Screening and evaluating microorganisms with broad-spectrum biogenic amine-degrading ability from naturally fermented dry sausage collected from Northeast China

This study aimed to screen autochthonous strains with broad-spectrum biogenic amine (BA) degradation ability from traditional dry sausages and to evaluate their BA-degrading ability in dry sausages. A total of 120 strains were isolated from dry sausages collected from various regions in Northeast China, and 35 of 120 isolates were identified as non-BA producing strains by the in vitro agar method. The random amplified polymorphic DNA polymerase chain reaction technique genotyped these 35 isolates into 18 biotypes. Moreover, high performance liquid chromatography (HPLC) quantification showed that six strains (Latilactobacillus sakei MDJ6; Lactiplantibacillus plantarum SH7; Weissella hellenica DQ9; Staphylococcus saprophyticus JX18 and SYS8; and Macrococcus caseolyticus SYS11) of the 18 biotypes exhibited broad-spectrum BA-degrading ability, all of which had various levels of amine oxidase activity with monoamine oxidase and diamine oxidase activities ranged of 6.60-619.04 and 26.32-352.81 U/mg protein, respectively. These six strains were subsequently inoculated into dry sausages and the results showed that they exhibited varying degrees of BA-degrading ability, of which strain Lat. sakei MDJ6 allowed to have less BA production on dry sausage with a final concentration of 61.33 mg/kg.

Interspecific differences and mechanisms of Lactobacillus-derived anti-inflammatory exopolysaccharides

Accumulating evidence has revealed the anti-inflammatory properties of Lactobacillus-derived exopolysaccharides (EPSs). However, interspecific differences among these Lactobacillus-derived anti-inflammatory EPSs have not been investigated. Cell experiments showed that Limosilactobacillus fermentum, Lacticaseibacillus rhamnosus, and Lactiplantibacillus plantarum-derived EPSs exhibited excellent anti-inflammatory efficacy in vitro. Subsequently, we used Lactobacillus-derived EPSs to treat colitis in mice. There was no significant difference in EPS's repair of the intestinal barrier from the five Lactobacillus species. However, Ligilactobacillus salivarius-derived EPSs and L. plantarum-derived EPSs more potently reduced proinflammatory cytokines (TNF-α, IL-1β, IL-6, TNF-γ, and IL-17), increasing IL-10 concentrations in the colon. Lactobacillus-derived EPS moieties from five species regulate intestinal bacteria at the strain level. Immunofluorescence staining revealed that owing to the different infiltration and polarization effects of Lactobacillus-derived EPSs on macrophages, the in vitro and in vivo anti-inflammatory effects of Lactobacillus-derived EPSs were inconsistent. The structure-activity relationship showed that Lactobacillus-derived EPSs with high fructose content had excellent anti-inflammatory activity in vivo. The results mentioned above revealed that the anti-inflammatory activity of Lactobacillus-derived EPSs had interspecific variability, and the mechanism of anti-inflammatory action in vitro and in vivo was different.

The efficacy of vaginal treatment for non-Lactobacillus dominant endometrial microbiota-A case-control study

AIM

Reduced Lactobacillus occupancy in the uterine microflora has been associated with implantation failure. This study aimed to evaluate a treatment for improving the uterine microflora.

METHODS

This study included patients diagnosed with repeated implantation failure-defined as failure to achieve pregnancy after two or more transfers of viable embryos-who were classified as non-Lactobacillus dominant. Treatment A comprised oral administration of antibiotics for 1 week, followed by oral probiotic butyrate tablets (3 g/day) for approximately 30 days. Treatment B comprised a 1-week course of oral (750 mg/day) and vaginal (250 mg/day) metronidazole, followed by a 1-week intravaginal administration of probiotic capsules (1 capsule/day) and continued oral administration of probiotics (1 capsule/day). Both treatments were compared in terms of efficacy in improving vaginal flora. Improvement was defined as Lactobacillus occupancy >90% or an increase in Lactobacillus occupancy >20%.

RESULTS

Seven (41.2%) of 17 patients in the Treatment A group improved in response to the treatment. Contrastingly, 9 (90.0%) of 10 patients improved in the Treatment B group (p = 0.0127). Following treatment, Lactobacillus occupancy in the Treatment B group (62.9% ± 12.7%) was significantly higher than that in the Treatment A group (5.7% ± 9.8%) (p = 0.0242).

CONCLUSIONS

This study demonstrates the effectiveness of combining antibiotics and probiotics in vaginal formulations for treating abnormal uterine microflora. However, its potential impact on in vitro fertilization outcomes remains unclear and warrants further investigation through larger, more comprehensive studies.

Investigating the efficacy of an exopolysaccharide (EPS)-producing strain Lactiplantibacillus plantarum L75 on oat silage fermentation at different temperatures

This study investigates the effectiveness of an exopolysaccharide (EPS)-producing strain (Lactiplantibacillus plantarum L75) alone or in combination with Saccharomyces cerevisiae on the fermentation characteristics, antioxidant capacities and microbial community successions of oat silage stored at various temperatures. A rapid decrease in pH and lactic acid accumulation was observed in silages treated with L. plantarum and S. cerevisiae (LS) as early as 3 days of ensiling (p < 0.05). Over the ensiling period of 7-60 days, L. plantarum (L)-inoculated groups showed the lowest pH, lowest ammonia nitrogen and the highest amount of lactic acid regardless of the storage temperatures. When the oat silage was stored at 15°C, LS-inoculated group exhibited a higher superoxide dismutase (SOD) activity than control and L-inoculated group. Furthermore, the proportion of Lactiplantibacillus in the combined inoculation group increased by 65.42% compared to the L-inoculated group (33.26%). Fungal community data revealed abundant Penicillium carneum in the control and L-inoculated groups stored at 15°C. Conclusively, these results showed that combined inoculation of L. plantarum L75 and S. cerevisiae improved the fermentation quality of oat silage at 15°C, thus proposing a technique for enhancing the fermentation quality of silage in regions with low temperatures during harvest season.

A case report of lactobacillus bacteremia in a patient on chronic parenteral nutrition

BACKGROUND AND AIMS

Short bowel syndrome is a malabsorption disorder typically caused by the physical loss of a portion of the intestine, whereafter the body is unable to adequately absorb nutrients, fluids, and electrolytes. Many patients with short bowel syndrome are reliant on home parenteral nutrition through a tunneled or peripherally inserted central catheter to ensure sufficient hydration and nutrition. Central venous catheters are a nidus for bacteria, and patients are at risk for infections associated with high levels of morbidity and mortality. Lactobacillus is a ubiquitous microorganism that most frequently colonizes mucosal surfaces such as the gastrointestinal tract. Lactobacillus bacteremia is rare, with limited occurrence in current medical literature.

METHODS

Our patient is a 60-year-old female with a past medical history significant for multiple abdominal surgeries resulting in short bowel syndrome, with subsequent dependence on home parenteral nutrition via peripherally inserted central catheter. She had type III chronic intestinal failure, category D2, and stage 1 moderate malnutrition. She was originally admitted to the hospital for a presumed pulmonary embolism and was found to have a deep vein thrombosis in the setting of her peripherally inserted central catheter. On admission her abdominal exam was unremarkable, she denied abdominal pain, and her only gastrointestinal complaint was chronic stable diarrhea. During the hospitalization she developed severe left lower quadrant abdominal pain and noted decreased frequency of her bowel movements. A computed tomography scan of her abdomen revealed chronic stable intestinal distension and was concerning for obstruction. Clinically she remained without symptoms of acute obstruction or ileus. During the admission she became febrile, with blood cultures from her peripherally inserted central catheter and peripheral IV growing out gram negative rods determined to be lactobacillus bacteremia. The infectious disease team recommended removal of her peripherally inserted central catheter given their concern for a line infection.

RESULTS

The patient was treated with broad-spectrum antibiotics, did well clinically, and was ultimately discharged following reinsertion of her peripherally inserted central catheter after negative repeat blood cultures. Though she initially did well in the outpatient setting, she ultimately passed away ten months later after re-presenting to the hospital in septic shock, secondary to bowel ischemia and suspected fungemia of her peripherally inserted central catheter.

CONCLUSIONS

In this case report, we describe an unusual case of a patient with short bowel syndrome on chronic parenteral nutrition who developed catheter-associated lactobacillus bacteremia - the first reported case in an adult patient on parenteral nutrition.

Characterization of key flavor substances and their microbial sources in traditional sour bamboo shoots

Identifying key flavor compounds and their producing bacteria in sour bamboo shoots is crucial for flavor stabilization and industrial production. This study analyzed 15 traditional sour bamboo shoot samples from northern Guangdong to determine key flavor substances and microbial community. Results showed key flavor substances were acetic acid (RTC ≥ 50% in 10 samples), lactic acid (RTC ≥ 50% in 5 samples), and p-cresol (ROC ≥ 93%). Lactobacillus (ARA: 54.62%) was the dominant genus, significantly correlated with p-cresol (r = 0.80, p ≤ 0.01). Levilactobacillus (ARA: 3.33%) was positively correlated with lactic acid and p-cresol (r = 0.78, p ≤ 0.01; r = 0.66, p ≤ 0.01). Lentilactobacillus (ARA: 4.29%) was positively correlated with acetic acid (r = 0.85, p ≤ 0.01). Levilactobacillus was isolated, screened, identified, and its ability to produce key flavor substances was tested. Four strains of Levilactobacillus spicheri and their mixed strains produced lactic acid (10.12-16.62 g/kg), acetic acid (10.21-21.60 g/kg), and p-cresol (25.67-143.87 mg/kg). This is the first report of Levilactobacillus spicheri producing p-cresol.

Inhibitory Effects of Latilactobacillus curvatus BYB3 Cell-Free Extract on Human Melanoma B16F10 Cells and Tumorigenic Mice

Latilactobacillus curvatus BYB3 (BYB3) is a species of lactic acid bacteria, formerly named Lactobacillus curvatus, which is isolated from kimchi. In this study, the effect of BYB3, Lactobacillus rhamnosus GG, and Lactobacillus acidophilus GP1B strain extracts at various concentrations was examined on B16F10, a mouse melanoma cell line. Cell viability was examined via MTT assay, and the results indicated that compared to the other two probiotics, BYB3 significantly decreased the total percentages of viable cells. The effects of BYB3 on cell migration and proliferation in B16F10 cells were evaluated using wound healing mobility and proliferation assays, respectively; the results indicated that BYB3 inhibits cell migration and proliferation in a concentration-dependent manner. Using human dermal fibroblast cells to investigate BYB3 extract in vivo had no effect on skin-related cells. Nonetheless, the BYB3 extract inhibited tumor growth in a mouse model, as demonstrated by liver slices. Therefore, this suggests that using BYB3 extract to inhibit melanoma may be a novel approach.

Protective effects of Lactobacillus on heat stress-induced intestinal injury in finisher broilers by regulating gut microbiota and stimulating epithelial development

Heat stress (HS) is a critical challenge in broilers due to the high metabolic rate and lack of sweat glands. Results from this study show that implementing a cyclic chronic HS (34 °C for 7 h/d) to finisher broilers decreased the diversity of cecal microbiota and impaired intestinal barrier, resulting in gut leak and decreased body weight (both P < 0.05). These alterations might be related to inflammatory outbursts and the retarded proliferation of intestinal epithelial cells (IECs) according to the transcriptome analysis. Considering the potential beneficial properties of Lactobacillus on intestinal development and function, the protective effects of Lactobacillus rhamnosus (L. rhamnosus) on the intestine were investigated under HS conditions in this study. Orally supplemented L. rhamnosus improved the composition of cecal microbiota and upregulated the transcription of tight junction proteins in both duodenum and jejunum, with a consequent suppression in intestinal gene expressions of pro-inflammatory cytokines and facilitation in digestive capability. Meanwhile, the jejunal villus height of the birds that received L. rhamnosus was significantly higher compared with those treated with the broth (P < 0.05). The expression abundances of genes related to IECs proliferation and differentiation were increased by L. rhamnosus, along with upregulated mRNA levels of Wnt3a and β-catenin in jejunum. In addition, L. rhamnosus attenuated enterocyte apoptosis as indicated by decreased caspase-3 and caspase-9 gene expressions. The results indicated that oral administration with L. rhamnosus mitigated HS-induced dysfunction by promoting intestinal development and epithelial maturation in broilers and that the effects of L. rhamnosus might be dependent of Wnt/β-catenin signaling.

Integrated 16S rRNA sequencing and metabolomic analysis reveals the potential protective mechanism of Germacrone on diabetic nephropathy in mice

Diabetic nephropathy (DN) is a severe complication of diabetes and the leading cause of end-stage renal disease and death. Germacrone (Ger) possesses anti-inflammatory, antioxidant and anti-DN properties. However, it is unclear whether the improvement in kidney damage caused by Ger in DN mice is related to abnormal compositions and metabolites of the gut microbiota. This study generates a mouse model of DN to explore the potent therapeutic ability and mechanism of Ger in renal function by 16S rRNA sequencing and untargeted fecal metabolomics. Although there is no significant change in microbiota diversity, the structure of the gut microbiota in the DN group is quite different. Serratia_marcescens and Lactobacillus_iners are elevated in the model group but significantly decreased after Ger intervention ( P<0.05). Under the treatment of Ger, no significant differences in the diversity and richness of the gut microbiota are observed. An imbalance in the intestinal flora leads to the dysregulation of metabolites, and non-targeted metabolomics data indicate high expression of stearic acid in the DN group, and oleic acid could serve as a potential marker of the therapeutic role of Ger in the DN model. Overall, Ger improves kidney injury in diabetic mice, in part potentially by reducing the abundance of Serratia_marcescens and Lactobacillus_iners, as well as regulating the associated increase in metabolites such as oleic acid, lithocholic acid and the decrease in stearic acid. Our research expands the understanding of the relationship between the gut microbiota and metabolites in Ger-treated DN. This contributes to the usage of natural products as a therapeutic approach for the treatment of DN via microbiota regulation.

The anticancer effect of potential probiotic L. fermentum and L. plantarum in combination with 5-fluorouracil on colorectal cancer cells

5-Fluorouracil (5-FU) is an effective chemotherapy drug in the treatment of colorectal cancer (CRC). However, auxiliary or alternative therapies must be sought due to its resistance and potential side effects. Certain probiotic metabolites exhibit anticancer properties. In this study evaluated the anticancer and potential therapeutic activities of cell extracts potential probiotic strains, Limosilactobacillus fermentum and Lactiplantibacillus plantarum isolated from the mule milk and the standard probiotic strain Lacticaseibacillus rhamnosus GG (LGG) against the human colon cancer cell line (HT-29) and the normal cell line (HEK-293) alone or in combination with 5-FU. In this study, L. plantarum and L. fermentum, which were isolated from mule milk, were identified using biochemical and molecular methods. Their probiotic properties were investigated in vitro and compared with the standard probiotic strain of the species L. rhamnosus GG. The MTT assay, acridine orange/ethidium bromide (AO/EB) fluorescent staining, and flow cytometry were employed to measure the viability of cell lines, cell apoptosis, and production rates of Th17 cytokines, respectively. The results demonstrated that the combination of lactobacilli cell extracts and 5-FU decreased cell viability and induced apoptosis in HT-29 cells. Furthermore, this combination protected HEK-293 cells from the cytotoxic effects of 5-FU, enhancing their viability and reducing apoptosis. Moreover, the combination treatment led to an increase in the levels of IL-17A, IFN-γ, and TNF-α, which can enhance anti-tumor immunity. In conclusion, the cell extracts of the lactobacilli strains probably can act as a potential complementary anticancer therapy.

Vaginal community state types (CSTs) alter environmental cues and production of the Staphylococcus aureus toxic shock syndrome toxin-1 (TSST-1)

Menstrual toxic shock syndrome (mTSS) is a rare but life-threatening disease associated with the use of high-absorbency tampons. The production of the Staphylococcus aureus toxic shock syndrome toxin-1 (TSST-1) superantigen is involved in nearly all cases of mTSS and is tightly controlled by regulators responding to the environment. In the prototypic mTSS strain S. aureus MN8, the major repressor of TSST-1 is the carbon catabolite protein A (CcpA), which responds to glucose concentrations in the vaginal tract. Healthy vaginal Lactobacillus species also depend on glucose for both growth and acidification of the vaginal environment through lactic acid production. We hypothesized that interactions between the vaginal microbiota [herein referred to as community state types (CSTs)] and S. aureus MN8 depend on environmental cues and that these interactions subsequently affect TSST-1 production. Using S. aureus MN8 ΔccpA growing in various glucose concentrations, we demonstrate that the supernatants from different CSTs grown in vaginally defined medium (VDM) could significantly decrease tst expression. When co-culturing CST species with MN8 ∆ccpA, we show that Lactobacillus jensenii completely inhibits TSST-1 production in conditions mimicking healthy menstruation or mTSS. Finally, we show that growing S. aureus in "unhealthy" or "transitional" CST supernatants results in higher interleukin 2 (IL-2) production from T cells. These findings suggest that dysbiotic CSTs may encourage TSST-1 production in the vaginal tract and further indicate that the CSTs are likely important for the protection from mTSS.IMPORTANCEIn this study, we investigate the impact of the vaginal microbiota against Staphylococcus aureus in conditions mimicking the vaginal environment at various stages of the menstrual cycle. We demonstrate that Lactobacillus jensenii can inhibit toxic shock syndrome toxin-1 (TSST-1) production, suggesting the potential for probiotic activity in treating and preventing menstrual toxic shock syndrome (mTSS). On the other side of the spectrum, "unhealthy" or "transient" bacteria such as Gardnerella vaginalis and Lactobacillus iners support more TSST-1 production by S. aureus, suggesting that community state types are important in the development of mTSS. This study sets forward a model for examining contact-independent interactions between pathogenic bacteria and the vaginal microbiota. It also demonstrates the necessity of replicating the environment when studying one as dynamic as the vagina.

Lactobacillus rhamnosus GG ameliorates hyperuricemia in a novel model

Hyperuricemia (HUA) is a metabolic syndrome caused by abnormal purine metabolism. Although recent studies have noted a relationship between the gut microbiota and gout, whether the microbiota could ameliorate HUA-associated systemic purine metabolism remains unclear. In this study, we constructed a novel model of HUA in geese and investigated the mechanism by which Lactobacillus rhamnosus GG (LGG) could have beneficial effects on HUA. The administration of antibiotics and fecal microbiota transplantation (FMT) experiments were used in this HUA goose model. The effects of LGG and its metabolites on HUA were evaluated in vivo and in vitro. Heterogeneous expression and gene knockout of LGG revealed the mechanism of LGG. Multi-omics analysis revealed that the Lactobacillus genus is associated with changes in purine metabolism in HUA. This study showed that LGG and its metabolites could alleviate HUA through the gut-liver-kidney axis. Whole-genome analysis, heterogeneous expression, and gene knockout of LGG enzymes ABC-type multidrug transport system (ABCT), inosine-uridine nucleoside N-ribohydrolase (iunH), and xanthine permease (pbuX) demonstrated the function of nucleoside degradation in LGG. Multi-omics and a correlation analysis in HUA patients and this goose model revealed that a serum proline deficiency, as well as changes in Collinsella and Lactobacillus, may be associated with the occurrence of HUA. Our findings demonstrated the potential of a goose model of diet-induced HUA, and LGG and proline could be promising therapies for HUA.

Interpretation of vaginal metagenomic characteristics in different types of vaginitis

Although vaginitis is closely related to vaginal microecology in females, the precise composition and functional potential of different types of vaginitis remain unclear. Here, metagenomic sequencing was applied to analyze the vaginal flora in patients with various forms of vaginitis, including cases with a clue cell proportion ranging from 1% to 20% (Clue1_20), bacterial vaginitis (BV), vulvovaginal candidiasis (VVC), and BV combined with VVC (VVC_BV). Our results identified Prevotella as an important biomarker between BV and Clue1_20. Moreover, a gradual decrease was observed in the relative abundance of shikimic acid metabolism associated with bacteria producing indole as well as a decline in the abundance of Gardnerella vaginalis in patients with BV, Clue1_20, and healthy women. Interestingly, the vaginal flora of patients in the VVC_BV group exhibited structural similarities to that of the VVC group, and its potentially functional characteristics resembled those of the BV and VVC groups. Finally, Lactobacillus crispatus was found in high abundance in healthy samples, greatly contributing to the stability of the vaginal environment. For the further study of L. crispatus, we isolated five strains of L. crispatus from healthy samples and evaluated their capacity to inhibit G. vaginalis biofilms and produce lactic acid in vitro to select the potential probiotic candidate for improving vaginitis in future clinical studies. Overall, we successfully identified bacterial biomarkers of different vaginitis and characterized the dynamic shifts in vaginal flora between patients with BV and healthy females. This research advances our understanding and holds great promise in enhancing clinical approaches for the treatment of vaginitis.

IMPORTANCE

Vaginitis is one of the most common gynecological diseases, mostly caused by infections of pathogens such as Candida albicans and Gardnerella vaginalis. In recent years, it has been found that the stability of the vaginal flora plays an important role in vaginitis. Furthermore, the abundant Lactobacillus-producing rich lactic acid in the vagina provides a healthy acidic environment such as Lactobacillus crispatus. The metabolites of Lactobacillus can inhibit the colonization of pathogens. Here, we collected the vaginal samples of patients with bacterial vaginitis (BV), vulvovaginal candidiasis (VVC), and BV combined with VVC to discover the differences and relationships among the different kinds of vaginitis by metagenomic sequencing. Furthermore, because of the importance of L. crispatus in promoting vaginal health, we isolated multiple strains from vaginal samples of healthy females and chose the most promising strain with potential probiotic benefits to provide clinical implications for treatment strategies.

Anti-oral cancer properties of potential probiotic lactobacilli isolated from traditional milk, cheese, and yogurt

This study investigates the probiotic and anti-cancer effects of 21 isolated Lactobacillus strains from cheese, milk, and yogurt in Kermanshah, Iran, on oral cancer cell lines KB and OSCC. Four selected isolates (Y33, M45, C5, and C28) displayed good viability and resistance to specific antibiotics. Notably, strains C28 and Y33 exhibited the best results, showing susceptibility or semi-susceptibility to five antibiotics. Y33, with high cell surface hydrophobicity (62%), demonstrated significant anti-pathogenic activity, inhibiting the growth of tested pathogens and displaying strong adhesion to human intestinal Caco-2 cells (52%). Further assessments, including acridine orange/ethidium bromide staining and mRNA expression analysis, revealed four isolates (C5, C28, M45, and Y33) with promising probiotic properties. Particularly, Y33's protein-based extract metabolites showed dose- and time-dependent inhibition of KB and OSCC cancer cell lines, inducing apoptosis without significant cytotoxic effects on normal cells. Y33 (Lactiplantibacillus plantarum) exhibited the strongest probiotic potential, surpassing conventional anti-cancer drugs, suggesting its therapeutic potential for preventing oral cancer cell proliferation and improving survival rates in oral cancer patients.

The effect of adding pomace on the bioactive composition and flavor volatiles in fermented orange juice with Lactobacillus

BACKGROUND

The consumption of oranges generates huge amounts of pomaces, which are the potential raw materials to increase the nutritional value of the products.

RESULTS

In this study, the bioactive composition and flavor volatiles in Lactobacillus fermented orange juice with added pomaces were researched. Results showed that the orange juices blended with pomaces were favorable substrates for Lactobacillus growth and the colony counts reached above 9.0 log CFU mL-1 , total phenolics, total flavonoids, and the antioxidant activity in orange juices were increased significantly after adding pomaces. Some amino acids, such as threonine (P < 0.0001), isoleucine (P < 0.01), and glycine (P < 0.01) were markedly higher in fermented orange juices with pomaces. The flavonoid diversity was more abundant by adding pomace fermentation and most flavonoids showed higher levels in fermented juices with the pomace, Lactobacillus fermentum 252 may transform some flavonoids through deglycosylation and reduction reaction. Furthermore, orange pomace mainly improved the flavor volatiles by increasing terpenoids and alcohol, such as d-limonene and benzyl alcohol, and decreasing volatile acids.

CONCLUSION

This study presented a novelty in elevating the nutritional value of juice by the utilization of pomaces, its findings can provide a new way to mine the bioactive ingredient from Citrus by Lactobacillus, and can be used as a guide for the development of new Citrus processing technologies and functional foods. © 2023 Society of Chemical Industry.

Lactobacillus strains reduce the toxic effects of a subchronic exposure to arsenite through drinking water

The aim of the present study was to determine the efficacy of LAB strains in reducing the intestinal toxicity of arsenite [As(III)] and its tissue accumulation. For this purpose, Balb/c mice were randomly separated in four groups. One group received no treatment (control), one group received only As(III) (30 mg/L) via drinking water and the remaining two groups received As(III) via water and a daily dose of two LAB strains (Lactobacillus intestinalis LE1 and Lacticaseibacillus paracasei BL23) by gavage during 2 months. The results show that both strains reduce the pro-inflammatory and pro-oxidant response observed at the colonic level, partially restore the expression of the intercellular junction proteins (CLDN3 and OCLN) responsible for the maintenance of epithelial integrity, and increase the synthesis of the major mucin of the colonic mucus layer (MUC2), compared to animals treated with As(III) alone. Microbial metabolism of short-chain fatty acids also undergoes a recovery and the levels of fatty acids in the lumen reach values similar to those of untreated animals. All these positive effects imply the restoration of mucosal permeability, and a reduction of the marker of endotoxemia LPS binding protein (LBP). Treatment with the bacteria also has a direct impact on intestinal absorption, reducing the accumulation of As in the internal organs. The data suggest that the protective effect may be due to a reduced internalization of As(III) in intestinal tissues and to a possible antioxidant and anti-inflammatory activity of the bacteria through activation of pathways such as Nrf2 and IL-10. In vitro tests show that the protection may be the result of the combined action of structural and metabolic components of the LAB strains.

Screening and molecular dynamics simulation of ACE inhibitory tripeptides derived from milk fermented with Lactobacillus delbrueckii QS306

Peptides in milk fermented with Lactobacillus delbrueckii QS306 before and after ultrahigh pressure treatment were identified using proteomics. Subsequently, 16 stable tripeptides were screened out based on activity score prediction, PeptideCutter analysis, and hydrophobicity calculations. Among them, WRP, WSR, and YRP showed the best angiotensin-converting enzyme (ACE) inhibitory activity, and their semi-inhibitory concentrations were 46.707, 300.121, and 89.555 μM, respectively. WRP and WSR were competitive inhibitors, whereas YRP was non-competitive. Gastrointestinal simulation revealed that WRP and YRP had better gastrointestinal stability. The values of RMSD, ΔGbind, ΔGpol, and RSMF obtained from molecular dynamics simulation indicated that the interaction of WRP and ACE was stable. Thus, Lactobacillus delbrueckii QS306-fermented milk can serve as an important source of ACE inhibitory peptides both before and after ultrahigh pressure treatment. The strategy of in silico screening, activity evaluation, and molecular dynamics simulation adopted in this study can be applied to the large-scale screening of novel peptides with high ACE inhibitory activity.

Novel mechanism by which extracellular vesicles derived from Lactobacillus murinus alleviates deoxynivalenol-induced intestinal barrier disruption

Deoxynivalenol (DON) is a common environmental pollutant that poses a serious health risk to humans worldwide. This study was aim to explore whether gut microbiota is involved in DON-induced intestinal toxicity as well as to reveal effect of probiotics derived from gut microbiota in protecting intestinal barrier and to elucidate mechanism. We found that DON caused disturbed gut microbiota, particularly Lactobacillus murinus (L. murinus) deficiency. DON enhanced M1 macrophage polarization and decreased tight junction protein expression. Microbiota transplantation experiments showed that transfer of DON-disrupted microbiota to healthy mice resulted in delivery of DON-induced intestinal toxicity. Besides, DON lost its damaging effect on macrophage and intestinal barrier in antibiotic-treated mice. Further intervention experiments revealed that L. murinus induce macrophage conversion from M1 to M2 phenotype through secreted extracellular vesicles (EVs) to alleviate DON-induced intestinal barrier disruption. Mechanistically, EVs activate TLR2 to promote M2 macrophage polarization and release IL-10, which in turn enhances intestinal barrier function. Upon successful translation of its efficacy into clinical practice, EVs created from L. murinus could be a novel possible treatment strategy for DON-induced gut disease.

Lactobacillus reuteri derived from horse alleviates Escherichia coli-induced diarrhea by modulating gut microbiota

Diarrhea is a prevalent health issue in farm animals and poses a significant challenge to the progress of animal husbandry. Recent evidence suggested that probiotics can alleviate diarrhea by maintaining gut microbial balance and enhancing the integrity of the intestinal barrier. However, there is a scarcity of studies investigating the efficacy of equine Lactobacillus reuteri in relieving E. coli-induced diarrhea. Hence, this study aimed to examine the potential of equine-derived Lactobacillus reuteri in alleviating E. coli diarrhea from the perspective of gut microbiota. Results demonstrated that supplementation of Lactobacillus reuteri had the potential to alleviate diarrhea induced by E. coli infection and restore the decline of tight junction genes, such as Claudin-1 and ZO-1. Additionally, Lactobacillus reuteri supplementation can restore the expression of inflammatory factors (IL-6, IL-10, TNF-α, and IFN-γ) and reduce colon inflammatory damage. Diversity analysis, based on amplicon sequencing, revealed a significant reduction in the diversity of gut microbiota during E. coli-induced diarrhea. Moreover, there were notable statistical differences in the composition and structure of gut microbiota among the different treatment groups. E. coli could induce gut microbial dysbiosis by decreasing the abundance of beneficial bacteria, including Lactobacillus, Bifidobacterium, Ligilactobacillus, Enterorhabdus, and Lachnospiraceae_UCG_001, in comparison to the control group. Conversely, supplementation with Lactobacillus reuteri could restore the abundance of beneficial bacteria and increase the diversity of the gut microbiota, thereby reshaping gut microbiota. Additionally, we also observed that supplementation with Lactobacillus reuteri alone improved the gut microbial composition and structure. In summary, the findings suggest that Lactobacillus reuteri can alleviate E. coli-induced diarrhea by preserving the integrity of the intestinal barrier and modulating the composition of the gut microbiota. These results not only contribute to understanding of the mechanism underlying the beneficial effects of Lactobacillus reuteri in relieving diarrhea, but also provide valuable insights for the development of probiotic products aimed at alleviating diarrheal diseases.

The pharmaceutical effect of Korean wild ginseng residue extract on the performance, microbiota quality, cytokine expression, and the ginseng saponin content of laying hen

In this study, a total of 312 Hyline brown laying hen of 1.92 ± 0.12 kg acquired at 24-wk old were employed to evaluate the pharmaceutical effect of Korean wild ginseng residue extract administered via drinking water on the performance, microbiota quality, cytokine expression, and the ginsenoside saponin (GS) content of laying hen for 12 wk. In the experiments, basic feed (CON) was compared with basic feed + 0.05% wild ginseng in drinking water (WGD1), basic feed + 0.1% wild ginseng in drinking water (WGD2), and basic feed + 0.5% wild ginseng in drinking water (WGD3). At the end of study, hen-day egg production (HDEP), average egg weight (AEW), and egg mass (EM) were linearly higher (p < 0.05) in WGD3 at wk 30 to 33, 34 to 37 wk, and the cumulative wk compared with CON. Feed conversion ratio (FCR) was linearly lower in WGD3 at 34 to 37 wk, and the cumulative wk compared with CON. Relative expression of tumor necrosis factor alpha (TNF-α) was linearly lower (p < 0.05) in the WGD3 at wk 30 to 33, and 34 to 37 wk compared with CON. The GS in egg yolk was linearly higher (p < 0.05) in laying hens supplemented the WGD3 treatment at wk 34 to 37, while the fecal microflora quantity of Lactobacillus was linearly higher (p < 0.05) in WGD3 at wk 30 to 33, till 34 to 37 wk, and Escherichia coli (E. coli) was linearly lower (p < 0.05) in the WGD2 and WGD3 from 2637 wk compared with CON. We concluded the result in HDEP, AEW, EM, and FCR were due to the increase in GS content, tentatively leading to an improvement in the TNF-α, and fecal microflora quality such as Lactobacillus and E. coli in the WGD3. We therefore recommend the use of WGD3 at application level 0.5% in drinking water for optimum laying performance from 30 to 37 wk.

Formulation and validation of probioticated foxtail millet laddu as a source of antioxidant for biological system using response surface methodology

Probiotics play a critical role in supporting a healthy gut microbiome, which significantly impacts overall health and well-being. While there has been an increase in the availability of probiotic foods in recent years, there may still be limited options and accessibility in certain regions. This study focused on formulating a traditional Indian sweet called laddu enriched with millet and Lactobacillus acidophilus. The formulation of laddu ingredients was optimized using Design Expert software to create an optimal product for testing. The probiotic Lactobacillus acidophilus culture was incorporated into the laddu in three forms: lyophilized, microencapsulated powder, and natural curd. The probiotic foxtail laddu was selected based on specific criteria such as color, odor, and texture. The nutritional analysis revealed that the laddu contained approximately 64.46 g of carbohydrates, 15.13 g of protein, and 5.06 g of fat per 100 g of laddu. A microbial count analysis was performed over a two-month storage period to assess the viability of the incorporated Lactobacillus acidophilus. The results showed that the lyophilized and microencapsulated culture demonstrated good viability, with counts of 6.10 ± 0.09 log CFU/g and 7.43 ± 0.02 log CFU/g, respectively, when stored at 4 °C. In comparison, storage at room temperature resulted in counts of 5.41 ± 0.08 log CFU/g and 6.97 ± 0.02 log CFU/g at the end of the storage period. Based on the findings, the probiotic millet laddu developed in this study has the potential to be a value-added food product that can enhance the overall health of consumers. Incorporating probiotics into traditional food items like laddu offers a convenient and enjoyable way to promote gut health and improve the product's nutritional value.

Lacticaseibacillus chiayiensis mediate intestinal microbiome and microbiota-derived metabolites regulating the growth and immunity of chicks

Emerging evidence confirms beneficial properties of probiotics in promoting growth and immunity of farmed chicken. However, the molecular mechanisms underlying the host-microbiome interactions mediated by probiotics are not fully understood. In this study, the internal mechanisms of Lacticaseibacillus chiayiensis-mediated host-microbiome interactions and to elucidate how it promotes host growth were investigated by additional supplementation with L. chiayiensis. We conducted experiments, including intestinal cytokines, digestive enzymes test, intestinal microbiome, metabolome and transcriptome analysis. The results showed that chickens fed L. chiayiensis exhibited higher body weight gain and digestive enzyme activity, and lower pro-inflammatory cytokines, compared to controls. Microbiota sequencing analysis showed that the gut microbiota structure was reshaped with L. chiayiensis supplementation. Specifically, Lactobacillus and Escherichia increased in abundance and Enterococcus, Lactococcus, Corynebacterium, Weissella and Gallicola decreased. In addition, the bacterial community diversity was significantly increased compared to controls. Metabolomic and transcriptomic analyses revealed that higher bile acids and N-acyl amides concentrations and lower carbohydrates concentrations in L. chiayiensis-fed chickens. Meanwhile, the expression of genes related to nutrient transport and absorption in the intestine was upregulated, which reflected the enhanced digestion and absorption of nutrients in chickens supplemented with L. chiayiensis. Moreover, supplementation of L. chiayiensis down-regulated genes involved in inflammation-related, mainly involved in NF-κB signaling pathway and MHC-II mediated antigen presentation process. Cumulatively, these findings highlight that host-microbiota crosstalk enhances the host growth phenotype in two ways: by enhancing bile acid metabolism and digestive enzyme activity, and reducing the occurrence of intestinal inflammation to promote nutrient absorption and maintain intestinal health. This provides a basis for the application of LAB as an alternative to antibiotics in animal husbandry.

Alleviative effects of exopolysaccharides from Limosilactobacillus mucosae CCFM1273 against ulcerative colitis via modulation of gut microbiota and inhibition of Fas/Fasl and TLR4/NF-κB pathways

Ulcerative colitis (UC) has become a public health challenge as its global prevalence increases annually. The use of prebiotics in healthcare has grown in recent years. Thus, the present study was designed to explore the alleviating effects and mechanisms of exopolysaccharides (EPS) produced by Limosilactobacillus mucosae CCFM1273 on UC. The results indicated that CCFM1273 EPS mitigated the disease symptoms and colonic pathologic damage in DSS-induced colitis mice. Moreover, CCFM1273 EPS improved the intestinal barrier by restoring goblet cell numbers and MUC2 production, enhancing intercellular junctions, and inhibiting epithelial cell apoptosis. In addition, CCFM1273 EPS inhibited colonic inflammation and oxidative stress. Importantly, CCFM1273 EPS augmented short-chain fatty acid (SCFA) producers, leading to increased levels of SCFAs (especially propionic acid), which inhibited the Fas/Fasl pathway and consequently inhibited epithelial apoptosis, and diminished Gram-negative bacteria, further decreasing lipopolysaccharides (LPS), which suppressed the TLR4/NF-κB pathway and consequently suppressed colonic inflammation, eventually relieving UC in mice. This study provides theoretical support for the use of prebiotics in clinical practice for UC.

Decarboxylase activity of the non-starter lactic acid bacterium Loigolactobacillus rennini gives crack defects in Gouda cheese through the production of γ-aminobutyric acid

Ten Gouda cheese wheels with an age of 31 weeks from six different batch productions were affected by a crack defect and displayed an unpleasant off-flavor. To unravel the causes of these defects, the concentrations of free amino acids, other organic acids, volatile organic compounds, and biogenic amines were quantified in zones around the cracks and in zones without cracks, and compared with those of similar Gouda cheeses without crack defect. The Gouda cheeses with cracks had a significantly different metabolome. The production of the non-proteinogenic amino acid γ-aminobutyric acid (GABA) could be unraveled as the key mechanism leading to crack formation, although the production of the biogenic amines cadaverine and putrescine contributed as well. High-throughput amplicon sequencing of the full-length 16S rRNA gene based on whole-community DNA revealed the presence of Loigolactobacillus rennini and Tetragenococcus halophilus as most abundant non-starter lactic acid bacteria in the zones with cracks. Shotgun metagenomic sequencing allowed to obtain a metagenome-assembled genome of both Loil. rennini and T. halophilus. However, only Loil. rennini contained genes necessary for the production of GABA, cadaverine, and putrescine. Metagenetics further revealed the brine and the rennet used during cheese manufacturing as the most plausible inoculation sources of both Loil. rennini and T. halophilus.IMPORTANCECrack defects in Gouda cheeses are still poorly understood, although they can lead to major economic losses in cheese companies. In this study, the bacterial cause of a crack defect in Gouda cheeses was identified, and the pathways involved in the crack formation were unraveled. Moreover, possible contamination sources were identified. The brine bath might be a major source of bacteria with the potential to deteriorate cheese quality, which suggests that cheese producers should regularly investigate the quality and microbial composition of their brines. This study illustrated how a multiphasic approach can understand and mitigate problems in a cheese company.

Fingerprinting and characterization of the polysaccharides from Polygonatum odoratum and the in vitro fermented effects on Lactobacillus johnsonii

Polygonatum odoratum (Yu-Zhu) can be utilized to treat the digestive and respiratory illness. Previous studies have revealed that the underlying therapeutic mechanism of P. odoratum polysaccharides (POPs) is associated with remodeling the gut microbiota. However, POPs in terms of the chemical composition and fermentation activities have been understudied. Here we developed the three-level fingerprinting approaches to characterize the structures of POPs and probed into the beneficial effects on promoting the growth and fermentation of Lactobacillus johnsonii. POPs were prepared by water decoction followed by alcohol sedimentation, while trifluoroacetic acid under different conditions to prepare the hydrolyzed oligosaccharides and monosaccharides. POPs exhibited three main molecular distribution of 601-620 kDa, 4.12-6.09 kDa, and 3.57-6.02 kDa. Hydrolyzed oligosaccharides with degree of polymerization (DP) 2-13 got primarily characterized by analyzing the rich fragmentation information obtained by hydrophilic interaction chromatography/ion mobility-quadrupole time-of-flight mass spectrometry (HILIC/IM-QTOF-MS). Amongst them, the DP5 oligosaccharide was characterized as 1,6,6-kestopentaose. The molecular ratio of Fru: Ara: Glc: Gal: Xyl was 87.72: 0.30: 11.56: 0.19: 0.23. In vitro fermentation demonstrated that 4.5 mg/mL of POPs could significantly promote the growth of L. johnsonii. Co-cultivated with 4.5 mg/mL of POPs, L. johnsonii exhibited stronger antimicrobial activity against Klebsiella pneumoniae. The concentrations of short-chain fatty acids in the POPs-lactobacilli fermented products, including acetic acid, isobutyric acid, and isovaleric acid, were increased. Conclusively, POPs represent the promising prebiotic candidate to facilitate lactobacilli, which is associated with exerting the health benefits.