Elephant's breast milk contains large amounts of glucosamine.

Hand-reared elephant calves that are nursed with milk substitutes sometimes suffer bone fractures, probably due to problems associated with nutrition, exercise, sunshine levels and/or genetic factors. As we were expecting the birth of an Asian elephant (Elephas maximus), we analyzed elephant's breast milk to improve the milk substitutes for elephant calves. Although there were few nutritional differences between conventional substitutes and elephant's breast milk, we found a large unknown peak in the breast milk during high-performance liquid chromatography-based amino acid analysis and determined that it was glucosamine (GlcN) using liquid chromatography/mass spectrometry. We detected the following GlcN concentrations [mean ± SD] (mg/100 g) in milk hydrolysates produced by treating samples with 6M HCl for 24 hr at 110°C: four elephant's breast milk samples: 516 ± 42, three cow's milk mixtures: 4.0 ± 2.2, three mare's milk samples: 12 ± 1.2 and two human milk samples: 38. The GlcN content of the elephant's milk was 128, 43 and 14 times greater than those of the cow's, mare's and human milk, respectively. Then, we examined the degradation of GlcN during 0-24 hr hydrolyzation with HCl. We estimated that elephant's milk contains >880 mg/100 g GlcN, which is similar to the levels of major amino acids in elephant's milk. We concluded that a novel GlcN-containing milk substitute should be developed for elephant calves. The efficacy of GlcN supplements is disputed, and free GlcN is rare in bodily fluids; thus, the optimal molecular form of GlcN requires a further study.

Relationship of aging and nutritional status to innate immunity in tube-fed bedridden patients.

BACKGROUND AND OBJECTIVES: Aging and malnutrition are known to influence immune functions. The aim of this study was to investigate the relationship of aging and malnutrition to innate immune functions in tube-fed bedridden patients. METHODS AND STUDY DESIGN: A cross-sectional survey was performed in 71 tube-fed bedridden patients aged 50-95 years (mean age±SD, 80.2±8.5 years) with serum albumin concentrations between 2.5 and 3.5 g/dL. We evaluated associations of age and nutritional variables with natural-killer cell activity, neutrophilphagocytic activity, and neutrophil-sterilizing activity. Nutritional variables included body mass index, weightadjusted energy intake, total lymphocyte count, and serum concentrations of albumin, transferrin, prealbumin, total cholesterol, C-reactive protein, and zinc. RESULTS: Natural-killer cell activity, neutrophil-phagocytic activity, and neutrophil-sterilizing activity were normal or increased in 67 (94%), 63 (89%), and 69 (97%) patients, respectively. Multiple linear regression analysis with a backward elimination method showed that natural-killer cell activity correlated negatively with aging and lymphocyte counts (p<0.01 for both) but positively with body mass index and transferrin (p<0.01 for both). Neutrophil-phagocytic and neutrophil-sterilizing activities were not associated with any variables. CONCLUSIONS: In tube-fed bedridden patients with hypo-albuminemia, natural-killer cell activity may be associated with aging, body mass index, transferrin, and lymphocyte counts.

Bifidobacterium breve alters immune function and ameliorates DSS-induced inflammation in weanling rats.

BACKGROUND: Bifidobacterium breve M-16V (M16V) is a probiotic bacterial strain with a long tradition of use in neonatal intensive care units in some countries. Previous study showed that the effects of M16V administration on gene expression were greater during the weaning period than in the neonatal period and were greater in the colon than in the small intestine and spleen, suggesting that M16V has anti-inflammatory effects. In this study, we evaluated the effects of inflammation during the weaning period and the effects of M16V on normal and inflammatory conditions. METHODS: From postnatal day (PD) 21 to 34, weanling rats were administered of 2.5 × 10(9) of M16V daily, and colitis was induced by administration of 2% dextran sulfate sodium from PD28 to 35. Colitis severity, immune function, and microbiota were investigated. RESULTS: Colitis caused a reduction in body weight gain, colon shortening, poor nutritional status, anemia, changes in blood and spleen lymphocyte populations, spleen T-cell malfunctions, and alterations in colon microbiota. M16V administration improved some but not all of the changes induced by colitis. CONCLUSION: M16V could suppress inflammation and, therefore, can be considered a safe strain to use not only during the neonatal period but also the weaning period.

Inhibition of intestinal polyp growth by oral ingestion of bovine lactoferrin and immune cells in the large intestine.

Studies using animal models have demonstrated that ingestion of bovine lactoferrin (bLF) inhibits carcinogenesis in the colon and other organs of experimental animals. As a result of these studies, a blinded, randomized, controlled clinical trial was conducted in the National Cancer Center Hospital, Tokyo, Japan to determine whether ingestion of bLF had an effect on the growth of colorectal polyps in humans. Patients with colorectal polyps ≤5 mm diameter and likely to be adenomas ingested 0, 1.5, or 3.0 g bLF daily for 1 year. Ingestion of 3.0 g bLF suppressed the growth of colorectal polyps and increased the level of serum human lactoferrin in trial participants 63 years old or younger. The purpose of the present study was to investigate correlations between immune parameters and changes in polyp size. Trial participants with regressing polyps had increased NK cell activity, increased serum hLF levels (indicating increased neutrophil activity), and increased numbers of CD4+ cells in the polyps. These findings are consistent with a correlation between higher immune activity and suppression of colorectal polyps. In addition, participants with regressing polyps had lower numbers of PMNs and increased numbers of S100A8+ cells in the polyps, consistent with a correlation between lower inflammatory potential in the colon and suppression of colorectal polyps. Trial participants ingesting bLF had increased serum hLF levels, a possible increase in systemic NK cell activity, and increased numbers of CD4+ and CD161+ cells in the polyps. Taken together, our findings suggest that bLF suppressed colorectal polyps by enhancing immune responsiveness.

Time-dependent expression profiles of microRNAs and mRNAs in rat milk whey.

Functional RNAs, such as microRNA (miRNA) and mRNA, are present in milk, but their roles are unknown. To clarify the roles of milk RNAs, further studies using experimental animals such as rats are needed. However, it is unclear whether rat milk also contains functional RNAs and what their time dependent expression profiles are. Thus, we prepared total RNA from whey isolated from rat milk collected on days 2, 9, and 16 postpartum and analyzed using microarrays and quantitative PCR. The concentration of RNA in colostrum whey (day 2) was markedly higher than that in mature milk whey (days 9 and 16). Microarray analysis detected 161 miRNAs and 10,948 mRNA transcripts. Most of the miRNAs and mRNA transcripts were common to all tested milks. Finally, we selected some immune- and development-related miRNAs and mRNAs, and analysed them by quantitative PCR (in equal sample volumes) to determine their time-dependent changes in expression in detail. Some were significantly more highly expressed in colostrum whey than in mature milk whey, but some were expressed equally. And mRNA expression levels of some cytokines and hormones did not reflect the protein levels. It is still unknown whether RNAs in milk play biological roles in neonates. However, our data will help guide future in vivo studies using experimental animals such as rats.

Purification of RNA from milk whey.

MicroRNAs (miRNAs) are small regulatory RNA molecules that modulate specific target mRNAs and play very important roles in physiological processes. They were recently detected in body fluids such as blood, urine, saliva, and milk. These body fluid miRNAs have been studied thoroughly as potential diagnostic biomarkers. However, there have been few studies of milk miRNAs, and their roles are not clearly understood. Milk is the only nutritional source for newborn infants, and bovine milk is used widely as a dairy product. Thus, it is important to study milk miRNAs. In general, body fluid RNA concentrations are extremely low and of diverse existence types. In this chapter, we compare two silica membrane column-based RNA purification kits, and also compare RNA obtained directly from whey with that isolated from whey-derived exosomes.

Long-term enteral immunonutrition containing lactoferrin in tube-fed bedridden patients: immunological and nutritional status.

OBJECTIVE: The aim of this study was to examine the efficacy and safety of a novel immune-enhancing enteral formula, Prem-8, which contains lactoferrin as an immunonutrient. DESIGN, SETTING, PATIENTS: A multicenter, randomized controlled trial was conducted in 5 hospitals in Japan, and 71 tube-fed bedridden patients with serum albumin concentrations between 2.5 and 3.5 g/dL were allocated to Prem-8 (n = 38) or control formula (n = 33) groups for an observation period of 12 weeks. MEASURES OF OUTCOME: Efficacy was evaluated by comparing immunological (natural killer cell activity, neutrophil-phagocytic activity, neutrophil-sterilizing activity, and C-reactive protein), and nutritional (anthropometric measurements and serum levels of nutritional assessment proteins and total cholesterol) variables. Safety was assessed by comparing the incidence of adverse events. In a secondary analysis, patients were subgrouped according to the amount of protein supplemented (1 g/kg/d) so that immunological and nutritional variables and safety could be further compared. RESULTS: Natural killer activity and neutrophil functions were normal for both groups throughout the study period, without significant between-group differences at any point. Nutritional status was stably maintained in both groups, although the body mass index at 12 weeks was marginally lower in the Prem-8 group than in the control group (p < 0.01). The incidence of adverse events were comparable between both groups, but the incidence of fever in the Prem-8 group (7/14) was significantly lower than in the control group (10/11) in a subgroup of patients whose supplemented protein was less than 1 g/kg/d (p < 0.05). CONCLUSION: Prem-8 did not demonstrate superiority to the control formula with respect to immunological and nutritional variables, whereas the body mass index of patients in the Prem-8 group marginally decreased. However, Prem-8 had a favorable effect on the incidence of fever in a subgroup of patients with low protein intake.

Energy requirement assessed by doubly-labeled water method in patients with advanced amyotrophic lateral sclerosis managed by tracheotomy positive pressure ventilation.

This study aimed to clarify the energy requirement in patients with amyotrophic lateral sclerosis (ALS) undergoing tracheostomy positive pressure ventilation with tracheostomy. Total energy expenditure (TEE) was measured in 10 hospitalized bedridden ALS patients using the doubly-labeled water (DLW) method. The mean TEE/day and TEE/fat- free mass estimated by DLW method were 934 ± 201 kcal/day and 34.8 ± 5.5 kcal/kg/day, respectively. The mean TEE/resting metabolic rate (RMR) was 0.85 when RMR was estimated by the Harris-Benedict equation, 0.91 by Dietary Reference Intake (DRI), and 0.97 by Ganpule's equation using fat-free mass (FFM). The ratios of TEE to measured RMR were 1.05, 1.15 and 1.23 in three patients. In conclusion, multiplying measured RMR by 1.1 to 1.2 is considered to be appropriate to estimate energy need. However, because it is difficult to measure RMR directly in a clinical setting, an appropriate equation for estimating RMR for ALS patient should be developed.

Partially hydrolyzed cow's milk formula has a therapeutic effect on the infants with mild to moderate atopic dermatitis: a randomized, double-blind study.

OBJECTIVE: The allergy-preventing effect of partially hydrolyzed cow's milk formula (phCMF) in infants at high risk of atopic dermatitis (AD) has been demonstrated in many studies. However, the therapeutic potential of phCMF in treating the infants with AD has not been reported. We sought to assess such therapeutic efficacy of phCMF in infants with mild to moderate AD. METHODS: From 2006 to 2008, 113 infants <6 months of age with AD were randomized to receive either partially hydrolyzed cow's milk formula (phCMF) or conventional cow's milk formula (CMF) in a double-blind clinical trial. Assessments were made at enrollment and at weeks 4, 8, and 12. The severity of AD was assessed using two scoring systems: Standard guideline for management (diagnosis, severity scoring, and therapy) of AD by the Japanese Dermatological Association Scoring System (JDASS) and the SCORing Atopic Dermatitis (SCORAD). Growth status of the infants was evaluated. Allergy profile was assessed by measuring total blood eosinophils (EOS), total/specific IgE, Th1/Th2 cytokine profiles, and the percentage of regulatory T cells. RESULTS: After follow-up for 12 wk, 27 infants (23.89%) dropped off study. Analysis was performed on 86 infants by the end of 12-wk observation. The AD severity scores were significantly reduced in the phCMF group (n = 56) compared with CMF group (n = 30) after 12 wk (p < 0.05). The severity scores of phCMF group were significantly reduced at weeks 4, 8, and 12 compared to enrollment (p < 0.05). In contrast, no significant improvement was observed for CMF group at any of those time points (p > 0.05). The number of AD flare-ups was significantly decreased in the phCMF group (p = 0.002). Th1/Th2 ratio in phCMF was significantly increased compared with CMF group (p = 0.041). The growth rates did not differ significantly between these feeding groups at any assessed time point (p > 0.05) and were in the normal range. CONCLUSION: This study suggests a novel therapeutic effect of phCMF in treating infants with mild to moderate AD during the first 6 months of their life without affecting their nutritional status.

Influences of casein hydrolysate ingestion on cerebral activity, autonomic nerve activity, and anxiety.

This study examined the influences of the oral ingestion of casein hydrolysate from bovine milk at rest physiologically and psychologically. Eleven male university students were given a casein hydrolysate drink (H) or a maltitol drink as a control (C) in a crossover study. Just before and one hour after ingestion of each drink, the total-hemoglobin (tHb) concentrations at ten points of the prefrontal cortex to evaluate cerebral activity, and heart rate variability (HRV) to evaluate autonomic nerve activity through spectral analysis were measured as physiological indicators. The Japanese version of the State--Trait Anxiety Inventory--state anxiety (STAI-s) score was also used, as a psychological indicator. In comparison between H and C ingestion, a significant difference is observed only in tHb concentrations at one of ten points. At this point, the change in tHb concentration was lower after H ingestion compared to C ingestion. And in comparison between before and after ingestion of each drink, a significant increase in tHb concentration at two points after C ingestion, a significant increase in parasympathetic activity and decrease in sympathetic activity after H ingestion, and a significant decrease in STAI-s score in H ingestion were observed. These results suggest that ingestion of the casein hydrolysate may keep prefrontal cortex activity stable while maltitol ingestion partially increases the activity. Moreover, there is a possibility that casein hydrolysate might decrease sympathetic activity, increase parasympathetic activity, and lower anxiety. We conclude that the bovine milk casein hydrolysate may have more relaxing effects than maltitol.

Effects of Bifidobacterium longum BB536 administration on influenza infection, influenza vaccine antibody titer, and cell-mediated immunity in the elderly.

Twenty-seven elderly subjects (mean age 86.7+/-6.6 years) were pre-administered a test food containing 1x10(11) cfu of BB536 daily for 5 weeks (P1), during which they also received influenza vaccination at week 3. The subjects were then randomized to a BB536 group and a placebo group for 14 weeks (P2). The proportion of subjects who contracted influenza was significantly lower in BB536 group than in the to placebo group. The proportion of subjects with fever was also significantly lower in the BB536 group than in the placebo group. In the P1 period, the NK cell activity and the bactericidal activity of the neutrophils were significantly higher at week 5 than to before BB536 administration. In the P2 period, although NK cell activity and neutrophilic activities declined at the end of the study in both the placebo and the BB536 group, neutrophil phagocytic activity and NK cell activity tended to maintain slightly higher levels in the BB536 group than in the placebo group. These results suggest that continuous ingestion of BB536 reduces the incidence of influenza and fever, probably by potentiating innate immunity.

Administration of anti-glucagon-like peptide-2 serum suppresses epithelial cell proliferation of the distal small intestine in weanling rats.

We investigated the effects of endogenous glucagon-like peptide-2 (GLP-2) on the development of intestinal mucosa in weanling rats. Three-week-old male weanling Sprague-Dawley rats were administered either anti-GLP-2 or normal rabbit serum every other day for 2 weeks. We then measured length, weight, and bromodeoxyuridine incorporation in the intestine on day 13 following the first injection. Administration of anti-GLP-2 serum significantly inhibited both epithelial proliferation in the distal ileum and elongation of the small intestine. These results suggest that intrinsic GLP-2 contributes to the growth of the small intestine during the weanling period.

alpha-Lactalbumin hydrolysate stimulates glucagon-like peptide-2 secretion and small intestinal growth in suckling rats.

We investigated whether bovine milk constituents influenced glucagon-like peptide (GLP)-2 secretion and intestinal growth in suckling rats. Male Sprague-Dawley rats (14 d old) received i.g. infusions of a milk protein fraction, a lactose solution, or the cream fraction of milk. The serum concentration of GLP-2, but not GLP-1, markedly increased in rats administered milk protein compared with those given the lactose solution or the cream fraction from 60 to 120 min after administration. In another experiment, both casein (CN) and whey protein isolate stimulated GLP-2 secretion at 120 min after administration, but soy protein and ovalbumin did not. Stimulation of GLP-2 secretion by several milk proteins was similar, including alpha-CN, alpha-lactalbumin (alpha-La), and beta-lactoglobulin, in a separate experiment. A hydrolysate of alpha-La obtained by incubation with protease A extracted from Aspergillus oryzae (LaHPA) caused almost twice the GLP-2 release due to intact alpha-La and other alpha-La hydrolysates. Free amino acid concentrations and molecular size distributions did not differ among alpha-La hydrolysates, including LaHPA. In rat pups reared with milk formulae containing alpha-La or LaHPA, LaHPA significantly promoted small intestinal elongation and increased the number of crypt epithelial cells compared with a formula containing intact alpha-La. LaHPA administration also increased the maltase:lactase activity ratio, a marker of maturation of the intestinal mucosa. In conclusion, milk proteins stimulate GLP-2 secretion and contribute to growth and maturation of the small intestine in suckling rats.

Inhibition of lactoperoxidase by its own catalytic product: crystal structure of the hypothiocyanate-inhibited bovine lactoperoxidase at 2.3-A resolution.

To the best of our knowledge, this is the first report on the structure of product-inhibited mammalian peroxidase. Lactoperoxidase is a heme containing an enzyme that catalyzes the inactivation of a wide range of microorganisms. In the presence of hydrogen peroxide, it preferentially converts thiocyanate ion into a toxic hypothiocyanate ion. Samples of bovine lactoperoxidase containing thiocyanate (SCN(-)) and hypothiocyanate (OSCN(-)) ions were purified and crystallized. The structure was determined at 2.3-A resolution and refined to R(cryst) and R(free) factors of 0.184 and 0.221, respectively. The determination of structure revealed the presence of an OSCN(-) ion at the distal heme cavity. The presence of OSCN(-) ions in crystal samples was also confirmed by chemical and spectroscopic analysis. The OSCN(-) ion interacts with the heme iron, Gln-105 N(epsilon1), His-109 N(epsilon2), and a water molecule W96. The sulfur atom of the OSCN(-) ion forms a hypervalent bond with a nitrogen atom of the pyrrole ring D of the heme moiety at an S-N distance of 2.8 A. The heme group is covalently bound to the protein through two ester linkages involving carboxylic groups of Glu-258 and Asp-108 and the modified methyl groups of pyrrole rings A and C, respectively. The heme moiety is significantly distorted from planarity, whereas pyrrole rings A, B, C, and D are essentially planar. The iron atom is displaced by approximately 0.2 A from the plane of the heme group toward the proximal site. The substrate channel resembles a long tunnel whose inner walls contain predominantly aromatic residues such as Phe-113, Phe-239, Phe-254, Phe-380, Phe-381, Phe-422, and Pro-424. A phosphorylated Ser-198 was evident at the surface, in the proximity of the calcium-binding channel.

Anticarcinogenesis pathways activated by bovine lactoferrin in the murine small intestine.

Oral administration of bovine lactoferrin (bLF) inhibits carcinogenesis in the colon and other organs in rats, and lung metastasis in mice. A likely mechanism by which bLF mediates its anticarcinogenesis effects is by enhanced expression of cytokines and subsequent activation of immune cells. Oral administration of bLF enhances expression of interleukin-18 (IL-18) mRNA in the mucosa of the small intestine of mice. Importantly, the pepsin hydrolysate of bLF (bLFH) also induced expression of IL-18 mRNA in the mouse small intestine and a peptide produced by pepsin digestion of bLF, bovine lactoferricin (bLFcin), induced expression of mature IL-18 in organ culture. In addition to IL-18, bLF and bLFcin both induced significant increases in caspase-1 activity in peritoneal macrophages and in organ cultures. The increase of mature IL-18 by macrophages was inhibited by caspase-1 inhibitor: caspase-1 is known to cleave the proform of IL-18 to produce active mature IL-18. Finally, bLF also induced expression of IFNgamma by peritoneal macrophages. Importantly, in IFNgamma knockout (GKO) mice, bLF administration resulted in increased expression of caspase-1 protein, but induction of IL-18 mRNA, caspase-1 activity, and mature IL-18 was not observed. These results indicate that orally administered bLF can induce expression of IFNgamma and caspase-1 in the small intestine. IFNgamma in turn increases expression of target genes, including IL-18. Active caspase-1 then cleaves pro-IL-18 to generate mature IL-18. Thus, bLF activates an effector pathway mediated by IFNgamma, caspase-1, and IL-18. We also show that ingested bLF is able to activate more than a single effector pathway. For example, in GKO mice while bLF administration could not activate the IFNgamma/caspase-1/IL-18 effector pathway, it was able to inhibit tumor growth and metastasis by activation of an IFNalpha/IL-7 effector pathway.

Lack of chronic oral toxicity of chemopreventive bovine lactoferrin in F344/DuCrj rats.

Studies were undertaken to determine whether bovine lactoferrin (bLF) and related compounds, shown to prevent carcinogenesis in the colon and other organs in rats, have any toxic effects in long-term feeding studies. In experiment I, male F344/DuCrj rats received a basal diet containing 0.2% bLF for 40 weeks. No adverse findings were noted, furthermore, serum triglyceride level was significantly decreased to 72% of the control level, suggesting preventive effects against the metabolic syndrome. In experiment II, male and female F344/DuCrj rats were fed a basal diet containing 0.02, 0.2, 2.0 and 5.0% bLF, 2.0% bLF hydrolysate (bLF-H) or 0.1% lactoferricin (LFcin), a peptide derived from bLF, for 60 weeks in males and 65 weeks in females. No toxicological effects, including carcinogenicity, were evident in either sex. The results of the studies provide subjective support for safety of clinical studies of bLF for supplement use.

Effects of orally administered bovine lactoperoxidase on dextran sulfate sodium-induced colitis in mice.

The effect of lactoperoxidase (LPO) on dextran sulfate sodium-induced colitis was examined in mice. After 9 d of colitis induction, weight loss, colon shortening, and the histological score were significantly suppressed in mice orally administered LPO (62.5 mg/body/d) as compared to a group administered bovine serum albumin. These results suggest that LPO exhibits anti-inflammatory effects in the gastrointestinal tract.

Inhibitory effects of bovine lactoferrin and lactoferricin B on Enterobacter sakazakii.

The susceptibility of Enterobacter sakazakii, a food-borne pathogen, to several metal-bound forms of bovine lactoferrin (LF), pepsin-hydrolyzed LF (LF-hyd), and LF-derived peptide lactoferricin B (LFcin B) was tested. MIC and MBC testing revealed that 4 strains of E. sakazakii show susceptibility to apo- and Cu-LF, LF-hyd, and LFcin B, but not to Fe-LF, similarly to Escherichia coli. A growth curve test indicated that E. sakazakii was inhibited in a dose-dependent manner by apo-LF at 0.5 to 8 mg/ml. Even after being heated at 80 degrees C, LF at above 1 mg/ml inhibited the bacterial growth. These results suggest that bovine LF-related compounds may be useful for the inhibition of E. sakazakii in foods.

Administration of phytosterols isolated from Aloe vera gel reduce visceral fat mass and improve hyperglycemia in Zucker diabetic fatty (ZDF) rats.

SUMMARY: We examined the effects of lophenol (Lo) and cycloartanol (Cy), minor phytosterols of Aloe vera gel, in obese animal model of type II diabetes, Zucker diabetic fatty (ZDF) rats. Male ZDF rats were administered Lo and Cy at 25 µg/(kg day) daily for 44 days. Consecutive treatment of phytosterols suppressed the hyperglycemia, and random blood glucose levels after 35 days of treatment were 39.6 and 37.2% lower than the control, in Lo and Cy treatment groups, respectively. Consistent with the random blood glucose level, hemoglobin A1c (HbA1c) values of phytosterols treated rats were also lower than the control (Lo: 5.5 ± 0.8, Cy: 4.6 ± 0.7 vs. control: 7.2 ± 1.5). In the oral glucose tolerance test (OGTT) after 28 days of administration, the glucose intolerance was improved in phytosterols treatment groups. Additionally, the continuous administration of Lo and Cy also reduced the serum free fatty acid (FFA) and triglyceride (TG) levels except total cholesterol (T-Cho). Furthermore, the weights of total abdominal fat tissues were significantly lower than the control in ZDF rats with Lo (27.7%) and Cy (26.3%) treatment. These observations suggest that Aloe vera-derived phytosterols could reduce visceral fat accumulation, and would be useful for the improvement of hyperlipidemia and hyperglycemia.:

Orally administered lactoperoxidase increases expression of the FK506 binding protein 5 gene in epithelial cells of the small intestine of mice: a DNA microarray study.

Lactoperoxidase (LPO) is a component of milk and other external secretions. To study the influence of ingested LPO on the digestive tract, we performed DNA microarray analysis of the small intestine of mice administered LPO. LPO administration upregulated 78 genes, including genes involved in metabolism, immunity, apoptosis, and the cell cycle, and downregulated nine genes, including immunity-related genes. The most upregulated gene was FK506 binding protein 5 (FKBP5), a glucocorticoid regulating immunophilin. The upregulation of this gene was confirmed by quantitative RT-PCR in other samples. In situ hybridization revealed that expression of the FKBP5 gene in the crypt epithelial cells of the small intestine was enhanced by LPO. These results suggest that ingested LPO modulates gene expression in the small intestine and especially increases FKBP5 gene expression in the epithelial cells of the intestine.