Effect of Lactobacillus rhamnosus HN001 and Bifidobacterium longum BB536 on the healthy gut microbiota composition at phyla and species level: a preliminary study

AIM: To evaluate the ability of Lactobacillus rhamnosus HN001 and Bifidobacterium longum BB536 to colonize the intestinal environment of healthy subjects and modify the gut microbiota composition. METHODS: Twenty healthy Italian volunteers, eight males and twelve females, participated in the study. Ten subjects took a sachet containing 4 × 109 colony-forming units (CFU) of Bifidobacterium longum BB536 and 109 CFU of Lactobacillus rhamnosus HN001, 30 min before breakfast (pre-prandial administration), while ten subjects took a sachet of probiotic product 30 min after breakfast (post-prandial administration). The ability of Lactobacillus rhamnosus HN001 and Bifidobacterium longum BB536 to colonize human gut microbiota was assessed by means of quantitative real-time PCR, while changes in gut microbiota composition were detected by using Ion Torrent Personal Genome Machine. RESULTS: Immediately after 1-mo of probiotic administration, B. longum BB536 and L. rhamnosus HN001 load was increased in the majority of subjects in both pre-prandial and post-prandial groups. This increase was found also 1 mo after the end of probiotic oral intake in both groups, if compared to samples collected before probiotic consumption. At phyla level a significant decrease in Firmicutes abundance was detected immediately after 1-mo of B. longum BB536 and L. rhamnosus HN001 oral intake. This reduction persisted up to 1 mo after the end of probiotic oral intake together with a significant decrease of Proteobacteria abundance if compared to samples collected before probiotic administration. Whereas, at species level, a higher abundance of Blautia producta, Blautia wexlerae and Haemophilus ducrey was observed, together with a reduction of Holdemania filiformis, Escherichia vulneris, Gemmiger formicilis and Streptococcus sinensis abundance. In addition, during follow-up period we observed a further reduction in Escherichia vulneris and Gemmiger formicilis, together with a decrease in Roseburia faecis and Ruminococcus gnavus abundance. Conversely, the abundance of Akkermansia muciniphila was increased if compared to samples collected at the beginning of the experimental time course. CONCLUSION: B. longum BB536 and L. rhamnosus HN001 showed the ability to modulate the gut microbiota composition, leading to a significant reduction of potentially harmful bacteria and an increase of beneficial ones. Further studies are needed to better understand the specific mechanisms involved in gut microbiota modulation

Metacognitive-strategy training promotes decision-making ability in older adults

AbstractResearch on decision making and aging has shown that some decision-making skills decrease with age. Despite these age-related declines, no study has yet investigated the possibility of promoting improvements in decision-making skills in older adults. The present study was designed to address this gap in literature by examining the efficacy of a metacognitive-strategy decision-making training on practiced and non-practiced tasks. The training was based on the use of specific metacognitive principles and analytical strategies for promoting an analytical mode of thinking in the decision-making process. We examined 66 older adults (Mage= 67.52 years, SD = 5.38; age range 60-81) assigned to two training groups: a metacognitive-strategy decision-making training group and an active control group involved in a strategic memory intervention. Both training groups attended four 2-hour training sessions conducted once a week. Results showed that, after intervention, the decision-making training group improved their decision-making skills significantly more than the active control training group. Crucially, the positive effect of the training was evident in both practiced and non-practiced decision-making tasks. This is the first study investigating the efficacy of a decision-making training in older adults based on metacognitive and strategic principles

In vitro selection of resistance in Escherichia coli and Klebsiella spp. at in vivo fluoroquinolone concentrations

<p>Abstract</p> <p>Background</p> <p>Fluoroquinolones are potent antimicrobial agents used for the treatment of a wide variety of community- and nosocomial- infections. However, resistance to fluoroquinolones in Enterobacteriaceae is increasingly reported. Studies assessing the ability of fluoroquinolones to select for resistance have often used antimicrobial concentrations quite different from those actually acquired at the site of infection. The present study compared the ability to select for resistance of levofloxacin, ciprofloxacin and prulifloxacin at concentrations observed <it>in vivo </it>in twenty strains of <it>Escherichia coli </it>and <it>Klebsiella </it>spp. isolated from patients with respiratory and urinary infections. The frequencies of spontaneous single-step mutations at plasma peak and trough antibiotic concentrations were calculated. Multi-step selection of resistance was evaluated by performing 10 serial cultures on agar plates containing a linear gradient from trough to peak antimicrobial concentrations, followed by 10 subcultures on antibiotic-free agar. <it>E. coli </it>resistant strains selected after multi-step selection were characterized for DNA mutations by sequencing <it>gyrA</it>, <it>gyrB</it>, <it>parC </it>and <it>parE </it>genes.</p> <p>Results</p> <p>Frequencies of mutations for levofloxacin and ciprofloxacin were less than 10^-11at peak concentration, while for prulifloxacin they ranged from <10^-11to 10^-5. The lowest number of resistant mutants after multistep selection was selected by levofloxacin followed by ciprofloxacin and prulifloxacin. Both ciprofloxacin- and prulifloxacin-resistant mutants presented mutations in <it>gyrA </it>and <it>parC</it>, while levofloxacin resistance was found associated only to mutations in <it>gyrA</it>.</p> <p>Conclusions</p> <p>Among the tested fluoroquinolones, levofloxacin was the most capable of limiting the occurrence of resistance.</p

In vitro activity of telithromycin against Haemophilus influenzae at epithelial lining fluid concentrations

<p>Abstract</p> <p>Background</p> <p><it>Haemophilus influenzae </it>is one of the main aetiological agents of community-acquired respiratory tract infections. The primary aim of this study was to evaluate the antibacterial activity of telithromycin against <it>H. influenzae </it>clinical isolates showing different pattern of resistance in comparison with azithromycin and clarithromycin at 1/4 ×, 1/2 ×, 1 ×, 2 ×, 4 × minimum inhibitory concentration (MIC) and to peak concentrations in epithelial lining fluid (ELF). The secondary aim was to determine the influence of CO₂enriched atmosphere on bacterial susceptibility.</p> <p>Results</p> <p>Telithromycin showed high activity against <it>H. influenzae</it>, including strains susceptible to β-lactams (n = 200), β-lactamase producer (n = 50) and β-lactamase negative ampicillin resistant (BLNAR) (n = 10), with MIC from ≤0.03 to 4 mg/L, and MIC₅₀/MIC₉₀of 1/2 mg/L with susceptibility rate of 100%, and minimum bactericidal concentrations (MBC) from 2 to 4-fold higher than the MIC. Azithromycin was the most active tested macrolide (range: 0.25 – 4 mg/L; MIC₅₀/MIC₉₀: 1/2 mg/L), comparable to telithromycin, while clarithromycin showed the highest MICs and MBCs (range: 0.25 – 8 mg/L; MIC₅₀/MIC₉₀: 2/8 mg/L). In time-kill studies, telithromycin showed a bactericidal activity at the higher concentrations (4 – 2 × MIC and ELF) against all the strains, being complete after 12 – 24 hours from drug exposition. At MIC concentrations, at ambient air, bactericidal activity of telithromycin and azithromycin was quite similar at 12 hours, and better than that of clarithromycin. Besides, telithromycin and clarithromycin at ELF concentrations were bactericidal after 12 hours of incubation for most strains, while 24 hours were needed to azithromycin to be bactericidal. Incubation in CO₂significantly influenced the MICs and MBCs, and only slightly the <it>in vitro </it>killing curves.</p> <p>Conclusion</p> <p>Telithromycin showed an <it>in-vitro </it>potency against <it>H. influenzae </it>comparable to azithromycin, with an <it>in-vitro </it>killing rate more rapid and superior to clarithromycin at 2X-MIC against β-lactamase producers and BLNAR strains, and to azithromycin at ELF concentrations against β-lactamase negative strains. Against all strains, MICs and MBCs were lower in the absence of CO₂for the tested antibiotics, showing an adverse effect of incubation in a CO₂environment. The <it>in-vitro </it>potency together with the tissue concentrations of the antimicrobial, should be considered in predicting efficacy.</p

Strain-dependent release of cytokines modulated by Lactobacillus salivarius human isolates in an in vitro model

<p>Abstract</p> <p>Background</p> <p>Oral administration of probiotics is known to modulate cytokines profile not only locally, but also systemically. Four strains of <it>Lactobacillus salivarius</it>, LDR0723, BNL1059, RGS1746 and CRL1528, were evaluated for their ability to modulate release of pro- and anti-inflammatory cytokines.</p> <p>Findings</p> <p>Strains were assessed for effects on production of Interleukin-12 (IL-12), Interferon-γ (IFN-γ), Interleukin-4 (IL-4) and Interleukin-5 (IL-5) by incubating bacterial suspensions with THP-1 macrophage like cells. Cytokines were determined by means of specific quantitative enzyme-linked immunosorbent assays.</p> <p>LDR0723 and CRL1528 led to a sustained increment in production of IL-12 and IFN-γ and to a decrease in release of IL-4 and IL-5, while BNL1059 and RGS1746 favoured Th2 response, leading to a decrease in Th1/Th2 ratio with respect to unstimulated cells.</p> <p>Conclusions</p> <p>In conclusion, capability of <it>L. salivarius </it>to modulate immune response was strictly strain dependent and strains of the same species might have opposite effects. Therefore, a careful evaluation of anti-inflammatory properties of lactobacilli should be performed on single strain, before any consideration on potential probiotic use.</p

Theory of Mind in aging: Comparing cognitive and affective components in the faux pas test

Objectives: Theory of Mind (ToM) is a complex human ability that allows people to make inferences on others' mental states such as beliefs, emotions and desires. Previous studies on ToM in normal aging have provided heterogeneous findings. In the present study we examined whether a mixed calculation of different aspects of ToM may have contributed to these conflicting results. We had two aims. First, we explored the age-related changes in the performance of cognitive vs. affective ToM. Second, we investigated the extent to which the effect of aging on cognitive vs. affective ToM is mediated by age-related differences in executive functions. Method: To address these issues three age groups (young, young-old, and old-old adults) were compared on cognitive and affective ToM using the faux pas test. In addition, participants were tested using a battery of executive function tasks tapping on inhibition, working memory updating, and word fluency. Results: The analyses indicated that young adults outperform both young-old and old-old adults on cognitive ToM but not on affective ToM. Correlations showed that, whereas cognitive ToM was significantly associated with age, working memory updating, and inhibition, affective ToM was not. Finally, analyses revealed that individual differences in working memory updating (but not inhibition) mediated the effect of age on cognitive ToM. Conclusion: Our findings support the view of selective age-related differences on cognitive, but not affective, ToM in normal aging. The distinction between the two ToM components is further supported by a dissociable pattern of correlations with executive function

Gluconeogenic Signals Regulate Iron Homeostasis via Hepcidin in Mice.

Hepatic gluconeogenesis provides fuel during starvation, and is abnormally induced in obese individuals or those with diabetes. Common metabolic disorders associated with active gluconeogenesis and insulin resistance (obesity, metabolic syndrome, diabetes, and nonalcoholic fatty liver disease) have been associated with alterations in iron homeostasis that disrupt insulin sensitivity and promote disease progression. We investigated whether gluconeogenic signals directly control Hepcidin, an important regulator of iron homeostasis, in starving mice (a model of persistently activated gluconeogenesis and insulin resistance).|We investigated hepatic regulation of Hepcidin expression in C57BL/6Crl, 129S2/SvPas, BALB/c, and wild-type and Creb3l3-/- null mice. Mice were fed a standard, iron-balanced chow diet or an iron-deficient diet for 9 days before death, or for 7 days before a 24- to 48-hour starvation period; liver and spleen tissues then were collected and analyzed by quantitative reverse-transcription polymerase chain reaction and immunoblot analyses. Serum levels of iron, hemoglobin, Hepcidin, and glucose also were measured. We analyzed human hepatoma (HepG2) cells and mouse primary hepatocytes to study transcriptional control of Hamp (the gene that encodes Hepcidin) in response to gluconeogenic stimuli using small interfering RNA, luciferase promoter, and chromatin immunoprecipitation analyses.|Starvation led to increased transcription of encodes phosphoenolpyruvate carboxykinase 1 (a protein involved in gluconeogenesis) in livers of mice, increased levels of Hepcidin, and degradation of Ferroportin, compared with nonstarved mice. These changes resulted in hypoferremia and iron retention in liver tissue. Livers of starved mice also had increased levels of Ppargc1a messenger RNA and Creb3l3 messenger RNA, which encode a transcriptional co-activator involved in energy metabolism and a liverspecific transcription factor, respectively. Glucagon and a cyclic adenosine monophosphate analog increased promoter activity and transcription of Hamp in cultured liver cells; levels of Hamp were reduced after administration of small interfering RNAs against Ppargc1a and Creb3l3. PPARGC1A and CREB3L3 bound the Hamp promoter to activate its transcription in response to a cyclic adenosine monophosphate analog. Creb3l3-/- mice did not up-regulate Hamp or become hypoferremic during starvation.|We identified a link between glucose and iron homeostasis, showing that Hepcidin is a gluconeogenic sensor in mice during starvation. This response is involved in hepatic metabolic adaptation to increased energy demands; it preserves tissue iron for vital activities during food withdrawal, but can cause excessive iron retention and hypoferremia in disorders with persistently activated gluconeogenesis and insulin resistance

Comparison of nested PCR and real time PCR of Herpesvirus infections of central nervous system in HIV patients

BACKGROUND: Molecular detection of herpesviruses DNA is considered as the reference standard assay for diagnosis of central nervous system infections. In this study nested PCR and real time PCR techniques for detection of Herpes simplex virus type 1 (HSV-1), Cytomegalovirus (CMV) and Epstein-Barr virus (EBV) in cerebrospinal fluid of HIV patients were compared. METHODS: Forty-six, 85 and 145 samples previously resulted positive for HSV-1, CMV and EBV by nested PCR and 150 randomly chosen negative samples among 1181 collected in the period 1996–2003 were retrospectively reassessed in duplicate by real time PCR and nested PCR. RESULTS: Samples giving positive results for CMV, HSV-1 and EBV with nested PCR were positive also with real time PCR. One of the negative samples resulted positive for HSV and one for EBV. Real time PCR showed comparable sensitivity and specificity vs nested PCR. CONCLUSION: Real time PCR proved to be a suitable method for diagnosis of herpesvirus infections in CNS, showing comparable sensitivity and being less time consuming than nested PCR

Medication use during pregnancy, gestational age and date of delivery: Agreement between maternal self-reports and health database information in a cohort

Supplemental tables. Table S1. Agreement between questionnaire and prescription redemption database for selected therapeutic classes by time of questionnaire completion. Table S2. Number of women with information on hypertension during pregnancy and agreement between questionnaire and birth certificate database. Table S3. Number of women with information on hypertension during pregnancy in questionnaire and in birth certificate database and use of antihypertensive medications according to questionnaire and prescription database. Positive Predictive Value and Negative Predictive Value of prescriptions for antihypertensive medications recorded in questionnaire and in birth certificate database. (DOCX 23 kb