ResearchPad - lactobacillus https://www.researchpad.co Default RSS Feed en-us © 2020 Newgen KnowledgeWorks <![CDATA[Broilers divergently selected for digestibility differ for their digestive microbial ecosystems]]> https://www.researchpad.co/article/elastic_article_15757 Improving the digestive efficiency of broiler chickens (Gallus gallus) could reduce organic waste, increase the use of alternative feed not used for human consumption and reduce the impact of feed in production costs. By selecting chicken lines divergently for their digestive efficiency, we showed previously that digestive efficiency is under genetic control and that the two resulting divergent lines, D+ (high digestive efficiency or “digestibility +”) and D- (low digestive efficiency or “digestibility -”), also differ for the abundance of specific bacteria in their caeca. Here we perform a more extensive census of the bacteria present in the digestive microbiota of 60 chickens selected for their low apparent metabolizable energy corrected for nitrogen balance (AMEn-) or high (AMEn+) digestive efficiency in a [D+ x D-] F8 progeny of 200 individuals. We sequenced the 16S rRNA genes of the ileal, jejunal and caecal microbiotas, and compared the compositions and predicted functions of microbiotas from the different intestinal segments for 20 AMEn+ and 19 AMEn- birds. The intestinal segment of origin was the main factor structuring the samples. The caecal microbiota was the most impacted by the differences in digestive efficiency, with 41 bacterial species with abundances differing between highly and poorly efficient birds. Furthermore, we predicted that the caecal microbiota of efficient birds might be enriched in genes contributing to the degradation of short chain fatty acids (SCFA) from non-starch polysaccharides. These results confirm the impact of the genetic selection led on digestibility on the caecal microbiota taxonomic composition. They open the way toward the identification of specific, causal genes of the host controlling variations in the abundances of bacterial taxons.

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<![CDATA[Anti-cancer effects of <i>Bifidobacterium</i> species in colon cancer cells and a mouse model of carcinogenesis]]> https://www.researchpad.co/article/elastic_article_14495 Probiotics are suggested to prevent colorectal cancer (CRC). This study aimed to investigate the anticancer properties of some potential probiotics in vitro and in vivo.Materials and methodsAnticancer effects of potential probiotic groups were investigated following of in LS174T cancer cells compared to IEC-18 normal cells. 1. a single strain of Bifidobacterium. breve, 2. a single strain of Lactobacillus. reuteri, 3. a cocktail of 5 strains of Lactobacilli (LC), 4. a cocktail of 5 strains of Bifidobacteria (BC), 5. a cocktail of 10 strains from Lactobacillus and Bifidobacterium (L+B). Apoptosis rate, EGFR, HER-2 and PTGS-2 (COX-2 protein) expression levels were assessed as metrics of evaluating anticancer properties. Effect of BC, as the most effective group in vitro, was further assessed in mice models.ResultsBC induced ~21% and only ~3% apoptosis among LS174T and IEC-18 cells respectively. BC decreased the expression of EGFR by 4.4 folds, HER-2 by 6.7 folds, and PTGS-2 by 20 folds among the LS174T cells. In all these cases, BC did not interfere significantly with the expression of the genes in IEC-18 cells. This cocktail has caused only 1.1 folds decrease, 1.8 folds increase and 1.7 folds decrease in EGFR, HER-2 and PTGS-2 expression, respectively. Western blot analysis confirmed these results in the protein level. BC significantly ameliorated the disease activity index, restored colon length, inhibited the increase in incidence and progress of tumors to higher stages and grades.ConclusionsBC was the most efficient treatment in this study. It had considerable “protective” anti-cancer properties and concomitantly down regulated EGFR, HER-2 and PTGS-2 (COX-2), while having significant anti-CRC effects on CRC mice models. In general, this potential probiotic could be considered as a suitable nutritional supplement to treat and prevent CRC. ]]> <![CDATA[In vitro and ex vivo evaluation of the anti-Giardia duodenalis activity of the supernatant of Slab51 (SivoMixx)]]> https://www.researchpad.co/article/5c8acce0d5eed0c4849901f8

The effects on Giardia duodenalis of Slab51 probiotic supernatants were evaluated in vitro and ex vivo. In vitro, Slab51 (101 UFC) was cultured and the obtained supernatant was filtered, adjusted at pH 7, and added (100μl/ml) as such (Slab51 FS) or after heat-treatment, to G. duodenalis cultures to evaluate its effects on G. duodenalis trophozoites growth and adherence. For comparison, negative and metronidazole (20μg/ml) treated controls were used. The morphological and ultrastructural alterations of G. duodenals trophozoites following treatment with Slab51 FS supernatant were investigated by transmission electron microscopy. Ex vivo, mice duodenal portions were cultivated in standard conditions with 5x105 G. duodenalis trophozoites/ml, while to further five duodenal portions similarly cultured and infected, Slab51 FS 200μl was added. After 12 and 18h, samples were fixed in 10% buffered formalin and histologically processed to score Giardia infection and cell damage. Cell proliferation/apoptosis was scored by Ki67, TUNEL and Caspase–3 tests. All experiments were conducted in triplicate throughout the study. All data were statistically evaluated (P< 0.05). Results showed that Slab51 FS significantly reduced Giardia growth and adherence respect to negative controls, but its efficacy was overall lower than that of metronidazole. Moreover, the effects of Slab51 FS were significantly lowered by heat-treatment and this reduction was statistically higher at 90°C than at 56°C, indicating a heat-sensitive nature of active Slab51 FS compounds. At the ultrastructural level, Slab51 FS treated Giardia trophozoites were swelling, increased in size and showed alterations of their cellular membrane and vacuole patterns, loss of the nuclear envelope and nuclear architecture. In ex vivo trials, viable G. duodenalis trophozoites and enterocyte TUNEL+ and Caspase-3 expression were significantly reduced in intestinal sections added with Slab51 FS, while enterocyte Ki67 expression was significantly increased, confirming the anti-G. duodenalis activity of Slab51 FS observed in vitro. In conclusion, results from this study showed that the fresh culture supernatant of the commercial probiotic Slab51 has anti-G. duodenalis properties both in vitro and ex vivo in a mouse model.

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<![CDATA[Association between vaginal washing and vaginal bacterial concentrations]]> https://www.researchpad.co/article/5c536b0ad5eed0c484a47f26

Vaginal washing is a common practice associated with adverse outcomes including bacterial vaginosis (BV) and HIV infection. Prior studies have not examined the associations between vaginal washing and individual vaginal bacteria, or whether these associations are independent of the effect of vaginal washing on BV. The purpose of this study was to characterize the association between vaginal washing and the presence and concentrations of vaginal bacteria associated with optimal and sub-optimal vaginal states. The analysis utilized data from participants in the placebo arm of the Preventing Vaginal Infections trial, which enrolled HIV-uninfected women from the United States and Kenya. Detection of bacterial taxa associated with BV was compared between visits with versus without reported vaginal washing. The effect of vaginal washing on a number of vaginal bacteria differed substantially (p<0.05) between the US and Kenya, so results were stratified by country. In US women, vaginal washing was associated with a significantly higher likelihood of detection of BV associated bacterium 1 (BVAB1) (relative risk [RR] 1.55, 95% confidence interval [CI] 1.15–2.09, p = 0.004), BVAB2 (RR 1.99, 95%CI 1.46–2.71, p<0.001), Mageeibacillus indolicus (RR 2.08, 95%CI 1.46–2.96, p<0.001), Atopobium vaginae (RR 1.34, 95%CI 1.13–1.59, p = 0.001), Leptotrichia/Sneathia species (RR 1.66, 95% CI 1.33–2.09, p<0.001), Megasphaera species (RR 1.78, 95%CI 1.34–2.37, p<0.001) and Gardnerella vaginalis (RR 1.08, 95%CI 1.01–1.16, p = 0.02). No significant association between vaginal washing and bacterial detection was found in Kenyan women. Adjustment for bacterial vaginosis diagnosed by Gram stain did not alter these results. This study provides evidence that the association between vaginal washing and detection of individual bacterial taxa can vary regionally. For some vaginal bacteria, the association with vaginal washing may be independent of the effect on Gram stain detection of BV. Larger prospective studies in diverse geographic settings should explore whether eliminating vaginal washing impacts the presence and concentrations of key vaginal bacteria.

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<![CDATA[Impact of intramammary inoculation of inactivated Lactobacillus rhamnosus and antibiotics on the milk microbiota of water buffalo with subclinical mastitis]]> https://www.researchpad.co/article/5c3d014ad5eed0c484039f42

Water buffalo mastitis represents a major issue in terms of animal health, cost of therapy, premature culling and decreased milk yeld. The emergence of antibiotic resistance has led to investigate strategies to avoid or reduce antibiotics’ based therapies, in particular during subclinical mastitis. The use of Generally Regarded As Safe bacteria (GRAS) such as Lactobacillus rhamnosus to restore the unbalance in mammary gland microbiota could provide potential corrective measures. The aim of this study was to investigate the changes in milk microbiota after the intramammary treatment with inactivated cultures of Lactobacillus rhamnosus of mammary gland quarters naturally affected by subclinical mastitis as compared to antibiotic therapy.A number of 43 quarters affected by subclinical mastitis with no signs of clinical inflammation and aerobic culture positive for pathogens were included in the study. The experimental design was as follows: 11 quarters were treated with antibiotics, 15 with inactivated cultures of Lactobacillus rhmnosus and 17 with PBS as negative control, by means of intrammary injection. Samples were collected at eight time points, pre- (T-29, T-21, T-15, T-7, T0 days) and post- treatment (T1, T2, and T6 days). Microbiological culture and Somatic Cell Count (SCC) were perfomed on all the samples, and microbiota was determined on milk samples collected at T0 and T6 by amplifying the V4 region of 16S rRNA gene by PCR and sequencing using next generation sequencing technique. Treatment with Lactobacillus rhamnosus elicited a strong chemotactic response, as determined by a significant increase of leukocytes in milk, but did not change the microbiological culture results of the treated quarters. For what concerns the analysis of the microbiota, the treatment with Lactobacillus rhamnosus induced the modification in relative abundance of some genera such as Pseudomonas and 5-7N15. As expected, antibiotic treatment caused major changes in microbiota structure with an increase of Methylobacterium relative abundance. No changes were detected after PBS treatment. In conclusion, the present findings demonstrated that the in vivo intrammmary treatment with Lactobacillus rhamnosus has a transient pro-inflammatory activity by increasing SCC and is capable to modify the microbiota of milk after six days from inoculation, albeit slightly, even when the bacterial cultures were heat inactivated. Further studies are necessary to assess the potential use of this GRAS as supportive therapy against mastitis.

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<![CDATA[Use of Lactobacillus crispatus to produce a probiotic cheese as potential gender food for preventing gynaecological infections]]> https://www.researchpad.co/article/5c3fa5c7d5eed0c484ca86ed

This research is aimed to evaluate the suitability of Squacquerone cheese to support the viability of Lactobacillus crispatus BC4, a vaginal strain endowed with a strong antimicrobial activity against urogenital pathogens and foodborne microorganisms, in order to recommend a gender food for woman wellbeing. The viability of L. crispatus BC4, used as adjunct culture, was evaluated during the refrigerated storage of Squacquerone cheese, as well as when the cheese was subjected to simulated stomach-duodenum passage tested by the patented Simulator of the Human Intestinal Microbial Ecosystem (SHIME). Moreover, the effects of L. crispatus BC4 addition were evaluated on product hydrolytic patterns, in terms of proteolysis, lipolysis and volatile molecule profiles. The data showed that L. crispatus BC4 maintained high viability, also in presence of physiological stress conditions, until the end of the refrigerated storage. Moreover, the inclusion of L. crispatus BC4 gave rise to cheese product with higher score of overall acceptability when compared to control cheese. In addition, the survival of L. crispatus BC4, carried in test cheese, in gastro intestinal conditions was confirmed by SHIME. The results showed that the vaginal Lactobacillus strain was more affected by the low pH of the stomach, simulated by the SHIME reactor, rather than to bile salts and pancreatic juices. Although only in vivo trials will be able to confirm the functionality of the cheese in the vaginal environment, these data represent a first step towards the employment of the Squacquerone cheese as probiotic food able to promote the woman’s health by preventing gynaecological infections.

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<![CDATA[Lack of mutagenicity, genotoxicity and developmental toxicity in safety assessment tests of Lactobacillus mali APS1]]> https://www.researchpad.co/article/5c1c0aeed5eed0c484426f00

Lactobacillus (L.) mali APS1 isolated from sugary kefir grains has been proven to affect energy and glucose homeostasis. However, without proper safety assessment it cannot be recommended as probiotics for human consumption. For genotoxicity, the Ames test showed no mutagenic effect of L. mali APS1 in the presence or absence of S9 mix metabolic activation. In-vitro mammalian chromosomal aberration test showed that the number of Chinese hamster ovary cells with abnormal chromosomes was <5% after L. mali APS1 treatment. Moreover, L. mali APS1 showed no risk of genotoxicity potential compared to the control. L. mali APS1 administration did not cause significant (p>0.05) changes in body weight, the number of reticulocytes, or in the occurrence percentage of micronucleus in Imprinting Control Region (ICR) mice. Based on the absence of maternal or fetal effects at any dosage level investigated, the teratogenicity could be defined as greater than 1,670 mg/kg b.w./day for maternal general toxicity and fetal development when L. mali APS1 was orally administered by gavage to pregnant SD rats during gestation days 6 to 15.

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<![CDATA[Comparative effectiveness and safety of interventions for acute diarrhea and gastroenteritis in children: A systematic review and network meta-analysis]]> https://www.researchpad.co/article/5c117b2dd5eed0c48469825e

Background

Many interventions have shown effectiveness in reducing the duration of acute diarrhea and gastroenteritis (ADG) in children. Yet, there is lack of comparative efficacy of interventions that seem to be better than placebo among which, the clinicians must choose. Our aim was to determine the comparative effectiveness and safety of the pharmacological and nutritional interventions for reducing the duration of ADG in children.

Methods

Data sources included Medline, Embase, CENTRAL, CINAHL, LILACS, and Global-Health up to May 2017. Eligible trials compared zinc (ZN), vitamin A, micronutrients (MN), probiotics, prebiotics, symbiotics, racecadotril, smectite(SM), loperamide, diluted milk, lactose-free formula(LCF), or their combinations, to placebo or standard treatment (STND), or among them. Two reviewers independently performed screening, review, study selection and extraction. The primary outcome was diarrhea duration. Secondary outcomes were stool frequency at day 2, diarrhea at day 3, vomiting and side effects. We performed a random effects Bayesian network meta-analysis to combine the direct and indirect evidence for each outcome. Mean differences and odds ratio with their credible intervals(CrI) were calculated. Coherence and transitivity assumptions were assessed. Meta-regression, subgroups and sensitivity analyses were conducted to explore the impact of effect modifiers. Summary under the cumulative curve (SUCRA) values with their CrI were calculated. We assessed the evidence quality and classified the best interventions using the Grading of Recommendations, Assessment, Development & Evaluation (GRADE) approach for each paired comparison.

Results

A total of 174 studies (32,430 children) proved eligible. Studies were conducted in 42 countries of which most were low-and middle-income countries (LMIC). Interventions were grouped in 27 categories. Most interventions were better than STND. Reduction of diarrhea varied from 12.5 to 51.1 hours. The combinations Saccharomyces boulardii (SB)+ZN, and SM+ZN were considered the best interventions (i.e., GRADE quality of evidence: moderate to high, substantial superiority to STND, reduction in duration of 35 to 40 hours, and large SUCRA values), while symbiotics (combination of probiotics+prebiotics), ZN, loperamide and combinations ZN+MN and ZN+LCF were considered inferior to the best and better than STND [Quality: moderate to high, superior to STND, and reduction of 17 to 25 hours]. In subgroups analyses, effect of ZN was higher in LMIC and was not present in high-income countries (HIC). Vitamin A, MN, prebiotics, kaolin-pectin, and diluted milk were similar to STND [Quality: moderate to high]. The remainder of the interventions had low to very-low evidence quality. Loperamide was the only intervention with more side effects than STND [Quality: moderate].

Discussion/Conclusion

Most interventions analyzed (except vitamin A, micronutrients, prebiotics, and kaolin-pectin) showed evidence of superiority to placebo in reducing the diarrhea. With moderate-to high-quality of evidence, SB+ZN and SM+ZN, demonstrated the best combination of evidence quality and magnitude of effect while symbiotics, loperamide and zinc proved being the best single interventions, and loperamide was the most unsafe. Nonetheless, the effect of zinc, SB+ZN and SM+ZN might only be applied to children in LMIC. Results suggest no further role for studies comparing interventions against no treatment or placebo, or studies testing loperamide, MN, kaolin-pectin, vitamin A, prebiotics and diluted milk.

PROSPERO registration

CRD42015023778.

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<![CDATA[Pilot assessment of probiotics for pregnant women in Rwanda]]> https://www.researchpad.co/article/5b498fc4463d7e0897c6e026

Background

While the global market for probiotics is soon to reach in excess of US$50 billion, the continent of Africa has been largely ignored, despite these products having the ability to reduce the burden of disease and death.

Trial design

The present randomised, blinded, placebo-controlled clinical trial was undertaken in Rwanda, a country devoid of well-documented probiotics. The primary outcome aim was to examine receptivity and compliance for orally administered probiotic capsules containing Lactobacillus rhamnosus GR-1 and Lactobacillus reuteri RC-14 in pregnant women and assess any initial side effects or changes to the vaginal microbiome.

Methods

Pregnant women between the ages of 18 and 55 were recruited from the Nyamata District Hospital in Rwanda and randomly assigned to receive probiotic or placebo capsules for one month. Clinicians were blinded to the treatments.

Results

The drop-out rate was 21%, with 13 of 18 women in the placebo group and 17 of 20 in the probiotic group completing the study. Only 13 women returned for birthing and additional sample collection. No side effects of either treatment group were reported. Microbiota and metabolomics data showed similar findings to those reported in the literature, with low bacterial diversity and Lactobacillus dominance associated with a healthy vagina, and birthing associated with high diversity. Despite the small sample size and lack of changes in the microbiota, women in the placebo arm were significantly more likely to give birth pre-term.

Conclusion

Overall women were receptive to the probiotic concept, but the lack of information on such products and logistical and economical challenges pose problems for wider population engagement.

Trial registration

ClinicalTrials.gov NCT02150655

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<![CDATA[Microbiome Composition and Function Drives Wound-Healing Impairment in the Female Genital Tract]]> https://www.researchpad.co/article/5989da37ab0ee8fa60b869de

The mechanism(s) by which bacterial communities impact susceptibility to infectious diseases, such as HIV, and maintain female genital tract (FGT) health are poorly understood. Evaluation of FGT bacteria has predominantly been limited to studies of species abundance, but not bacterial function. We therefore sought to examine the relationship of bacterial community composition and function with mucosal epithelial barrier health in the context of bacterial vaginosis (BV) using metaproteomic, metagenomic, and in vitro approaches. We found highly diverse bacterial communities dominated by Gardnerella vaginalis associated with host epithelial barrier disruption and enhanced immune activation, and low diversity communities dominated by Lactobacillus species that associated with lower Nugent scores, reduced pH, and expression of host mucosal proteins important for maintaining epithelial integrity. Importantly, proteomic signatures of disrupted epithelial integrity associated with G. vaginalis-dominated communities in the absence of clinical BV diagnosis. Because traditional clinical assessments did not capture this, it likely represents a larger underrepresented phenomenon in populations with high prevalence of G. vaginalis. We finally demonstrated that soluble products derived from G. vaginalis inhibited wound healing, while those derived from L. iners did not, providing insight into functional mechanisms by which FGT bacterial communities affect epithelial barrier integrity.

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<![CDATA[Urinary Microbiota Associated with Preterm Birth: Results from the Conditions Affecting Neurocognitive Development and Learning in Early Childhood (CANDLE) Study]]> https://www.researchpad.co/article/5989da22ab0ee8fa60b7f7c6

Preterm birth (PTB) is the leading cause of infant morbidity and mortality. Genitourinary infection is implicated in the initiation of spontaneous PTB; however, examination of the urinary microbiota in relation to preterm delivery using next-generation sequencing technologies is lacking. In a case-control study nested within the Conditions Affecting Neurocognitive Development and Learning in Early Childhood (CANDLE) study, we examined associations between the urinary microbiota and PTB. A total of 49 cases (delivery < 37 weeks gestation) and 48 controls (delivery ≥ 37 weeks gestation) balanced on health insurance type were included in the present analysis. Illumina sequencing of the 16S rRNA gene V4 region was performed on urine samples collected during the second trimester. We observed no difference in taxa richness, evenness, or community composition between cases and controls or for gestational age modeled as a continuous variable. Operational taxonomic units (OTUs) classified to Prevotella, Sutterella, L. iners, Blautia, Kocuria, Lachnospiraceae, and S.marcescens were enriched among cases (FDR corrected p≤ 0.05). A urinary microbiota clustering partition dominated by S. marcescens was also associated with PTB (OR = 3.97, 95% CI: 1.19–13.24). These data suggest a limited role for the urinary microbiota in PTB when measured during the second trimester by 16S rRNA gene sequencing. The enrichment among cases in several organisms previously reported to be associated with genitourinary pathology requires confirmation in future studies to rule out the potential for false positive findings.

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<![CDATA[Characterisation of Early-Life Fecal Microbiota in Susceptible and Healthy Pigs to Post-Weaning Diarrhoea]]> https://www.researchpad.co/article/5bd41049d5eed0c4847c5664

Early-life microbial exposure is of particular importance to growth, immune system development and long-lasting health. Hence, early microbiota composition is a promising predictive biomarker for health and disease but still remains poorly characterized in regards to susceptibility to diarrhoea. In the present study, we aimed to assess if gut bacterial community diversity and composition during the suckling period were associated with differences in susceptibility of pigs to post-weaning diarrhoea. Twenty piglets from 5 sows (4 piglets / litter) were weaned in poor housing conditions to challenge their susceptibility to post-weaning diarrhoea. Two weeks after weaning, 13 pigs exhibited liquid faeces during 2 or 3 days and were defined as diarrhoeic (D) pigs. The other 7 pigs did not have diarrhea during the whole post-weaning experimental periodand were defined as healthy (H) pigs. Using a molecular characterisation of fecal microbiota with CE-SSCP fingerprint, Next Generation Sequencing and qPCR, we show that D and H pigs were mainly discriminated as early as postnatal day (PND) 7, i.e. 4 weeks before post-weaning diarrhoea occurence. At PND 7 H pigs displayed a lower evenness and a higher abundance of Prevotellaceae, Lachnospiraceae, Ruminocacaceae and Lactobacillaceae compared to D pigs. The sPLS regression method indicates that these bacterial families were strongly correlated to a higher Bacteroidetes abundance observed in PND 30 H pigs one week before diarrhoea. These results emphasize the potential of early microbiota diversity and composition as being an indicator of susceptibility to post-weaning diarrhoea. Furthermore, they support the health promoting strategies of pig herds through gut microbiota engineering.

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<![CDATA[Investigation of Factors Affecting Aerobic and Respiratory Growth in the Oxygen-Tolerant Strain Lactobacillus casei N87]]> https://www.researchpad.co/article/5989da02ab0ee8fa60b74a62

Aerobic and respiratory cultivations provide benefits for some lactic acid bacteria (LAB). Growth, metabolites, enzymatic activities (lactate dehydrogenase; pyruvate and NADH oxidases, NADH peroxidase; catalase), antioxidant capability and stress tolerance of Lactobacillus casei N87 were evaluated in anaerobic, aerobic and respiratory (aerobiosis with heme and menaquinone supplementation) batch cultivations with different dissolved oxygen (DO) concentrations. The expression of pox (pyruvate oxidase) and cydABCD operon (cytochrome bd oxidase complex) was quantified by quantitative Real Time polymerase chain reaction. Respiration increased biomass production compared to anaerobiosis and unsupplemented aerobiosis, and altered the central metabolism rerouting pyruvate away from lactate accumulation. All enzymatic activities, except lactate dehydrogenase, were higher in respiratory cultures, while unsupplemented aerobiosis with 60% of DO promoted H2O2 and free radical accumulation. Respiration improved the survival to oxidative and freeze-drying stresses, while significant numbers of dead, damaged and viable but not cultivable cells were found in unsupplemented aerobic cultures (60% DO). Analysis of gene expression suggested that the activation of aerobic and respiratory pathways occurred during the exponential growth phase, and that O2 and hemin induced, respectively, the transcription of pox and cydABCD genes. Respiratory cultivation might be a natural strategy to improve functional and technological properties of L. casei.

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<![CDATA[Effects of dietary nutrient levels on microbial community composition and diversity in the ileal contents of pregnant Huanjiang mini-pigs]]> https://www.researchpad.co/article/5989db53ab0ee8fa60bdca64

The mammalian gut microbiota influences various metabolic and physiological processes. Substantial metabolic changes occur during a healthy pregnancy that may be related to microbiota composition dynamics. However, the effect of diet on intestinal microbiota composition and diversity during pregnancy remains unclear. We examined the ileal contents of Huanjiang mini-pigs at two pregnancy stages to determine the effects of dietary nutrient levels on such microbial communities. Animals received either a higher-nutrient (HN) diet formulated to meet US National Research Council requirements or a lower-nutrient (LN) diet that met the Chinese National Feeding Standard recommendations. On day 45 or 75 of pregnancy, sows were euthanized and their ileal contents sampled. Experimental diet and pregnancy stage did not affect ileal bacterial richness or diversity, as determined by Chao1 and ACE species richness measures and Shannon and Simpson indices, respectively. The phyla Firmicutes and Proteobacteria, accounting for 69.99–85.44% and 5.82–15.17% of the total reads, respectively, predominated regardless of diet. At the genus level, diet significantly affected the abundance of Lactobacillus species, which was greater in pigs given HN feed (P < 0.05), but had little impact on that of Megasphaera species (P = 0.096). Pregnancy stage had a minimal effect on Proteobacteria numbers (P = 0.053). The number of bacteria of the phylum Firmicutes and genus Lactobacillus decreased, while that of the phylum Proteobacteria, family Enterobacteriaceae, and genus Bacteroides increased between days 45 and 75 of pregnancy. Of the short-chain fatty acids (SCFAs) measured, only propionate levels changed significantly, with higher concentrations observed on day 45 than on day 75. Our findings indicate that Firmicutes and Proteobacteria dominate pregnant sow ileal bacterial profiles. Excepting a tendency for the number of Proteobacteria to increase as pregnancy progressed, pregnancy stage and diet had little effect on ileal microbiotic composition and diversity and luminal SCFA concentrations.

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<![CDATA[Investigating the Effect of Different Treatments with Lactic Acid Bacteria on the Fate of Listeria monocytogenes and Staphylococcus aureus Infection in Galleria mellonella Larvae]]> https://www.researchpad.co/article/5989daa5ab0ee8fa60ba71d4

The use of Galleria mellonella as a model host to elucidate microbial pathogenesis and search for novel drugs and therapies has been well appreciated over the past years. However, the effect of microorganisms with functional appeal in the specific host remains scarce. The present study investigates the effect of treatment with selected lactic acid bacteria (LAB) with probiotic potential, as potential protective agents by using live or heat-killed cells at 6 and 24 h prior to infection with Listeria monocytogenes and Staphylococcus aureus or as potential therapeutic agents by using cell-free supernatants (CFS) after infection with the same pathogens. The employed LAB strains were Lactobacillus pentosus B281 and Lactobacillus plantarum B282 (isolated from table olive fermentations) along with Lactobacillus rhamnosus GG (inhabitant of human intestinal tract). Kaplan-Meier survival curves were plotted while the pathogen’s persistence in the larval hemolymph was determined by microbiological analysis. It was observed that the time (6 or 24 h) and type (live or heat-killed cells) of challenge period with LAB prior to infection greatly affected the survival of infected larvae. The highest decrease of L. monocytogenes population in the hemolymph was observed in groups challenged for 6 h with heat-killed cells by an average of 1.8 log units compared to non challenged larvae for strains B281 (p 0.0322), B282 (p 0.0325), and LGG (p 0.0356). In the case of S. aureus infection, the population of the pathogen decreased in the hemolymph by 1 log units at 8 h post infection in the groups challenged for 6 h with heat-killed cells of strains B281 (p 0.0161) and B282 (p 0.0096) and by 1.8 log units in groups challenged with heat-killed cells of LGG strain (p 0.0175). Further use of CFS of each LAB strain did not result in any significant prolonged survival but interestingly it resulted in pronounced decrease of L. monocytogenes in the hemolymph at 24 h and 48 h after infection by more than 1 log unit (p < 0.05) depending on the strain. The results of the present work support the broader use of G. mellonella larvae as a low cost in vivo tool for screening for probiotic properties.

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<![CDATA[Novel approaches for the taxonomic and metabolic characterization of lactobacilli: Integration of 16S rRNA gene sequencing with MALDI-TOF MS and 1H-NMR]]> https://www.researchpad.co/article/5989db51ab0ee8fa60bdc4cb

Lactobacilli represent a wide range of bacterial species with several implications for the human host. They play a crucial role in maintaining the ecological equilibrium of different biological niches and are essential for fermented food production and probiotic formulation. Despite the consensus about the ‘health-promoting’ significance of Lactobacillus genus, its genotypic and phenotypic characterization still poses several difficulties. The aim of this study was to assess the integration of different approaches, genotypic (16S rRNA gene sequencing), proteomic (MALDI-TOF MS) and metabolomic (1H-NMR), for the taxonomic and metabolic characterization of Lactobacillus species. For this purpose we analyzed 40 strains of various origin (intestinal, vaginal, food, probiotics), belonging to different species. The high discriminatory power of MALDI-TOF for species identification was underlined by the excellent agreement with the genotypic analysis. Indeed, MALDI-TOF allowed to correctly identify 39 out of 40 Lactobacillus strains at the species level, with an overall concordance of 97.5%. In the perspective to simplify the MALDI TOF sample preparation, especially for routine practice, we demonstrated the perfect agreement of the colony-picking from agar plates with the protein extraction protocol. 1H-NMR analysis, applied to both culture supernatants and bacterial lysates, identified a panel of metabolites whose variations in concentration were associated with the taxonomy, but also revealed a high intra-species variability that did not allow a species-level identification. Therefore, despite not suitable for mere taxonomic purposes, metabolomics can be useful to correlate particular biological activities with taxonomy and to understand the mechanisms related to the antimicrobial effect shown by some Lactobacillus species.

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<![CDATA[Lectin-Like Molecules of Lactobacillus rhamnosus GG Inhibit Pathogenic Escherichia coli and Salmonella Biofilm Formation]]> https://www.researchpad.co/article/5989da50ab0ee8fa60b8dc16

Objectives

Increased antibiotic resistance has catalyzed the research on new antibacterial molecules and alternative strategies, such as the application of beneficial bacteria. Since lectin molecules have unique sugar-recognizing capacities, and pathogens are often decorated with sugars that affect their survival and infectivity, we explored whether lectins from the probiotic strain Lactobacillus rhamnosus GG have antipathogenic properties.

Methods

The genome sequence of L. rhamnosus GG was screened for the presence of lectin-like proteins. Two genes, LGG_RS02780 and LGG_RS02750, encoding for polypeptides with an N-terminal conserved L-type lectin domain were detected and designated Llp1 (lectin-like protein 1) and Llp2. The capacity of Llp1 and Llp2 to inhibit biofilm formation of various pathogens was investigated. Sugar specificity was determined by Sepharose beads assays and glycan array screening.

Results

The isolated lectin domains of Llp1 and Llp2 possess pronounced inhibitory activity against biofilm formation by various pathogens, including clinical Salmonella species and uropathogenic E. coli, with Llp2 being more active than Llp1. In addition, sugar binding assays with Llp1 and Llp2 indicate specificity for complex glycans. Both proteins are also involved in the adhesion capacity of L. rhamnosus GG to gastrointestinal and vaginal epithelial cells.

Conclusions

Lectins isolated from or expressed by beneficial lactobacilli could be considered promising bio-active ingredients for improved prophylaxis of urogenital and gastrointestinal infections.

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<![CDATA[Chlorogenic Acid Combined with Lactobacillus plantarum 2142 Reduced LPS-Induced Intestinal Inflammation and Oxidative Stress in IPEC-J2 Cells]]> https://www.researchpad.co/article/5989d9e4ab0ee8fa60b6aa9b

This study was carried out to investigate protective effect of chlorogenic acid against lipopolysaccharide-induced inflammation and oxidative stress in intestinal epithelial cells. As a marker of inflammatory response, IL-6, IL-8, TNF-α mRNA and protein levels, furthermore, COX-2 mRNA level were followed up. Intracellular redox status and extracellular H2O2 level were also monitored by two fluorescent assays (DCFH-DA, Amplex Red). Moreover, the effect of gut microbiota metabolites in the above mentioned processes was taken into account in our model using Lactobacillus plantarum 2142 bacterial strain. Our data revealed that chlorogenic acid had significant lowering effect on the inflammatory response. Treatment with chlorogenic acid (25–50 μM) significantly decreased gene expression and concentration of proinflammatory cytokines IL-6 and IL-8 compared to LPS-treated cells. COX-2 and TNF-α mRNA levels were also reduced. Furthermore, chlorogenic acid reduced the level of reactive oxygen species in IPEC-J2 cells. Simultaneous application of chlorogenic acid and Lactobacillus plantarum 2142 supernatant resulted protective effect against LPS-induced inflammation and oxidative stress as well.

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<![CDATA[Different Effects of Three Selected Lactobacillus Strains in Dextran Sulfate Sodium-Induced Colitis in BALB/c Mice]]> https://www.researchpad.co/article/5989db44ab0ee8fa60bd7f12

Aim

To analyze the changes of different Lactobacillus species in ulcerative colitis patients and to further assess the therapeutic effects of selected Lactobacillus strains on dextran sulfate sodium (DSS)-induced experimental colitis in BALB/c mice.

Methods

Forty-five active ulcerative colitis (UC) patients and 45 population-based healthy controls were enrolled. Polymerase chain reaction (PCR) amplification and real-time PCR were performed for qualitative and quantitative analyses, respectively, of the Lactobacillus species in UC patients. Three Lactobacillus strains from three species were selected to assess the therapeutic effects on experimental colitis. Sixty 8-week-old BALB/c mice were divided into six groups. The five groups that had received DSS were administered normal saline, mesalazine, L. fermentum CCTCC M206110 strain, L. crispatus CCTCC M206119 strain, or L. plantarum NCIMB8826 strain. We assessed the severity of colitis based on disease activity index (DAI), body weight loss, colon length, and histologic damage.

Results

The detection rate of four of the 11 Lactobacillus species decreased significantly (P < 0.05), and the detection rate of two of the 11 Lactobacillus species increased significantly (P < 0.05) in UC patients. Relative quantitative analysis revealed that eight Lactobacillus species declined significantly in UC patients (P < 0.05), while three Lactobacillus species increased significantly (P < 0.05). The CCTCC M206110 treatment group had less weight loss and colon length shortening, lower DAI scores, and lower histologic scores (P < 0.05), while the CCTCC M206119 treatment group had greater weight loss and colon length shortening, higher histologic scores, and more severe inflammatory infiltration (P < 0.05). NCIMB8826 improved weight loss and colon length shortening (P < 0.05) with no significant influence on DAI and histologic damage in the colitis model.

Conclusions

Administration of an L. crispatus CCTCC M206119 supplement aggravated DSS-induced colitis. L. fermentum CCTCC M206110 proved to be effective at attenuating DSS-induced colitis. The potential probiotic effect of L. plantarum NCIMB8826 on UC has yet to be assessed.

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<![CDATA[Spatial Distribution of the Metabolically Active Microbiota within Italian PDO Ewes' Milk Cheeses]]> https://www.researchpad.co/article/5989da0dab0ee8fa60b78595

Italian PDO (Protected Designation of Origin) Fiore Sardo (FS), Pecorino Siciliano (PS) and Pecorino Toscano (PT) ewes’ milk cheeses were chosen as hard cheese model systems to investigate the spatial distribution of the metabolically active microbiota and the related effects on proteolysis and synthesis of volatile components (VOC). Cheese slices were divided in nine sub-blocks, each one separately subjected to analysis and compared to whole cheese slice (control). Gradients for moisture, and concentrations of salt, fat and protein distinguished sub-blocks, while the cell density of the main microbial groups did not differ. Secondary proteolysis differed between sub-blocks of each cheese, especially when the number and area of hydrophilic and hydrophobic peptide peaks were assessed. The concentration of free amino acids (FAA) agreed with these data. As determined through Purge and Trap (PT) coupled with Gas Chromatography-Mass Spectrometry (PT-GC/MS), and regardless of the cheese variety, the profile with the lowest level of VOC was restricted to the region identified by the letter E defined as core. As shown through pyrosequencing of the 16S rRNA targeting RNA, the spatial distribution of the metabolically active microbiota agreed with the VOC distribution. Differences were highlighted between core and the rest of the cheese. Top and bottom under rind sub-blocks of all three cheeses harbored the widest biodiversity.

The cheese sub-block analysis revealed the presence of a microbiota statistically correlated with secondary proteolysis events and/or synthesis of VOC.

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