lactoferrin and Gastroenteritis

Infectious diarrhea is a major cause of morbidity. A rapid and inexpensive assay for the diagnosis of infectious gastroenteritis would expedite appropriate therapy and prevent unnecessary and potentially invasive testing. This article summarizes assays for the diagnosis of infectious gastroenteritis based on the host response to bacterial, viral, or parasitic infection. This includes both systemic biomarkers (such as C-reactive protein, erythrocyte sedimentation rate, and serum cytokines) and fecal biomarkers (such as lactoferrin, fecal leukocyte analysis, and calprotectin). Although some of these assays have value as adjunct diagnostics, they lack sensitivity and specificity as stand-alone tests in this setting.

Topics: Biomarkers; Blood Sedimentation; C-Reactive Protein; Cytokines; Diagnosis, Differential; Feces; Gastroenteritis; Host-Pathogen Interactions; Humans; Lactoferrin; Leukocyte Count; Leukocyte L1 Antigen Complex; Occult Blood; Sensitivity and Specificity

Although lactoferrin has many biological functions, the host-protective effects against pathogenic microorganisms including bacteria, fungi, and viruses are regarded as one of the most important. Here, we review research on the protective role of lactoferrin administration against common viral infections. Many studies have shown the in vitro antiviral activity of lactoferrin against viral pathogens that cause common infections such as the common cold, influenza, gastroenteritis, summer cold, and herpes, where lactoferrin inhibits mainly viral attachment to the target cells. Recently, studies indicating the in vivo protective effects of lactoferrin by oral administration against common viral infections have been increasing. For instance, norovirus is an extremely important emerging human pathogen that causes a majority of gastroenteritis outbreaks worldwide that may be a target candidate for lactoferrin. Lactoferrin consumption reduced the incidence of noroviral gastroenteritis in children and a similar effect was observed in a wide range of ages in a preliminary survey. A recent in vitro study reported that lactoferrin inhibits both cellular attachment of the murine norovirus, a virus closely-related to the human norovirus, and viral replication in the cells by inducing antiviral cytokines interferon (IFN)-α/β. Lactoferrin administration also enhances NK cell activity and Th1 cytokine responses, which lead to protection against viral infections. In conclusion, lactoferrin consumption may protect the host from viral infections through inhibiting the attachment of a virus to the cells, replication of the virus in the cells, and enhancement of systemic immune functions.

Topics: Anti-Infective Agents; Caliciviridae Infections; Common Cold; Gastroenteritis; Herpes Simplex; Humans; Influenza, Human; Lactoferrin; Norovirus; Rotavirus Infections; Seasons

Gastrointestinal (GI) symptoms including abdominal pain, bloating and diarrhoea are a relatively common reason for consulting a physician. They may be due to inflammatory bowel disease (inflammatory bowel disease; Crohn's disease, ulcerative colitis and indeterminate colitis), malignancy (colorectal cancer), infectious colitis or irritable bowel syndrome (IBS). Differentiation between these involves the use of clinical, radiological, endoscopic and serological techniques, which are invasive or involve exposure to radiation. Serological markers include C-reactive protein, erythrocyte sedimentation rate and antibodies (perinuclear antineutrophil cytoplasm antibody and anti-Saccharomyces cerevisiae antibody). Faecal markers that can aid in distinguishing inflammatory disorders from non-inflammatory conditions are non-invasive and generally acceptable to the patient. As IBS accounts for up to 50% of cases presenting to the GI clinic and is a diagnosis of exclusion (Rome III criteria), any test that can reliably distinguish IBS from organic disease could speed diagnosis and reduce endoscopy waiting times. Faecal calprotectin, lactoferrin, M2-PK and S100A12 will be reviewed.

Topics: Biomarkers; Colitis, Ulcerative; Crohn Disease; Diagnosis, Differential; Feces; Gastroenteritis; Humans; Inflammatory Bowel Diseases; Irritable Bowel Syndrome; Lactoferrin; Leukocyte L1 Antigen Complex; Practice Guidelines as Topic; Pyruvate Kinase; S100 Proteins; S100A12 Protein

Topics: Female; Gastroenteritis; Humans; Immunoglobulin A; Infant; Infant, Newborn; Lactoferrin; Lactoglobulins; Milk, Human; Muramidase

Rotaviral gastroenteritis causes a high rate of infant mortality and severe healthcare implications worldwide. Several studies have pointed out that human milk and dairy fractions, such as whey and buttermilk, possess antirotaviral activity. This activity has been mainly associated with glycoproteins, among them lactoferrin (LF). Thermal treatments are necessary to provide microbiological safety and extend the shelf life of milk products, though they may diminish their biological value. High hydrostatic pressure (HHP) treatment is a non-thermal method that causes lower degradation of food components than other treatments. Thus, the main objective of this study was to prove the antirotaviral activity of LFs from different origin and to evaluate the effect of several thermal and HHP treatments on that activity. LF exerted a high antirotaviral activity, regardless of its origin. Native LFs from bovine, ovine, swine and camel milk, and the human recombinant forms, at 1 mg/mL, showed neutralizing values in the range 87.5-98.6%, while human LF neutralized 58.2%. Iron saturation of bovine LF did not modify its antirotaviral activity. Results revealed interspecies differences in LFs heat susceptibility. Thus, pasteurization at 63 °C for 30 min led to a decrease of 60.1, 44.5, 87.1, 3.8 and 8% of neutralizing activity for human, bovine, swine, ovine and camel LFs, respectively. Pasteurization at 75 °C for 20 s was less harmful to the activity of LFs, with losses ranging from 0 to 13.8%. HHP treatment at 600 MPa for 15 min did not cause any significant decrease in the neutralizing activity of LFs.

Topics: Animals; Anti-Retroviral Agents; Cattle; Gastroenteritis; Hot Temperature; Humans; Hydrostatic Pressure; Lactoferrin; Milk, Human; Pasteurization; Rotavirus; Sheep; Swine

Translocation of bacteria, primarily Gram-negative pathogenic flora, from the intestinal lumen into the circulatory system leads to sepsis. In newborns, and especially very low birth weight infants, sepsis is a major cause of morbidity and mortality. The results of recently conducted clinical trials suggest that lactoferrin, an iron-binding protein that is abundant in mammalian colostrum and milk, may be an effective agent in preventing sepsis in newborns. However, despite numerous basic studies on lactoferrin, very little is known about how metal saturation of this protein affects a host's health. Therefore, the main objective of this study was to elucidate how iron-depleted, iron-saturated, and manganese-saturated forms of lactoferrin regulate intestinal barrier function via interactions with epithelial cells and macrophages. For these studies, a human intestinal epithelial cell line, Caco-2, was used. In this model, none of the tested lactoferrin forms induced higher levels of apoptosis or necrosis. There was also no change in the production of tight junction proteins regardless of lactoferrin metal saturation status. None of the tested forms induced a pro-inflammatory response in Caco-2 cells or in macrophages either. However, the various lactoferrin forms did effectively inhibit the pro-inflammatory response in macrophages that were activated with lipopolysaccharide with the most potent effect observed for apolactoferrin. Lactoferrin that was not bound to its cognate receptor was able to bind and neutralize lipopolysaccharide. Lactoferrin was also able to neutralize microbial-derived antigens, thereby potentially reducing their pro-inflammatory effect. Therefore, we hypothesize that lactoferrin supplementation is a relevant strategy for preventing sepsis.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Apoproteins; Apoptosis; Caco-2 Cells; Cattle; Cytokines; Epithelial Cells; Gastroenteritis; Humans; Intestinal Mucosa; Intestines; Iron; Lactoferrin; Lipopolysaccharides; Macrophage Activation; Macrophages; Manganese; Tight Junction Proteins

This study evaluates potential markers in blood and stools for their ability to distinguish bacterial from viral gastroenteritis. A total of 108 patients were prospectively recruited, of which 27 showed bacterial, 30 viral, and 51 no detectable pathogen, respectively. Cytokines, C-reactive protein (CRP), and white blood cells as well as the 2 fecal markers lactoferrin and calprotectin were determined. Statistics comprised Kruskal-Wallis test and U test in addition to an assessment of receiver operating characteristic. Interferon γ (IFNγ) levels were significantly increased in the viral group compared to the bacterial and nonspecific group. For the bacterial group, both fecal markers lactoferrin and calprotectin as well as CRP were significantly higher in comparison to the other 2 groups. To differentiate between bacterial and viral gastroenteritis, CRP, serum IFNγ, and the fecal proteins lactoferrin and calprotectin may be useful. A corresponding algorithm should be evaluated prospectively.

Topics: Adult; Aged; Aged, 80 and over; Bacterial Infections; Biomarkers; Blood Chemical Analysis; C-Reactive Protein; Cytokines; Diagnosis, Differential; Feces; Female; Gastroenteritis; Humans; Lactoferrin; Leukocyte L1 Antigen Complex; Male; Middle Aged; Virus Diseases

Diarrhea is a major public health problem that affects the development of children. Anthropometric data were collected from 274 children with (N = 170) and without (N = 104) diarrhea. Stool specimens were analyzed by conventional culture, polymerase chain reaction for enteroaggregative Escherichia coli (EAEC), Shigella, Cryptosporidium, Entamoeba, and Giardia species, and by enzyme-linked immunosorbent assay for fecal lactoferrin levels. About 50% of the study population was mildly to severely malnourished. Fecal lactoferrin levels were higher in children with diarrhea (P = 0.019). Children who had EAEC infection, with or without diarrhea, had high mean lactoferrin levels regardless of nutritional status. The EAEC and Cryptosporidium were associated with diarrhea (P = 0.048 and 0.011, respectively), and malnourished children who had diarrhea were often co-infected with both Cryptosporidium and EAEC. In conclusion, the use of DNA-biomarkers revealed that EAEC and Cryptosporidium were common intestinal pathogens in Accra, and that elevated lactoferrin was associated with diarrhea in this group of children.

Topics: Case-Control Studies; Child Nutrition Disorders; Child, Preschool; Cross-Sectional Studies; Diarrhea; Dysentery, Bacillary; Enterohemorrhagic Escherichia coli; Escherichia coli Infections; Feces; Female; Gastroenteritis; Ghana; Humans; Infant; Infant, Newborn; Lactoferrin; Male; Parasitic Diseases; Polymerase Chain Reaction; Prospective Studies; Virulence

Calprotectin and lactoferrin are specific neutrophil-derived proteins, which can be measured in the feces because they are released by cells in inflammatory conditions. We evaluated the efficacy of calprotectin and lactoferrin in detecting organic disease as assessed by colonoscopy.. The study comprised 144 patients undergoing colonoscopy for lower gastrointestinal symptoms (abdominal pain, altered bowel habits, and bloody stools) (67), or inflammatory bowel disease activity, or surveillance for dysplasia (77). A single stool sample was assayed for calprotectin and lactoferrin. The proportion of patients correctly diagnosed with each test and the relationship with endoscopic and histological findings were measured.. Fecal excretion of calprotectin significantly correlated with the finding of colonic inflammation at endoscopy, both in ulcerative colitis and in Crohn's disease (p<0,001 and p<0,008, respectively), while lactoferrin excretion significantly correlated with histological inflammation (p=0.001 and p=0.009 respectively). Recommended cut-off values need to be adjusted in the inflammatory bowel disease group. Overall sensitivity, specificity, positive predictive value, and diagnostic efficacy were 78, 83, 86, and 80% for calprotectin and 80, 85, 87, and 81% for lactoferrin, respectively.. Fecal calprotectin and lactoferrin appear to be equally recommendable as inflammatory disease markers in patients with lower gastrointestinal symptoms. Both tests are needed to accurately discriminate activity in inflammatory bowel disease patients.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Colitis, Ulcerative; Colonoscopy; Crohn Disease; Feces; Female; Gastroenteritis; Humans; Inflammatory Bowel Diseases; Lactoferrin; Leukocyte L1 Antigen Complex; Male; Middle Aged; Predictive Value of Tests; Sensitivity and Specificity

Topics: Animals; Cattle; Child, Preschool; Diarrhea, Infantile; Female; Gastroenteritis; Humans; Infant; Infant, Newborn; Lactoferrin; Male; Rotavirus Infections; Treatment Outcome; Vomiting

Intestinal inflammation in mice is most frequently assessed by histology or FACS, processes that necessitate sacrificing mice. We developed a lactoferrin ELISA for murine feces to quantify intestinal inflammation in mice with enteric infections or colitis. Levels of fecal lactoferrin, a protein secreted by activated neutrophils, were consistent with neutrophil infiltration as assessed by histology, indicating that this fecal lactoferrin ELISA is a good alternative to histology. The fecal lactoferrin ELISA provides a non-invasive, quantitative assessment of intestinal inflammation, which should facilitate longitudinal studies of the development of and/or therapies reducing intestinal inflammation in individual mice and reduce the number of mice needed for such studies.

Topics: Animals; Biomarkers; Colitis; Detergents; Dextran Sulfate; Enzyme-Linked Immunosorbent Assay; Feces; Female; Gastroenteritis; Intestine, Small; Lactoferrin; Mice; Mice, Inbred BALB C; Neutrophils; Reproducibility of Results; Salmonella Infections; Sensitivity and Specificity; Time Factors; Yersinia Infections; Yersinia pseudotuberculosis Infections

Because acute bacterial gastroenteritis is often inflammatory, rapid stool assays that detect intestinal inflammation might be used to distinguish between bacterial and nonbacterial gastroenteritis. We performed meta-analyses to determine the discriminatory power, in developed and in resource-poor countries, of rapid stool assays that test for lactoferrin, fecal leukocytes, fecal erythrocytes, and occult blood. In developed countries, the area under the summary receiver operating characteristic curve (AUC/SROC) was 0.89 for fecal leukocytes and 0.81 for occult blood. In resource-poor countries, the AUC/SROC was 0.79 for lactoferrin, 0.72 for fecal leukocytes, 0.63 for occult blood, and 0.61 for fecal erythrocytes. In developed countries, positive and negative likelihood ratios (LR+ and LR-, respectively) for fecal leukocytes were 4.56 and 0.32 when a threshold of >5 cells/high-power field was used, compared with 2.94 and 0.6 in resource-poor countries; for lactoferrin, LR+ was 1.34 and LR- was 0.17 in resource-poor countries when the threshold was an agglutination rating of "+" and a dilution of 1:50. In developing countries, rapid stool assays performed poorly, whereas in developed countries, tests for fecal leukocytes, lactoferrin, and occult blood were moderately useful and could identify patients who were more likely to benefit from empirical antibiotic therapy.

Topics: Developed Countries; Developing Countries; Erythrocytes; Feces; Gastroenteritis; Health Resources; Humans; Inflammation; Lactoferrin; Leukocytes; Occult Blood; Retrospective Studies

The aim of this study was to determine the isolation trends of common and emerging pathogens in children over a 12-month period. The study group included 412 children under 6 years with diarrhoea who were either hospitalised, or seen in the outpatients department of The Sydney Children's Hospital. Pathogens were detected in 137 (33%) samples, with rotavirus most common (40%), followed by adenovirus (26%), astrovirus (12%), Campylobacter jejuni (12%), Salmonella spp. (10%) and Giardia lamblia (< 1 %). Giardia-specific antigen (GSA) was detected in 11 of 382 (3%) using an enzyme immunoassay (EIA), and this included four samples in which cysts of G. lamblia were detected by microscopy. Using electron microscopy (EM), viruses were detected in 29 of 120 (24%) samples from hospitalised children and 53 of 171 (31%) outpatients (P = 0.23). Amongst this subset, Norwalk-like viruses (NLVs) were detected by RT-PCR in 10 samples including six of 14 with small round viruses, one of seven with small viral-like particles (SVLPs), and three of 126 EM-negative samples. Lactoferrin, detected by EIA, was 59% more likely to be positive in samples infected with salmonella/campylobacter than in samples in which bacterial pathogens were not isolated. As an indicator for infection with these bacterial agents, the assay showed a sensitivity and specificity of 95 and 40.3%, respectively. A routine microbiological analysis of stools from children of this age group should include a screen for foodborne bacterial agents and rotavirus. Tests for adenovirus, astrovirus and NLVs should be secondary. The cost-effectiveness of including the EIAs for lactoferrin and G. lamblia in the routine testing protocol needs to be evaluated.

Topics: Animals; Campylobacter; Child, Preschool; Diarrhea; DNA, Viral; Feces; Gastroenteritis; Giardia lamblia; Humans; Immunoenzyme Techniques; Infant; Infant, Newborn; Lactoferrin; Mamastrovirus; Microscopy, Electron; Norovirus; Outpatients; Reverse Transcriptase Polymerase Chain Reaction; Rotavirus; Salmonella

Different milk proteins were analyzed for their inhibitory effect on either rotavirus-mediated agglutination of human erythrocytes or rotavirus infection of the human enterocyte-like cell line HT-29. Proteins investigated were alpha-lactalbumin, beta-lactoglobulin, apo-lactoferrin, and Fe(3+)-lactoferrin, and their antiviral action was compared with the activity of mucin, a milk glycoprotein known to affect rotavirus infection. Results obtained demonstrated that beta-lactoglobulin, apo- and Fe(3+)-lactoferrin are able to inhibit the replication of rotavirus in a dose-dependent manner, apo-lactoferrin being the most active. It was shown that apo-lactoferrin hinders virus attachment to cell receptors since it is able to bind the viral particles and to prevent both rotavirus haemagglutination and viral binding to susceptible cells. Moreover, this protein markedly inhibited rotavirus antigen synthesis and yield in HT-29 cells when added during the viral adsorption step or when it was present in the first hours of infection, suggesting that this protein interferes with the early phases of rotavirus infection.

Topics: Animals; Antiviral Agents; Apoproteins; Cattle; Cytopathogenic Effect, Viral; Gastroenteritis; Hemagglutination, Viral; HT29 Cells; Humans; Lactalbumin; Lactoferrin; Lactoglobulins; Milk Proteins; Receptors, Virus; Rotavirus; Rotavirus Infections; Virus Replication

Because of its low yield in unselected specimens, stool culture is often cost ineffective. We tested 55 fecal samples from Fairfax Hospital (46 patients with diarrhea and 9 from controls without diarrhea) for lactoferrin by latex agglutination (LFLA) with the Leukotest (Techlab, Blacksburg, Va.) as a marker for inflammatory diarrhea. Of the 28 samples with Salmonella, Shigella, or Campylobacter infection, 93% had detectable fecal lactoferrin at > or = 1:50 (61% had LFLA titers of > or = 1:400), while 83% of 18 samples with rotavirus or no detectable pathogen were LFLA negative at a titer of 1:50 (100% were negative at 1:400). All 9 controls without diarrhea were LFLA negative at 1:50. The use of fecal lactoferrin to screen for inflammatory diarrhea selects specimens for which stool culture is fivefold more likely to yield an invasive bacterial pathogen (reducing the cost per positive result by over $800) and thus may greatly enhance a cost-effective approach to evaluating diarrheal illness.

Topics: Adolescent; Adult; Aged; Bacterial Infections; Bacteriological Techniques; Biomarkers; Case-Control Studies; Child; Child, Preschool; Cost-Benefit Analysis; Diagnostic Errors; Diarrhea; Feces; Gastroenteritis; Humans; Infant; Lactoferrin; Latex Fixation Tests; Middle Aged

The degrees of human lactoferrin (HLf) and bovine lactoferrin (BLf) binding in 169 Escherichia coli strains isolated from human intestinal infections, and in an additional 68 strains isolated from healthy individuals, were examined in a 125I-labelled protein binding assay. The binding was expressed as a percentage calculated from the total labelled ligand added to bacteria. The HLf and BLf binding to E. coli was in the range 3.7 to 73.4% and 4.8 to 61.6%, respectively. Enterotoxigenic strains demonstrated a significantly higher HLf binding (median = 19%) than enteropathogenic, enteroinvasive, enterohaemorrhagic strains or normal intestinal E. coli isolates (medians 6 to 9). Enteropathogenic strains belonging to serotypes O44 and O127 demonstrated significantly higher HLf binding compared to O26, O55, O111, O119 and O126. No significant differences in the degree of HLf or BLf binding were found between aerobactin-producing and non-producing strains. The interaction was further characterized in a high Lf-binding EPEC strain, E34663 (serotype O127). The binding was stable in the pH range 4.0 to 7.5, did not dissociate in the presence of 2M NaCl or 2M urea, and reached saturation within two h. Unlabelled HLf and BLf displaced the 125I-HLf binding to E34663 in a dose-dependent manner. Apo- and iron-saturated forms of Lf demonstrated similar binding to E34663. Among various unlabelled subepithelial matrix proteins and carbohydrates tested (in 10(4)-fold excess) only fibronectin and fibrinogen caused a moderate inhibition of 125I-HLf binding. According to Scatchard plot analysis, 5,400 HLf-binding sites/cell, with an affinity constant (Ka) of 1.4 x 10(-7) M, were estimated in strain E34663. These data establish the presence of a specific Lf-binding mechanism in E. coli.

Topics: Animals; Cattle; Escherichia coli; Escherichia coli Infections; Gastroenteritis; Humans; Lactoferrin

Topics: Anemia, Hypochromic; Animals; Cattle; Escherichia coli Infections; Female; Food, Fortified; Gastroenteritis; Humans; Infant; Infant Nutritional Physiological Phenomena; Infant, Newborn; Infant, Premature, Diseases; Iron; Lactoferrin; Milk; Milk, Human; Protein Binding