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The increasing knowledge about the human microbiome leads to the awareness of how important probiotics can be for our health. Although further substantiation is required, it appears ...that several pathologies could be treated or prevented by the administration of pharmaceutical formulations containing such live health-beneficial bacteria. These pharmabiotics need to provide their effects until the end of shelf life, which can be optimally achieved by drying them before further formulation. However, drying processes, including spray-, freeze-, vacuum- and fluidized bed drying, induce stress on probiotics, thus decreasing their viability. Several protection strategies can be envisaged to enhance their viability, including addition of protective agents, controlling the process parameters and prestressing the probiotics prior to drying. Moreover, probiotic viability needs to be maintained during long-term storage. Overall, lower storage temperature and low moisture content result in good survival rates. Attention should also be given to the rehydration conditions of the dried probiotics, as this can exert an important effect on their revival. By describing not only the characteristics, but also the viability results obtained by the most relevant drying techniques in the probiotic industry, we hope to facilitate the deliberate choice of drying process and protection strategy for specific probiotic and pharmabiotic applications.
Mixed hemi/ad-micelle sodium dodecyl sulfate (SDS)-coated magnetic iron oxide nanoparticles (MHAMS-MIONPs) were used as an efficient adsorbent for both removal and preconcentration of two important ...carcinogenic xanthine dyes named rhodamine-B (RB) and rhodamine-6G (RG). To gain insight in the configuration of SDS molecules on the surface of MIONPs, zeta potential measurements were performed in different SDS/MIONP ratios. Zeta potential data indicated that mixed hemi/ad-micelle MHAM was formed in SDS/MIONP ratios over the range of 1.1 to 7.3. Parameters affecting the adsorption of dyes were optimized as removal efficiency by one variable at-a-time and response surface methodology; the obtained removal efficiencies were ∼100%. Adsorption kinetic and equilibrium studies, under the optimum condition (pH = 2; amount of MIONPs = 87.15 mg; SDS/MIONP ratio = 2.9), showed that adsorption of both dyes are based on the pseudo-second-order and the Langmuir isotherm models, respectively. The maximum adsorption capacities for RB and RG were 385 and 323 mg g–1, respectively. MHAMS-MIONPs were also applied for extraction of RB and RG. Under optimum conditions (pH = 2; amount of damped MHAMS-MIONPs = 90 mg; eluent solvent volume = 2.6 mL of 3% acetic acid in acetonitrile), extraction recoveries for 0.5 mg L–1 of RB and RG were 98% and 99%, with preconcentration factors of 327 and 330, respectively. Limit of detection obtained for rhodamine dyes were <0.7 ng mL–1. Finally, MHAMS-MIONPs were successfully applied for both removal and trace determination of RB and RG in environmental and wastewater samples.
Biofortification of staple crops could help to alleviate micronutrient deficiencies in humans. We show that folates in stored rice grains are unstable, which reduces the potential benefits of folate ...biofortification. We obtain folate concentrations that are up to 150 fold higher than those of wild-type rice by complexing folate to folate-binding proteins to improve folate stability, thereby enabling long-term storage of biofortified high-folate rice grains.
This research aims to evaluate different-sized nanoparticles consisting of (polyethylene glycol) (PEG) poly(lactic-co-glycolic acid) (PLGA), loaded with fluorescein isothiocyanate for nanoparticle ...uptake and intracellular fate in sialoadhesin-expressing macrophages, while being functionalized with anti-sialoadhesin antibody. Sialoadhesin is a macrophage-restricted receptor, expressed on certain populations of resident tissue macrophages, yet is also upregulated in some inflammatory conditions. The nanocarriers were characterized for nanoparticle size (84–319 nm), zeta potential, encapsulation efficiency, and in vitro dye release. Small (86 nm) antibody-functionalized PEG PLGA nanoparticles showed persisting benefit from sialoadhesin-targeting after 24 h compared to the control groups. For small (105 nm) PLGA nanoparticles, uptake rate was higher for antibody-conjugated nanoparticles, though the total amount of uptake was not enhanced after 24 h. For both plain and functionalized small-sized (PEG) PLGA nanoparticles, no co-localization between nanoparticles and (early/late) endosomes nor lysosomes could be observed after 1-, 4-, or 24-h incubation time. In conclusion, decorating (PEG) PLGA nanocarriers with anti-sialoadhesin antibodies positively impacts macrophage targeting, though it was found to be formulation-specific.
This study investigated the application of a dynamic control strategy in an aerobic granular sludge (AGS) reactor treating real variable brewery/bottling wastewater. For 482 days, the anaerobic and ...aerobic reaction steps in a lab-scale AGS system were controlled dynamically. A pH-based control was used for the anaerobic step, and an oxygen uptake rate (OUR) based control for the aerobic step. Additionally, the effect of an elongated aerobic step, and the effect of the removal of the suspended solids from the influent, on AGS formation were also investigated. In comparison to a static operation, the dynamic operation resulted in similar reactor performance, related to effluent quality and the anaerobic dissolved organic carbon (DOC) uptake efficiency, while the organic loading rate was significantly higher. The removal of suspended solids from the influent by chemical coagulation with FeCl
turned hybrid floccular-granular sludge into fully granular sludge. The granulation coincided with a significant increase in the abundance of the glycogen-accumulating Candidatus Competibacter and an increase in the content of gel-forming EPS to respectively around 14% and 30%. In conclusion, this study showed the successful application of a dynamic control strategy based on common and low-cost sensors for AGS treatment of industrial wastewater.
Summary
A number of clinical studies have shown protective effects of lactobacilli against Candida species in the gastrointestinal tract, the urogenital tract and the oral cavity, while others did ...not show clear effects. Evidence on the mode of action of lactobacilli against Candida is also still lacking. In this study, the anti‐Candida activity of the model probiotic strain Lactobacillus rhamnosus GG was explored in different assays to determine molecular interactions. We found that L. rhamnosus GG was able to interfere with Candida growth, morphogenesis and adhesion. These three aspects of Candida's physiology are all crucial to its opportunistic pathogenesis. In follow‐up assays, we compared the activity of L. rhamnosus GG wild‐type with its exopolysaccharide (EPS)‐deficient mutant and purified EPS to evaluate the involvement of this outer carbohydrate layer. Our data demonstrate that purified EPS can both interfere with hyphal formation and adhesion to epithelial cells, which indicates that EPS is part of a combined molecular mechanism underlying the antihyphal and anti‐adhesion mechanisms of L. rhamnosus GG.
Our results indicate that model probiotic Lactobacillus rhamnosus GG can interfere with the growth, hyphal formation and adhesion of Candida albicans. Next, we investigated the role of the galactose‐rich exopolysaccharides of LGG and found that they can also inhibit hyphal formation and adhesion of C. albicans.
Lactobacilli Have a Niche in the Human Nose De Boeck, Ilke; van den Broek, Marianne F.L.; Allonsius, Camille N. ...
Cell reports (Cambridge),
05/2020, Letnik:
31, Številka:
8
Journal Article
Recenzirano
Odprti dostop
Although an increasing number of beneficial microbiome members are characterized for the human gut and vagina, beneficial microbes are underexplored for the human upper respiratory tract (URT). In ...this study, we demonstrate that taxa from the beneficial Lactobacillus genus complex are more prevalent in the healthy URT than in patients with chronic rhinosinusitis (CRS). Several URT-specific isolates are cultured, characterized, and further explored for their genetic and functional properties related to adaptation to the URT. Catalase genes are found in the identified lactobacilli, which is a unique feature within this mostly facultative anaerobic genus. Moreover, one of our isolated strains, Lactobacillus casei AMBR2, contains fimbriae that enable strong adherence to URT epithelium, inhibit the growth and virulence of several URT pathogens, and successfully colonize nasal epithelium of healthy volunteers. This study thus demonstrates that specific lactobacilli are adapted to the URT and could have a beneficial keystone function in this habitat.
•Lactic acid bacteria are enriched in the healthy human nose and nasopharynx•Lactobacillus casei AMBR2 is functionally adapted to the upper respiratory tract•L. casei AMBR2 has antimicrobial and immunomodulatory properties•Live L. casei AMBR2 is safe for intranasal application in healthy humans
De Boeck et al. show that lactobacilli are decreased in patients with chronic rhinosinusitis and enriched in healthy controls. They isolate one strain adapted to the nasopharyngeal mucosa that shows beneficial probiotic effects and safety in the form of a nasal spray in healthy volunteers.
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Formulating poorly water soluble drugs using ordered mesoporous silica materials is an emerging approach to tackle solubility-related bioavailability problems. The current study was ...conducted to assess the bioavailability-enhancing potential of ordered mesoporous silica in man. In this open-label, randomized, two-way cross-over study, 12 overnight fasted healthy volunteers received a single dose of fenofibrate formulated with ordered mesoporous silica or a marketed product based on micronized fenofibrate. Plasma concentrations of fenofibric acid, the pharmacologically active metabolite of fenofibrate, were monitored up to 96h post-dose. The rate (Cmax/dose increased by 77%; tmax reduced by 0.75h) and extent of absorption (AUC0–24h/dose increased by 54%) of fenofibrate were significantly enhanced following administration of the ordered mesoporous silica based formulation. The results of this study serve as a proof of concept in man for this novel formulation approach.
Summary
The preservation of the viability of microorganisms in probiotic formulations is the most important parameter ensuring the adequate concentration of live microorganisms at the time of ...administration. The formulation and processing techniques used to produce these probiotic formulations can influence the preservation of the microbial viability. However, it is also required that the bacteria maintain their key probiotic capacities during processing, formulation and shelf life. In this study, we investigated the impact of spray‐drying on different cell wall properties of the model probiotic strain Lactobacillus rhamnosus GG, including its adherence to intestinal epithelial cells. The dltD gene knock‐out mutant, L. rhamnosus GG CMPG5540, displaying modified cell wall lipoteichoic acids, showed significantly increased colony‐forming units after spray‐drying and subsequent storage under standard conditions compared to wild‐type L. rhamnosus GG. In contrast, disruption of the biosynthesis of exopolysaccharides or pili expression did not impact survival. However, spray‐drying did significantly affect the adherence capacity of L. rhamnosus GG. Scanning electron microscopy confirmed that the pili, key surface factors for adherence to intestinal cells and mucus, were sheared off during the spray‐drying process. These data thus highlight that both the functionality and viability of probiotics should be assessed during the spray‐drying process and subsequent storage.
The impact of spray‐drying on the viability and functioniality of different cell wall properties of the model probiotic strain Lactobacillus rhamnosus GG was investigated. A detailed functional and microscopic analysis with dedicated cell wall mutants showed that the major long and thin surface appendages (i.e. the pili) of L. rhamnosus GG are affected by the spray‐drying process.
In vitro studies suggest that certain probiotic bacterial strains have potential activity against opportunistic infections such as
Candida
. There are few in vivo trials using probiotics as a single ...treatment for acute
Candida
vulvovaginitis (CV). In this open-label, proof-of-concept study, selected
Lactobacillus
strains were tested in women with acute
Candida
vaginitis. Twenty women diagnosed with proven, symptomatic CV were instructed to administer a vaginal probiotic gel with
L. plantarum YUN-V2.0
,
L. pentosus YUN-V1.0
and
L. rhamnosus YUN-S1.0
for 10 consecutive days. Vaginal rinsing fluid, vaginal culture swab and vaginal smear for fresh wet-mount microscopy were collected before and 7, 14 and 28 days after start of treatment. On average, participating women were 39 years old and had an history of 5 vaginal infections of which 95% was CV. Nine women (45%) completed the study without the need of rescue medication. Women who needed rescue treatment experienced twice as much
Candida
infections in the past. A negative correlation was found between the clinical composite score and the time to use rescue medication (
R
2
= 0.127). Seventy-four per cent of participants found the study gel comfortable to use, and 42% of all women would use the tested gel again for this indication. Forty-five per cent of women were treated successfully for acute CV with a novel vaginal gel containing 3 selected
Lactobacillus
strains. Patients needing rescue treatment were suffering from more severe and long-standing disease. These results warrant for further testing of this new product, especially of its potential in cases with mild to moderate severity, as an adjuvant to antimycotics or as a preventive measure in women with recurrent vulvovaginal candidosis.
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