A Method of Direct Quantitation of Lactobacillus spp. in Intestinal Contents Based on Real-Time PCR.

The method of direct quantitation of Lactobacillus spp. and L. acidophilus in intestinal contents based on real-time PCR was developed. It does not require culturing and allows estimating the number of living lactobacilli cells (measured in lg CFU) in absolute quantitative PCR format.

Mycotoxin Removal by Lactobacillus spp. and Their Application in Animal Liquid Feed.

The removal of mycotoxins from contaminated feed using lactic acid bacteria (LAB) has been proposed as an inexpensive, safe, and promising mycotoxin decontamination strategy. In this study, viable and heat-inactivated L. acidophilus CIP 76.13T and L. delbrueckii subsp. bulgaricus CIP 101027T cells were investigated for their ability to remove aflatoxin B1 (AFB1), ochratoxin A (OTA), zearalenone (ZEA), and deoxynivalenol (DON) from MRS medium and PBS buffer over a 24 h period at 37 °C. LAB decontamination activity was also assessed in a ZEA-contaminated liquid feed (LF). Residual mycotoxin concentrations were determined by UHPLC-FLD/DAD analysis. In PBS, viable L. acidophilus CIP 76.13T and L. delbrueckii subsp. bulgaricus CIP 101027T cells removed up to 57% and 30% of ZEA and DON, respectively, while AFB1 and OTA reductions were lower than 15%. In MRS, 28% and 33% of ZEA and AFB1 were removed, respectively; OTA and DON reductions were small (≤15%). Regardless of the medium, heat-inactivated cells produced significantly lower mycotoxin reductions than those obtained with viable cells. An adsorption mechanism was suggested to explain the reductions in AFB1 and OTA, while biodegradation could be responsible for the removal of ZEA and DON. Both viable LAB strains reduced ZEA by 23% in contaminated LF after 48 h of incubation. These findings suggest that LAB strains of L. acidophilus CIP 76.13T and L. delbrueckii subsp. bulgaricus CIP 101027T may be applied in the feed industry to reduce mycotoxin contamination.

Precision modification of the human gut microbiota targeting surface-associated proteins.

This work describes a new procedure that allows the targeted modification of the human gut microbiota by using antibodies raised against bacterial surface-associated proteins specific to the microorganism of interest. To this end, a polyclonal antibody recognising the surface-associated protein Surface Layer Protein A of Lactobacillus acidophilus DSM20079T was developed. By conjugating this antibody with fluorescent probes and magnetic particles, we were able to specifically identify this bacterium both in a synthetic, and in real gut microbiotas by means of a flow cytometry approach. Further, we demonstrated the applicability of this antibody to deplete complex human gut microbiotas from L. acidophilus in a single step. L. acidophilus was found to interact with other bacteria both in synthetic and in real microbiotas, as reflected by its concomitant depletion together with other species. Further optimization of the procedure including a trypsin step enabled to achieve the selective and complete isolation of this species. Depleting a single species from a gut microbiota, using antibodies recognizing specific cell surface elements of the target organism, will open up novel ways to tackle research on the specific immunomodulatory and metabolic contributions of a bacterium of interest in the context of a complex human gut microbiota, including the investigation into therapeutic applications by adding/depleting a key bacterium. This represents the first work in which an antibody/flow-cytometry based application enabled the targeted edition of human gut microbiotas, and represents the basis for the design of precision microbiome-based therapies.

Inhibition of Human Cervical Cancer Hela Cell Line by Meat-Derived Lactic Acid Bacteria of Lactobacillus plantarum IIA-1A5 and Lactobacillus acidophilus IIA-2B4.

<b>Background and Objective:</b> Two Indonesian lactic acid bacteria of<i> L. plantarum </i>I IA-1A5 and <i>L. acidophilus </i>IIA-2B4 were previously isolated from beef with some functional probiotic properties. Nevertheless, the possibility of these strains to have anticancer activity remains unknown. Current study aimed to evaluate the inhibitory properties of intra-and extracellular protein extracts of these two strains against cervical cancer HeLa cells. <b>Materials and Methods:</b> The intracellular and extracellular proteins extract from <i>L. plantarum </i>IIA-1A5 and <i>L. acidophilus </i>IIA-2B4 were collected and designated as IP-LP, IP-LA, EP-LP and EP-LA, respectively. The effect of these extracts on the viability and morphology of HeLa cells were observed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay and confocal microscopy, respectively. <b>Results:</b> Both IP-LP and IP-LA inhibited HeLa cells in a concentration-dependent manner, with IC₅₀ values of 352.62 and 120.97 µg mL¹, respectively. Meanwhile, the inhibition activity was also observed for EP-LP and EP-LA, <i>albeit</i> very low. The inhibition effect was also confirmed by morphological analysis under confocal electron microscopy which showed the changes in the cell shapes and numbers. <b>Conclusion:</b> Altogether, for the first time this study proposed that the probiotic isolated from Indonesian beef are promising to inhibit cancer cell lines.

Assessment of oncogenic role of intestinal microbiota in colorectal cancer patients.

INTRODUCTION: The direct association between some microbial species and cancers, such as in colorectal cancer (CRC), has been disclosed. OBJECTIVE: The aim of this study was to evaluate the changes in intestinal microbiota in subjects with CRC compared with healthy group. METHODS: Three-hundred fecal specimens were gathered from patients with CRC and 300 from healthy individuals during March 2014 to October 2019 from two hospitals in Tehran. The informed consent form and the questionnaire were completed by the patients. Following the identification of Lactobaccilus acidophilus (L. acidophilus), Lactobacillus palntarom (L. palntarom), and Enterococcus faecalis (E. faecalis), the number of bacteria was determined using quantitative real-time PCR (qPCR). RESULTS: The patients' age range was 20-76 years (mean: 55.34 ± 3.66). The qPCR clarified that number of E. faecalis was 2.2-fold higher in patients with CRC compared to healthy population (p = 0.0013). Additionally, the number of L. acidophilus and L. plantarom was 3.4-fold (p < 0.0001) and 4.8-fold (p < 0.0001) higher in healthy population. CONCLUSION: The inhibitory effect of intestinal microflora against the CRC development was proposed by observation of the changes in intestinal microbiota and determining their composition in subjects with CRC compared with that of healthy individuals. Microbiota was considered as a goal for the prevention and treatment of CRC. The relationship between microbiota and human health would be known deeper; this knowledge provides insights into the management of intestinal microbiota and therapeutics.

Preventive Effect of Lactobacillus acidophilus XY27 on DSS-Induced Ulcerative Colitis in Mice.

INTRODUCTION: Lactobacillus acidophilus is widely used as probiotic supplement in functional foods due to its beneficial regulatory effects on host, such as immune regulation, anti-inflammatory, and antioxidant activities. AIM: This study aimed to determine the preventive effect of Lactobacillus acidophilus XY27 (L. acidophilus XY27) on colitis induced by dextran sodium. METHODS: The mice were randomly divided into five groups. Except for the control group, the other four groups were induced for ulcerative colitis (UC) with dextran sodium sulfate (DSS), and three groups in DSS-groups were treated with L. acidophilus XY27, L. bulgaricus, and salicylazosulfapyridine. The weight change, DAI score, colon length, and length to weight ratio were tested. The oxidation index and the levels of inflammatory cytokines in the serum were measured. Subsequently, the gene expression levels of inflammatory factors in the colon tissue were determined by the Real-Time quantitative polymerase chain reaction (qRT-PCR) method. RESULTS: The results showed that the mice in the L. acidophilus XY27 group performed better in terms of weight, DAI score, colon length, and length to weight ratio or colonic pathological sections compared with the DSS-induced group. Further, the levels of tumor necrosis factor α (TNF-α), Interleukin-6 (IL-6), Interleukin-12 (IL-12) and Interleukin-1ß (IL-1ß), malondialdehyde (MDA) content, and myeloperoxidase activity in the serum of UC mice treated with L. acidophilus XY27 significantly decreased, while the levels of Interferon-γ (IFN-γ), Interleukin-10 (IL-10), Catalase (CAT), and total superoxide dismutase (SOD) significantly increased. The gene expression levels of Ets-like transcription factor-1 (EIK-1), IL-12, IL-1ß, Cyclooxygenase 2 (COX-2), TNF-α, Escherichia coli, Lipopolysaccharide (LPS), and p100 in the colon significantly decreased while those of tight junction protein 1 (ZO-1), nuclear factor kappa B (NF-kB), p53, and NF-kappa-B inhibitor alpha (IκB-α) increased in the L. acidophilus XY27 group. CONCLUSION: The results of the experiment suggested that L. acidophilus XY27 prevented colitis and alleviated symptoms in mice with DSS-induced UC, and also repaired the intestinal barrier function.

Different Ultrasound Exposure Times Influence the Physicochemical and Microbial Quality Properties in Probiotic Goat Milk Yogurt.

Despite goat milk having health benefits over cow milk, goat milk yogurt (GY) presents low consistency and viscosity, which reduces its overall acceptability by the consumer. Thus, new innovative methods can be an alternative to improve the quality of GY. Hence, this study aimed to investigate the effect of ultrasound (US) treatment with different sonication times on quality parameters of probiotic GY during refrigerated storage. US treatment was conducted at 20 KHz for 3, 6, and 9 min in yogurt. Lactobacillus bulgaricus and Lactobacillus acidophilus LA-5 were sensitive to US treatment, presenting a decrease in the yogurts stocked. This loss of viability led to reduced post-acidification due to smaller lactose metabolization in yogurt samples submitted to the US. Among tested treatments, the application of 6 min enhanced the apparent viscosity and consistency index of GY yogurts. In addition, this time also reduced tyramine and total biogenic amine (BAs) content. These findings suggest that 6 min of sonication is a promising way to improve the rheological properties and reduce the acidity and BAs content in GY. Further studies should be performed to optimize the US setting conditions to preserve the probiotic culture viability in yogurts.

Optimization of Alginate-Whey Protein Isolate Microcapsules for Survivability and Release Behavior of Probiotic Bacteria.

The present study aimed to improve the survivability of L. acidophilus encapsulated in alginate-whey protein isolate (AL-WPI) biocomposite under simulated gastric juice (SGJ) and simulated intestinal juice (SIJ). Microcapsules were prepared based on emulsification/internal gelation technique. Optimal compositions of AL and WPI and their ratio in the aqueous phase were evaluated based on minimizing mean diameter (MD) of the microcapsules and maximizing encapsulation efficiency (EE), survivability of cells under SGJ (Viability), and release of viable cells under SIJ (Release) using Box-Behnken experimental design. Optimal composition comprising 4.54% (w/v) AL, 10% (w/v) WPI, and 10% (v/v) AL-WPI gum in the aqueous phase was determined statistically. Physicochemical characteristics of the optimized matrix were investigated by SEM, FTIR, and XRD analysis to determine surface morphology, molecular bonds, and crystalline nature of such hydrocolloid. It could be concluded that the proposed biocomposite is a good promise for nutrients encapsulation in the food industry.

Combined dietary supplementation of long chain inulin and Lactobacillus acidophilus W37 supports oral vaccination efficacy against Salmonella Typhimurium in piglets.

Routine use of antibiotics in livestock animals strongly contributed to the creation of multidrug-resistant Salmonella Typhimurium strains (STM). Vaccination is an alternative to the use of antibiotics but often suffers from low efficacy. The present study investigated whether long-chain inulin (lcITF) and Lactobacillus acidophilus W37 (LaW37) can support vaccination efficacy against STM and if the interventions influence possible gut microbiota changes. Piglets received daily supplementation until sacrifice. Animals were vaccinated on day 25 after birth, one day after weaning, and were challenged with STM on days 52-54. Dietary intervention with lcITF/LaW37 enhanced vaccination efficacy by 2-fold during challenge and resulted in higher relative abundance of Prevotellaceae and lower relative abundance of Lactobacillaceae in faeces. Although strongest microbial effects were observed post STM challenge on day 55, transient effects of the lcITF/LaW37 intervention were also detected on day 10 after birth, and post-weaning on day 30 where increased relative abundance of faecal lactobacilli was correlated with higher faecal consistency. LcITF treatment increased post-weaning feed efficiency and faecal consistency but did not support vaccination efficacy. Vaccination in immune-immature young animals can be enhanced with functional additives which can simultaneously promote health in an ingredient-dependent fashion.

Mechanism analysis of improved glucose homeostasis and cholesterol metabolism in high-fat-induced obese mice treated with La-SJLH001 via transcriptomics and culturomics.

This study aimed to evaluate the functional and probiotic properties of Lactobacillus acidophilus SJLH001 (La-SJLH001) isolated from fermented food via mechanism analysis based on transcriptomics and culturomics. La-SJLH001 exhibited good tolerance to acid and bile salt conditions with anti-diabetic ability and cholesterol assimilation activity in vitro. Supplementation with La-SJLH001 also resulted in a significant reduction in host oral glucose and serum total cholesterol levels in vivo. Transcriptome profiles and qPCR analysis suggested that La-SJLH001 significantly regulated the transcription of key genes involved in glucose transportation, cholesterol metabolism, ion channels, and immune response, resulting in improved glucose homeostasis and cholesterol metabolism. La-SJLH001 significantly affected the structure of intestinal microbiota when analyzed by using culturomics coupled with MALDI-TOF MS. These results indicated that La-SJLH001 may be a mechanistic target for the control of diabetes with great potential in the application of probiotic products.

Antimicrobial and inflammatory properties of South African clinical Lactobacillus isolates and vaginal probiotics.

Bacterial vaginosis (BV) causes genital inflammation and increased HIV acquisition risk. The standard-of-care for BV, antibiotic therapy, is associated with high recurrence rates. Probiotics may improve treatment outcomes, although substantial heterogeneity in efficacy has been observed during clinical trials. To evaluate the potential to improve existing probiotics, we compared the inflammatory and antimicrobial (adhesion, H2O2, D-lactate and L-lactate production) characteristics of 23 vaginal Lactobacillus isolates from South African women, commercial vaginal probiotics (L. casei rhamnosus, L. acidophilus) and 4 reference strains. All lactobacilli induced inflammatory cytokine production by genital epithelial cells and produced D-lactate. Of six isolates assessed, five suppressed inflammatory responses to Gardnerella vaginalis. Although the L. acidophilus probiotic was the most adherent, many clinical isolates produced greater amounts of H2O2, D-lactate and L-lactate than the probiotics. The most L-lactate and H2O2 were produced by L. jensenii (adjusted p = 0.0091) and L. mucosae (adjusted p = 0.0308) species, respectively. According to the characteristics evaluated, the top 10 isolates included 4 L. jensenii, 2 L. crispatus, 1 L. mucosae, 1 L. vaginalis and the L. acidophilus probiotic. There is potential to develop an improved vaginal probiotic using clinical Lactobacillus isolates. Inflammatory profiles are critical to evaluate as some isolates induced substantial cytokine production.

Isolation and characterization of Lactobacillus-derived membrane vesicles.

Bacterial membrane vesicles have been implicated in a broad range of functions in microbial communities from pathogenesis to gene transfer. Though first thought to be a phenomenon associated with Gram-negative bacteria, vesicle production in Staphylococcus aureus, Lactobacillus plantarum, and other Gram-positives has recently been described. Given that many Lactobacillus species are Generally Regarded as Safe and often employed as probiotics, the engineering of Lactobacillus membrane vesicles presents a new avenue for the development of therapeutics and vaccines. Here we characterize and compare the membrane vesicles (MVs) from three different Lactobacillus species (L. acidophilus ATCC 53544, L. casei ATCC 393, and L. reuteri ATCC 23272), with the aim of developing future strategies for vesicle engineering. We characterize the vesicles from each Lactobacillus species comparing the physiochemical properties and protein composition of each. More than 80 protein components from Lactobacillus-derived MVs were identified, including some that were enriched in the vesicles themselves suggesting vesicles as a vehicle for antimicrobial delivery. Additionally, for each species vesicular proteins were categorized based on biological pathway and examined for subcellular localization signals in an effort to identify possible sorting mechanisms for MV proteins.

Dose-interval study of a dual probiotic in preterm infants.

OBJECTIVE: The objective of this study was to investigate the appropriate dosing interval of a probiotic (Infloran) given daily, biweekly and weekly in preterm infants <32 weeks' gestation. METHODS: There were 8 infants in the daily group, 8 infants in the biweekly group and 10 infants in the weekly group, all born between 25 and 32 weeks' gestation. The control group consisted of 12 preterm infants who did not receive the probiotic. Infloran (250 mg/capsule), containing Bifidobacterium bifidum (1×109 colony-forming unit (CFU)) and Lactobacillus acidophilus (1×109 CFU), was administered in 2.5 mL of breast milk per kilogram weight of the infant (2×109 CFU of bacteria in total), until 34 weeks postmenstrual age (PMA). Stool samples were collected at 31, 34, 41 and 44 weeks PMA and frozen at -20°C. RESULTS: After administration of the probiotic at 31 weeks PMA, Bifidobacterium were significantly higher in the daily group (45%) in comparison with the biweekly (17%) and weekly (9%) groups. At 34 weeks PMA, Bifidobacterium were significantly higher again in the daily (60%) group in comparison with the biweekly (21%), weekly (23%) and control (15%) groups. At 41 weeks PMA a decrease in the relative abundances of Streptococcaceae and Enterococcaceae was found in all three probiotic groups, and by 44 weeks PMA significantly higher levels of Lactobacillus were found in the biweekly group (16.5%) in comparison with the weekly group (2.1%). CONCLUSION: Our results indicate that a daily dose of Infloran is a suitable dosage for preterm infants in the neonatal intensive care unit, with significantly higher levels of Bifidobacterium found in the daily probiotic group up to 44 weeks PMA.

Potencial efeito preventivo do Lactobacillus acidophilus e Lactobacillus plantarum em pacientes com pólipos ou câncer colorretal / Potential preventive effect of lactobacillus acidophilus and lactobacillus plantarum in patients with polyps or colorectal câncer

ABSTRACT BACKGROUND: Colorectal cancer is one of the major causes of death worldwide. Many studies have been done on the biology of its formation as well as its treatment in recent years. One of the factors involved in the formation or treatment of this malignancy can be attributed to the microbial flora in the intestine. OBJECTIVE: This study investigate the potential preventive effect of Lactobacillus acidophilus and Lactobacillus plantarum in patients with polyps or colorectal cancer (CRC). METHODS: A total of 77 samples were selected in the form of three groups including individuals suffering from CRC, polyps and healthy subjects. Genomic DNA of fecal specimens and standard strains were extracted and amplified employing primers targeting of the 16S rRNA gene for initial detection. Absolute Real Time PCR quantification was used to determine the copy of the bacterial expression per gram of feces. RESULTS: No significant difference were observed between age and gender in the mentioned groups (P=0.06). The average copy number of Lactobacillus acidophilus shows Significant difference between the healthy group and those with polyps (P<0.0001), the healthy group and those with colorectal cancer (P<0.0001), as well as those with polyps and the colorectal cancer patients (P<0.0001). CONCLUSION: These results may indicate that taking Lactobacillus acidophilus in people with a family history of CRC and people with polyps may be a way of preventing, treating or reducing the severity of CRC.

RESUMO CONTEXTO: O câncer colorretal é uma das principais causas de morte em todo o mundo. Muitos estudos têm sido feitos sobre a biologia de sua formação, bem como o seu tratamento nos últimos anos. Um dos fatores envolvidos na formação ou no tratamento desta malignidade pode ser atribuído à flora microbiana no intestino. OBJETIVO: Este estudo investigou o potencial efeito preventivo de Lactobacillus acidophilus e Lactobacillus plantarum em pacientes com pólipos ou câncer colorretal (CCR). MÉTODOS: Um total de 77 amostras foram selecionadas e três grupos foram formados, a saber, indivíduos portadores de CCR, pólipos e indivíduos saudáveis. O DNA genomico de espécimes fecais e de amostras padrão foi extraído e amplificado empregando primers que focalizaram o gene do rRNA 16S para a deteção inicial. A quantificação do PCR em tempo real absoluto foi utilizada para determinar a cópia da expressão bacteriana por grama de fezes. RESULTADOS: Não foram observadas diferenças significativas entre idade e sexo nos grupos citados (P=0,06). O número médio de cópias de Lactobacillus acidophilus mostra diferença significativa entre o grupo saudável e aqueles com pólipos (P<0,0001), o grupo saudável e aqueles com câncer colorretal (P<0,0001), bem como aqueles com pólipos e câncer colorretal pacientes (P<0,0001). CONCLUSÃO: Estes resultados podem indicar que a ingestão de Lactobacillus acidophilus em pessoas com antecedentes familiares de CCR e pessoas com pólipos pode ser uma forma de prevenir, tratar ou reduzir a gravidade da CCR.

A Double Whammy: Lactobacillus acidophilus Bacteremia and Subsequent Lactobacillus rhamnosus Prosthetic Valve Infective Endocarditis in an Elderly Diabetic Patient.

The clinical significance of the relatively avirulent organ- ism, Lactobacillus, has been debated in the past. At times misdiagnosed as a contaminant, Lactobacillus has uncommonly been reported to cause intra-abdominal abscesses, peritonitis, meningitis, bacteremia, pneumonia and endocarditis, especially in the population of patients with underlying comorbid conditions including malignancy, diabetes, recent surgery or organ transplantation. We report a case of a 74-year-old male with Lactobacillus bacteremia leading to prosthetic valve infective endocarditis complicated by an aortic root abscess. He was managed with IV antibiotic therapy, ultimately penicillin G, and aortic valve replacement, and completely recovered after a period of rehabilitation. Several factors that predispose to Lactobacillus bacteremia were identified in our patient. This case further supports the proposition that Lactobacillus is not always a contaminant; when pathogenic, underlying disease conditions should be investigated.

Quantitative analysis of biofilm bacteria according to different stages of early childhood caries.

OBJECTIVE: Monitoring selected key species related to health or disease may facilitate caries risk assessment and discovery of novel ecological preventive and therapeutic approaches. This study aimed at quantifying Actinomyces naeslundii, Bifidobacterium spp., Lactobacillus acidophilus, Lactobacillus casei group, Streptococcus gordonii, Mitis group and Streptococcus mutans by quantitative polymerase chain reaction (qPCR) in dental biofilm from Brazilian children with different stages of early childhood caries (ECC). DESIGN: Seventy-five preschool children were clinically evaluated by ICDAS criteria and divided into groups: caries-free (CF; n = 20), enamel caries lesions (ECL; n = 17) and dentine caries lesions (DCL; n = 38). Plaque samples from all children were collected for detection and quantification of the selected bacteria. RESULTS: L. acidophilus and L. casei group were absent in almost all plaque samples. No differences in relative proportions of A. naeslundii, Mitis group and S. gordonii were observed in any stage of caries. However, S. mutans and Bifidobacterium spp. were present at higher concentrations in the biofilm of children with DCL (p < 0.001). Multivariate analysis showed that S. mutans and Bifidobacterium spp. were strongly associated with biofilm in children with DCL. CONCLUSION: Differences were observed in the proportion of acidogenic and aciduric bacteria with dental caries progression. The data indicate that S. mutans and Bifidobacterium spp. in dental biofilm may be involved in some progression processes for ECC.

The effect of fiber-reinforced composite versus band and loop space maintainers on oral Lactobacillus acidophilus and Streptococcus mutans levels in saliva.

BACKGROUND: Orthodontic bands have been shown to alter oral microbial flora that lead to convert caries-free patients to moderate or high caries risk individuals. AIM: This study aimed to evaluate the effect of conventional band and loop space maintainers versus fiber-reinforced composite (FRC) resin space maintainer on the salivary cariogenic microflora (Lactobacillus and Streptococcus mutans) in children over a period of 6 months. MATERIALS AND METHODS: The study sample was divided equally into two groups: Group A: 25 patients received FRC (INFIBRA®: Reinforcing ribbon, Bioloren, Italy) space maintainer and Group B: 25 patients received band and loop space maintainers. The saliva samples were collected from the patients before the insertion of the space maintainer and at 2 weeks, 3 months, and 6 months postinsertion. RESULTS AND CONCLUSION: The Lactobacillus acidophilus isolated was 1.7 colony-forming unit (CFU) (×106) and 1.8 CFU (×106) in Group A and Group B, respectively, prior to the insertion of space maintainers. There was no significant increase in L. acidophilus over the follow-up of 6 months in both the groups (P > 0.05). However, the Streptococcus mutans isolated before insertion in both Group A and Group B was 2.6 CFU (×106), which over a period of 6 months showed significant increase to 3.13 CFU (×106) in Group B (P < 0.05) and no increase was seen in Group A. S. mutans level increased considerably in patients with band and loop space maintainer over the follow-up of 6 months. No significant increase in the L. acidophilus count was observed over the same period in both the groups.

Quantification of live Lactobacillus acidophilus in mixed populations of live and killed by application of attenuated reflection Fourier transform infrared spectroscopy combined with chemometrics.

Since culture-based methods are costly and time consuming, alternative methods are investigated for the quantification of probiotics in commercial products. In this work ATR- FTIR vibration spectroscopy was applied for the differentiation and quantification of live Lactobacillus (La 5) in mixed populations of live and killed La 5, in the absence and in the presence of enteric polymer Eudragit® L 100-55. Suspensions of live (La 5_L) and killed in acidic environment bacillus (La 5_K) were prepared and binary mixtures of different percentages were used to grow cell cultures for colony counting and spectral analysis. The increase in the number of colonies with added%La 5_L to the mixture was log-linear (r2 = 0.926). Differentiation of La 5_L from La 5_K was possible directly from the peak area at 1635 cm-1 (amides of proteins and peptides) and a linear relationship between%La 5_L and peak area in the range 0-95% was obtained. Application of partial least squares regression (PLSR) gave reasonable prediction of%La 5_L (RMSEp = 6.48) in binary mixtures of live and killed La 5 but poor prediction (RMSEp = 11.75) when polymer was added to the La 5 mixture. Application of artificial neural networks (ANNs) improved greatly the predictive ability for%La 5_L both in the absence and in the presence of polymer (RMSEp = 8.11 × 10-8 for La 5 only mixtures and RMSEp = 8.77 × 10-8 with added polymer) due to their ability to express in the calibration models more hidden spectral information than PLSR.

POTENTIAL PREVENTIVE EFFECT OF LACTOBACILLUS ACIDOPHILUS AND LACTOBACILLUS PLANTARUM IN PATIENTS WITH POLYPS OR COLORECTAL CÂNCER.

BACKGROUND: Colorectal cancer is one of the major causes of death worldwide. Many studies have been done on the biology of its formation as well as its treatment in recent years. One of the factors involved in the formation or treatment of this malignancy can be attributed to the microbial flora in the intestine. OBJECTIVE: This study investigate the potential preventive effect of Lactobacillus acidophilus and Lactobacillus plantarum in patients with polyps or colorectal cancer (CRC). METHODS: A total of 77 samples were selected in the form of three groups including individuals suffering from CRC, polyps and healthy subjects. Genomic DNA of fecal specimens and standard strains were extracted and amplified employing primers targeting of the 16S rRNA gene for initial detection. Absolute Real Time PCR quantification was used to determine the copy of the bacterial expression per gram of feces. RESULTS: No significant difference were observed between age and gender in the mentioned groups (P=0.06). The average copy number of Lactobacillus acidophilus shows Significant difference between the healthy group and those with polyps (P<0.0001), the healthy group and those with colorectal cancer (P<0.0001), as well as those with polyps and the colorectal cancer patients (P<0.0001). CONCLUSION: These results may indicate that taking Lactobacillus acidophilus in people with a family history of CRC and people with polyps may be a way of preventing, treating or reducing the severity of CRC.

Probiotics modulate gut microbiota and improve insulin sensitivity in DIO mice.

Obesity and type 2 diabetes are characterized by subclinical inflammatory process. Changes in composition or modulation of the gut microbiota may play an important role in the obesity-associated inflammatory process. In the current study, we evaluated the effects of probiotics (Lactobacillus rhamnosus, L. acidophilus and Bifidobacterium bifidumi) on gut microbiota, changes in permeability, and insulin sensitivity and signaling in high-fat diet and control animals. More importantly, we investigated the effects of these gut modulations on hypothalamic control of food intake, and insulin and leptin signaling. Swiss mice were submitted to a high-fat diet (HFD) with probiotics or pair-feeding for 5 weeks. Metagenome analyses were performed on DNA samples from mouse feces. Blood was drawn to determine levels of glucose, insulin, LPS, cytokines and GLP-1. Liver, muscle, ileum and hypothalamus tissue proteins were analyzed by Western blotting and real-time polymerase chain reaction. In addition, liver and adipose tissues were analyzed using histology and immunohistochemistry. The HFD induced huge alterations in gut microbiota accompanied by increased intestinal permeability, LPS translocation and systemic low-grade inflammation, resulting in decreased glucose tolerance and hyperphagic behavior. All these obesity-related features were reversed by changes in the gut microbiota profile induced by probiotics. Probiotics also induced an improvement in hypothalamic insulin and leptin resistance. Our data demonstrate that the intestinal microbiome is a key modulator of inflammatory and metabolic pathways in both peripheral and central tissues. These findings shed light on probiotics as an important tool to prevent and treat patients with obesity and insulin resistance.