Prediction of subclinical atherosclerosis in low Framingham risk score individuals by using the metabolic syndrome criteria and insulin sensitivity index.

Background: Subclinical atherosclerosis can be present in individuals with an optimal cardiovascular risk factor profile. Traditional risk scores such as the Framingham risk score do not adequately capture risk stratification in low-risk individuals. The aim of this study was to determine if markers of metabolic syndrome and insulin resistance can better stratify low-risk individuals. Methods: A cross-sectional study of 101 healthy participants with a low Framingham risk score and no prior morbidities was performed to assess prevalence of subclinical atherosclerosis using computed tomography (CT) and ultrasound. Participants were compared between groups based on Metabolic Syndrome (MetS) and Insulin-Sensitivity Index (ISI-cal) scores. Results: Twenty three individuals (23%) had subclinical atherosclerosis with elevated CT Agatston score ≥1. Presence of both insulin resistance (ISI-cal <9.23) and fulfillment of at least one metabolic syndrome criterion denoted high risk, resulting in significantly improved AUC (0.706 95%CI 0.588-0.822) over the Framingham risk score in predicting elevated CT Agatston score ≥1, with net reclassification index of 50.9 ± 23.7%. High-risk patients by the new classification also exhibited significantly increased carotid intima thickness. Conclusions: The overlap of insulin resistance and presence of ≥1 criterion for metabolic syndrome may play an instrumental role in identifying traditionally low-risk individuals predisposed to future risk of atherosclerosis and its sequelae.

Gender differences in fasting and postprandial metabolic traits predictive of subclinical atherosclerosis in an asymptomatic Chinese population.

The prediction utility of Framingham Risk Score in populations with low conventional cardiovascular risk burden is limited, particularly among women. Gender-specific markers to predict cardiovascular risk in overtly healthy people are lacking. In this study we hypothesize that postprandial responses triggered by a high-calorie meal test differ by gender in their ability to triage asymptomatic subjects into those with and without subclinical atherosclerosis. A total of 101 healthy Chinese subjects (46 females, 55 males) at low risk of coronary heart disease completed the study. Subjects underwent cardiovascular imaging and postprandial blood phenotyping after consuming a standardized macronutrient meal. Prediction models were developed using logistic regression and subsequently subjected to cross-validation to obtain a de-optimized receiver operating characteristic (ROC) curve. Distinctive gender differences in postprandial trajectories of glucose, lipids and inflammatory markers were observed. We used gender-specific association with different combinations of postprandial predictors to develop 2 models for predicting risk of subclinical atherosclerosis in males (ROC AUC = 0.7867, 95% CI 0.6567, 0.9166) and females (ROC AUC = 0.9161, 95% CI 0.8340, 0.9982) respectively. We report novel postprandial models for predicting subclinical atherosclerosis in apparently healthy Asian subjects using a gender-specific approach, complementing the conventional Framingham Risk Score.Clinical Trial Registration: The trial was registered at clinicaltrials.gov as NCT03531879.

Clinical- and omics-based models of subclinical atherosclerosis in healthy Chinese adults: a cross-sectional exploratory study.

BACKGROUND: Classical risk factors, such as fasting cholesterol, blood pressure (BP), and diabetes status are used today to predict the risk of developing cardiovascular disease (CVD). However, accurate prediction remains limited, particularly in low-risk groups such as women and younger individuals. Growing evidence suggests that biomarker concentrations following consumption of a meal challenge are better and earlier predictors of disease development than biomarker concentrations. OBJECTIVE: To test the hypothesis that postprandial responses of circulating biomarkers differ between healthy subjects with and without subclinical atherosclerosis (SA) in an Asian population at low risk of coronary artery disease (CAD). METHODS: One hundred healthy Chinese subjects (46 women, 54 men) completed the study. Subjects consumed a mixed-meal test and 164 blood biomarkers were analyzed over 6 h by using a combination of chemical and NMR techniques. Models were trained using different methodologies (including logistic regression, elastic net, random forest, sparse partial least square) on a random 75% subset of the data, and their performance was evaluated on the remaining 25%. RESULTS: We found that models based on baseline clinical parameters or fasting biomarkers could not reliably predict SA. By contrast, an omics model based on magnitude and timing of postprandial biomarkers achieved high performance [receiving operating characteristic (ROC) AUC: 91%; 95% CI: 77, 100). Investigation of key features of this model enabled derivation of a considerably simpler model, solely based on postprandial BP and age, with excellent performance (AUC: 91%; 95% CI: 78, 100). CONCLUSION: We report a novel model to detect SA based on postprandial BP and age in a population of Asian subjects at low risk of CAD. The use of this model in large-scale CVD prevention programs should be explored. This trial was registered at ClinicalTrials.gov as NCT03531879.

Malnutrition in Relation with Dietary, Geographical, and Socioeconomic Factors among Older Chinese.

OBJECTIVE: Nutrition is closely related to the health of the elderly population. This study aimed to provide a comprehensive picture of the nutrition status of elderly Chinese and its related dietary, geographical, and socioeconomic factors. METHODS: A total of 13,987 ≥ 60-year-old persons from the 2010-2013 Chinese National Nutrition and Health Survey were included to evaluate various aspects of malnutrition, including underweight, overweight or obesity, and micronutrient inadequacy. RESULTS: Overall, the prevalence of obesity, overweight, and underweight was 12.4%, 34.8%, and 5.7%, respectively, with disparities both geographically and socioeconomically. The prevalence of underweight was higher among the older old (≥ 75 years), rural residents and those with low income, with low education status, and residing in undeveloped West areas. More than 75% of the elderly do not meet the Dietary Reference Intakes for vitamins A, B 1, B 2, and E, folate, calcium, selenium, potassium, biotin, and choline, with the prevalence of inadequate intake increasing with age for most nutrients. At the population level, the mean intakes of numerous food groups did not meet the recommendations by the Chinese Dietary Guideline. CONCLUSIONS: Obesity epidemic, inadequacy of micronutrient intake, and high prevalence of underweight and anemia in susceptible older people are the major nutrition challenges for the rapidly aging population in China.

Differential expression analysis throughout the weaning period in the mouse cerebral cortex.

At weaning, mammals switch from drinking mother's milk to eating foods of environmental origin. These foods contain natural compounds with novel tastes and textures, which are provided to the young for the first time following the termination of breastfeeding. This novel eating experience may alter the cognitive brain function of mammalian babies, increasing their reactions to their food environments. Because the cerebral cortex is a central organ for cognition and learning, we investigated differences in whole-gene expression profiles in the mouse cerebral cortex using microarray analysis before and after weaning. Of 45,037 murine genes, 35 genes were upregulated and 31 genes were downregulated, in response to weaning. In particular, immediate early genes, molecular chaperones, and myelin-related genes were upregulated. In situ hybridization analysis revealed that the mRNA for an immediate early gene, Egr-2/KROX-20, was transported from the nucleus to the cell body at layer 5/6 of the somatosensory cortex during weaning. In contrast, in animals without any food supply other than mother's milk, Egr-2/KROX-20 mRNA was retained within the nucleus at the somatosensory cortex. These data suggest that the novel experience of food intake modulates gene expression profiles in the murine cerebral cortex at the weaning stage.

Effect of oral L-arginine supplementation on blood pressure: a meta-analysis of randomized, double-blind, placebo-controlled trials.

BACKGROUND: Previous studies suggest that L-arginine, an amino acid and a substrate of nitric oxide synthase, may have blood pressure (BP)-lowering effect. Because some studies were performed with limited number of patients with hypertension and therefore limited statistical power with sometimes inconsistent results, we aimed to examine the effect of oral L-arginine supplementation on BP by conducting a meta-analysis of randomized, double-blind, placebo-controlled trials. METHODS: PubMed, Cochrane Central Register of Controlled Trials, and the ClinicalTrials.gov databases were searched through June 2011 to identify randomized, double-blind, placebo-controlled trials of oral L-arginine supplementation on BP in humans. We also reviewed reference lists of obtained articles. Either a fixed-effects or, in the presence of heterogeneity, a random-effects model was used to calculate the combined treatment effect. RESULTS: We included 11 randomized, double-blind, placebo-controlled trials involving 387 participants with oral L-arginine intervention ranging from 4 to 24 g/d. Compared with placebo, L-arginine intervention significantly lowered systolic BP by 5.39 mm Hg (95% CI -8.54 to -2.25, P = .001) and diastolic BP by 2.66 mm Hg (95% CI -3.77 to -1.54, P < .001). Sensitivity analyses restricted to trials with a duration of 4 weeks or longer and to trials in which participants did not use antihypertensive medications yielded similar results. Meta-regression analysis suggested an inverse, though insignificant (P = .13), relation between baseline systolic BP and net change in systolic BP. CONCLUSIONS: This meta-analysis provides further evidence that oral L-arginine supplementation significantly lowers both systolic and diastolic BP.

New method for selection of hydrogen peroxide adapted bifidobacteria cells using continuous culture and immobilized cell technology.

BACKGROUND: Oxidative stress can severely compromise viability of bifidobacteria. Exposure of Bifidobacterium cells to oxygen causes accumulation of reactive oxygen species, mainly hydrogen peroxide, leading to cell death. In this study, we tested the suitability of continuous culture under increasing selective pressure combined with immobilized cell technology for the selection of hydrogen peroxide adapted Bifidobacterium cells. Cells of B. longum NCC2705 were immobilized in gellan-xanthan gum gel beads and used to continuously ferment MRS medium containing increasing concentration of H2O2 from 0 to 130 ppm. RESULTS: At the beginning of the culture, high cell density of 10(13) CFU per litre of reactor was tested. The continuous culture gradually adapted to increasing H2O2 concentrations. However, after increasing the H2O2 concentration to 130 ppm the OD of the culture decreased to 0. Full wash out was prevented by the immobilization of the cells in gel matrix. Hence after stopping the stress, it was possible to re-grow the cells that survived the highest lethal dose of H2O2 and to select two adapted colonies (HPR1 and HPR2) after plating of the culture effluent. In contrast to HPR1, HPR2 showed stable characteristics over at least 70 generations and exhibited also higher tolerance to O2 than non adapted wild type cells. Preliminary characterization of HPR2 was carried out by global genome expression profile analysis. Two genes coding for a protein with unknown function and possessing trans-membrane domains and an ABC-type transporter protein were overexpressed in HPR2 cells compared to wild type cells. CONCLUSIONS: Our study showed that continuous culture with cell immobilization is a valid approach for selecting cells adapted to hydrogen peroxide. Elucidation of H2O2 adaptation mechanisms in HPR2 could be helpful to develop oxygen resistant bifidobacteria.

A Mesocosm of Lactobacillus johnsonii, Bifidobacterium longum, and Escherichia coli in the mouse gut.

The relative contribution of competition and cooperation at the microbe-microbe level is not well understood for the bacteria constituting the gut microbiota. The high number and variability of human gut commensals have hampered the analysis. To get some insight into the question how so many different bacterial species can coexist in the mammalian gut, we studied the interaction between three human gut commensals (Escherichia coli K-12, Lactobacillus johnsonii NCC533, and Bifidobacterium longum NCC2705) in the intestine of gnotobiotic mice. The bacterial titers and their anatomical distribution were studied in the colonized mice. L. johnsonii achieved the highest cell counts in the stomach, while B. longum dominated the colon. The colon was also the intestinal location in which B. longum displayed the highest number of expressed genes, followed by the cecum and the small intestine. Addition of further bacterial strains led to strikingly different results. A Lactobacillus paracasei strain coexisted, while a second B. longum strain was excluded from the system. Notably, this strain lacked an operon involved in the degradation, import, and metabolism of mannosylated glycans. Subsequent introduction of the E. coli Nissle strain resulted in the elimination of L. johnsonii NCC533 and E. coli K-12, while B. longum NCC2705 showed a transient decrease in population size, demonstrating the dynamic nature of microbe-microbe interactions. The study of such simple interacting bacterial systems might help to derive some basic rules governing microbial ecology within the mammalian gut.

Physiological and biochemical characterization of the two alpha-L-rhamnosidases of Lactobacillus plantarum NCC245.

This work is believed to be the first report on the physiological and biochemical characterization of alpha-l-rhamnosidases in lactic acid bacteria. A total of 216 strains representing 37 species and eight genera of food-grade bacteria were screened for alpha-l-rhamnosidase activity. The majority of positive bacteria (25 out of 35) were Lactobacillus plantarum strains, and activity of the L. plantarum strain NCC245 was examined in more detail. The analysis of alpha-l-rhamnosidase activity under different growth conditions revealed dual regulation of the enzyme activity, involving carbon catabolite repression and induction: the enzyme activity was downregulated by glucose and upregulated by l-rhamnose. The expression of the two alpha-l-rhamnosidase genes rhaB1 and rhaB2 and two predicted permease genes rhaP1 and rhaP2, identified in a probable operon rhaP2B2P1B1, was repressed by glucose and induced by l-rhamnose, showing regulation at the transcriptional level. The two alpha-l-rhamnosidase genes were overexpressed and purified from Escherichia coli. RhaB1 activity was maximal at 50 degrees C and at neutral pH and RhaB2 maximal activity was detected at 60 degrees C and at pH 5, with high residual activity at 70 degrees C. Both enzymes showed a preference for the alpha-1,6 linkage of l-rhamnose to beta-d-glucose, hesperidin and rutin being their best substrates, but, surprisingly, no activity was detected towards the alpha-1,2 linkage in naringin under the tested conditions. In conclusion, we identified and characterized the strain L. plantarum NCC245 and its two alpha-l-rhamnosidase enzymes, which might be applied for improvement of bioavailability of health-beneficial polyphenols, such as hesperidin, in humans.

Bile affects the synthesis of exopolysaccharides by Bifidobacterium animalis.

By using cryo-scanning electron microscopy and quantification with lectin-conjugated probes, we have detected the production of exopolysaccharides (EPS) in Bifidobacterium animalis subsp. lactis in the presence of bile. In addition, the expression of gtf01207, which codifies a putative priming glycosyltransferase involved in EPS synthesis, was induced by bile.

Identification of genes associated with the long-gut-persistence phenotype of the probiotic Lactobacillus johnsonii strain NCC533 using a combination of genomics and transcriptome analysis.

Lactobacillus johnsonii strains NCC533 and ATCC 33200 (the type strain of this species) differed significantly in gut residence time (12 versus 5 days) after oral feeding to mice. Genes affecting the long gut residence time of the probiotic strain NCC533 were targeted for analysis. We hypothesized that genes specific for this strain, which are expressed during passage of the bacterium through the gut, affect the phenotype. When the DNA of the type strain was hybridized against a microarray of the sequenced NCC533 strain, we identified 233 genes that were specific for the long-gut-persistence isolate. Whole-genome transcription analysis of the NCC533 strain using the microarray format identified 174 genes that were strongly and consistently expressed in the jejunum of mice monocolonized with this strain. Fusion of the two microarray data sets identified three gene loci that were both expressed in vivo and specific to the long-gut-persistence isolate. The identified genes included LJ1027 and LJ1028, two glycosyltransferase genes in the exopolysaccharide synthesis operon; LJ1654 to LJ1656, encoding a sugar phosphotransferase system (PTS) transporter annotated as mannose PTS; and LJ1680, whose product shares 30% amino acid identity with immunoglobulin A proteases from pathogenic bacteria. Knockout mutants were tested in vivo. The experiments revealed that deletion of LJ1654 to LJ1656 and LJ1680 decreased the gut residence time, while a mutant with a deleted exopolysaccharide biosynthesis cluster had a slightly increased residence time.

Gene expression of commensal Lactobacillus johnsonii strain NCC533 during in vitro growth and in the murine gut.

Work with pathogens like Vibrio cholerae has shown major differences between genes expressed in bacteria grown in vitro and in vivo. To explore this subject for commensals, we investigated the transcription of the Lactobacillus johnsonii NCC533 genome during in vitro and in vivo growth using the microarray technology. During broth growth, 537, 626, and 277 of the 1,756 tested genes were expressed during exponential phase, "adaptation" (early stationary phase), and stationary phase, respectively. One hundred one, 150, and 33 genes, respectively, were specifically transcribed in these three phases. To explore the in vivo transcription program, we fed L. johnsonii containing a resistance plasmid to antibiotic-treated mice. After a 2-day washout phase, we determined the viable-cell counts of lactobacilli that were in the lumina and associated with the mucosae of different gut segments. While the cell counts showed a rather uniform distribution along the gut, we observed marked differences with respect to the expression of the Lactobacillus genome. The largest number of transcribed genes was in the stomach (n = 786); the next-largest numbers occurred in the cecum (n = 391) and the jejunum (n = 296), while only 26 Lactobacillus genes were transcribed in the colon. In vitro and in vivo transcription programs overlapped only partially. One hundred ninety-one of the transcripts from the lactobacilli in the stomach were not detected during in vitro growth; 202 and 213 genes, respectively, were transcribed under all in vitro and in vivo conditions; but the core transcriptome for all growth conditions comprised only 103 genes. Forty-four percent of the NCC533 genes were not detectably transcribed under any of the investigated conditions. Nontranscribed genes were clustered on the genome and enriched in the variable-genome part. Our data revealed not only major differences between in vitro- and in vivo-expressed genes in a Lactobacillus gut commensal organism but also marked changes in the expression of genes along the digestive tract.

Global transcriptome analysis of the heat shock response of Bifidobacterium longum.

Bifidobacteria are natural inhabitants of the human gastrointestinal tract and have been widely used as functional foods in different products. During industrial processing, bacterial cells undergo several stresses that can limit large-scale production and stability of the final product. To better understand the stress-response mechanisms of bifidobacteria, microarrays were used to obtain a global transcriptome profile of Bifidobacterium longum NCC2705 exposed to a heat shock treatment at 50 degrees C for 3, 7 and 12 min. Gene expression data highlighted a profound modification of gene expression, with 46% of the genes being altered. This analysis revealed a slow-down of Bi. longum general metabolic activity during stress with a simultaneous activation of the classical heat shock stimulon. Moreover, the expression of several genes with unknown function was highly induced under stress conditions. Three of these were conserved in other bacteria species where they were also previously shown to be induced by high temperature, suggesting their widespread role in the heat stress response. Finally, the implication of the trans-translation machinery in the response of Bi. longum cells to heat shock was suggested by the induction of the gene encoding the tmRNA-associated small protein B (SmpB) with concomitant high constitutive expression of the tmRNA gene.

Similarity and differences in the Lactobacillus acidophilus group identified by polyphasic analysis and comparative genomics.

A set of lactobacilli were investigated by polyphasic analysis. Multilocus sequence analysis, DNA typing, microarray analysis, and in silico whole-genome alignments provided a remarkably consistent pattern of similarity within the Lactobacillus acidophilus complex. On microarray analysis, 17 and 5% of the genes from Lactobacillus johnsonii strain NCC533 represented variable and strain-specific genes, respectively, when tested against four independent isolates of L. johnsonii. When projected on the NCC533 genome map, about 10 large clusters of variable genes were identified, and they were enriched around the terminus of replication. A quarter of the variable genes and two-thirds of the strain-specific genes were associated with mobile DNA. Signatures for horizontal gene transfer and modular evolution were found in prophages and in DNA from the exopolysaccharide biosynthesis cluster. On microarray hybridizations, Lactobacillus gasseri strains showed a shift to significantly lower fluorescence intensities than the L. johnsonii test strains, and only genes encoding very conserved cellular functions from L. acidophilus hybridized to the L. johnsonii array. In-silico comparative genomics showed extensive protein sequence similarity and genome synteny of L. johnsonii with L. gasseri, L. acidophilus, and Lactobacillus delbrueckii; moderate synteny with Lactobacillus casei; and scattered X-type sharing of protein sequence identity with the other sequenced lactobacilli. The observation of a stepwise decrease in similarity between the members of the L. acidophilus group suggests a strong element of vertical evolution in a natural phylogenetic group. Modern whole-genome-based techniques are thus a useful adjunct to the clarification of taxonomical relationships in problematic bacterial groups.

Sugar transport systems of Bifidobacterium longum NCC2705.

Here we present the complement of the carbohydrate uptake systems of the strictly anaerobic probiotic Bifidobacterium longum NCC2705. The genome analysis of this bacterium predicts that it has 19 permeases for the uptake of diverse carbohydrates. The majority belongs to the ATP-binding cassette transporter family with 13 systems identified. Among them are permeases for lactose, maltose, raffinose, and fructooligosaccharides, a commonly used prebiotic additive. We found genes that encode a complete phosphotransferase system (PTS) and genes for three permeases of the major facilitator superfamily. These systems could serve for the import of glucose, galactose, lactose, and sucrose. Growth analysis of NCC2705 cells combined with biochemical characterization and microarray data showed that the predicted substrates are consumed and that the corresponding transport and catabolic genes are expressed. Biochemical analysis of the PTS, in which proteins are central in regulation of carbon metabolism in many bacteria, revealed that B. longum has a glucose-specific PTS, while two other species (Bifidobacterium lactis and Bifidobacterium bifidum) have a fructose-6-phosphate-forming fructose-PTS instead. It became obvious that most carbohydrate systems are closely related to those from other actinomycetes, with a few exceptions. We hope that this report on B. longum carbohydrate transporter systems will serve as a guide for further in-depth analyses on the nutritional lifestyle of this beneficial bacterium.

A serpin from the gut bacterium Bifidobacterium longum inhibits eukaryotic elastase-like serine proteases.

Serpins form a large class of protease inhibitors involved in regulation of a wide spectrum of physiological processes. Recently identified prokaryotic members of this protein family may provide a key to the evolutionary origins of the unique serpin fold and the associated inhibitory mechanism. We performed a biochemical characterization of a serpin from Bifidobacterium longum, an anaerobic Gram-positive bacterium that naturally colonizes human gastrointestinal tract. The B. longum serpin was shown to efficiently inhibit eukaryotic elastase-like proteases with a stoichiometry of inhibition close to 1. Porcine pancreatic elastase and human neutrophil elastase were inhibited with the second order association constants of 4.7 x 10(4) m(-1) s(-1) and 2.1 x 10(4) m(-1) s(-1), respectively. The B. longum serpin is expected to be active in the gastrointestinal tract, because incubation of the purified recombinant serpin with mouse feces produces a stable covalent serpin-protease adduct readily detectable by SDS-PAGE. Bifidobacteria may encounter both pancreatic elastase and neutrophil elastase in their natural habitat and protection against exogenous proteolysis may play an important role in the interaction between these commensal bacteria and their host.

Lactose-over-glucose preference in Bifidobacterium longum NCC2705: glcP, encoding a glucose transporter, is subject to lactose repression.

Analysis of culture supernatants obtained from Bifidobacterium longum NCC2705 grown on glucose and lactose revealed that glucose utilization is impaired until depletion of lactose. Thus, unlike many other bacteria, B. longum preferentially uses lactose rather than glucose as the primary carbon source. Glucose uptake experiments with B. longum cells showed that glucose transport was repressed in the presence of lactose. A comparative analysis of global gene expression profiling using DNA arrays led to the identification of only one gene repressed by lactose, the putative glucose transporter gene glcP. The functionality of GlcP as glucose transporter was demonstrated by heterologous complementation of a glucose transport-deficient Escherichia coli strain. Additionally, GlcP exhibited the highest substrate specificity for glucose. Primer extension and real-time PCR analyses confirmed that expression of glcP was mediated by lactose. Hence, our data demonstrate that the presence of lactose in culture medium leads to the repression of glucose transport and transcriptional down-regulation of the glucose transporter gene glcP. This may reflect the highly adapted life-style of B. longum in the gastrointestinal tract of mammals.

Lessons from the genomes of bifidobacteria.

The gut microbiota is a complex ecosystem composed of hundreds of different bacterial species that altogether play an important role in the physiology of their host. In the past few years the complete genome sequence of a number of bacterial strains isolated from the human gastrointestinal tract has been established including that of Bifidobacterium longum NCC2705 isolated from the feces of a healthy infant. Bifidobacteria are among the first species to colonise the human gastrointestinal tract and as such are believed to play an important role in gut homeostasis and normal development. The genome sequence of NCC2705 has revealed a number of features that suggest how this bacterium has adapted to its environment and that could help understanding how it interacts with its host. Here, we review general features of bifidobacteria and illustrate how genome-based approaches can help us better understand the biology of these organisms.

The genome sequence of the probiotic intestinal bacterium Lactobacillus johnsonii NCC 533.

Lactobacillus johnsonii NCC 533 is a member of the acidophilus group of intestinal lactobacilli that has been extensively studied for their "probiotic" activities that include, pathogen inhibition, epithelial cell attachment, and immunomodulation. To gain insight into its physiology and identify genes potentially involved in interactions with the host, we sequenced and analyzed the 1.99-Mb genome of L. johnsonii NCC 533. Strikingly, the organism completely lacked genes encoding biosynthetic pathways for amino acids, purine nucleotides, and most cofactors. In apparent compensation, a remarkable number of uncommon and often duplicated amino acid permeases, peptidases, and phosphotransferase-type transporters were discovered, suggesting a strong dependency of NCC 533 on the host or other intestinal microbes to provide simple monomeric nutrients. Genome analysis also predicted an abundance (>12) of large and unusual cell-surface proteins, including fimbrial subunits, which may be involved in adhesion to glycoproteins or other components of mucin, a characteristic expected to affect persistence in the gastrointestinal tract (GIT). Three bile salt hydrolases and two bile acid transporters, proteins apparently critical for GIT survival, were also detected. In silico genome comparisons with the >95% complete genome sequence of the closely related Lactobacillus gasseri revealed extensive synteny punctuated by clear-cut insertions or deletions of single genes or operons. Many of these regions of difference appear to encode metabolic or structural components that could affect the organisms competitiveness or interactions with the GIT ecosystem.