Plasma Lipopolysaccharide-binding Protein Levels Research Articles

Plasma Lipopolysaccharide-Binding Protein (LBP) Is Induced in Critically Ill Females with Gram-Negative Infections—Preliminary Study

Background/Objectives: Men are more susceptible to sepsis than women, but the underlying pathways have not been fully clarified. Lipopolysaccharide-binding protein (LBP) is an acute-phase protein that is highly elevated in sepsis. Experimental evidence shows that LBP increases to a much greater extent in male than in female mice following exposure to lipopolysaccharide. However, gender-specific studies of circulating LBP levels in sepsis patients are scarce. Methods: In the plasma of 189 patients with systemic inflammatory response syndrome (SIRS), sepsis, and septic shock, LBP levels were measured by enzyme-linked immunosorbent assay. Results: Patients with liver cirrhosis had reduced circulating LBP levels, regardless of gender. Further analysis within the non-cirrhotic patients showed no significant differences in LBP levels between sexes in patients with SIRS, sepsis, and septic shock. Ventilation, dialysis, and vasopressor therapy had no effect on LBP levels in either sex. A positive correlation between LBP and C-reactive protein was observed in the total cohort, males, and females. Infection with Gram-negative or Gram-positive bacteria had no effect on plasma LBP levels in males. However, female patients with Gram-negative infection had increased plasma LBP levels compared to females with negative and Gram-positive blood cultures, and 70 µg/mL LBP discriminates Gram-negative infections in females with a sensitivity of 88% and a specificity of 74%. Infection with SARS-CoV-2 did not change plasma LBP levels in either men or women. Female patients who did not survive had lower plasma LBP levels compared to female survivors and male non-survivors. Conclusions: This investigation highlights the influence of sex on plasma LBP levels in SIRS/sepsis patients, suggesting that LBP could be a sex-specific biomarker in critically ill patients.

Lactiplantibacillus plantarum HEAL9 attenuates cognitive impairment and progression of Alzheimer's disease and related bowel symptoms in SAMP8 mice by modulating microbiota-gut-inflammasome-brain axis.

Background: Growing evidence highlights the relevance of the microbiota-gut-brain axis in Alzheimer's disease (AD). AD patients display gut dysbiosis, altered intestinal barrier and enteric inflammation that, besides bowel symptoms, can contribute to brain pathology. In this context, the modulation of gut microbiota is emerging as a therapeutical option to halt or slow down central pathology. Herein, we examined the effects of Lactiplantibacillus plantarum HEAL9 in a spontaneous mouse model of AD. Methods: Senescence-accelerated mouse prone 8 (SAMP8) mice and control SAMR1 mice were treated orally with HEAL9 1 × 109 CFU per mouse per day or placebo for two months to evaluate the effects of the probiotic during the earliest stages of AD, before the development of brain pathology. Cognitive impairment, in vivo and in vitro colonic motility, astrocyte and microglia reactive response, brain and colonic amyloid-β1-42 (Aβ1-42) levels, and inflammasome components activation (NLRP3, ASC, caspase-1 and interleukin-1β) were assessed. In addition, gut barrier alterations [circulating lipopolysaccharide-binding protein (LBP) levels] and acidic mucus were evaluated. Results: HEAL9 administration significantly attenuated cognitive impairment and counteracted colonic dysmotility in SAMP8 mice. Moreover, HEAL9 decreased astrogliosis and microgliosis, Aβ1-42 accumulation and inflammasome activation in colon and brain and normalized plasma LBP levels and colonic acidic mucus content. Conclusion: HEAL9 intake alleviated cognitive decline and normalized colonic motility in the prodromal phases of AD via the modulation of microbiota-gut-inflammasome-brain signalling. Thus, dietary supplementation with HEAL9 could be considered as a suitable therapeutical option for the treatment of AD and related intestinal symptoms in the early stages of the disease.

Immune activation and inflammation in lactating women on combination antiretroviral therapy: role of gut dysfunction and gut microbiota imbalance.

Combination antiretroviral therapy (cART) effectively controls HIV; however, chronic low-level viremia and gut microbiota dysbiosis remain significant drivers of gut and systemic inflammation. In this study, we explored the relationship between gut microbiota composition, intestinal inflammation, microbial translocation, and systemic inflammation in women on cART in Sub-Saharan Africa. We conducted a study in HIV-infected and HIV-uninfected lactating women followed up at 6 weeks and 6 months postpartum in Harare, Zimbabwe. We used 16S ribosomal Ribonucleic Acid (rRNA) sequencing and MesoScale Discovery V-Plex assays to examine the gut microbiome and to quantify plasma inflammatory biomarkers, respectively. In addition, we measured fecal calprotectin, plasma lipopolysaccharide-binding protein (LBP), and soluble cluster of differentiation 14 (sCD14) by enzyme-linked immunosorbent assay to assess gut inflammation, microbial translocation, and monocyte/macrophage activation. A group of 77 lactating women were studied, of which 35% were HIV-infected. Fecal calprotectin levels were similar by HIV status at both follow-up time points. In the HIV-infected group at 6 weeks postpartum, fecal calprotectin was elevated: median (interquartile range) [158.1 µg/g (75.3-230.2)] in women who had CD4+ T-lymphocyte counts <350 cells/µL compared with those with ≥350 cells/µL [21.1 µg/g (0-58.4)], p = 0.032. Plasma sCD14 levels were significantly higher in the HIV-infected group at both 6 weeks and 6 months postpartum, p < 0.001. Plasma LBP levels were similar, but higher levels were observed in HIV-infected women with elevated fecal calprotectin. We found significant correlations between fecal calprotectin, LBP, and sCD14 with proinflammatory cytokines. Gut microbial alpha diversity was not affected by HIV status and was not affected by use of antibiotic prophylaxis. HIV significantly affected microbial beta diversity, and significant differences in microbial composition were noted. The genera Slackia and Collinsella were relatively more abundant in the HIV-infected group, whereas a lower relative abundance of Clostriduim sensu_stricto_1 was observed. Our study also found correlations between gut microbial taxa abundance and systemic inflammatory biomarkers. HIV-infected lactating women had increased immune activation and increased microbial translocation associated with increased gut inflammation. We identified correlations between the gut inflammation and microbial composition, microbial translocation, and systemic inflammation. The interplay of these parameters might affect the health of this vulnerable population.

Yogurt Supplementation Attenuated Insulin Resistance in Obese Mice by Reducing Systemic Markers of Metabolic Endotoxemia and Inflammation

Abstract Objectives To understand the mechanisms by which yogurt attenuates insulin resistance and chronic inflammation in a diet-induced obesity model. Methods C57BL6 mice were fed either a chow diet (C) or a high-fat diet (HFD) (F) for 11 weeks to induce obesity. Mice were then randomized to receive either a western diet (WD) (CC or FC) or a yogurt-supplemented WD (CY or FY) for 3 weeks to evaluate the impact of yogurt consumption on markers of energy metabolism, metabolic endotoxemia, chronic inflammation, and the gut microbiota. Biological samples were collected at necropsy (Week 14): Plasma samples were used to assess glucose by colorimetric method, insulin and lipopolysaccharide-binding protein (LBP) levels by ELISA kits, and cytokine levels by a Meso Scale Discovery biomarker assay kit. Cecal samples were used to assess the microbiota by 16S rRNA sequencing. Results Female mice showed a mild increase in Homeostatic Model Assessment for Insulin Resistance (HOMA-IR; calculated from plasma glucose and insulin levels) in response to HFD. Among male mice, however, compared to CC and CY, FC had significantly higher HOMA-IR (p &amp;lt; 0.05 for comparisons between CC-FC &amp; CY-FC by ANOVA, followed by Tukey HSD as the post-hoc test), accompanied by significantly elevated plasma LBP, TNF-α, IL-10, and leptin levels (p &amp;lt; 0.05 by ANOVA &amp; Tukey HSD), as well as higher relative abundance of cecal bacteria, Dorea longicatena (p &amp;lt; 0.05 by likelihood-ratio test), which was associated with elevated risks for metabolic syndrome and diabetes. In contrast, FY significantly attenuated HOMA-IR and plasma LBP, IL-10, TNF-α, and leptin levels compared to FC (p &amp;lt; 0.05 by ANOVA &amp; Tukey HSD). Also, beta-diversity of cecal microbiota from FY was significantly different from the rest of three groups (p &amp;lt; 0.01 by Analysis of similarities), and the relative abundance of Dorea longicatena was significantly attenuated in FY than in FC (p &amp;lt; 0.05 by likelihood-ratio test). Conclusions Yogurt supplementation attenuated HFD-induced insulin resistance while modulating the gut microbiota, markers of metabolic endotoxemia, and systemic inflammation. This study helps explain the specific mechanisms by which yogurt consumption modulates inflammation in obesity. Funding Sources National Dairy Council, University of Wisconsin Dairy Innovation Hub.

Plasma Lipopolysaccharide-Binding Protein Reflects Risk and Progression of Parkinson’s Disease

Lipopolysaccharide-binding protein (LBP) presents bacterial endotoxin, lipopolysaccharides, to cellular surface pattern receptors for immune responses in the gut-brain axis of Parkinson's disease (PD). We investigated whether plasma LBP levels were associated with PD severity and progression. This study included 397 participants (248 PD patients and 149 controls). We measured participants' plasma levels of LBP and pro-inflammatory cytokines, including TNF-α, IL-6, andIL-17A. PD patients underwent motor and cognition evaluations at baseline and at a mean follow-up interval of 4.7±2.3 years. We assessed the progression of motor and cognition symptoms based on changes in the Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS) part III motor score and Mini-Mental State Examination (MMSE) score, respectively. Plasma LBP levels were lower in PD patients than controls (9.08±2.91 vs. 10.10±3.00μg/ml, p < 0.01). A multiple logistic regression model with adjustment for age, sex, and plasma cytokine levels revealed that reduced plasma LBP levels were associated with increased PD risk (odds ratio 0.816, [95% CI 0.717-0.929], p = 0.002). Among PD patients, LBP levels were correlated with MDS-UPDRS part III motor score after adjustment for confounders (coefficient = 0.636, p = 0.017), but not with MMSE score. Adjusted Cox regression analysis showed that higher plasma LBP levels associated with faster motor progression (adjusted hazard ratio 1.084 [95% CI 1.011-1.163], p = 0.024) during follow-up. Our results demonstrated that plasma LBP levels reflect risk, motor symptom severity and progression in patients with PD.

Lipopolysaccharide Binding Protein and Cardiovascular Changes in Obese Children

Objective: Despite the growing evidence that lipopolysaccharide binding protein (LBP) plays a major role in cardiovascular disease (CVD) pathophysiology and obesity, data regarding this association in children are rare. Therefore, our objectives were to assess whether there was a difference between overweight/obese and normal-weight children in plasma LBP levels and to assess the cardiovascular changes in both groups. Methods: In an observational, case-control study, a total of 30 children as obese and overweight children. Obese children with body mass index (BMI) above 95th percentile, and overweight children with BMI between 85th and 95th percentile were recruited if they aged between 8-16 years old. A similar number of matched controls were included. Serum LBP was measured by enzyme-linked immunosorbent assay (ELISA) technique. Results: With regard to serum LBP, the mean LBP was significantly higher in obese children than in the control group (52.74 ± 17.25 versus 12.34 ± 2.67 μg/mL, respectively; p 0.001). The ROC curve showed that the serum LBP, at a cutoff value of >19 μg/mL, was a significant discriminator of obesity with a sensitivity of 96.67% and specificity of 100%. The regression analysis showed that BMI was an independent predictor of serum LBP (B coefficient = 0.684; p = 0.024). The serum LBP correlated significantly with age (r = 0.58; p = 0.001), BMI (r = 0.834; p = 0.001), and LV longitudinal strain (r = 0.362; p = 0.05). Conclusion: In conclusion, our findings showed that obesity was associated with a worse lipid profile and cardiovascular function. LBP is a promising predictor of obesity in children.

Plasma lipopolysaccharide binding protein level statistically mediates between body mass index and chronic microinflammation in Japanese patients with type 1 diabetes.

Recently, it is widely recognized that microinflammation plays important roles in the pathophysiology of metabolic diseases, especially obesity-related disorders, diabetes and their complications. Lipopolysaccharide-binding protein (LBP) is a liver-derived acute-phase protein responsive to lipopolysaccharides (LPS) produced by gram-negative bacteria, thus reflects the systemic inflammation caused by the infection of those bacteria including gut dysbiosis. In this study, we evaluated the plasma LBP levels and investigated its clinical significance in 67 Japanese patients with type 1 diabetes. Univariable analysis showed that LBP levels were significantly associated with body mass index (BMI; r = 0.43, p < 0.01) and serum high-sensitivity C-reactive protein (hs-CRP; r = 0.64, p < 0.001) levels. However, there was no significant association between plasma LBP levels and diabetic complications. Mediation analysis revealed that LBP had significant mediation effects on the association between hs-CRP and BMI (0.27 [95% confidence interval 0.10-0.48]). These results suggest that the systemic condition where the LBP level increases, such as gut dysbiosis, at least partly, impacts onchronic microinflammation in patients with type 1 diabetes.

A Protein Microarray Analysis of Plasma Proteins for the Prediction of Spontaneous Preterm Delivery in Women with Preterm Labor.

We aimed to identify novel biomarkers in maternal plasma that predict spontaneous preterm delivery (SPTD) in women with preterm labor (PTL) using an antibody microarray and to develop the best prediction model for SPTD based on these biomarkers in combination with clinical and ultrasound factors. This retrospective cohort study included 215 women with singleton pregnancies and PTL (23-33weeks) who gave plasma samples. In a nested case-control study design, plasma proteomes from SPTD (case subjects, n = 15) and term delivery (control subjects, n = 15) groups were differentially profiled using a membrane-based antibody microarray. Six candidate biomarkers of interest were validated by enzyme-linked immunosorbent assay (ELISA) in the total cohort (n = 215). Cervical lengths were also measured. The primary outcome measure was SPTD within 48h after sampling. Twenty of the molecules studied displayed significant intergroup differences. Validation by ELISA confirmed significantly higher levels of plasma endostatin and lipopolysaccharide binding protein (LBP) in women who had SPTD within 48h than in those delivering after 48h. However, plasma macrophage inflammatory protein (MIP)-1α levels were significantly lower in women who delivered within 48h. A combined model was developed to predict SPTD within 48h using a stepwise regression procedure, which included plasma endostatin and LBP levels, nulliparity, and cervical length (area under the curve = 0.920). Plasma LBP, endostatin, and MIP-1α are potential new biomarkers for predicting imminent SPTD and a combined noninvasive model based on these biomarkers and clinical and ultrasound factors can accurately predict imminent SPTD in women with PTL.

Lactobacillus Pentosus Strain S-PT84 Attenuates Insulin Resistance and Steatohepatitis by Maintaining Gut Permeability and Polarizing M2 Macrophages

Obesity or high-fat diet enhances gut permeability and metabolic endotoxemia, which can trigger insulin resistance and NASH. However, there are few promising treatments targeting lipotoxicity-mediated endotoxemia in NASH. The Lactobacillus pentosus strain S-PT84 has immunomodulatory functions including Th1/Th2 balance modulatory effects and natural killer (NK)/NKT cell activation. In this study, we examined the effect of S-PT84 on diet-induced NASH. C57BL/6 mice were fed a high-cholesterol/high-fat diet (CL) alone or with 1×1010 S-PT84 (CL + S-PT) for 22 weeks. We quantified intrahepatic immune cells using a fluorescence-activated cell sorter (FACS). S-PT84 administration improved hepatic steatosis by decreasing TG and FFA levels by 34% and 37%, respectively. S-PT84 also inhibited the development of hepatic inflammation and fibrosis, lowering F4/80+ macrophage/Kupffer cell infiltration and the hydroxyproline content of the liver. S-PT84 administration in mice fed a CL diet led to improved hyperinsulinemia as well as enhanced hepatic insulin signal assessed by phospho-Akt. FACS analysis revealed that mice fed the CL+S-PT had 71% more CD11c-CD206+ M2 macrophages than mice fed the CL diet, resulting in a predominance of the M2 over the M1 macrophage population. S-PT84, however, showed little effect on NK/NKT cell and T regulatory cell populations in the liver. Furthermore, CL diet increased intestinal permeability as measured with the carboxyfluoresce assay and increased plasma lipopolysaccharide binding protein (LBP) levels. S-PT84 diminished increased intestinal permeability and plasma LBP levels. Additionally, S-PT84 reduced IL-17 producing T cells and increased ZO-1, occludin, and claudin proteins constituting tight junction in colon. In conclusion, S-PT84 treatment attenuated lipotoxicity-induced insulin resistance and NASH by maintaining gut permeability and polarizing M2 liver macrophages. Disclosure Y. Sakai: None. M. Nagashimada: None. T. Ota: None.

Impact of dietary induced precocious gut maturation on cecal microbiota and its relation to the blood-brain barrier during the postnatal period in rats.

Precocious maturation of the gastrointestinal barrier (GIB) in newborn mammals can be induced by dietary provocation, but how this affects the gut microbiota and the gut-brain axis remains unknown. The objective of this study was to investigate effects of induced GIB maturation on gut microbiota composition and blood-brain barrier (BBB) permeability. Suckling rats were studied at 72h after gavage with phytohemagglutinin (PHA) or microbial protease (PT) to induce maturation of GIB. For comparison, untreated suckling and weaned rats were included (n=10). Human serum albumin (HSA) was administered orally and analyzed in blood to assess permeability of the GIB, while intraperitoneally injected bovine serum albumin (BSA) was measured in the brain tissue for BBB permeability. The cecal microbial composition, plasma lipopolysaccharide-binding protein (LBP) levels and short-chain fatty acids in serum and brain were analyzed. Cessation of HSA passage to blood after PHA or PT treatment was similar to that seen in weaned rats. Interestingly, concomitant increases in cecal Bacteroidetes and plasma LBP levels were observed after both PHA and PT treatments. The BBB passage of BSA was surprisingly elevated after weaning, coinciding with lower plasma LBP levels and specific microbial taxa and increased acetate uptake into the brain. This study provides evidence that the gut microbiota alteration following induced precocious GIB maturation may induce low-grade systemic inflammation and alter SCFAs utilization in the brain which may also play a potential role in GIB-BBB dysfunction disorders in neonates.

Markers of intestinal permeability are already altered in early stages of non-alcoholic fatty liver disease: Studies in children.

Background & aimsRecent studies have shown that patients with manifest non-alcoholic fatty liver disease (NAFLD), e.g. steatosis grade 3 or steatohepatitis with or without beginning fibrosis frequently show altered fecal microbiota composition and elevated bacterial endotoxin levels. However, if these alterations are signs of a progressing disease or are already found in initial disease stages has not yet been clarified.MethodsTwenty children with simple steatosis (grade 1) diagnosed by ultrasound and 29 normal weight healthy control children (age <10 years) were included in the study (mean age 7.6 ± 1.1 years). Metabolic parameters, markers of intestinal barrier function and inflammation were determined.ResultsActivity of alanine aminotransferase, concentrations of some markers of inflammation and insulin resistance were significantly higher in plasma of NAFLD children than in controls. When compared to controls, plasma bacterial endotoxin and lipopolysaccharide-binding protein (LBP) levels were significantly higher in NAFLD children (+50% and +24%, respectively), while soluble CD14 serum and D-lactate plasma levels as well as the prevalence of small intestinal bacterial overgrowth did not differ between groups. Plasma endotoxin and LBP levels were positive associated with proinflammatory markers like plasminogen activator inhibitor-1, c-reactive protein, interleukin-6 and leptin while no associations with markers of insulin resistance were found.ConclusionsTaken together, our results indicate that even in juvenile patients with early stages of NAFLD e.g. simple steatosis grade 1, plasma endotoxin concentrations are already elevated further suggesting that intestinal barrier dysfunction might be present already in the initial phases of the disease.

Molecular Properties of Guar Gum and Pectin Modify Cecal Bile Acids, Microbiota, and Plasma Lipopolysaccharide-Binding Protein in Rats.

Bile acids (BAs) act as signaling molecules in various physiological processes, and are related to colonic microbiota composition as well as to different types of dietary fat and fiber. This study investigated whether guar gum and pectin—two fibers with distinct functional characteristics—affect BA profiles, microbiota composition, and gut metabolites in rats. Low- (LM) or high-methoxylated (HM) pectin, and low-, medium-, or high-molecular-weight (MW) guar gum were administered to rats that were fed either low- or high-fat diets. Cecal BAs, short-chain fatty acids (SCFA) and microbiota composition, and plasma lipopolysaccharide-binding protein (LBP) levels were analyzed, by using novel methodologies based on gas chromatography (BAs and SCFAs) and 16S rRNA gene sequencing on the Illumina MiSeq platform. Strong correlations were observed between cecal BA and SCFA levels, microbiota composition, and portal plasma LBP levels in rats on a high-fat diet. Notably, guar gum consumption with medium-MW increased the cecal amounts of cholic-, chenodeoxycholic-, and ursodeoxycholic acids as well as α-, β-, and ω-muricholic acids to a greater extent than other types of guar gum or the fiber-free control diet. In contrast, the amounts of cecal deoxycholic- and hyodeoxycholic acid were reduced with all types of guar gum independent of chain length. Differences in BA composition between pectin groups were less obvious, but cecal levels of α- and ω-muricholic acids were higher in rats fed LM as compared to HM pectin or the control diet. The inflammatory marker LBP was downregulated in rats fed medium-MW guar gum and HM pectin; these two fibers decreased the cecal abundance of Oscillospira and an unclassified genus in Ruminococcaceae, and increased that of an unclassified family in RF32. These results indicate that the molecular properties of guar gum and pectin are important for their ability to modulate cecal BA formation, gut microbiota composition, and high-fat diet induced inflammation.

Lipopolysaccharide-binding protein (LBP) serum levels in children with OSA and obesity

Obstructive sleep apnea (OSA) has been linked to obesity and the metabolic syndrome (MetS). All these conditions are further tightly linked to inflammation, the origin of the latter still being under debate. In recent years, the gut microbiota and/or gut permeability have emerged as important factors in the vicious cycle of obesity, MetS and inflammation. The gut microbiota, which serves as reservoir for bacterial lipopolysaccharides (LPS), could be altered by OSA and trigger inflammation. Lipopolysaccharide-binding protein (LBP) is a 65-kDa acute-phase protein derived from the liver which has been viewed as a surrogate marker of underlying low level endotoxemia brought about by LPS from the gut. We hypothesized that systemic LBP levels would be higher in obese children and in those with OSA. Consecutive snoring and non-snoring children (mean age: 6.8 ± 1.3 years) were included after they underwent overnight polysomnographic evaluation and a fasting blood sample was drawn the morning after the sleep study. Children were subidivided into 4 sub-groups based on the presence of obesity (BMI z score > 1.65) or OSA (obstructive AHI > 2/hrTST). Plasma LBP levels were assayed using commercial ELISA kits. Of the children studied to date ( n = 56), non-obese controls had lowest levels of LBP, and the presence of obesity without OSA was associated with significant increases in LBP levels ( p < 0.03). Non-obese children with OSA exhibited LBP leves that were similar to those of obese children without OSA ( p < 0.01 vs. non-obese without OSA), with obese children with OSA demonstrating the highest LBP levels of all 4 groups ( p < 0.02 vs. all 3 other groups). Systemic low level endotoxemia and resultant systemic inflammation is present in children who are either obese or suffer from OSA, and is particularly prominent when both conditions are present. We postulate that altered sleep and other factors facilitating obesity such as high fat diet may disrupt the gut microbiome, and lead to increased systemic LPS leaks with resultant inflammation. NIH HL65270.

Identification of single nucleotide polymorphisms in hematopoietic cell transplant patients affecting early recognition of, and response to, endotoxin

Hematopoietic cell transplant (HCT) is a life-saving therapy for many malignant and non-malignant bone marrow diseases. Associated morbidities are often due to transplant-related toxicities and infections, exacerbated by regimen-induced immune suppression and systemic incursion of bacterial products. Patients undergoing myeloablative conditioning for HCT become endotoxemic and display blood/plasma changes consistent with lipopolysaccharide (LPS)-induced systemic innate immune activation. Herein, we addressed whether patients scheduled for HCT display differences in recognition/response to LPS ex vivo traceable to specific single nucleotide polymorphisms (SNPs). Two SNPs of LPS binding protein (LBP) were associated with changes in plasma LBP levels, with one LBP SNP also associating with differences in efficiency of extraction and transfer of endotoxin to myeloid differentiation factor-2 (MD-2), a step needed for activation of TLR4. None of the examined SNPs of CD14, bactericidal/permeability-increasing protein (BPI), TLR4 or MD-2 were associated with corresponding protein plasma levels or endotoxin delivery to MD-2, but CD14 and BPI SNPs significantly associated with differences in LPS-induced TNF-α release ex vivo and infection frequency, respectively. These findings suggest that specific LBP, CD14 and BPI SNPs might be contributory assessments in studies where clinical outcome may be affected by host response to endotoxin and bacterial infection.

Beneficial effect of oral administration of Lactobacillus casei strain Shirota on insulin resistance in diet-induced obesity mice

This study aimed at determining whether oral administration of a probiotic strain, Lactobacillus casei strain Shirota (LcS), can improve insulin resistance, which is the underlying cause of obesity-associated metabolic abnormalities, in diet-induced obesity (DIO) mice. DIO mice were fed a high-fat diet without or with 0·05% LcS for 4 weeks and then subjected to an insulin tolerance test (ITT) or oral glucose tolerance test (OGTT). Oral administration of LcS not only accelerated the reduction in plasma glucose levels during the ITT, but also reduced the elevation of plasma glucose levels during the OGTT. In addition, plasma levels of lipopolysaccharide-binding protein (LBP), which is a marker of endotoxaemia, were augmented in the murine models of obese DIO, ob/ob, db/db and KK-A(y) and compared to those of lean mice. LcS treatment suppressed the elevation of plasma LBP levels in DIO mice, but did not affect intra-abdominal fat weight. LcS improves insulin resistance and glucose intolerance in DIO mice. The reduction in endotoxaemia, but not intra-abdominal fat, may contribute to the beneficial effects of LcS. This study suggests that LcS has the potential to prevent obesity-associated metabolic abnormalities by improving insulin resistance.

568 Small Intestinal Bacterial Overgrowth (SIBO) and Lipoploysaccharide (LPS) Receptors in Non-Alcoholic Steatohepatitis (NASH)

Background: Experimental and clinical studies suggest an association between SIBO and NASH. Liver injury and fibrosis could be related to exposure to a bacterial burden, notably endotoxins, of intestinal origin. Moreover, the gut microbiota and endotoxemia have been described to play a contributory role in metabolic dysfunction, particularly insulin resistance, which is a key factor in NASH development. The extracellular receptor molecules for LPS are Lipopolysaccharide Binding Protein (LBP), CD14, toll-like receptor-4 (TLR-4) and myeloid differentiation-2 (MD-2). Endotoxaemia also induces proinflammatory cytokine release from immune cells. Aim: To investigate the prevalence of small intestinal bacterial overgrowth (SIBO) and relationships to LPS receptors and systemic cytokines in NASH. Methods: 18 NASH patients (8 males and 10 females) and 16 ageand gender-matched healthy volunteers were studied. SIBO was assessed by the lactulose breath hydrogen test (LHBT), plasma LBP levels were measured by ELISA and expression (as a %) of TLR-2 and 4 on CD14 positive cells determined by flow cytometry. Proinflammatory mediators (IL-1β, IL-6, IL-8 and TNFα) were measured in plasma by MSD (Meso Scale Discovery). Results: SIBO was more common in NASH patients (71%) than in control subjects (35.7%). This was mainly due to H2 production which was significantly greater in NASH than control at time points 45, 60, 75 and 90minutes during the LHBT (p=0.0241, 0.0476, 0.0470 and 0.0139 respectively). On the other hand, CH4 production was similar in NASH and control groups. No significant differences were detected between NASH and controls for LBP levels, p=0.5448. TLR-4/ MD-2 expression on CD14 positive was significantly higher among NASH patients than in control subjects: % expression, mean ± SEM, NASH vs control: 20.95± 2.91% vs 12.73 ± 2.29%, p=0.048 while TLR-2 expression was not significantly different. Among the cytokines studied, IL-8 levels were significantly higher in patients than control (p=0.0413) and correlated positively with TLR-4 (r=0.5123, p=0.0355) expression but not with TLR-2 expression. Conclusion: Small intestinal bacterial overgrowth is common in NASH, largely related to excess production of H2 and is associated with increased circulating levels of IL-8 and upregulation of TLR-4/MD2.

Plasma lipopolysaccharide-binding protein levels in neonatal early-onset bacterial infection

Plasma lipopolysaccharide-binding protein levels in neonatal early-onset bacterial infection

Significance of changes in plasma bactericidal/permeability-increasing protein levels in patients with severe surgical infection

To investigate changes in endogenous bactericidal/permeability-increasing protein (BPI) levels and their significance in patients with surgical sepsis. In the prospective study, 19 surgical patients with infection were involved. The plasma BPI, lipopolysaccharide-binding protein (LBP) and interleukin-6 levels were measured on post-infected days 1, 3, 5, 7 and 14 by an enzyme-linked immunosorbent assay (ELISA). Plasma endotoxin concentrations were determined by the modified chromogenic Limulus Amebocyte Lysate (LAL). Compared with normal controls, significant lower plasma BPI/LBP ratios were observed in septic patients on days 1 to 5 after infection (P < 0.01), and in severe septic patients on days 1 to 7 (P < 0.01). Moreover, plasma BPI/LBP ratios were much lower in severe sepsis than those in sepsis on days 1 to 3 after infection (P < 0.05). Plasma BPI and LBP levels increased rapidly after infection, but BPI/LBP ratios were significantly decreased during sepsis. Plasma BPI/LBP ratios appear to be closely related to the severity of sepsis in patients complicated by surgical infection.

Interleukin-1 receptor antagonist synthesis by peripheral blood mononuclear cells: a novel predictor of morbidity among hemodialysis patients.

Proinflammatory cytokines have been implicated in the short- and long-term morbidity experienced by hemodialysis (HD) patients. The present study, which is based on long-term follow-up of a cohort of 37 patients, relates peripheral blood mononuclear cell (PBMC) interleukin-1 receptor antagonist (IL-1Ra) synthesis (a reliable marker of IL-1beta synthesis in HD patients) and plasma levels of an acute phase reactant, lipopolysaccharide binding protein (LBP), to clinical outcomes. In July 1993, predialysis blood samples from these patients were collected and IL-1Ra synthesis by PBMC and plasma LBP was measured. Hospital records were reviewed and patient follow-up data were obtained until December 1997 (54 mo) or death, whichever occurred earlier. The effect of age, diabetes, endotoxin- and IgG-stimulated IL-1Ra synthesis, and plasma LBP levels on mortality was assessed using the Cox proportional hazard regression model. Poisson regression was used to determine potential relationships between the number of outcome events and each continuous risk factor. Twenty-two patients (59%) died during the follow-up period. Mortality was unrelated to IL-1Ra synthesis but did increase with age (relative risk, 1.05/yr; P: = 0.01) and diabetes (relative risk, 3.00/yr; P: = 0.03). Cardiovascular event rates were higher among older individuals and in those with higher endotoxin-stimulated PBMC IL-1Ra synthesis. Cardiovascular events increased with plasma LBP levels in the range of 9,000 to 12,000 pg/ml but then seemed to decrease. In contrast, older age and low IgG-stimulated IL-1Ra synthesis were associated with an increased risk of infectious events. The results of this study demonstrate an interesting link between stimulus-dependent variability in IL-1Ra synthesis by PBMC and clinical outcomes among patients on chronic HD and provide interesting targets for therapeutic interventions in this vulnerable patient population.

Isolation, partial characterization, and concentration in experimental sepsis of baboon lipopolysaccharide-binding protein

Lipopolysaccharide-binding protein (LBP) is important for mediating host responses to lipopolysaccharide (LPS). The structure and properties of human, rabbit, and murine LBP have been previously described. In this study we partially characterized baboon LBP and investigated its appearance in experimental sepsis. Recurrent bacteremia was induced in baboons by infusion of live Escherichia coli organisms over a 2-hour period at 0, 24, and 48 hours. To assay baboon plasma LBP levels, an enzyme-linked immunosorbent assay with cross-reactive antibodies to human LBP was developed. Control baboon plasma LBP concentrations were 2 to 5 μg/mL. During experimental sepsis, baboon plasma LBP levels increased to between 200 and 350 μg/mL and in parallel with the increase in C-reactive protein levels. Baboon LBP was isolated from acute phase serum by ion-exchange chromatography followed by immuno-affinity chromatography. Its NH2-terminal sequence (XNPGLVARTTNKGLEYSAQE) and its molecular weight (~60 kd) were determined and were proved to be highly homologous to human LBP. (J Lab Clin Med 2000;136:363-70)