Avaliação dos efeitos probióticos de cepas clínicas de Lactobacillus spp. sobre diferentes espécies de Candida / Evaluation of probiotic effects of clinical strains of Lactobacillus spp. on different species of Candida

Devido ao aumento das infecções causadas por Candida albicans e espécies não-albicans, surge a necessidade de novas estratégias terapêuticas, como a identificação de cepas bacterianas com características probióticas. Assim, o objetivo foi avaliar a ação antimicrobiana de cepas clínicas de Lactobacillus paracasei, Lactobacillus fermentum e Lactobacillus rhamnosus sobre diferentes espécies de Candida (C. albicans, C. glabrata, C. krusei e C. tropicalis). Foram utilizadas cepas de Lactobacillus isoladas da cavidade bucal de indivíduos livres de cárie e cepas de Candida isoladas de lesões de candidose orofaríngea obtidas em estudos anteriores. Para estudo in vitro, foram formados biofilmes monoespécies de Candida (Grupo controle) e biofilmes mistos de Candida e Lactobacillus, nos quais os lactobacilos foram acrescentados antes da cepa de Candida (Grupo Profilático), após a cepa de Candida (Grupo Terapêutico) ou ao mesmo tempo da cepa de Candida (Grupo Simultâneo). Após 48 h de incubação, foi realizada a contagem do número de células viáveis de Candida (UFC/mL). Para estudo in vivo, os micro-organismos foram inoculados em larvas de G. mellonella e o desenvolvimento da candidose foi monitorado pela curva de sobrevivência, estudando-se os grupos experimentais descritos acima. Nos resultados in vitro, foi verificado que os efeitos inibitórios mais significativos de Lactobacillus sobre Candida ocorreram nos grupos profiláticos. As cepas de C. tropicalis e C. krusei foram mais sensíveis a ação de Lactobacillus do que C. albicans e C. glabrata. Além disso, foi verificado que as três espécies de Lactobacillus estudadas (L. paracasei, L. rhamnosus e L. fermentum) tiveram ação inibitória sobre Candida. Em relação ao estudo in vivo, também foi verificado que os grupos profiláticos tiveram maiores efeitos inibitórios sobre a candidose experimental em relação aos grupos terapêuticos, levando a um aumento significativo nas taxas de sobrevivência das larvas. Em relação as cepas estudadas, os efeitos profiláticos de Lactobacillus sobre a candidose, foram encontrados, de forma semelhante, para todas as cepas de Candida e Lactobacillus estudadas. Assim, concluiu-se que as cepas clínicas de L. paracasei 28.4, L. rhamnosus 5.2 e L. fermentum 20.4 foram capazes de inibir a formação de biofilme e desenvolvimento de candidose causados por C. albicans, C. krusei, C. tropicalis e C. glabrata, principalmente quando Lactobacillus foi administrado de forma profilática(AU)

Due to the increase of infections caused by Candida albicans and non-albicans species, there is a need for new therapeutic strategies, such as the identification of bacterial strains with probiotic characteristics. The objective of this study was to evaluate the antimicrobial action of Lactobacillus paracasei, Lactobacillus fermentum and Lactobacillus rhamnosus strains on different Candida species (C. albicans, C. glabrata, C. krusei and C. tropicalis). We used Lactobacillus strains isolated from the oral cavity of caries-free and Candida strains isolated from lesions of oropharyngeal candidiasis. For in vitro study, monospecies of Candida (Control Group) and mixed biofilms of Candida and Lactobacillus were prepared, in which the lactobacillus were attached before the Candida strain (Profile Group), after a Candida (Therapeutic Group) strain or same time as the Candida strain (Simultaneous Group). After 48 h of incubation, we counting the number of viable Candida cells (CFU/mL). For in vivo study, we inoculate the microorganisms in larvae of G. mellonella and the development of the application for monitoring by survival curve, studying the experimental groups described above. In the in vitro results, we find that the most significant inhibitory effects of Lactobacillus on Candida occurred in the prophylactic groups. The strains of C. tropicalis and C. krusei were more sensitive to the action of Lactobacillus than C. albicans and C. glabrata. In addition, it we verified that the three species of Lactobacillus studied (L. paracasei, L. rhamnosus and L. fermentum) had an inhibitory action on Candida. In relation to the in vivo study, we verified that the prophylactic groups had more inhibitory effects on an experimental candidose in relation to the therapeutic groups, leading to a significant increase in the survival rates of the larvae. In relation to the studied strains, the prophylactic effects of Lactobacillus on candidiasis were similarly for all Candida and Lactobacillus strains studied. Thus, it concluded that the clinical strains of L. paracasei 28.4, L. rhamnosus 5.2 and L. fermentum 20.4 were able to inhibit a biofilm formation and development of Candida caused by C. albicans, C. krusei, C. tropicalis and C. glabrata, especially when Lactobacillus was given prophylactically(AU)

Screening and characterization of lactic acid bacterial strains that produce fermented milk and reduce cholesterol levels

ABSTRACT Objective To screen for and characterize lactic acid bacteria strains with the ability to produce fermented milk and reduce cholesterol levels. Methods The strains were isolated from traditional fermented milk in China. In vitro and in vivo evaluation of cholesterol-reduction were used to identify and verify strains of interest. Characteristics were analyzed using spectrophotometry and plate counting assays. Results The isolate HLX37 consistently produced fermented milk with strong cholesterol-reducing properties was identified as Lactobacillus plantarum (accession number: KR105940) and was thus selected for further study. The cholesterol reduction by strain HLX37 was 45.84%. The isolates were acid-tolerant at pH 2.5 and bile-tolerant at 0.5% (w/v) in simulated gastric juice (pH 2.5) for 2 h and in simulated intestinal fluid (pH 8.0) for 3 h. The auto-aggregation rate increased to 87.74% after 24 h, while the co-aggregation with Escherichia coli DH5 was 27.76%. Strain HLX37 was intrinsically resistant to antibiotics such as penicillin, tobramycin, kanamycin, streptomycin, vancomycin and amikacin. Compared with rats in the model hyperlipidemia group, the total cholesterol content in the serum and the liver as well as the atherogenic index of rats in the viable fermented milk group significantly decreased by 23.33%, 32.37% and 40.23%, respectively. Fewer fat vacuoles and other lesions in liver tissue were present in both the inactivated and viable fermented milk groups compared to the model group. Conclusion These studies indicate that strain HLX37 of L. plantarum demonstrates probiotic potential, potential for use as a candidate for commercial use for promoting health.

Escherichia coli GutM4 produces 2, 5-diketopiperazines and inhibits human pathogens in vitro

Background: It has been a very common practice to use probiotics or their metabolites as alternative antimicrobial strategies for the treatment and prevention of infections as rampant and indiscriminate use of antibiotics causes the development of antibiotic-resistant pathogens. The objective of this study was to select a potential antimicrobial probiotic strain of Escherichia coli from the human gastrointestinal tract and investigate the production of diketopiperazines that contribute to the antimicrobial activity. Results: E. coli GutM4 was isolated from the feces of a healthy adult. E. coli GutM4 showed significant antagonistic activity against 10 indicator pathogens, and this activity was no less than that of the reference strain E. coli Nissle 1917 against eight of the indicator pathogens. Moreover, E. coli GutM4 produced antagonistic substances containing trypsin-targeted peptide bonds because the inhibitory effects of E. coli GutM4 supernatant significantly decreased upon treatment with trypsin. Consistent with the antagonistic activity and peptide compounds of E. coli GutM4, 14 2,5-diketopiperazines were isolated from the fermented broth of E. coli GutM4, including 12 cyclo(Pro-Phe), 3 cyclo(Pro-Tyr), and 5 cyclo(4-hydroxyl-Pro-Leu), which are reported to have antipathogenic activity. Conclusion: E. coli GutM4 produces 2,5-diketopiperazines that are partly involved in antagonistic action against human pathogens in vitro.

[ effect of microencapsulation with calcium alginate and resistant starch on the lactobacillus acidophilus [LA5] survival rate in simulated gastrointestinal juice conditions]

Microencapsulation of probiotic cells is the newest method for increasing probiotics' survival in probiotic food products in gastrointestinal conditions and safely transferring them to the large intestine. The aim of this study was to investigate the effect of microencapsulation with calcium alginate and resistant starch on the lactobacillus acidophilus [La5], and the survival rate in simulated gastrointestinal juice conditions. Survivability of this bacteria was conducted in 0.6% bile salt solution and simulated gastric juice[PH1.55], followed by incubation in simulated intestinal juice with and without 0.6% bile salt. In this study the extrusion method was performed for the microencapsulation process. Data were analyzed using an independent t-test. Our results showed that survivability of microencapsulated cells in a simulated gastric juice condition, and also in simulated intestinal juice with and without 0.6% bile salt, is significantly more than free cells[p<0/05]

Propiedades probióticas de Lactobacillus spp aislados de biopsias gástricas de pacientes con y sin infección por Helicobacter pylori / Probiotic properties of Lactobacillus spp isolated from gastric biopsies of Helicobacter pylori infected and non-infected individuals

Background: Gastric microbiota is a complex ecosystem, composed by diverse microorganisms, where H pylori and Lactobacillus are relevant species. Aim: To study the probiotic properties of Lactobacillus spp isolated from gastric biopsies of subjects bearing or not H pylori. Materials and Methods: Gastric biopsies from 197 individuals that consulted for gastrointestinal disorders were cultivated in media specific for H pylori and Lactobacillus spp. Probiotic properties of lactobacilli isolates and histological diagnosis of H pylori colonized patients were performed. Results: Among 197 individuals evaluated, Hpylori was detected in 43 percent, Lactobacillus spp in 24 percent, while 8 percent presented both bacteria simultaneously. Forty one percent of the Lactobacillus spp strains produced hydrogen peroxide, S'3 percent presented a highly hydrophobic surface and 32 percent had an inhibitory effect upon Hpylori ATCC 43504, even greater than Lactobacillus LGG or LAL reference strains. The main pathological diagnosis of patients ivas chronic non-atrophic gastritis (73 percent) followed by intestinal metaplasia (19 percent). A similar proportion of both conditions were observed in patients colonized by Lactobacillus spp, while not colonized individuals developed preferentially chronic non-atrophic gastritis (p =0.002). Conclusions: Lactobacillus spp and H pylori were mutually excluded, suggesting a competitive colonization model between probiotic bacteria and pathogens.

O efeito da composição de cultura e da suplementação do leite no crescimento, na taxa de acidificação, na sobrevivência e no metabolismo de bactérias probióticas em leite fermentado / The effect of culture composition and the implementation of milk on the growth, acidification rate, survival and metabolism of probiotic bacteria in fermented milk

Os produtos lácteos probióticos e/ou simbióticos são líderes dentro do mercado de alimentos funcionais e têm prioridade de pesquisa em diversos países. Os resultados deste trabalho mostraram que a qualidade do leite fermentado foi fortemente influenciada tanto pela composição das co-culturas probióticas quanto por diferentes prebióticos, como oligofrutose, polidextrose, maltodextrina e inulina. A cinética de acidificação foi influenciada pela composição das culturas probióticas e pelos ingredientes prebióticos no leite fermentado. A suplementação do leite com a inulina reduziu o tempo de fermentação das co-culturas Streptococcus thermophilus + Lactobacillus acidophilus (St-La); Streptococcus thermophilus + Lactobacillus rhamnosus (St-Lr) e Streptococcus thermophilus + Bifidobacterium lactis (St-Bl), além de melhorar a firmeza do leite fermentado probiótico. Foram também relatadas que as quantidades de ácido linoléico conjugado (CLA) aumentaram no leite fermentado pela co-cultura de S. thermophilus + L. acidophilus, suplementado com maltodextrina. No que diz respeito às contagens, a adição de inulina favorece a viabilidade das bactérias probióticas durante o armazenamento a 4°C além de causar um efeito bifidogênico, in vitro, estimulando o crescimento de B. lactis. Em relação ao estudo metabólico entre as co-culturas homofermentativas (St-La e St-Lb), feitas neste presente trabalho, pode-se dizer que a lactose foi apenas parcialmente fermentada a ácido lático, a galactose foi metabolizada em certa medida, e se formaram diacetil e acetoína em níveis apreciáveis. A acetoína e o diacetil provavelmente foram produzidos pelas atividades da α-acetolactato sintase e da α-acetolactato descarboxilase de S. thermophilus.

Probiotics dairy products and/or symbiotic are leaders in the functional foods market and have the research priority in several countries. The results of this study showed that the quality of fermented milk was strongly influenced by composition of probiotic co-cultures and different prebiotics, such as oligofructose, polydextrose, maltodextrin and inulin. The acidification kinetics was influenced by the composition of the probiotic co-cultures and prebiotic ingredients in the fermented milk. The milk supplementation with inulin reduced the fermentation time of the co-cultures of Streptococcus thermophilus + Lactobacillus acidophilus (St-La); Streptococcus thermophilus + Lactobacillus rhamnosus (St-Lr) and Streptococcus thermophilus + Bifidobacterium lactis (St-Bl), and improved the firmness of the probiotic fermented milk. It has also been observed that the amount of conjugated linoleic acid (CLA) increased in the milk fermented by the co-culture S. thermophilus + L. acidophilus supplemented with maltodextrin. As far as the bacterial counts are concerned, the inulin addition promoted the viability of probiotic bacteria during storage at 4°C and led to a bifidogenic effect, in vitro, stimulating the growth of B. lactis. As regards to the metabolic studies of the homofermentative co-cultures (St-La and St-Lb), studied in this work, it can be said that lactose was only partially fermented to lactic acid, galactose was metabolized to some extent, diacetyl and acetoin formed at appreciable levels. The acetoin and diacetyl were probably produced by the activities of α-acetolactate synthase and α-acetolactate decarboxylase of S. thermophilus.

The Effect of Lactic Acid Bacteria Isolates on the Urinary Tract Pathogens to Infants In Vitro

Urinary tract infections are common clinical problems in children, even though lots of treatment strategies have been tried. Many studies of the application of probiotics for urinary tract infection in female adults exist, but there is a lack of studies in children. The aims of this study were to screen probiotic strains for inhibiting the uropathogens in vitro, to find candidates for in vivo study. Nine strains of E. coli were isolated from children with urinary tract infection and six uropathogens were obtained from Korean Colletion for Type Cultures and American Type Culture Collection. Also 135 lactic acid bacteria (LAB) strains were isolated from healthy children, and were identified through physiologic, biochemical methods, 16S rDNA PCR, and data analysis. And with agar disk diffusion assay technique the antimicrobial activities of these LAB strains against those uropathogens were examined. Three strains of separated LAB strains demonstrated major antimicrobial activity against all the uropathogens. In the agar disk diffusion assay technique, antimicrobial activities increased most in the 4th day culture broth with separated Lactobacillus. In summary, some LAB can be used as candidates to develop the probiotic microorganisms that inhibit uropathogens in children, and are expected to be applied to treatment and prevention of pediatric urinary tract infection.

Effect of a probiotic mixed culture on texture profile and sensory performance of Minas fresh cheese in comparison with the traditional products / Efeito de uma cultura probiótica mista sobre o perfil de textura e o desempenho sensorial de queijo Minas frescal, em comparação aos produtos tradicionais

The effect of a mixed probiotic culture on instrumental texture, and on sensorial and related properties of Minas fresh cheese during refrigerated storage was investigated. Three cheese-making trials were prepared: T1, with the traditional type O starter culture (Lactococcus lactis subsp. lactis + L. lactis subsp. cremoris), T2 with only lactic acid and T3, with lactic acid and the probiotic ABT culture (Lactobacillus acidophilus La-5 + Bifidobacterium animalisBb-12 + Streptococcus thermophilus). Instrumental texture profile analysis and related properties were monitored during storage for up to 21 days. Lb. acidophilus and B. animalis were present in high levels throughout storage of cheeses T3, above 6 log cfu.g-1, threshold required for probiotic activity, and stimulation of the La-5 growth was observed. Cheeses with added probiotic ABT culture, as well as those made adding lactic acid only, showed to be less brittle and with more favorable sensorial features, due to higher pH values. Results indicated that the use of probiotic ABT culture complementary to lactic acid for the purpose of substituting the type O (Lc. lactis subsp. lactis + Lc. lactis subsp. cremoris) culture, traditionally employed for Minas cheese production, is advantageous.

Efeito de uma cultura probiótica mista sobre o perfil de textura e o desempenho sensorial de queijo Minas frescal, em comparação aos produtos tradicionais. O presente trabalho investigou o efeito de uma cultura probiótica mista sobre a textura instrumental, as características sensoriais e as propriedades relacionadas de queijoMinas frescal durante seu armazenamento refrigerado. Três variáveis de elaboração de queijo Minas frescal foram estudadas: T1, empregando-se a cultura lática mesofílica tradicional tipo O (Lactococcus lactis subsp. lactis + L. lactis subsp. cremoris), T2,produzido somente com ácido lático e T3, empregando-se ácido lático e a cultura probiótica ABT (Lactobacillus acidophilus La-5 + Bifidobacterium animalis Bb-12 + Streptococcus thermophilus). O perfil de textura instrumental e as propriedades relacionadas foram monitorados durante 21 dias de armazenamento dos queijos. As populações de Lb. acidophilus e de B. animalis estiveram elevadas durante o armazenamento do queijo T3, acima de 6 log UFC.g-1,população mínima requerida para apresentar efeito probiótico, e foiobservado um estímulo da multiplicação de La-5. Os queijos produzidos com a cultura probiótica ABT, assim como aqueles somente com ácido lático, apresentaram-se menos frágeis e com atributos sensoriais mais favoráveis, devido ao pH mais elevado. Os resultados indicaram ser vantajoso o emprego da cultura probiótica ABT complementarmente ao ácido lático para o propósito de substituição da cultura tipo O (Lc. lactis subsp. lactis + Lc. lactis subsp. cremoris), tradicionalmenteempregada para a produção de queijo Minas frescal.

Efeito do teor de soro, açúcar e de frutooligossacarídeos sobre a população de bactérias láctica probióticas em bebidas fermentadas / Effect of whey, suggar and frutooligosacharides on the probiotic lactic acid bacteria population in fermented beverages

Nos últimos anos tem havido muito interesse por produtos alimemtícios de baixas calorias e probióticos. A incorporação de Lactobacillus acidophillus e Bifidobacterium em bebidas fermentadas pode resultar em um produto lácteo com extraordinário valor terapêutico e eficaz redução calórica. O objetivo deste trabalho foi estudar o efeito do teor de soro, açúcar e de frutooligossacarídeos sobre a população de bactérias lácticas de doze formulações de bebidas fermentadas. Foram determinadas as populaçõs de Streptococcus thermophilus, Lactobacillus delbrueckii subsp. bulgaricus, Bifidobacterium e Lactobacillus acidophilus. As maiores populações de microrganismos probióticos foram observadas nas bebidas com mais baixa acidez e elevado teor de sólidos...

Evaluación de la actividad de cultivos probióticos sobre Listeria monocytogenes durante la producción y almacenamiento de yogur / Evaluation of the activity of probiotic cultures over Listeria monocytogenes during the production and storage of yogurt

The effect of probiotic cultures over Listeria monocytogenes during the production and storage of yogurt was evaluated. A yogurt mixture (10.6 per cent non-fat solid liquids, 3 per cent fat and 0.3 per cent gelatin) was prepared, homogenized and pasteurized. Yogurt was inoculated with 0, 10(2), 10(4) and 10(6) CFU/mL of L. monocytogenes and 0.02 per cent of traditional lactic culture YC 180 (Streptococcus thermophilus and Lactobacillus bulgaricus) and probiotic culture ABY-1 (Bifidobacterium longum, B. bifidum, B, infantis, Lactobacillus acidophilus, Streptococcus thermophilus y Lactobacillus delbrueckii subsp. bulgaricus). It was incubated for 3 h at 43 degrees C until pH reached an approximate value of 4.8, followed by refrigeration at 5 degrees C for 21 days. During fermentation, samples were taken every hour, and during storage every 3 days, analyzing pH and lactic, bifidobacteria and pathogen count for each time. It was demonstrated that there was no significant simple effect for the type of culture used (ABY-1 and YC 180) (p = 0.684) over the amount of L. monocytogenes present in yogurt during the fermentation and storage periods. The presence of bifidobacteria in the ABY-1 culture did not present a significant effect over L. monocytogenes. Neither the effect of time presented a significant effect over L. monocytogenes (p = 0.448). In this case, the ABY-1 and YC 180 cultures present a bacteriostatic effect over the pathogen. The probiotic cultures had a bacteriostatic but not bactericidal effect over L. monocytogenes. This is not related to the protective effect of these cultures in bowel, since in-vivo conditions favor the production of antimicrobial substances, such as bacteriocins that act over pathogens.

Aspectos tecnológicos de alimentos funcionais contendo probióticos / Technological aspects of functional foods containing probiotics

Os alimentos funcionais constitutem hoje prioridade de pesquisa em todo mundo com a finalidade de elucidar as propriedades e os efeitos que estes produtos podem apresentar na promoçäo da saúde. As bactérias probióticas säo microrganismos vivos que, quando consumidos, exercem efeitos benéficos sobre o hospedeiro conferindo propriedades à microbiota endógena. Algumas propriedades benéficas atribuídas às culturas probióticas necessitam de estudos mais controlados para serem definitivamente esclarecidas. Neste artigo säo enfocados os aspectos tecnológicos dos probióticos, os efeitos associados ao consumo de produtos contendo probióticos e as principais cepas empregadas. Säo apresentadados resultados experimentais...

Studies on probiotics properties of two lactobacillus strains

Foram realizados estudos"in vitro" para selecionar cepas de Lactobacillus com características probióticas. Duas cepas de Lactobacillus foram avaliadas quanto as características específicas que definem sua potencialidade como probióticos (velocidade específica de crescimento, tempo de geraçäo, e resistência a ácido, bile e substâncias antimicrobianas). Os testes "in vitro" indicaram que ambas as cepas apresentaram um grande potencial para ser utilizadas na obtençäo de probióticos