Effect of metronidazole on the growth of vaginal lactobacilli in female athletes

Lactobacillus strains isolated from female athletes were tested. MRS broth was supplemented with a range of Metronidazole concentrations from 128 to 2000 μg/ml. The growth of these strains was monitored by measuring optical density at 3-hour intervals over 24 hours. Results: It was observed that at Metronidazole concentrations up to 128 μg/ml, there was no significant impact on the growth of the Lactobacillus strains. However, at concentrations above 512 μg/ml, Metronidazole significantly inhibited their growth. The response to Metronidazole varied among different Lactobacillus strains. For instance, at a concentration of 256 μg/ml, Lactobacillus delbrueckii, Lactobacillus jensenii, and Lactobacillus vaginalis showed notable inhibition, whereas Lactobacillus crispatus, Lactobacillus gasseri, and Lactobacillus fermentum were not significantly affected. Discussion: High concentrations of Metronidazole were found to inhibit the growth of the six Lactobacillus strains isolated from female athletes. Lower concentrations had negligible effects. The differential response of Lactobacillus strains to varying concentrations of Metronidazole (between 128 μg/ml and 512 μg/ml) highlights the need for careful consideration of Metronidazole use in managing vaginal microbiota health in female athletes (AU)

Gut Microbiota Mediates Lactobacillus rhamnosus GG Alleviation of Deoxynivalenol-Induced Anorexia.

Deoxynivalenol (DON) is a widespread mycotoxin and causes anorexia and emesis in humans and animals; Lactobacillus rhamnosus GG (LGG), a well-characterized probiotic, can improve intestinal barrier function and modulate immune response. Currently, it is unclear whether LGG has a beneficial effect on DON-induced anorexia. In the present study, mice were treated with DON, LGG, or both by gavage for 28 days to evaluate the effects of LGG on DON-induced anorexia. Antibiotic treatment and fecal microbiota transplant (FMT) experiment were also conducted to investigate the link between DON, LGG, and gut microbiota. LGG significantly increased the villus height and reduced the crypt depth in jejunum and ileum, enhanced the tight junction proteins expression in the intestine, and regulated the TLR4/NF-κB signaling pathway, consequently attenuating the intestinal inflammation caused by DON. In addition, LGG increased the relative abundance of Lactobacillus and butyric acid production of cecal contents; remodeled phenylalanine metabolism and tryptophan metabolism; reduced plasma peptide tyrosine tyrosine (PYY), 5-hydroxytryptamine (5-HT), and glucagon-like peptide-1 (GLP-1) concentrations; and promoted hypothalamic NPY and AgPR gene expression, which will further promote food intake and reduce weight loss, ultimately alleviating DON-induced anorexia in mice. Interestingly, antibiotic treatment diminished the intestinal toxicity of DON. The FMT experiment showed that DON-originated microbiota promotes intestinal inflammation and anorexia, while LGG + DON-originated microbiota has no adverse effects on mice. Both antibiotic treatment and FMT experiment have proved that gut microbiota was the primary vector for DON to exert its toxic effects and an essential mediator of LGG protection. In summary, our findings demonstrate that gut microbiota plays essential roles in DON-induced anorexia, and LGG can reduce the adverse effects caused by DON through its structure and regulate the gut microbiota, which may lay the important scientific foundation for future applications of LGG in food and feed products.

Antimicrobial plant secondary metabolites, MDR transporters and antimicrobial resistance in cereal-associated lactobacilli: is there a connection?

Cereal-associated lactobacilli resist antimicrobial plant secondary metabolites. This study aimed to identify multi-drug-resistance (MDR) transporters in isolates from mahewu, a Zimbabwean fermented cereal beverage, and to determine whether these MDR-transporters relate to resistance against phenolic compounds and antibiotics. Comparative genomic analyses indicated that all seven mahewu isolates harbored multiple MATE and MFS MDR proteins. Strains of Lactiplantibacillus plantarum and Limosilactobacillus fermentum encoded for the same gene, termed mahewu phenolics resistance gene mprA, with more than 99% nucleotide identity, suggesting horizontal gene transfer. Strains of Lp. plantarum were more resistant than strains of Lm. fermentum to phenolic acids, other antimicrobials and antibiotics but the origins of strains were not related to resistance. The resistance of several strains exceeded EFSA thresholds for several antibiotics. Analysis of gene expression in one strain each of Lp. plantarum and Lm. fermentum revealed that at least one MDR gene in each strain was over-expressed during growth in wheat, sorghum and millet relative to growth in MRS5 broth. In addition, both strains over-expressed a phenolic acid reductase. The results suggest that diverse lactobacilli in mahewu share MDR transporters acquired by lateral gene transfer, and that these transporters mediate resistance to secondary plant metabolites and antibiotics.

Impact of vaginal douching products on vaginal Lactobacillus, Escherichia coli and epithelial immune responses.

We compared the effect of commercial vaginal douching products on Lactobacillus crispatus, L. jensenii, L. gasseri, L. iners, E. coli, and immortalized vaginal epithelial cells (VK2). All studied douching products (vinegar, iodine and baking soda based) induced epithelial cell death, and all inhibited growth of E. coli. Co-culture of vaginal epithelial cells with any of the lactobacilli immediately following exposure to douching products resulted in a trend to less human cell death. However, co-culture of epithelial cells with L. iners was associated with higher production of IL6 and IL8, and lower IL1RA regardless of presence or type of douching solution. Co-culture with L. crispatus or L. jensenii decreased IL6 production in the absence of douches, but increased IL6 production after exposure to vinegar. Douching products may be associated with epithelial disruption and inflammation, and may reduce the anti-inflammatory effects of beneficial lactobacilli.

Serum Untargeted Metabolism Reveals the Mechanism of L. plantarum ZDY2013 in Alleviating Kidney Injury Induced by High-Salt Diet.

A high-salt diet (HSD) is one of the key risk factors for hypertension and kidney injury. In this study, a HSD C57BL/6J mice model was established with 4% NaCl, and then different concentrations of Lactobacillus plantarum ZDY2013 were intragastrically administered for 2 weeks to alleviate HSD-induced renal injury. For the study, 16S rRNA gene sequencing, non-targeted metabonomics, real-time fluorescent quantitative PCR, and Masson's staining were used to investigate the mechanism of L. plantarum ZDY2013 in alleviating renal damage. Results showed that HSD caused intestinal inflammation and changed the intestinal permeability of mice, disrupted the balance of intestinal flora, and increased toxic metabolites (tetrahydrocorticosteron (THB), 3-methyhistidine (3-MH), creatinine, urea, and L-kynurenine), resulting in serious kidney damage. Interestingly, L. plantarum ZDY2013 contributed to reconstructing the intestinal flora of mice by increasing the level of Lactobacillus and Bifidobacterium and decreasing that of Prevotella and Bacteroides. Moreover, the reconstructed intestinal microbiota significantly changed the concentration of the metabolites of hosts through metabolic pathways, including TCA cycle, ABC transport, purine metabolism, and histidine metabolism. The content of uremic toxins such as L-kynurenine, creatinine, and urea in the serum of mice was found to be decreased by L. plantarum ZDY2013, which resulted in renal injury alleviation. Our data suggest that L. plantarum ZDY2013 can indeed improve chronic kidney injury by regulating intestinal flora, strengthening the intestinal barrier, limiting inflammatory response, and reducing uremic toxins.

Biological Transformation of Zearalenone by Some Bacterial Isolates Associated with Ruminant and Food Samples.

Zearalenone (ZEA) is a secondary metabolite produced by Fusarium spp., the filamentous fungi. Food and feed contamination with zearalenone has adverse effects on health and economy. ZEA degradation through microorganisms is providing a promising preventive measure. The current study includes isolation of 47 bacterial strains from 100 different food and rumen samples. Seventeen isolates showed maximum activity of ZEA reduction. A bacterial isolate, RS-5, reduced ZEA concentration up to 78.3% through ELISA analysis and 74.3% as determined through HPLC. Ten of the most efficient strains were further selected for comparison of their biodegradation activity in different conditions such as incubation period, and different growth media. The samples were analyzed after 24 h, 48 h, and 72 h of incubation. De Man Rogosa Sharp (MRS) broth, Tryptic soy broth, and nutrient broth were used as different carbon sources for comparison of activity through ELISA. The mean degradation % ± SD through ELISA and HPLC were 70.77% ± 3.935 and 69.11% ± 2.768, respectively. Optimum reducing activity was detected at 72 h of incubation, and MRS broth is a suitable medium. Phylogenetic analysis based on 16S rRNA gene nucleotide sequences confirmed that one of the bacterial isolate RS-5 bacterial isolates with higher mycotoxin degradation is identified as Bacillus subtilis isolated from rumen sample. B05 (FSL-8) bacterial isolate of yogurt belongs to the genus Lactobacillus with 99.66% similarity with Lactobacillus delbrukii. Similarly, three other bacterial isolates, D05, H05 and F04 (FS-17, FSL-2 and FS-20), were found to be the sub-species/strains Pseudomonas gessardii of genus Pseudomonas based on their similarity level of (99.2%, 96% and 96.88%) and positioning in the phylogenetic tree. Promising detoxification results were revealed through GC-MS analysis of RS-5 and FSL-8 activity.

Hernandulcin Production in Cell Suspensions of Phyla Scaberrima: Exploring Hernandulcin Accumulation through Physical and Chemical Stimuli.

Hernandulcin (HE) is a non-caloric sweetener synthesized by the Mexican medicinal plant Phyla scaberrima. Herein we present the results of HE production through cell suspensions of P. scaberrima as well as the influence of pH, temperature, biosynthetic precursors and potential elicitors to enhance HE accumulation. The incorporation of mevalonolactone (30-400 mg L-1 ) farnesol (30-400 mg L-1 ), AgNO3 (0.025-0.175 M), cellulase (5-60 mg L-1 ; 0.3 units/mg), chitin (20-140 mg L-1 ) and (+)-epi-α-bisabolol (300-210 mg L-1 ) to the cell suspensions, resulted in a differential accumulation of HE and biomass. Among elicitors assayed, chitin, cellulase and farnesol increased HE production from 93.2 to ∼160 mg L-1 but, (+)-epi-α-bisabolol (obtained by a synthetic biology approach) increased HE accumulation up to 182.7 mg L-1 . HE produced by the cell suspensions was evaluated against nine strains from six species of gastrointestinal bacteria revealing moderate antibacterial activity (MIC, 214-465 µg mL-1 ) against Staphylococcus aureus, Escherichia coli and Helicobacter pylori. Similarly, HE showed weak toxicity against Lactobacillus sp. and Bifidobacterium bifidum (>1 mg mL-1 ), suggesting a selective antimicrobial activity on some species of gut microbiota. According to our results, chitin and (+)-epi-α-bisabolol were the most effective molecules to enhance HE accumulation in cell suspensions of P. scaberrima.

Dietary supplementation of alpha-lipoic acid mitigates the negative effects of heat stress in broilers.

Heat stress accounts for substantial economic loss in the poultry industry by altering the health and performance of chickens. Alpha-lipoic acid (ALA) is a water and fat-soluble antioxidant which is readily absorbed from the intestine resulting in maximum bioavailability. Moreover, ALA acts as a coenzyme in glucose metabolism and helps generate other antioxidants. Considering these benefits, we hypothesized that dietary supplementation of ALA would help mitigate heat stress in poultry. A total of 72 Day-old broiler chicks were randomly assigned into three treatment groups: no heat stress (NHS), heat stress with basal diet (HS), and heat stress with alpha-lipoic acid (HS+ALA); each treatment group had 6 replicate pens with 4 birds in each pen (n = 24/group). The allocated birds were raised under standard husbandry practices for 3 weeks. After 21 d, birds in the HS and HS+ALA groups were exposed to heat stress (33°C for 8 hours during the day) for 3 weeks, while the NHS group was reared under normal conditions (22-24°C). The HS+ALA group received a basal finisher diet fortified with ALA (500 mg/kg) during the treatment period (22 to 42 d), while other birds were provided with the basal finisher diet. Weekly body weight and feed intake were recorded. The cecum digesta for volatile fatty acids (VFAs) analysis and 16S rRNA sequencing for the gut microbiota analysis; and the ileum tissue samples for histological and gene expression analyses were collected on d 42. Exposure to heat stress decreased (P<0.05) average daily gain (ADG) and final body weight (FBW) in the HS group compared to the NHS group, the supplementation of ALA improved (P<0.05) ADG and FBW in heat-stressed birds. Furthermore, birds in the HS+ALA group had increased (P<0.05) expression of HSP90, PRDX1, GPX3, SOD2, OCLN, and MUC2 genes and higher (P<0.05) concentrations of major VFAs (acetate, propionate, and butyrate). The dietary ALA supplementation also improved the villus height and villus height to crypt depth ratio in the HS+ALA group. The microbial diversity analysis revealed significant abundance (P<0.05) of beneficial bacteria Lactobacillus and Peptostreptococcaceae in the cecum of the ALA group. These results indicate that dietary ALA supplementation effectively mitigates the negative effects of heat stress in broilers by improving the expression of heat-shock, tight-junction, antioxidants, and immune-related genes in the intestine, improving villus structures, increasing concentration of major VFAs, and enriching the beneficial microbiota.

Immunosuppressive activity is attenuated by Astragalus polysaccharides through remodeling the gut microenvironment in melanoma mice.

Astragalus polysaccharides (APS), the main effective component of Astragalus membranaceus, can inhibit tumor growth, but the underlying mechanisms remain unclear. Previous studies have suggested that APS can regulate the gut microenvironment, including the gut microbiota and fecal metabolites. In this work, our results showed that APS could control tumor growth in melanoma-bearing mice. It could reduce the number of myeloid-derived suppressor cells (MDSC), as well as the expression of MDSC-related molecule Arg-1 and cytokines IL-10 and TGF-ß, so that CD8+ T cells could kill tumor cells more effectively. However, while APS were administered with an antibiotic cocktail (ABX), MDSC could not be reduced, and the growth rate of tumors was accelerated. Consistent with the changes in MDSC, the serum levels of IL-6 and IL-1ß were lowest in the APS group. Meanwhile, we found that fecal suspension from mice in the APS group could also reduce the number of MDSC in tumor tissues. These results revealed that APS regulated the immune function in tumor-bearing mice through remodeling the gut microbiota. Next, we focused on the results of 16S rRNA, which showed that APS significantly regulated most microorganisms, such as Bifidobacterium pseudolongum, Lactobacillus johnsonii and Lactobacillus. According to the Spearman analysis, the changes in abundance of these microorganisms were related to the increase of metabolites like glutamate and creatine, which could control tumor growth. The present study demonstrates that APS attenuate the immunosuppressive activity of MDSC in melanoma-bearing mice by remodeling the gut microbiota and fecal metabolites. Our findings reveal the therapeutic potential of APS to control tumor growth.

Exopolysaccharides produced by Pediococcus acidilactici MT41-11 isolated from camel milk: Structural characteristics and bioactive properties.

In this study, the chemical structure and bioactive properties of the EPS of Pediococcus acidilactici MT41-11 isolated from camel milk were investigated. Two polysaccharide fractions (EPS-1, EPS-2) with molecular weights about 69.0 kDa were obtained, which were purified using DEAE-Sepharose and Sephadex G-100 chromatography. Based on monosaccharide composition, FT-IR, and 1D, 2D NMR spectra, concluded that EPS-1 had a backbone composed of →2)-α-d-Manp-(1→, →3)-α-d-Manp-(1→ and with branches containing α-d-Manp-(1→, EPS-2 had a backbone composed of →6)-ß-d-Glcp-(1→, and with branches containing →2)-α-l-Fucp-(1→, →3)-α-d-Glcp-(1→, →2)-α-d-Glcp-(1→, ß-d-Glcp-(1→, and α-d-Glcp-(1→. Remarkably, in vitro assays showed that EPS possessed multiple bioactive properties, including stimulating Lactobacillus growth and a high DPPH free radical scavenging activity. Also, it has a good ability to anti-biofilms. Overall, the analysis of all data showed EPS from P. acidilactici MT41-11 can be used as anti-oxidant, anti-biofilm agent, and also as a potential candidate prebiotic for health food or medicine industry.

The impact of cell-free supernatants of Lactococcus lactis subsp. lactis strains on the tyramine formation of Lactobacillus and Lactiplantibacillus strains isolated from cheese and beer.

Tyramine is one of the most toxic biogenic amines and it is produced commonly by lactic acid bacteria in fermented food products. In present study, we investigated the influence of selected nisin-producing Lactococcus lactis subsp. lactis strains and their cell-free supernatants (CFSs) on tyramine production by four Lactobacillus and two Lactiplantibacillus strains isolated from cheese and beer. Firstly, we examined the antimicrobial effect of the CFSs from twelve Lactococcus strains against tested tyramine producers by agar-well diffusion assay. Six Lactococcus strains whose CFSs showed the highest antimicrobial effect on tyramine producers were further studied. Secondly, we investigated the influence of the selected six Lactococcus strains and their respective CFSs on tyramine production by tested Lactobacillus and Lactiplantibacillus strains in MRS broth supplemented with 2 g.L-1 of l-tyrosine. Tyramine production was monitored by HPLC-UV. The tyramine formation of all tested Lactobacillus and Lactiplantibacillus strains was not detected in the presence of Lc. lactis subsp. lactis CCDM 71 and CCDM 702, and their CFSs. Moreover, the remainder of the investigated Lactococcus strains (CCDM 670, CCDM 686, CCDM 689 and CCDM 731) and their CFSs decreased tyramine production significantly (P < 0.05) - even suppressing it completely in some cases - in four of the six tested tyramine producing strains.

The beneficial effects of polysaccharide obtained from persimmon (Diospyros kaki L.) on the proliferation of Lactobacillus and gut microbiota.

The objective of this study was to investigate the effect of polysaccharide extracts from persimmon (PPE) on the proliferation of Lactobacillus and the gut microbiota of mice. Lactobacillus strains were cultured in medium containing PPE, and differential gene expression was evaluated using transcriptomics. In addition, 16S rDNA was employed to analyze the abundance and diversity of fecal colonies in mice, and the influence of PPE on the intestinal flora in mice was further examined. The results showed that Lactobacillus acidophilus NCFM and Lactobacillus acidophilus CICC 6075 could proliferate in PPE medium. Gene ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomics (KEGG) pathway analysis indicated that glucose metabolism-related genes, such as phosphoyruvate hydratase (eno) and PTS mannose transporter subunit IIAB (manX), were up-regulated. The metabolic pathways of fructose and mannose were also significantly up-regulated. After gavage of mice with PPE, 16S rDNA sequencing of mouse feces indicated that the beneficial bacteria in the intestines proliferated and the abundance of harmful bacteria was reduced. PPE can maintain the balance of intestinal microorganisms in mice. Therefore, PPE has a significant positive effect on both Lactobacillus proliferation and gut microbiota of mice.

Effects of enzymatic hydrolysis on the structural, rheological, and functional properties of mulberry leaf polysaccharide.

Effects of enzymatic hydrolysis on the structural, rheological, and functional properties of mulberry leaf polysaccharide (MLP) were characterized in this study. The enzymatic hydrolysis of MLP raised the carbonyl, carboxyl, and hydroxyl groups from 7.21 ± 0.86 to 10.08 ± 0.28 CO/100 Glu, 9.40 ± 0.13 to 17.55 ± 0.34 COOH/100 Glu, and 5.71 ± 0.33 to 8.14 ± 0.24 OH/100 Glu, respectively. Meanwhile, an increase in thixotropic performance and structure-recovery capacities were observed in hydrolyzed MLP, while the molecular weight, surface tension, apparent viscosity, and thermal stability were decreased. An improved antioxidant activity of MLP was also achieved after the enzymatic degradation. Moreover, the hydrolyzed MLP showed greater ability to promote the growths of Bifidobacterium bifidum, Bifidobacterium adolescentis, Lactobacillus rhamnosus, and Lactobacillus acidophilus and the production of acetic acid, butyric acid, and lactic acid. The results demonstrate that enzymatic modification is a useful approach for polysaccharide processing.

Fermentation characteristics and bacterial dynamics during Chinese sauerkraut fermentation by Lactobacillus curvatus LC-20 under varied salt concentrations reveal its potential in low-salt suan cai production.

Salt profoundly affects the physicochemical properties and microbial abundance of fermented foods such as suan cai, a popular traditional fermented food in China. It is vital to systematically investigate the effects of salt concentrations on fermented suan cai for high fermentation quality and large-scale production. We elucidated the effects of salt concentrations on Lactobacillus curvatus (LC-20) and suan cai during fermentation, and found that salt (0-1%) favoured an increase in LC-20 growth and a decrease in pH (salt: 0-2%). For suan cai fermentation, the results from sensory scoring judged 1% salt treatment the highest. Salt concentration also affected the nitrite content of the fermentation system with peak nitrite values in low salt treatments being significantly higher on the first day, and gradually decreasing to similar levels. After fermentation, the total titratable acid and lactic acid concentrations in the 0-1% treatments were higher (p < 0.05) than those in 2-5% treatments. The colony forming units of lactic acid bacteria increased initially and then decreased after 6 d of fermentation. At the phylum level, Firmicutes and Proteobacteria were predominant in all treatments, and at the genus level, Lactobacillus dominated the fermentation. Other lactic acid bacteria such as Lactococcus and Weissella were also detected. Quantitative PCR showed DNA concentration of LC-20 at 0.5-2% salt treatments were higher than that in other treatments and L. curvatus was the dominant microorganism during fermentation. Hence, we conclude that L. curvatus could be used for suan cai product at low salt concentrations.

Acetate Activates Lactobacillus Bacteriocin Synthesis by Controlling Quorum Sensing.

Bacteriocins are useful for controlling the composition of microorganisms in fermented food. Bacteriocin synthesis is regulated by quorum sensing mediated by autoinducing peptides. In addition, short-chain fatty acids, especially acetic acid, reportedly regulate bacteriocin synthesis. Five histidine kinases that regulated the synthesis of bacteriocins were selected to verify their interactions with acetate. Acetate activated the kinase activity of PlnB, SppK, and HpK3 in vitro and increased the yield of their cognate bacteriocins plantaricin EF, sakacin A, and rhamnosin B in vivo. The antimicrobial activity against Staphylococcus aureus of the fermentation supernatants of Lactobacillus plantarum, Lactobacillus sakei, and Lactobacillus rhamnosus with addition of acetate increased to 298%, 198%, and 289%, respectively, compared with that in the absence of acetate. Our study elucidated the activation activity of acetate in bacteriocin synthesis, and it might provide a potential strategy to increase the production of bacteriocin produced by Lactobacillus. IMPORTANCE Bacteriocins produced by lactic acid bacteria (LAB) are particularly useful in food preservation and food safety. Bacteriocins might increase bacterial competitive advantage against the indigenous microbiota of the intestines; at the same time, bacteriocins could limit the growth of undesired microorganisms in yogurt and other dairy products. This study confirmed that three kinds of histidine kinases were activated by acetate and upregulated bacteriocin synthesis both in vitro and in vivo. The increasing yield of bacteriocins reduced the number of pathogens and increased the number of probiotics in milk. Bacteriocin synthesis activation by acetate may have a broad application in the preservation of dairy products and forage silage.

Effect of honeycomb, granular, and powder activated carbon additives on continuous lactic acid fermentation of complex food waste with mixed inoculation.

To accelerate and stabilize lactic acid fermentation from food waste, three types of activated carbon, including honeycomb activated carbon, granular activated carbon, and powder activated carbon, were tested as additives in continuous food waste fermentation processes. The results showed that carbohydrate was the primary substrate for lactic acid production, but its conversion reached a high, stable level after a long period of microbial acclimation in the control system. Activated carbon, especially honeycomb activated carbon accelerated the stabilization of lactic acid fermentation and enhanced the tolerance of fermentation systems to a hostile and fluctuating environment. The addition of activated carbon increased the oxidation-reduction potential to approximately 100 mV and altered the microbial communities. Homolactic fermentation bacteria were dominant in all the systems, and the honeycomb activated carbon addition stimulated the growth of unclassified Lactobacillus and immobilized Lactobacillus panis with strong carbohydrate metabolism. In addition, powder activated carbon enhanced the degradation of protein due to the multiplying Pseudomonas. At the stable stage, the organic conversion rates were close in the control system and the systems with the activated carbon addition, and the lactic acid concentrations in these systems remained at 8000-10,000 mg/L. Considering the cost of the additives, honeycomb activated carbon is a good choice to stabilize lactic acid production from food waste.

Enhancing bile tolerance of Lactobacilli is involved in the hypolipidemic effects of liraglutide.

Liraglutide is an analog of human glucagon-like peptide-1 which play essential roles in regulation of glycolipid metabolism. To investigate role of lactic acid bacteria (LAB) in lipid-lowering effect of liraglutide, 40 mice were divided into normal food diet (NFD), high-fat food (HFD), 10.0 mg/kg/d simvastatin-treated HFD (SIM + HFD), 200 and 400 µg/kg/d liraglutide-treated HFD (LL + HFD and HL + HFD) groups for 5 weeks. We found that liraglutide could upregulate cholesterol 7α-hydroxylase (CYP7A1) and LDL-receptor (LDLR), whereas downregulate 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR). Besides, liraglutide enhance abundance of lactobacillaceae in gut of hyperlipidemic mice and increase bile tolerance ability of LAB by upregulating bile salt hydrolases, and the lysate of liraglutide-sensitive LAB could also directly downregulate HMGCR, the key enzyme in cholesterol synthesis, and inhibit hepatocyte steatosis. These findings might provide new theoretical guidance for clinical application of liraglutide and research and development of antiobesity, hypolipidemic, and cholesterol-lowering drugs or functional foods.

Role of milk and honey in the tolerance of lactobacilli to oxidative stress.

In the development of functional probiotic food, the carrier matrices should be carefully selected and optimized to ensure the highest levels of probiotic survival in the symbiotic food along storage. Because milk and honey food matrices are rich in antioxidant substances, the aim of the research was to evaluate their effect in protecting lactobacilli from reactive oxygen species (ROS) generated by the addition of hydrogen peroxide. Viability assays were performed with and without the addition of H2O2, in three different matrices: 0.9% peptone saline, 5% honey, or 12% reconstituted skim milk. The milk matrix provided protection for the Lacticaseibacillus paracasei DTA83 and Lacticaseibacillus rhamnosus DTA76. However, this protective effect was not observed in the survival of Lactobacillus acidophilus La 5. Honey solution did not maintain the viability of probiotic microorganisms exposed to hydrogen peroxide and, on the contrary, caused a significant reduction in the population of L. rhamnosus DTA76 (p < 0.001). Lower membrane lipid peroxidation due to H2O2 exposure was observed in L. acidophilus La 5 and L. rhamnosus DTA76, but this marker showed no relation with viability. It was concluded: (i) lactobacilli from the Lacticaseibacillus genus were the ones that benefited most from the lactic environment; (ii) the absence of the protective effect of honey was possibly due to the presence of Fe2+ which reacts with H2O2 to produce hydroxyl radicals; and (iii) cell viability did not correlate with membrane lipid peroxidation, and it is not a good marker to evaluate this type of damage in cells of different microorganisms.

The impact of medical cannabis consumption on the oral flora and saliva.

OBJECTIVE: To evaluate the effect of medical cannabis consumption on oral flora and saliva. DESIGN: A clinical prospective study, at the rheumatology clinic of the Nazareth Hospital in Nazareth, recruiting consecutively patients approved for medical cannabis, evaluating their saliva flow, pH and microbial load of Streptococcus mutans and Lactobacillus, prior to and under medical cannabis treatment. METHODS: Patients recently licensed for medical cannabis treatment, were recruited just prior to starting medical cannabis consumption (week 0), 1 and 4 weeks later, patients provided 5-minute time saliva samples, which were measured for their volume and pH, and cultured on a special microbial kit, evaluating the growth of Streptococcus mutans and Lactobacillus. RESULTS: Out of 16 patients enrolled, 14 were female and had fibromyalgia. The mean age of the patients was 52.8±12.9 years. The mean saliva flow at week 0, week 1 and week 4 were 5.38±3.36 ml/5-minutes, 6 (p = 0.769) and 5.45 (p = 0.391), respectively, and for saliva pH were 6.28, 5.94 (p = 0.51) and 5.5 (p = 0.07) respectively also. The mean Streptococcus mutans growth score at weeks 0, 1 and 4 was1.8±0.75, 1.6±0.83 (p = 0.234), and 2.4±0.84 (p = 0.058), respectively. The mean Lactobacilli growth score at weeks 0, 1 and 4 was 2.59±0.88, 3.1±0.69 (p = 0.033) and 3.3±0.67 (p = 0.025), respectively. CONCLUSIONS: The results of this study show that medical cannabis consumption has no significant effect on saliva volume or pH, but it may be associated with changes in salivary levels of oral microbes such as Streptococcus mutans and Lactobacilli.

Oral administration of PEGylated TLR7 ligand ameliorates alcohol-associated liver disease via the induction of IL-22.

Effective therapies for alcohol-associated liver disease (ALD) are limited; therefore, the discovery of new therapeutic agents is greatly warranted. Toll-like receptor 7 (TLR7) is a pattern recognition receptor for single-stranded RNA, and its activation prevents liver fibrosis. We examined liver and intestinal damage in Tlr7-/- mice to determine the role of TLR7 in ALD pathogenesis. In an alcoholic hepatitis (AH) mouse model, hepatic steatosis, injury, and inflammation were induced by chronic binge ethanol feeding in mice, and Tlr7 deficiency exacerbated these effects. Because these results demonstrated that endogenous TLR7 signaling activation is protective in the AH mouse model, we hypothesized that TLR7 activation may be an effective therapeutic strategy for ALD. Therefore, we investigated the therapeutic effect of TLR7 agonistic agent, 1Z1, in the AH mouse model. Oral administration of 1Z1 was well tolerated and prevented intestinal barrier disruption and bacterial translocation, which thus suppressed ethanol-induced hepatic injury, steatosis, and inflammation. Furthermore, 1Z1 treatment up-regulated the expression of antimicrobial peptides, Reg3b and Reg3g, in the intestinal epithelium, which modulated the microbiome by decreasing and increasing the amount of Bacteroides and Lactobacillus, respectively. Additionally, 1Z1 up-regulated intestinal interleukin (IL)-22 expression. IL-22 deficiency abolished the protective effects of 1Z1 in ethanol-induced liver and intestinal damage, suggesting intestinal IL-22 as a crucial mediator for 1Z1-mediated protection in the AH mouse model. Collectively, our results indicate that TLR7 signaling exerts protective effects in the AH mouse model and that a TLR7 ligand, 1Z1, holds therapeutic potential for the treatment of AH.