scholarly journals Evaluation of the Probiotic Properties and the Capacity to Form Biofilms of Various Lactobacillus Strains

2020 ◽  
Vol 8 (7) ◽  
pp. 1053
Author(s):  
Célia Chamignon ◽  
Virgile Guéneau ◽  
Sonia Medina ◽  
Julien Deschamps ◽  
Angel Gil-Izquierdo ◽  
...  

Over the last 20 years, Lactobacillus species inhabiting the gastrointestinal tract (GIT) have received much attention, and their health-promoting properties are now well-described. Probiotic effects cannot be generalized, and their uses cover a wide range of applications. It is thus important to proceed to an accurate selection and evaluation of probiotic candidates. We evaluate the probiotic potential of six strains of Lactobacillus in different in vitro models representing critical factors of either survival, efficacy, or both. We characterized the strains for their ability to (i) modulate intestinal permeability using transepithelial electrical resistance (TEER), (ii) form biofilms and resist stressful conditions, and (iii) produce beneficial host and/or bacteria metabolites. Our data reveal the specificity of Lactobacillus strains to modulate intestinal permeability depending on the cell type. The six isolates were able to form spatially organized biofilms, and we provide evidence that the biofilm form is beneficial in a strongly acidic environment. Finally, we demonstrated the ability of the strains to produce γ-aminobutyric acid (GABA) that is involved in the gut-brain axis and beneficial enzymes that promote the bacterial tolerance to bile salts. Overall, our study highlights the specific properties of Lactobacillus strains and their possible applications as biofilms.

Antioxidants ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 609 ◽  
Author(s):  
Amjad Khan ◽  
Muhammad Ikram ◽  
Jong Ryeal Hahm ◽  
Myeong Ok Kim

Neurodegenerative disorders have emerged as a serious health issue in the current era. The most common neurodegenerative disorders are Alzheimer’s disease (AD), Parkinson’s disease, multiple sclerosis, and amyotrophic lateral sclerosis (ALS). These diseases involve progressive impairment of neurodegeneration and memory impairment. A wide range of compounds have been identified as potential neuroprotective agents against different models of neurodegeneration both in vivo and in vitro. Hesperetin, a flavanone class of citrus flavonoid, is a derivative of hesperidin found in citrus fruits such as oranges, grapes, and lemons. It has been extensively reported that hesperetin exerts neuroprotective effects in experimental models of neurodegenerative diseases. In this systematic review, we have compiled all the studies conducted on hesperetin in both in vivo and in vitro models of neurodegeneration. Here, we have used an approach to lessen the bias in each study, providing a least biased, broad understanding of findings and impartial conclusions of the strength of evidence and the reliability of findings. In this review, we collected different papers from a wide range of journals describing the beneficial effects of hesperetin on animal models of neurodegeneration. Our results demonstrated consistent neuroprotective effects of hesperetin against different models of neurodegeneration. In addition, we have summarized its underlying mechanisms. This study provides the foundations for future studies and recommendations of further mechanistic approaches to conduct preclinical studies on hesperetin in different models.


LWT ◽  
2019 ◽  
Vol 106 ◽  
pp. 201-208 ◽  
Author(s):  
Aarti A. Boricha ◽  
Satyamitra L. Shekh ◽  
Sheetal P. Pithva ◽  
Padma S. Ambalam ◽  
Bharatkumar Rajiv Manuel Vyas

2019 ◽  
Vol 71 (2) ◽  
pp. 647-657 ◽  
Author(s):  
J.G. Silva ◽  
R.D. Castro ◽  
F.M. Sant’Anna ◽  
R.M. Barquete ◽  
L.G. Oliveira ◽  
...  

ABSTRACT Minas artisanal cheese is made from endogenous starter cultures, including lactic acid bacteria (LAB). Some LAB may possess probiotic potential. Thus, this study aimed to evaluate the in vitro probiotic properties of lactobacilli isolated from Minas artisanal cheeses produced in Minas Gerais. Ten samples of lactobacilli, formerly isolated from those cheeses, were submitted to the following assays: antimicrobial susceptibility, tolerance to artificial gastric juice and biliary salts, production of hydrogen peroxide and antagonism against pathogenic and non-pathogenic micro-organisms. Only L. plantarum (C0) was sensitive to all tested antimicrobials, while the other LAB samples were resistant to at least one drug. Six samples were tolerant to artificial gastric juice, and L. brevis (A6) even grew in that medium. Three samples were tolerant to biliary salts. Only L. brevis (E35) produced hydrogen peroxide. Difference (P< 0.05) was observed among the means of inhibition haloes of lactobacilli against Enterococcus faecalis ATCC 19433 and Lactobacillus plantarum C24 in spot-on-the-lawn assay. All samples of lactobacilli inhibited Escherichia coli ATCC 25922, Salmonella enterica var. Typhimurium ATCC 14028 in co-culture antagonism test (P< 0.0001). Most lactobacilli samples showed in vitro probiotic potential. From the tested samples, L. brevis (A6) presented the best results considering all in vitro probiotic tests.


2014 ◽  
Vol 910 ◽  
pp. 137-140
Author(s):  
Chao Hui Xue ◽  
Lan Wei Zhang ◽  
Hong Bo Li ◽  
Shu Mei Wang

Three Lactobacillus strains were screened on the basis of probiotic characteristics (i.e., resistance to low pH and bile salts, adhesion to the human gastrointestinal tract, inhibition of pathogenic strains). They further exhibited producing antimicrobial activities of non-acid molecule (s). In addition, antibacterial peptides were isolated and purified from the cell-free culture supernatants of these three probiotic strains. Based on TricineSDSPAGE, the antimicrobial peptide was approximately 10 kDa in size. After analyzing the sequence of the 16SrDNA regions of these three strains, they were identified asLactobacillus crispatus Lactobacillus rhamnosus and Lactobacillus rhamnosua GG.Using an in vitro system simulating gastric transit, our findings indicated that the three probiotic strains had the ability to tolerate gastroenteric environment and the adhesive capacity to HT-29 cells. It was demonstrated that the probiotic strains inhibited subsequent adhesion of E. coli to the HT-29 cell. Among the selected strains,L. rhamnosusF1333 showed a high probiotic potential and could be used in health-promoting food products.


2021 ◽  
Author(s):  
Renan Eugênio Araujo Piraine ◽  
Gustavo M Retzlaf ◽  
Vitória S. Gonçalves ◽  
Rodrigo C Cunha ◽  
Fabio Pereira Leivas Leite

Abstract Non-conventional yeasts can be isolated from a wide range of environmental sources, often found in beverage industry in mixed fermentations, in which the microorganisms’ inoculum usually is not fully known. It is important to know starter cultures, since in addition to favoring reproducibility, other properties can be discovered. Thus, the objective of this work was to identify and characterize yeasts isolated from environment, evaluating their probiotic potential and possible use in brewery. Isolates were obtained from flowers, fruits, leaves and mixed-fermentation beers, being identified by PCR. Yeasts with promising activity were evaluated regarding their growth under different pHs, temperature and presence of organic acids. To explore probiotic potential, in vitro tests were performed of antimicrobial activity and co-aggregation with food pathogens, auto-aggregation, and survival in simulated gastrointestinal tract conditions. In our study, Pichia kluyveri (LAR001), Hanseniaspora uvarum (PIT001) and Candida intermedia (ORQ001) were selected among 20 isolates. P. kluyveri was the only one that tolerated pH 2.5. Lactic acid was not inhibitory, while acetic acid and incubation at 37 °C had a partially inhibitory effect on yeasts growth. All yeasts tolerated α-acids from hops and NaCl up to 1%. It is suggested that isolates are able to adhere to intestinal cells and influence positively the organism in combating pathogens, as they showed auto-aggregation rates above 99% and antagonistic activity to pathogenic bacteria. The yeasts tolerated gastric environment conditions, however were more sensitive to pancreatic conditions. We conclude that isolated non-conventional yeasts showed probiotic potential and promising application in beer fermentation.


2021 ◽  
Vol 12 (1) ◽  
pp. 125-134
Author(s):  
Leonie Korn ◽  
Stephan Dahlmanns ◽  
Steffen Leonhardt ◽  
Marian Walter

Abstract Volume measurement is beneficial in left ventricular assist device (LVAD) therapy to quantify patient demand. In principle, an LVAD could provide a platform that allows bioimpedance measurements inside the ventricle without requiring additional implants. Conductance measured by the LVAD can then be used to estimate the ventricular radius, which can be applied to calculate ventricular volume. However, established methods that estimate radius from conductance require elaborate individual calibration or show low accuracy. This study presents two analytical calculation methods to estimate left ventricular radius from conductance using electric field theory. These methods build on the established method of Wei, now considering the dielectric properties of muscle and background tissue, the refraction of the electric field at the blood-muscle boundary, and the changes of the electric field caused by the measurements. The methods are validated in five glass containers of different radius. Additional bioimpedance measurements are performed in in-vitro models that replicate the left ventricle’s shape and conductive properties. The proposed analytical calculation methods estimate the radii of the containers and the in-vitro models with higher accuracy and precision than Wei’s method. The lead method performs excellently in glass cylinders over a wide range of radii (bias: 1.66%–2.48%, limits of agreement < 16.33%) without calibration to specific geometries.


2019 ◽  
Vol 7 (8) ◽  
pp. 262
Author(s):  
McLeod ◽  
Fagerlund ◽  
Rud ◽  
Axelsson

Considerable attention has been given to the species Lactobacillus plantarum regarding its probiotic potential. L. plantarum strains have shown health benefits in several studies, and even nonstrain-specific claims are allowed in certain markets. L. plantarum strain MF1298 was considered a candidate probiotic, demonstrating in vitro probiotic properties and the ability to survive passage through the human intestinal tract. However, the strain showed an unfavorable effect on symptoms in subjects with irritable bowel syndrome in a clinical trial. The properties and the genome of this strain are thus of general interest. Obtaining the complete genome of strain MF1298 proved difficult due to its large plasmid complement. Here, we exploit a combination of sequencing approaches to obtain the complete chromosome and plasmid assemblies of MF1298. The Oxford Nanopore Technologies MinION long-read sequencer was particularly useful in resolving the unusually large number of plasmids in the strain, 14 in total. The complete genome sequence of 3,576,440 basepairs contains 3272 protein-encoding genes, of which 315 are located on plasmids. Few unique regions were found in comparison with other L. plantarum genomes. Notably, however, one of the plasmids contains genes related to vitamin B12 (cobalamin) turnover and genes encoding bacterial reverse transcriptases, features not previously reported for L. plantarum. The extensive plasmid information will be important for future studies with this strain.


2012 ◽  
Vol 57 (No. 11) ◽  
pp. 529-539 ◽  
Author(s):  
K. Saelim ◽  
N. Sohsomboon ◽  
S. Kaewsuwan ◽  
S. Maneerat

A bacteriocin-like substance (BLS) producing Enterococcus faecium CE5-1 was isolated from the gastrointestinal tract (GIT) of Thai indigenous chickens. Investigations of its probiotic potential were carried out. The competition between the BLS probiotic strain and antibiotic-resistant enterococci was also studied. Ent. faecium CE5-1 exhibited a good tolerance to pH 3.0 after 2 h and in 7% fresh chicken bile after 6 h, but the viability of Ent. faecium CE5-1 decreased by about 2&ndash;3 log CFU/ml after 2 h incubation in pH 2.5. It was susceptible to the antibiotics tested (tetracycline, erythromycin, penicillin G, and vancomycin). The maximum BLS production from Ent. faecium CE5-1 was observed at 15 h of cultivation. It showed activity against Listeria monocytogenes DMST17303, Pediococcus pentosaceus 3CE27, Lactobacillus sakei subsp. sakei JCM1157, and antibiotic-resistant enterococci. The detection by polymerase chain reaction (PCR) in the enterocin structural gene determined the presence of enterocin A gene in Ent. faecium CE5-1 only. Ent. faecium CE5-1 showed the highest inhibitory activity against two antibiotic-resistant Ent. faecalis VanB (from 6.68 to 4.29 log CFU/ml) and Ent. gallinarum VanC (from 6.76 to 4.31 log CFU/ml) after 12 h of co-cultivation. The results show the future possible use of Ent. faecium CE5-1 as a probiotic strain for livestock to control antibiotic-resistant enterococci. &nbsp;


10.5219/1479 ◽  
2021 ◽  
Vol 15 ◽  
pp. 143-150
Author(s):  
Saad Sabah Fakhry ◽  
Farqad Abdullah Rashid ◽  
Maha Muhamaed Khudiar ◽  
Lubna Ayad Ismail ◽  
Sarah Khattab Ismail ◽  
...  

An isolated Lactobacillus from several various sources were identified depending on morphological, microscopically and biochemical tests in vitro analysis of probiotic properties that included: an ability to tolerate in different concentration of bile salt, survival in acidic conditions, their antimicrobial activity, and S-layer characterizations were carried out. It was noticed that isolates of Lactobacillus rhamnosus and L. delbrueckii have a broad activity of antimicrobial and found the isolate L. rhamnosus represented with a survival percentage 6.9% at pH 4.5 and 5.1% at pH 2.0) also L. rhamnosus (5.7% at pH 4.5 and 4.9% at pH 2.0) tolerated acidic media, Lactobacillus spp. has antimicrobial activity against all gram-positive and negative tested isolates. 70 kDa of S-layer protein bands were detected with whole-cell SDS-PAGE analysis, and it's predominant in cells of isolates which grown in MRS broth anaerobically. It was noticed that the collected Lactobacillus isolates could be used as probiotic.


Foods ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 640 ◽  
Author(s):  
Foteini Pavli ◽  
Eleni Gkana ◽  
Oluwabunmi Adebambo ◽  
Kimon-Andreas Karatzas ◽  
Efstathios Panagou ◽  
...  

In the present study, 33 strains of lactic acid bacteria (LAB) previously isolated from natural black Conservolea olives were assessed for their probiotic potential in vitro, as well as for their autoinducer-2 (AI-2) activity under standard growth conditions and the production of γ-aminobutyric acid (GABA). The probiotic tests included the in vitro resistance to low pH and resistance to bile salts, the evaluation of bile salt hydrolase activity, as well as safety tests regarding their possible haemolytic activity and their antimicrobial activity against pathogens. The results indicated that 17 strains were able to survive in low pH and in the presence of bile, with 15 of them also exhibiting partial bile salt hydrolase activity. None of the strains exhibited haemolytic activity or inhibited the growth of any of the examined pathogens. Moreover, the strains displayed generally low AI-2 activity under the growth conditions tested, regardless of the species. Interestingly, in contrast to what has been found in most foods, none of the isolates were found to produce GABA after 48 h of growth. The results from the AI-2 activity and extracellular GABA detection were considered as unexpected for LAB with probiotic attributes.


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