (L. crispatus) and Lactobacillus iners (L. iners), two of the most common vaginal bacteria, was characterized at physiologically relevant concentrations. Subsequently, the ability of SERS to detect L. crispatus and L. iners in both pure mixtures and when mixed with a synthetic vaginal fluid mimicking solution was determined. In both pure and complex solutions, SERS coupled with partial least squares regression predicted the ratiometric bacterial content with less than 10% error and strong goodness of prediction (Q2 > 0.9). This developed method highlights the applicability of SERS to predict the dominant Lactobacillus in the vaginal micro-environment toward the monitoring of this community.