Background and Objective: According to microbiological investigations, microorganisms, especially Lactobacillus strains, considerably increase after using fixed orthodontic appliances. One of the Lactobacilli bacteria found in the oral cavity is Lactobacillus acidophilus. The purpose of this study was to compare the adhesion of Lactobacillus acidophilus to metal and ceramic brackets with coated and uncoated nickel titanium (NiTi) orthodontic archwires. Methods: Forty () samples were divided into four groups for this in vitro study: 10 metal brackets with coated NiTi archwire, 10 metal brackets with uncoated NiTi archwire, 10 ceramic brackets with coated NiTi archwire, and 10 ceramic brackets with uncoated NiTi archwire. Elisa Reader was used to count the number of Lactobacillus acidophilus attachments, and the one-way ANOVA and Tukey HSD tests were used to analyze all results. Results: The results showed significant differences in the attachment of Lactobacillus Acidophilus between the ceramic bracket and coated NiTi archwire sample groups and the metal bracket and uncoated NiTi archwire sample groups (P= 0.01). The adherence of Lactobacillus acidophilus to the ceramic bracket and uncoated NiTi archwire group was higher than the metal bracket and coated NiTi archwire group, and the metal bracket and uncoated NiTi archwire group. The attachment of Lactobacillus acidophilus to the metal bracket and uncoated NiTi archwire groups was the lowest of all sample groups in this study. Conclusion The highest Lactobacillus acidophilus adherence was in the ceramic bracket with coated NiTi archwire group compared to the other three groups.
Lactobacillus acidophilus ; Orthodontic Brackets ; Orthodontic Wires

OBJECTIVE

The aim of this study was to investigate the protective effects of Lactobacillus brevis BIOTECH 1766 against oxidative damage in the brain, liver, and kidneys induced by aluminum (Al) poisoning in ICR mice.

Twenty mice were divided into four groups (n = 5): (I) control, (II) Al, (III) citric acid (CA), and (IV) L. brevis BIOTECH 1766 group. A 14-day treatment period was implemented, wherein groups I and II received sterile water, while groups III and IV received 10 mg/kg bw of CA and 1 x 109 cfu/kg bw of L. brevis BIOTECH 1766, respectively. On day 15, all except the control group received a single oral dose of 1438 mg/kg bw of AlCl3. 6H2O. After 24 h, mice were euthanized to collect the brain, liver, and kidneys for the oxidative stress marker analyses and histopathological examination.

Acute intoxication of Al led to a significant increase in tissue malondialdehyde (MDA) and a significant decrease in the tissue's reduced glutathione (GSH), catalase (CAT), and superoxide dismutase (SOD). Mice pretreated with CA or L. brevis BIOTECH 1766 have markedly reduced CAT activity in the liver, and SOD in all three organs. Extensive organ injuries were also prevented by CA and L. brevis BIOTECH 1766 pretreatment, with the latter providing better protection against liver damage.

The findings showed that L. brevis BIOTECH 1766 provides a protective effect against acute Al poisoning in mice by ameliorating oxidative damage in the brain, liver, and kidneys.

A growing body of evidence has linked the gut microbiota to liver metabolism. The manipulation of intestinal microflora has been considered as a promising avenue to promote liver health. However, the effects of Lactobacillus gasseri LA39, a potential probiotic, on liver metabolism remain unclear. Accumulating studies have investigated the proteomic profile for mining the host biological events affected by microbes, and used the germ-free (GF) mouse model to evaluate host-microbe interaction. Here, we explored the effects of L. gasseri LA39 gavage on the protein expression profiles of the liver of GF mice. Our results showed that a total of 128 proteins were upregulated, whereas a total of 123 proteins were downregulated by treatment with L. gasseri LA39. Further bioinformatics analyses suggested that the primary bile acid (BA) biosynthesis pathway in the liver was activated by L. gasseri LA39. Three differentially expressed proteins (cytochrome P450 family 27 subfamily A member 1 (CYP27A1), cytochrome P450 family 7 subfamily B member 1 (CYP7B1), and cytochrome P450 family 8 subfamily B member 1 (CYP8B1)) involved in the primary BA biosynthesis pathway were further validated by western blot assay. In addition, targeted metabolomic analyses demonstrated that serum and fecal β‍-muricholic acid (a primary BA), dehydrolithocholic acid (a secondary BA), and glycolithocholic acid-3-sulfate (a secondary BA) were significantly increased by L. gasseri LA39. Thus, our data revealed that L. gasseri LA39 activates the hepatic primary BA biosynthesis and promotes the intestinal secondary BA biotransformation. Based on these findings, we suggest that L. gasseri LA39 confers an important function in the gut‒liver axis through regulating BA metabolism.
Mice ; Animals ; Bile Acids and Salts/metabolism* ; Lactobacillus gasseri ; Proteomics ; Liver/metabolism* ; Biotransformation

γ-aminobutyric acid can be produced by a one-step enzymatic reaction catalyzed by glutamic acid decarboxylase. The reaction system is simple and environmentally friendly. However, the majority of GAD enzymes catalyze the reaction under acidic pH at a relatively narrow range. Thus, inorganic salts are usually needed to maintain the optimal catalytic environment, which adds additional components to the reaction system. In addition, the pH of solution will gradually rise along with the production of γ-aminobutyric acid, which is not conducive for GAD to function continuously. In this study, we cloned the glutamate decarboxylase LpGAD from a Lactobacillus plantarum capable of efficiently producing γ-aminobutyric acid, and rationally engineered the catalytic pH range of LpGAD based on surface charge. A triple point mutant LpGAD^{S24R/D88R/Y309K} was obtained from different combinations of 9 point mutations. The enzyme activity at pH 6.0 was 1.68 times of that of the wild type, suggesting the catalytic pH range of the mutant was widened, and the possible mechanism underpinning this increase was discussed through kinetic simulation. Furthermore, we overexpressed the Lpgad and Lpgad^{S24R/D88R/Y309K} genes in Corynebacterium glutamicum E01 and optimized the transformation conditions. An optimized whole cell transformation process was conducted under 40 ℃, cell mass (OD₆₀₀) 20, 100 g/L l-glutamic acid substrate and 100 μmol/L pyridoxal 5-phosphate. The γ-aminobutyric acid titer of the recombinant strain reached 402.8 g/L in a fed-batch reaction carried out in a 5 L fermenter without adjusting pH, which was 1.63 times higher than that of the control. This study expanded the catalytic pH range of and increased the enzyme activity of LpGAD. The improved production efficiency of γ-aminobutyric acid may facilitate its large-scale production.
Glutamate Decarboxylase/genetics* ; Lactobacillus plantarum/genetics* ; Catalysis ; gamma-Aminobutyric Acid ; Hydrogen-Ion Concentration ; Glutamic Acid

Objective: To explore the characteristics and correlations of vaginal flora in women with cervical lesions. Methods: A total of 132 women, including 41 women diagnosed with normal cervical (NC), 39 patients with low-grade cervical intraepithelial neoplasia (CIN 1), 37 patients with high-grade cervical intraepithelial neoplasia (CIN 2/3) and 15 patients with cervical squamous cell carcinoma (SCC), who came from the gynecological clinic of Second Hospital of Shanxi Medical University during January 2018 to June 2018, were enrolled in this study according to the inclusive and exclusive criteria strictly. The vaginal flora was detected by 16S rDNA sequencing technology. Co-occurrence network analysis was used to investigate the Spearman correlations between different genera of bacteria. Results: The dominant bacteria in NC, CIN 1 and CIN 2/3 groups were Lactobacillus [constituent ratios 79.4% (1 869 598/2 354 098), 63.6% (1 536 466/2 415 100) and 58.3% (1 342 896/2 301 536), respectively], while Peptophilus [20.4% (246 072/1 205 154) ] was the dominant bacteria in SCC group. With the aggravation of cervical lesions, the diversity of vaginal flora gradually increased (Shannon index: F=6.39, P=0.001; Simpson index: F=3.95, P=0.012). During the cervical lesion progress, the ratio of Lactobacillus gradually decreased, the ratio of other anaerobes such as Peptophilus, Sneathia, Prevotella and etc. gradually increased, and the differential bacteria (LDA score >3.5) gradually evolved from Lactobacillus to other anaerobes. The top 10 relative abundance bacteria, spearman correlation coefficient>0.4 and P<0.05 were selected. Co-occurrence network analysis showed that Prevotella, Peptophilus, Porphyrinomonas, Anaerococcus, Sneathia, Atopobium, Gardnerella and Streptococcus were positively correlated in different stages of cervical lesions, while Lactobacillus was negatively correlated with the above anaerobes. It was found that the relationship between vaginal floras in CIN 1 group was the most complex and only Peptophilus was significantly negatively correlated with Lactobacillus in SCC group. Conclusions: The increased diversity and changed correlations between vaginal floras are closely related to cervical lesions. Peptophilus is of great significance in the diagnosis, prediction and early warning of cervical carcinogenesis.
Female ; Humans ; Vagina/microbiology* ; Uterine Cervical Neoplasms/genetics* ; Uterine Cervical Dysplasia ; Cervix Uteri ; Lactobacillus/genetics* ; Papillomavirus Infections

Biorefinery of chemicals from straw is an effective approach to alleviate the environmental pollution caused by straw burning. In this paper, we prepared gellan gum immobilized Lactobacillus bulgaricus T15 gel beads (LA-GAGR-T15 gel beads), characterized their properties, and established a continuous cell recycle fermentation process for D-lactate (D-LA) production using the LA-GAGR-T15 gel beads. The fracture stress of LA-GAGR-T15 gel beads was (91.68±0.11) kPa, which was 125.12% higher than that of the calcium alginate immobilized T15 gel beads (calcium alginate-T15 gel beads). This indicated that the strength of LA-GAGR-T15 gel beads was stronger, and the strain was less likely to leak out. The average D-LA production was (72.90±2.79) g/L after fermentation for ten recycles (720 h) using LA-GAGR-T15 gel beads as the starting strain and glucose as the substrate, which was 33.85% higher than that of calcium alginate-T15 gel beads and 37.70% higher than that of free T15. Subsequently, glucose was replaced by enzymatically hydrolyzed corn straw and fermented for ten recycles (240 h) using LA-GAGR-T15 gel beads. The yield of D-LA reached (1.74±0.79) g/(L·h), which was much higher than that of using free bacteria. The wear rate of gel beads was less than 5% after ten recycles, which indicated that LA-GAGR is a good carrier for cell immobilization and can be widely used in industrial fermentation. This study provides basic data for the industrial production of D-LA using cell-recycled fermentation, and provides a new way for the biorefinery of D-LA from corn straw.
Fermentation ; Lactobacillus delbrueckii ; Zea mays ; Lactic Acid ; Alginates/chemistry* ; Glucose

The construction of efficient and stable Lactobacillus expression vector is critical for strain improvement and development of customized strains. In this study, four endogenous plasmids were isolated from Lacticaseibacillus paracasei ZY-1 and subjected to functional analysis. The Escherichia coli-Lactobacillus shuttle vectors pLPZ3N and pLPZ4N were constructed by combining the replicon rep from pLPZ3 or pLPZ4, the chloramphenicol acetyltransferase gene cat from pNZ5319 and the replicon ori from pUC19. Moreover, the expression vectors pLPZ3E and pLPZ4E with the promoter P_ldh3 of lactic acid dehydrogenase and the mCherry red fluorescent protein as a reporter gene were obtained. The size of pLPZ3 and pLPZ4 were 6 289 bp and 5 087 bp, respectively, and its GC content, 40.94% and 39.51%, were similar. Both shuttle vectors were successfully transformed into Lacticaseibacillus, and the transformation efficiency of pLPZ4N (5.23×10²-8.93×10² CFU/μg) was slightly higher than that of pLPZ3N. Furthermore, the mCherry fluorescent protein was successfully expressed after transforming the expression plasmids pLPZ3E and pLPZ4E into L. paracasei S-NB. The β-galactosidase activity of the recombinant strain obtained from the plasmid pLPZ4E-lacG constructed with P_ldh3 as promoter was higher than that of the wild-type strain. The construction of shuttle vectors and expression vectors provide novel molecular tools for the genetic engineering of Lacticaseibacillus strains.
Lacticaseibacillus ; Lacticaseibacillus paracasei ; Plasmids/genetics* ; Genetic Vectors/genetics* ; Lactobacillus/genetics* ; Escherichia coli/genetics*

Background: The rising public health threat brought about by antibiotic resistance, such as of Staphylococcus aureus, opened doors of opportunities for natural products research to explore novel antimicrobial agents. Objective: This study aimed to determine the antimicrobial activity of cell-free supernatants from Lactobacillus plantarum BS25 and Pediococcus acidilactici S3 against Staphylococcus aureus (ATCC# 25923) and methicillin-resistant S. aureus (ATCC# 33591). Methodology: Cell-free supernatants (CFS) of Lactobacillus plantarum BS25 and Pediococcus acidilactici S3, isolated from fermented rice-fish mixture balao-balao and fermented spicy sausage longganisa, respectively, were tested against methicillin-susceptible (MSSA, ATCC 25923) and methicillin-resistant (MRSA, ATCC 33591) Staphylococcus aureus strains for antibacterial activity using the resazurin assay. Results: Both BS25 and S3 CFS showed high activities against MSSA and partial inhibition against MRSA. Proteinaceous components of the CFS were extracted using ammonium sulfate precipitation with BS25 and S3 exhibited low activities against MSSA but partial inhibition was observed against MRSA. Other small molecules were extracted from the CFS through liquid-liquid extraction using ethyl acetate and tested in 100, 250, 500, 750, and 1000 ppm concentrations. The 1000-ppm concentrations of the BS25 and S3 ethyl acetate extracts achieved the highest antibacterial activity against MSSA and MRSA. Conclusion This study showed that the crude cell-free supernatants, ammonium sulfate precipitates, and ethyl acetate extracts of BS25 and S3 CFS exhibited potential in inhibiting Gram-positive MSSA and MRSA. However, the partially-purified samples require relatively high concentrations in order to produce significant inhibition activities and therefore require further purification.
Lactobacillus plantarum ; Pediococcus acidilactici ; Methicillin-Resistant Staphylococcus aureus

Aims: This study aimed to evaluate antidiabetic potential of indigenous Lactobacillus isolates by measuring the ability of α-glucosidase inhibitory (AGI) and antioxidant activity. The mechanism of probiotics as antidiabetic can occur through the AGI and antioxidant activity of LAB, which is able to suppress oxidative stress that causes chronic inflammation and pancreatic β cell apoptosis, and then through the ability to produce exopolysaccharide (EPS) and short chain fatty acids (SCFA). Methodology and results: MRS broth enriched with 10% glucose was selected as the growth medium for Lactobacillus. The growth medium was then centrifuged to obtain CFS and CFE was produced by extracting the medium with 96% ethanol as a solvent. The results showed that Lactobacillus pentosus MK42 had the highest AGI activity of 80.32 ± 2.20%. Antioxidant activity was not significantly different (P>0.05) among the tested Lactobacillus isolates. Lactobacillus paracasei RK41 produced the highest EPS (360.13 ± 50.01 mg/L), which was not significantly different (P>0.05) from Lactobacillus plantarum1 RB210. All Lactobacillus isolates were able to produce acetic acid, but not all were able to produce propionic and butyric acid. The highest propionic acid was produced by L. plantarum1 RB210 at 0.40 ± 0.31 mmol/L and the highest butyric acid was produced by L. plantarum1 MK2 at 0.22 ± 0.08 mmol/L. Conclusion, significance and impact of study The results show definitively that indigenous Lactobacillus isolates have considerable α-glucosidase inhibitor, antioxidant activity and the ability to produce of EPS and SCFA. This preliminary study suggests the use of indigenous Lactobacillus isolates which have the potential as antidiabetic agent, although the responsible compounds are unknown.
alpha-Glucosidases ; Antioxidants ; Lactobacillus--isolation & ; purification ; Hypoglycemic Agents

Objectives: Probiotic supplementation often only leads to transient improvement in the gut microbiome. Potential prebiotics, such as the oligosaccharide-rich varieties of Dioscorea esculenta tubers, can potentially bridge the gap between supplementation and persistent colonization. Thus, this study aimed to assess the ability of D. esculenta tubers to promote the growth of probiotic Lactobacillus sp. in vitro selectively.

Methods: The prebiotic activity of the selected varieties of Dioscorea esculenta tubers was evaluated via compe titive growth assay, wherein the ratios of probiotic Lactobacillus sp. over enterotoxigenic Escherichia coli (ETEC) or "prebiotic ratios" were compared following treatment.

Results: Negative control (0.9% NaCl solution) produced a ratio of 0.88, Lowland and Highland varieties produced ratios of 1.26 and 1.29, respectively, and positive control (inulin) produced 1.54. The two varieties had comparable ratios to one another (p > 0.05), and significantly higher ratios than the negative control (p < 0.05). Both varieties have significant prebiotic activity. Compared to inulin, the two varieties' prebiotic activity was 84% as effective.

Conclusion: Overall, the tubers promoted the growth of Lactobacillus sp. over ETEC. The crude tuber samples, given their availability and affordability, can be easily integrated into the local diet to contribute to the improvement of the general population's health.