Effect of dietary nucleosides on growth and maturation of the developing gut in the rat

Dietary nucleotides influences intestinal barrier function, immune responses and microbiota in 3-day-old weaned piglets

Nucleotides (NTs) play a pivotal role in the growth and development of the intestine. This study aimed to evaluate the effects of nucleotides supplementation on the intestinal barrier function, immune responses and microbiota in 3-day-old weaned piglets. Ninety-six piglets weaned at 3-days after birth were randomly assigned to 2 treatments (6 replicates/treatment, 8 piglets/replicate) according to the average body weight. The dietary treatments consisted of the control (CON; fed a basal artificial milk) and nucleotides groups (NT; fed a basal artificial milk with 0.035 % nucleotides, the contents of CMP, UMP, AMP, GMP, and IMP were 1:1:1:1:1, respectively). Diarrhea rates were recorded, and blood and intestinal samples were collected on day 35 of the piglets. The current study showed that NTs supplementation tended to decrease the diarrhea rate of weaned piglets (P < 0.10). NTs increased villus height and the villus height-to-crypt depth (V/C) ratio in the ileum (P < 0.05). Dietary NTs up-regulated protein expression of ZO-1 in ileal mucosa (P < 0.05), and the protein expression of Occludin tended to increase. Furthermore, NTs up-regulated the mRNA expression of Mucin (MUC)2, while the mRNA expression of MUC4 was down-regulated in the ileal mucosa (P < 0.05). Besides, supplementation with NTs increased the ileal mucosa genes expression of IL-21, INF-γ, IL-10, IL-4, IL-6 and TNF-α (P < 0.05). Furthermore, dietary NTs increased the protein expression of NF-κB, IL-6 and TNF-α (P < 0.05), and the proteins expression of Occludin and p-NF-κB tended to be up-regulated in the ileal mucosa (P < 0.10). Furthermore, NTs supplementation increased short chain fatty acid in the colonic (P < 0.05). And NTs supplementation reduced the Firmicutes/Bacteroidota ratio in the colon, at the genus level, NTs enriched the relative abundance of Prevotella, Faecalibacterium and Olsenella (P < 0.05). These data indicate that NTs could increase the villus height, increase the V/C, regulate the expression of tight junction protein and mucin, improve the intestinal barrier of piglets, regulate the secretion of cytokines, improve the biological immunity, increase the abundance of beneficial bacteria, and thus reduce the diarrhea of piglets.

Maternal Nutrition During Late Gestation and Lactation: Association With Immunity and the Inflammatory Response in the Offspring

The immature immune system at birth and environmental stress increase the risk of infection in nursing pigs. Severe infection subsequently induces intestinal and respiratory diseases and even cause death of pigs. The nutritional and physiological conditions of sows directly affect the growth, development and disease resistance of the fetus and newborn. Many studies have shown that providing sows with nutrients such as functional oligosaccharides, oils, antioxidants, and trace elements could regulate immunity and the inflammatory response of piglets. Here, we reviewed the positive effects of certain nutrients on milk quality, immunoglobulin inflammatory response, oxidative stress, and intestinal microflora of sows, and further discuss the effects of these nutrients on immunity and the inflammatory response in the offspring.

Yeast-based nucleotide supplementation in mother sows modifies the intestinal barrier function and immune response of neonatal pigs

In the present study, we aimed to evaluate the effects of maternal yeast-based nucleotide (YN) supplementation on the intestinal immune response and barrier function in neonatal pigs, as well as the diarrhoea rate and growth performance in suckling piglets. Sixty-four late-gestation sows were assigned to the following groups: the CON (fed a basal diet) and YN groups (fed a basal diet with 4 g YN/kg diet). The experiment started on d 85 of gestation and ended on d 20 of lactation. Diarrhoea rate and average daily gain of the piglets were recorded, and samples of blood and intestines from neonatal piglets were collected before they consumed colostrum during farrowing. Compared with the CON group, maternal YN supplementation increased the weaning weight of litter and decreased the diarrhoea rate (P < 0.01). In addition, maternal YN supplementation promoted the ileal villus development in the neonates compared with that in the CON group (P < 0.01). Maternal YN supplementation also increased the ileal secretory immunoglobulin A (sIgA) level compared with that in the CON group (P < 0.05). The real-time PCR results showed that maternal dietary YN supplementation increased the jejunal and ileal expression of interleukin (IL)-17, IL-8, IL-1β, IL-10 and tumor necrosis factor (TNF)- α in the neonates compared with that in the CON group (P < 0.05). Overall, maternal nucleotide supplementation improved the villus development and innate immunity of neonatal piglets during late pregnancy. This may be associated with the decrease in diarrhoea and the increase in weaning weight of the litter of suckling piglets.

Preparation and chromatographic evaluation of the hydrophilic interaction chromatography stationary phase based on nucleosides or nucleotides

In this work, a series of novel hydrophilic interaction chromatography (HILIC) stationary phases were prepared by grafting nucleosides or nucleotides on the surface of silica gel. Firstly, the silica was modified with 3-glycidoxypropyltrimethoxysilane (GPTMS). And then nucleosides or nucleotides were bonded on the surface of GPTMS-modified silica through the epoxy-amine ring-opening reaction to provide four HILIC materials. These obtained stationary phases were successfully characterized by Fourier transform-infrared spectroscopy (FT-IR) and elemental analysis (EA), respectively. Effects of column temperature, water content of the mobile phase, pH and buffer concentration on the retention behavior of these HILIC materials and the corresponding separation mechanism were evaluated using various nucleosides and nucleobases, respectively. In addition, polar and hydrophilic compounds such as amino acids and water-soluble vitamins were successfully separated using the corresponding columns, showing application potential for the separation of bioactive substances.

Characterization of a bovine intestinal myofibroblast cell line and stimulation using phytoglycogen-based nanoparticles bound to inosine monophosphate

The goal of the present study was to characterize a novel bovine intestinal myofibroblast (BT-IMF) cell line isolated from a fetal bovine intestine. This cell type is of importance as intestinal myofibroblasts play a key role in controlling intestinal epithelial cell proliferation, intestinal regulation, wound healing, epithelial cell turnover, and structural support. The present work demonstrates that BT-IMF cells could be successfully cryopreserved and thawed and cultured past 25 passages. Immunocytochemical staining of the BT-IMF cell line was positive for vimentin and smooth muscle actin (α-SMA) and negative for pancytokeratin, suggesting that the cells are myofibroblastic in type. Growth kinetic experiments demonstrate that hydrocortisone negatively impacts BT-IMF growth and non-essential amino acids enhance its proliferation. Inosine monophosphate (IMP) is a dietary nucleotide and is essential for supporting animal health. Stimulation with IMP bound to a novel phytoglycogen-based nanocarrier (IMP-NP) showed enhanced cell proliferation. BT-IMF provides a new tool for studying bovine cells in vitro and may be of particular interest for cultured meat manufacturing in the future.

Nucleotide Supplementation to Whole Milk Has Beneficial Effects on Post-Weaning Holstein Calf Performance

The positive effects of nucleotide (NU) supplementation in milk replacer have been elucidated in infants and in dairy calves; however, NU addition to whole milk has not been evaluated previously. This study aimed to assess NU supplementation in the whole milk on calf growth and health. Thirty Holstein calves (body weight: 39.1 ± 1.0 kg; 3 d after birth) were randomly assigned to the following treatments: whole milk without any supplementation (NU0), whole milk + 0.5 g/d added a NU-containing supplement to whole milk (NUCS0.5), and whole milk + 1 g/d added a NU-containing supplement to whole milk (NUCS1). Calves were weaned at d 55 and stayed on study until d 75. Calves had free access to feed and water throughout the study. Dry matter intakes (DMI) were similar among treatments (p > 0.05) during the pre-weaning period; however, increasing NU resulted in a linear (p < 0.05) increase in DMI during the post weaning period (2158, 2432, and 2518 g/d for NU0, NUCS0.5, and NUCS1, respectively). Treatments did not affect body weight (BW) at the first and second month of study, but final BW linearly increased as NU was added (87.1, 90.6, and 95.4 kg for NU0, NUCS0.5, and NUCS1, respectively). Neither pre-weaning average daily gain nor post-weaning average daily gain was affected by treatments; accordingly, feed efficiency was similar among treatment groups. Days with loose fecal score were linearly decreased as NU was added to whole milk during the first month of life, while the fecal score did not differ among treatments until the end of the study. No difference was observed in the skeletal growth of calves in the current study. Therefore, it can be concluded that NU supplementation in the whole milk has some beneficial effects on calf performance in terms of final BW, post-weaning DMI, and less days with loose feces.

In ovo Administration of Nucleosides Improved the Performance, Apparent Metabolizable Energy and Gut Development in Broiler Chickens

An in ovo study on the effect of the administration of a combination of nucleosides (25, 50, and 100 mg/egg) on hatchability, growth performance, energy metabolizability, and intestinal morphology in broilers was carried out. Four hundred eighty (480) fertile eggs were divided into four groups (in four replicates each having 30 eggs). On the 18th days of incubation of the eggs, candling was carried out and the fertile eggs were selected and given one of the four in ovo administrations. Group one served as control and was injected with phosphate-buffered saline (PBS). The other groups were given in ovo administration of nucleosides (25, 50, and 100 mg/egg) at 100 μl through the yolk sac route, and chicks of respective groups were hatched out. Among the experimental groups, the hatchability was comparable; however, the hatchability was affected in the group injected with a higher level of nucleosides at 100 mg/egg. The hatched out chicks from higher doses of nucleosides (50 and 100 mg) had higher body weight (BW) (P < 0.05) than the control. Higher energy metabolizability (%) was observed in nucleoside-injected groups. Plasma protein concentration was higher in groups administered with nucleosides (50 and 100 mg). Histologically, the intestinal villi length was maximum in 100 mg-injected group followed by 50 and 25 mg. Relative expression of homeobox (Cdx) in the jejunum was significantly (P < 0.05) upregulated in all the injected groups at 3, 7, and 14 days of age. Nucleoside-administered groups had better performance, energy metabolizability, and intestinal morphology. Among the experimental groups, the administration of nucleosides at 50 mg/egg resulted in higher growth performance, plasma protein, intestinal surface, and villi development in broiler chickens.

Short communication: Performance of Holstein calves fed high-solid milk with or without nucleotide

Our initial hypothesis was that the exogenous supply of nucleotides to neonatal calves would improve the development and functionality of gastrointestinal tissue, thereby enhancing their capacity to efficiently digest and utilize the nutrients in high-solids milk. Twenty 3-d-old male Holstein calves (37.9 ± 2.24 kg of body weight) were distributed randomly to 1 of 2 treatments (1 calf per pen; 10 pens per treatment) without or with added nucleotides to their daily milk. Dry milk powder was added to pasteurized milk and offered as 4 L/d from d 3 to 15, 6 L/d from d 16 to 49 (at 0900 and 1600 h), and 2 L/d in morning feeding from d 50 to 55. High-solids milk (fat = 4.47%, protein = 4.64%, lactose = 8.13%, and total solids = 17.7%) was made through the addition of milk powder into whole milk and supplemented without or with 2 g/d of a commercially available nucleotide product, and then fed until weaning. Nucleotide supplementation had no effect on preweaning growth rate, but tended to increase postweaning daily weight gain (d 56-75). Unexpectedly, nucleotide supplementation tended to increase fecal score within the 10 d of calf life; thereafter (until weaning), no difference was detected in fecal consistency. Nucleotide supplementation tended to increase and increased pre- and postweaning dry matter intake, respectively. Efficiency of feed utilization (kilogram of weight gain per kilogram of dry matter intake) was not influenced with treatment. The net gain (d 1-70) of withers height and hip height tended to be greater in nucleotide-fed calves. Overall, addition of nucleotides to the high-solids milk had marginal effects on preweaning performance and tended to increase fecal scores (looser feces) in the initial phase of life; however, it increased starter feed intake and growth rate after weaning. A longer-feeding experiment is recommended to elucidate the potential effects of nucleotide supplementation in high-solids milk on calf performance.

Maternal dietary uridine supplementation reduces diarrhea incidence in piglets by regulating the intestinal mucosal barrier and cytokine profiles

BACKGROUND

Nucleotides play an important role in the regulation of cellular energy and protein homeostasis, which facilitate the repair, recovery and repletion of tissue function. This study tested the effects of maternal uridine (UR) supplementation during late pregnancy and lactation of sows on the immune function of the small intestine in neonatal and suckling piglets.

RESULTS

Results showed that compared to the control group, maternal dietary UR supplementation significantly decreased incidence of diarrhea in suckling piglets (P < 0.01); and increased both duodenal and ileal average villus height (P < 0.01) as well as villus height/crypt depth in ileum (P = 0.017) in neonatal piglets. RT-qPCR results showed that maternal UR supplementation decreased mRNA expression of claudin-1 in jejunum and ileum of neonatal piglets (P < 0.05), while significantly increased mRNA expression of claudin-1 in duodenum and jejunum of suckling piglets. Furthermore, in suckling piglets, maternal dietary UR supplementation increased mRNA expression of IL-6, IL-8 and IL-1β in duodenum, jejunum and ileum (P < 0.05), increased IL-10 expression in both jejunal and ileal mucosa (P < 0.05) and increased mRNA expression of IKB and TLR4 in ileal mucosa (P < 0.05).

CONCLUSIONS

These results suggest that maternal dietary supplementation with UR contributed to reducing incidence of diarrhea by regulating cytokine secretion and intestinal mucosal barrier function in suckling piglets. © 2020 Society of Chemical Industry.

Uridine/UMP metabolism and their function on the gut in segregated early weaned piglets

Uridine monophosphate (UMP) is a major nucleotide analogue in mammalian milk and uridine (UR) is its gastro-intestinal metabolite in vivo. This study aims to investigate the functional effects of UMP and UR on the gut in vitro and in vivo. Twenty-one piglets were randomly allotted into three groups, the control group, UMP group and UR group, and orally administered UMP or UR for 10 days. Results showed that UMP and UR supplements improved the ADG of piglets, and decreased the diarrhea rate. UR increased the jejunum villus length/crypt depth ratio, Claudin-3 and E-cadherin expression, and the pyrimidine nucleotide metabolic enzymes including CMPK1, RRM2, UPRT, CTPS1 and CTPS2 in the duodenal mucosa. Both the UMP and UR decreased the expression of CAD and RRM2 at the jejunal mucosa. Moreover, UMP and UR increased the apoptosis ratio of intestinal epithelial cells in in vivo and in vitro experiments. Taken together, oral administration of UR and UMP could improve the small intestinal morphology, promote epithelial cell apoptosis and renewal of intestinal villus tips, and benefit intestinal development and health thus improving the growth performance and reducing the risk of diarrhea in early-weaned piglets.

Supplemental effects of dietary nucleotides on intestinal health and growth performance of newly weaned pigs

Intestinal challenges upon weaning would increase the needs of nucleotides for enterocyte proliferation, whereas de novo synthesis maybe insufficient. This study aimed to evaluate supplemental effects of dietary nucleotides on intestinal health and growth performance in newly weaned pigs. Fifty newly weaned pigs (19-d-old, 25 barrows and 25 gilts, 4.76 ± 0.42 kg BW) were individually housed and allotted to 5 treatments with increasing nucleotide supplementation (0, 50, 150, 250, and 500 mg/kg) based on a randomized complete block design with the initial BW and sex as blocks. Dietary nucleotides were provided from YT500 (Hinabiotech, Guangzhou, China). Pigs were fed for 21 d based on 2 phases (phase 1: 11 d and phase 2: 10 d) and experimental diets were formulated to meet or exceed nutrient requirements suggested by NRC (2012). Feed intake and BW were recorded. Titanium oxide (0.4%) was added as an indigestible marker from day 17. Plasma collected on day 18 was used to measure tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and malondialdehyde (MDA). Pigs were euthanized on day 21 to collect tissues to evaluate TNF-α, IL-6, MDA, morphology, and crypt cell proliferation rate in the jejunum. Ileal digesta were collected to measure ileal nutrient digestibility. Data were analyzed using contrasts in the MIXED procedure of SAS. Nucleotide supplementation increased (P < 0.05) ADFI in phase 1. Nucleotide supplementation at 50 and 150 mg/kg increased (P < 0.05) ADG in phase 1, whereas increased (P < 0.05) ADFI and tended to increase (P = 0.082) ADG in overall. Increasing nucleotide supplementation changed (quadratic, P < 0.05) villus height-crypt ratio (at 247 mg/kg) and decreased (linear, P < 0.05) crypt cell proliferation rate in the jejunum. Increasing nucleotide supplementation reduced (P < 0.05) jejunal IL-6 (at 50 and 150 mg/kg) and tended to change (quadratic, P = 0.074) plasma MDA (at 231 mg/kg). Nucleotide supplementation at 50 and 150 mg/kg increased (P < 0.05) ileal digestibility of energy and ether extract. In conclusion, nucleotide supplementation at a range of 50 to 250 mg/kg in the diets seems to be beneficial to newly weaned pigs by enhancing growth performance possibly due to reduced intestinal inflammation and oxidative stress as well as improved intestinal villi structure and energy digestibility.

Dietary supplement with nucleotides in the form of uridine monophosphate or uridine stimulate intestinal development and promote nucleotide transport in weaned piglets

BACKGROUND

Nucleotides are key constituents of milk, where they are utilized in cell replication, although there are limited studies for weaned piglets. This study evaluated the effects of uridine monophosphate (UMP) with uridine (UR) feed supplementation on the intestinal development and nucleotide transport in weaned piglets.

RESULTS

Supplementation with UMP significantly increased (P < 0.05) plasma glucose, and UR supplementation significantly reduced (0.05 < P < 0.10) the plasma total cholesterol (TC) of piglets when compared with that of the control group, although non-significant difference (P > 0.05) in growth performance was observed among three groups. Piglets fed supplementary UR exhibited greater (P < 0.05) crypt depth in the duodenum and ileum when compared with those in the supplementary UMP and control groups. Real-time quantitative polymerase chain reaction (RT-qPCR) results revealed that UR supplementation increased (P < 0.05) the relative mRNA levels of genes encoding the transmembrane proteins ZO-1 and occludin in the duodenum mucosa, and ZO-1 in the jejunum mucosa (P < 0.05). Similarly, UR supplementation increased (P < 0.05) expression of solute carriers SLC28A1 and SLC29A1 in the duodenum mucosa. Conversely, claudin-1 expression in the duodenum mucosa was inhibited (P < 0.05) by dietary supplementation with UMP or UR.

CONCLUSION

Collectively, our data indicated that dietary supplementation with UMP or UR was conducive to stimulating intestinal development and promoting nucleotide transport in weaned piglets. © 2019 Society of Chemical Industry.

Temporal variations of nucleosides and nucleotides in rabbit milk

Nucleotides and nucleosides have a preeminent role in physiological and biochemical processes for newborns, the major source of these during early development is the breast milk. Different biomolecules exhibit daily fluctuations in maternal milk that could transfer temporal information that synchronize newborn circadian system. As a first approach, we characterized the diurnal profile of nucleotides and nucleosides contained in maternal milk of rabbits during the first week of lactation. It is possible that some nucleosides, such as adenosine, play a relevant role in setting up the emerging circadian rhythmicity, whereas uridine and guanosine could participate in the maintenance of rhythmicity.

Non-antibiotic feed additives in diets for pigs: A review

A number of feed additives are marketed to assist in boosting the pigs' immune system, regulate gut microbiota, and reduce negative impacts of weaning and other environmental challenges. The most commonly used feed additives include acidifiers, zinc and copper, prebiotics, direct-fed microbials, yeast products, nucleotides, and plant extracts. Inclusion of pharmacological levels of zinc and copper, certain acidifiers, and several plant extracts have been reported to result in improved pig performance or improved immune function of pigs. It is also possible that use of prebiotics, direct-fed microbials, yeast, and nucleotides may have positive impacts on pig performance, but results have been less consistent and there is a need for more research in this area.

Effects of dietary nucleotide supplementation on growth in infants: a meta-analysis of randomized controlled trials

PURPOSE

Dietary nucleotides are thought to be conditionally essential nutrients in infancy. However, studies have reported inconsistent findings regarding the association between nucleotide supplementation and infant physical growth. We conducted this meta-analysis to examine the efficacy of nucleotide supplementation of infant formula in promoting early infant growth.

METHODS

Randomized controlled trials that evaluated the association between nucleotide supplementation and infant growth through June 2017 were included. Study quality was assessed using the Cochrane Collaboration's Risk of Bias tool. Standardized mean differences (SMD) with 95% confidence intervals (CIs) were calculated. Heterogeneity was assessed using Q and I² tests.

RESULTS

Nucleotide supplementation significantly increased the rate of weight gain (SMD 0.26; 95% CI 0.06-0.47), but had no effect on weight (SMD - 0.16; 95% CI - 0.55-0.23), weight Z score (SMD, - 0.42; 95% CI - 1.64-0.81), length (SMD 0.01; 95% CI - 0.18-0.21) and length Z score (SMD 0.15; 95% CI - 0.10-0.40). Occipitofrontal head circumference (OFC) at 7-8 weeks (SMD 0.30; 95% CI 0.10-0.50) and the rate of OFC gain (SMD 0.34; 95% CI 0.09-0.58) were significantly improved with nucleotide supplementation, whereas, 16- and 20-week OFC values did not differ.

CONCLUSIONS

Our meta-analysis indicated that nucleotide supplementation can increase the rate of weight gain, OFC and rate of OFC gain; however, we cannot conclude that it affects weight, weight Z score, length or length Z score. Large-scale randomized controlled trials of long-term nucleotide supplementation are needed to reach definitive conclusions.

Dietary supplementation with a nucleotide-rich yeast extract modulates gut immune response and microflora in weaned pigs in response to a sanitary challenge

An experiment was carried out to evaluate the short-term effect of supplementing a nucleotide-rich yeast extract (NRYE) on growth performance, gut structure, immunity and microflora of piglets raised under sanitary and unsanitary conditions. A total of 84, 21-day old piglets were used in this study; 42 piglets were raised in a room designated as the clean room that was washed once per week, whereas the other 42 piglets were raised in a room designated as the unclean room in which 7 kg of manure from the sow herd was spread on each pen floor on day 1 and 7 and the room was not washed throughout the experiment. The pigs were fed a corn-soybean meal-based diet without or with 0.1% NRYE. Each treatment had 7 replicate pens in each room, and each pen housed 3 pigs. Feed disappearance and BW were recorded on day 1 and 14. On day 14, one pig per pen was euthanized to collect ileum, mesenteric lymph nodes and spleen tissues, and cecum and colon digesta. Overall, NRYE supplementation did not affect growth performance in both clean and unclean conditions, improved kidney weight in both clean (P=0.0002) and unclean room (P<0.0001) and tended to improve the villus height/crypt depth ratio in the clean room (P=0.073). Supplementing NRYE was associated with upregulation of Ileal programmed cell death gene-1 (P=0.0003), interleukin (IL)-1β (P<0.0001), IL-6 (P=0.0003), IL-10 (P<0.0001) and tumor necrosis factor-α (TNF-α) (P<0.0001) in pigs raised in the unclean room. Supplementing the NRYE in pigs raised in the clean room suppressed growth of cecal Enterobacteriacea (P<0.0001) members and colonic Enterococcus spp. (P<0.019), improved proliferation of cecal Lactobacillus spp. (P<0.002) and colonic Clostridium cluster IV (P<0.011) and XVIa members (P<0.0002). Supplementing the NRYE in the unclean room improved proliferation of cecal Clostridium cluster IV (P<0.026) and suppressed proliferation of colonic Enterococcus spp. (P<0.037). In conclusion, supplementing the NRYE to piglets under unsanitary conditions improved ileal immune response by upregulating inflammatory cytokines, and positively modulated proliferation of beneficial gut bacteria and suppression of harmful ones in both clean and unclean rooms.

Rôles of glutamine and nucleotides in combination in growth, immune responses and FMD antibody titres of weaned pigs

This study examined the effects of glutamine and nucleotides on growth, intestinal villous height and immune responses of weaned pigs. Eighty weaned pigs (Landrace ✕ Yorkshire ✕ Duroc) were randomly assigned to five treatments, including a control diet and a 2 (glutamine 1·0 and 1·5%) by 2 (nucleotides 500 and 1000 p.p.m.) factorial design. There were no differences among the five treatments in weight gain from weeks 0 to 4 and 0 to 8 of the experiment. However, the food intake of treatment 3 (glutamine 1·0% and nucleotides 1000 p. p. m. ) for weeks 4 to 8 was higher (P < 0·05) than that of the control group. Intestinal villous height, and serum immunoglobulin-G concentration 2 h post lipopolysaccharide injection, were higher (P < 0·05) for pigs administered treatment 3 than for controls. Furthermore, foot and mouth disease (FMD) neutralizing antibody titres were also higher (P < 0·05) than the control group for pigs given treatment 3 when measured 3 weeks following vaccination with FMD antigen. These observations suggest that a combination of 10% of glutamine and 1000 p. p. m. of nucleotides in the diet could improve food intake and intestinal villous height and promote the immune responses and FMD antibody titres of weaned pigs.

Should perioperative immunonutrition for elective surgery be the current standard of care?

Postoperative infectious complications are independently associated with increased hospital length of stay (LOS) and cost and contribute to significant inpatient morbidity. Many strategies such as avoidance of long periods of preoperative fasting, re-establishment of oral feeding as early as possible after surgery, metabolic control and early mobilization have been used to either prevent or reduce the incidence of postoperative infections. Despite these efforts, it remains a big challenge to our current healthcare system to mitigate the cost of postoperative morbidity. Furthermore, preoperative nutritional status has also been implicated as an independent risk factor for postoperative morbidity. Perioperative nutritional support using enteral and parenteral routes has been shown to decrease postoperative morbidity, especially in high-risk patients. Recently, the role of immunonutrition (IMN) in postoperative infectious complications has been studied extensively. These substrates have been found to positively modulate postsurgical immunosuppression and inflammatory responses. They have also been shown to be cost-effective by decreasing both tpostoperative infectious complications and hospital LOS. In this review, we discuss the postoperative positive outcomes associated with the use of perioperative IMN, their cost-effectiveness, current guidelines and future clinical implications.

The role of dietary nucleotides in single-stomached animals

The transition from liquid to solid feed during weaning results in morphological, histological and microbial changes in the young animal's intestinal tract and often is associated with diarrhoea. The ban of in-feed antibiotics in pig production in the European Union has led to increasing interest in alternatives to overcome weaning-associated problems. Among others, nucleotides may have the potential to alleviate health impairments due to weaning. Nucleotides are natural components of the non-protein fraction of milk and have important effects on the maintenance of health in young animals. Nucleotides and their related metabolic products play key roles in many biological processes and become essential dietary components when endogenous supply is insufficient for normal function. The present review summarises nucleotide composition of milk from different species, the biology of nucleotides and possible effects of dietary nucleotides on intestinal morphology and function, intestinal microbiota, immune function, nutrient metabolism, hepatic morphology and function as well as growth performance. Special attention is given to data available for pigs, and suggestions are made for inclusion of nucleotides in the diet to benefit piglets' health and reduce the consequences accompanying early weaning.

Distribution of nucleosides in populations of Cordyceps cicadae

A rapid HPLC method had been developed and used for the simultaneous determination of 10 nucleosides (uracil, uridine, 2'-deoxyuridine, inosine, guanosine, thymidine, adenine, adenosine, 2'-deoxyadenosine and cordycepin) in 10 populations of Cordyceps cicadae, in order to compare four populations of Ophicordyceps sinensis and one population of Cordyceps militaris. Statistical analysis system (SAS) 8.1 was used to analyze the nucleoside data. The pattern of nucleoside distribution was analyzed in the sampled populations of C. cicadae, O. sinensis and C. militaris, using descriptive statistical analysis, nested analysis and Q cluster analysis. The total amount of the 10 nucleosides in coremium was 1,463.89–5,678.21 µg/g in 10 populations of C. cicadae, 1,369.80–3,941.64 µg/g in sclerotium. The average contents of the 10 analytes were 4,392.37 µg/g and 3,016.06 µg/g in coremium and sclerotium, respectively. The coefficient of variation (CV) of nucleosides ranged from 8.36% to 112.36% in coremium of C. cicadae, and from 10.77% to 155.87% in sclerotium of C. cicadae. The CV of the nucleosides was wide within C. cicadae populations. The nested variation analysis by the nine nucleosides’ distribution indicated that about 42.29% of the nucleoside variability in coremium was attributable to the differentiation among populations, and the remaining 57.71% resided in the populations. It was also shown that about 28.94% of the variation in sclerotium was expressed between populations, while most of the variation (71.06%) corresponded to the populations.

Identification of Nucleosides and Nucleobases from Cultured Cordyceps militaris

Four nucleosides and seven nucleobases were isolated from the BuOH subfraction of the extract of cultured Cordyceps militaris; one of them, 6-acetylpurine (1) is a new natural compound. The structure of 1 was determined on the basis of HR-ESI-MS, and 1D and 2D NMR spectroscopic analysis.

Nutritional interventions to prevent and rear low-birthweight piglets

Selection for hyperprolific sows, as a means of increasing litter size and profit, has resulted in an increased number of low-birthweight (LBW) piglets. These LBW piglets might suffer from increased morbidity and mortality during the early neonatal period. In addition, they show reduced growth performance, meat and carcass quality, which leads to an important economic loss for the farmer in the post-natal period. Therefore, nutritional interventions can be undertaken to prevent and rear LBW piglets. In the first part of this review, the preventive strategies at the sow level will be discussed. Approaches in preventing LBW piglets are to optimize the intrauterine environment via supplementing the sow during gestation. In the second part of this review, the interventions at the piglet level will be described. To increase the survival and growth rates of LBW piglets, one must focus on ensuring adequate colostrum and milk intake. Interventions include supplementing piglets, split nursing, split weaning and cross-fostering. Additional interventions increasing the probability of optimal post-natal food intake will be discussed.

Novel aspects of health promoting compounds in meat

Meat is an integral part of the human diet. Besides essential amino acids and nutritive factors of high quality and availability, meat provides often overlooked components of importance for human health. These are amino acids and bioactive compounds that may be very important in i) preventing muscle wasting diseases, such as in sarcopenia, ii) reducing food and caloric intake to prevent metabolic syndrome, iii) blood pressure homeostasis via ACE-inhibitory components from connective tissue, and iv) maintaining functional gut environment through meat-derived nucleotides and nucleosides. In addition, meat could be an important source of phytanic acid, conjugated linoleic acids and antioxidants. Further, it becomes increasingly apparent that design of in vitro meat will be possible, and that this development may lead to improved health benefits from commercially viable and sustainable meat products.

Effect of a fermented brown rice extract on the gastrointestinal function in methotrexate-treated rats

We investigated the protective effect of a hydrous ethanol extract of brown rice fermented with Aspergillus oryzae (ERF) which contained nucleobases and low fiber on the methotrexate (MTX)-induced gastrointestinal damage in rats. The rats were assigned to three groups: control (CON), MTX, and MTX-ERF. The rats in the CON and MTX groups were fed for 4 weeks on a basal diet, and those in the MTX-ERF group were fed on a 9.16% ERF-containing basal diet. The rats in the MTX and MTX-ERF groups were administered with MTX after 3 weeks. The survival rate and incidence rate of diarrhea were monitored over 1 week. On day 4 after the administration, half of the rats in each group were killed, and gastrointestinal samples were collected. Feeding with ERF improved the incidence rate of diarrhea, increased the protein content in small intestinal mucosa, and also apparently improved the survival rate. These results indicate that dietary ERF could protect against MTX-induced gastrointestinal damage.

Effect of dietary nucleotide supplementation on performance and development of the gastrointestinal tract of broilers

1. Two experiments were conducted to determine the effects of dietary nucleotide supplementation on broiler performance, and physical and morphological development of the gastrointestinal tract. 2. Experiment 1: A total of 180 one-d-old male chicks were placed in battery brooders in 3 × 6 replicate pens containing 10 chicks each. Chicks were randomly assigned to one of the three dietary treatments; a maize-soyabean meal based diet supplemented with 0, 0·25, and 0·50% Torula yeast RNA (as a source of nucleotides) from 0 to 16 d of age. 3. Experiment 2: A total of 1344 one-d-old male chicks were placed in floor pens and reared on recycled wood shavings (two flocks) under a high stocking density (0·068 m(2)/bird). Chicks were randomly assigned to one of the 4 dietary treatments (0, 0·25% Torula yeast RNA, 2% and 6% Nupro®) for the starter period (0 to 14 d of age) with 6 replicate pens containing 56 chicks each. All the birds were fed on the same common grower diet with no supplementation of nucleotides from 15 to 32 d of age. 4. Experiment 1: Supplementing the diets with up to 0·50% Torula yeast RNA did not affect broiler performance, or relative intestinal tract weight and length of broilers at any periods measured. 5. Experiment 2: From 0 to 14 d of age, broilers fed on the diets supplemented with 0·25% Torula yeast RNA and 2 and 6% Nupro® were significantly heavier and had improved feed conversion (feed:gain) ratios as compared with the birds fed on the control diet. Supplementing the starter diet only with 2% Nupro® supplementation significantly improved body weight (BW) gain as compared with the control diet over the entire experiment (0 to 32 d of age). Broilers fed on the diets supplemented with 2 and 6% Nupro® from 0 to 14 d of age had better feed conversion (feed:gain) ratios over the entire experiment (0 to 32 d of age) as compared with the birds fed on the control diet, even though the birds were only fed on the diets supplemented with Nupro® from 0 to 14 d of age. The broilers fed on the diets supplemented with 0·25% Torula yeast RNA and 2% Nupro® had higher villus height and an improved villus height-to-crypt depth ratio as compared with birds fed on the control or 6% Nupro® diet at 14 d of age. 6. It is generally assumed that nucleotides are not an essential nutrient; thus there is no need to supplement the diets of broilers reared under normal conditions. However, dietary nucleotide supplementation may be important to maintain maximum growth performance when birds are exposed to stress conditions, such as high stocking density combined with dirty litter.

The role of nucleotides in the immune and gastrointestinal systems: potential clinical applications

Nucleotides are low molecular weight biological molecules key to biochemical processes. Sources include de novo synthesis, recovery via salvage mechanisms, and dietary intakes. Although endogenous production serves as the main nucleotide source, evidence suggests that exogenous sources are essential to immune competence, intestinal development, and recovery. Dietary nucleotides serve a marked role in rapidly proliferating cells where they are necessary for optimal function. Accordingly, dietary nucleotides are deemed conditionally essential in the presence of various physiological stresses, including growth and development, recovery from injury, infection, and certain disease states. Clinical studies that evaluated nutrition formulations of nucleotides in combination with other specific nutrient substances demonstrated improved clinical outcomes in patients characterized as critically ill, injured, immune suppressed, or with chronic gastrointestinal conditions. However, conclusions regarding specific benefits of nucleotides are limited. Scientific substantiation of nucleotide supplementation in infant formula has been reported to improve the maturation and development of the intestinal tract as well as immune function. All medical nutrition products except for one immune-modulating formulation are devoid of nucleotides. In an effort to build on this, the current review presents the data to support potential clinical applications for nucleotides in enteral nutrition that may contribute to improved outcomes in physiologically stressed patients.

Dietary nucleotides increase the mucosal IgA response and the secretion of transforming growth factor beta from intestinal epithelial cells in mice

We have investigated the influence of dietary nucleotides on the intestinal immune system in ovalbumin (OVA)-specific T-cell receptor (TCR) transgenic mice (OVA-TCR Tg mice). When mice were supplied with water supplemented with 2% OVA ad libitum, the faecal OVA-specific immunoglobulin A (IgA) level significantly increased in those fed a nucleotide-supplemented diet (NT(+) diet) compared with those fed a nucleotide-free control diet (NT(-) diet). In the NT(+) diet-fed mice, secretion of transforming growth factor beta (TGF-beta), which is an isotype-specific switch factor for IgA, from intestinal epithelial cells (IECs) was significantly increased. Furthermore, an increased proportion of intestinal intraepithelial lymphocytes (IELs) bearing gammadelta TCR (TCRgammadelta(+) IELs) and increased secretion from IECs of interleukin 7 (IL-7), which is essential for the development of TCRgammadelta(+) IELs, were also observed in OVA-TCR-Tg mice fed the NT(+) diet, as we previously demonstrated using BALB/c mice (Nagafuchi et al., Biosci. Biotechnol. Biochem. 64: 1459-65 (2000)). Considering that TCRgammadelta(+) T cells and TGF-beta are important for an induction of the mucosal IgA response, our results suggest that dietary nucleotides augment the mucosal OVA-specific IgA response by increasing the secretion of TGF-beta from IECs and the proportion of TCRgammadelta(+) IELs.

Profile of nucleotides and nucleosides in Taiwanese human milk

BACKGROUND

Human milk-borne nucleotides and their related metabolic products have been reported to have important physiological roles in breast-fed infants. The purpose of this study was to measure the concentrations of free nucleotides and nucleosides in human milk from Taiwanese women.

METHODS

A total of 24 individual milk specimens were collected from women in Taipei and Kaohsiung, at four stages of lactation. Vegetarian or non-vegetarian dietary patterns were recorded. The samples were analyzed for nucleotides and nucleosides by high-performance liquid chromatography.

RESULTS

The mean (±standard deviation) free nucleotide and nucleoside concentrations in Taiwanese human milk were 213.13 ± 76.26 μmol/L and 16.38 ± 7.11 μmol/L. The predominant nucleotide was cytidine diphosphate for almost all samples, regardless of the location, stage of lactation, or dietary status of the subjects. Overall, the mean concentrations of cytidine diphosphate, cytidine monophosphate, uridine monophosphate, guanosine monophosphate, adenosine monophosphate, and inosine monophosphate, in milk samples were 129.86 μmol/L, 49.10 μmol/L, 5.60 μmol/L, 0.82 μmol/L, 2.96 μmol/L, and 25.25 μmol/L, respectively (equivalent to 61.0%, 23.1%, 2.6%, 0.4%, 1.0%, and 11.9% of free nucleotide composition). In free nucleosides, cytidine and uridine were predominant during all stages of lactation. The average concentrations of cytidine, uridine, adenosine, guanosine, and inosine, in milk samples were 9.25 μmol/L, 6.33 μmol/L, 0.18 μmol/L, 0.36 μmol/L, and 0.23 μmol/L, respectively (equivalent to 56.5%, 38.7%, 1.1%, 2.2%, and 1.4% of free nucleoside composition). Comparing vegetarian and non-vegetarian statuses, it was found that the total free nucleotide concentration was high in the vegetarian group (p=0.037).

CONCLUSION

Our data showed a wide range of concentrations of individual nucleotides and nucleosides in Taiwanese human milk. Unique dietary status could affect the nucleotide and nucleoside levels in human milk, especially the nucleotides in our study. However, the mechanism of modulation of nucleotide and nucleoside levels in human milk is not clear.

Dietary nucleotides and early growth in formula-fed infants: a randomized controlled trial

BACKGROUND

Dietary nucleotides are nonprotein nitrogenous compounds that are found in high concentrations in breast milk and are thought to be conditionally essential nutrients in infancy. A high nucleotide intake has been suggested to explain some of the benefits of breastfeeding compared with formula feeding and to promote infant growth. However, relatively few large-scale randomized trials have tested this hypothesis in healthy infants.

OBJECTIVE

We tested the hypothesis that nucleotide supplementation of formula benefits early infant growth.

PATIENTS AND METHODS

Occipitofrontal head circumference, weight, and length were assessed in infants who were randomly assigned to groups fed nucleotide-supplemented (31 mg/L; n=100) or control formula without nucleotide supplementation (n=100) from birth to the age of 20 weeks, and in infants who were breastfed (reference group; n=101).

RESULTS

Infants fed with nucleotide-supplemented formula had greater occipitofrontal head circumference at ages 8, 16, and 20 weeks than infants fed control formula (mean difference in z scores at 8 weeks: 0.4 [95% confidence interval: 0.1-0.7]; P=.006) even after adjustment for potential confounding factors (P=.002). Weight at 8 weeks and the increase in both occipitofrontal head circumference and weight from birth to 8 weeks were also greater in infants fed nucleotide-supplemented formula than in those fed control formula.

CONCLUSIONS

Our data support the hypothesis that nucleotide supplementation leads to increased weight gain and head growth in formula-fed infants. Therefore, nucleotides could be conditionally essential for optimal infant growth in some formula-fed populations. Additional research is needed to test the hypothesis that the benefits of nucleotide supplementation for early head growth, a critical period for brain growth, have advantages for long-term cognitive development.

Effects of 5'-uridylic acid feeding on postprandial plasma concentrations of metabolites and metabolic hormones in pre-weaning goats

5'-Uridylic acid (UMP), which is present at high concentrations in cow's colostrum, has been shown to cause a reduction in increased plasma levels of insulin and glucose after ingestion of milk replacer in pre-weaning calves. However, the precise mechanisms of UMP action have not been investigated, and its action has not been investigated in other pre-weaning ruminants. In order to demonstrate whether UMP causes changes in postprandial metabolic and hormonal parameters in pre-weaning goats, 11 Saanen kids were given milk replacer (twice a day) without (n = 5) or with (n = 6) UMP (1 g for each meal, 2 g/day for each head) for 14 days. Analysis of blood samples taken in the morning of day 14 demonstrated that the feeding of milk replacer with UMP abolished the significant changes in postprandial plasma glucose, NEFA, GH and insulin concentrations induced by feeding of milk replacer alone, and demonstrated a tendency to increase IGF-I levels. However, there was no significant difference between the two groups at any sampling time. We conclude that UMP feeding with milk replacer showed a tendency to blunt the postprandial changes in levels of some plasma metabolites and hormones that are induced by replacer alone in pre-weaning goats.

Adenosine: An immune modulator of inflammatory bowel diseases

Inflammatory bowel disease (IBD) is a common and lifelong disabling gastrointestinal disease. Emerging treatments are being developed to target inflammatory cytokines which initiate and perpetuate the immune response. Adenosine is an important modulator of inflammation and its anti-inflammatory effects have been well established in humans as well as in animal models. High extracellular adenosine suppresses and resolves chronic inflammation in IBD models. High extracellular adenosine levels could be achieved by enhanced adenosine absorption and increased de novo synthesis. Increased adenosine concentration leads to activation of the A2a receptor on the cell surface of immune and epithelial cells that would be a potential therapeutic target for chronic intestinal inflammation. Adenosine is transported via concentrative nucleoside transporter and equilibrative nucleoside transporter transporters that are localized in apical and basolateral membranes of intestinal epithelial cells, respectively. Increased extracellular adenosine levels activate the A2a receptor, which would reduce cytokines responsible for chronic inflammation.

Can nutraceuticals affect the structure of intestinal mucosa? Qualitative and quantitative microanatomy in L-glutamine diet-supplemented weaning piglets

Weaning piglets were fed an L-glutamine-supplemented diet with the aim of monitoring the effects on gut mucosal turnover and barrier function, to elucidate the potential preventive or therapeutic roles of glutamine as a nutraceutical or 'functional food'. Sixteen female weaning piglets were divided into two groups, which were fed a control diet (Ctr group: n = 8) or a Ctr + 0.5% L-glutamine diet (G group: n = 8) for 28 days. In the ileum of group G piglets the villus height (V) and crypt depth (C) were increased, and the V:C ratio was decreased (p < 0.01). The PCNA and TUNEL immunoreactivities were also tested. The number of mitotic mucosal cells (M) was increased, and that of mucosal cells with apoptotic nuclei (A) decreased in such a way that the A:M index diminished (p < 0.01). The A:M index also decreased at the level of some components of the gut-associated lymphatic tissue (GALT), thus indicating a positive effect on the gut barrier function. This trial showed that L: -glutamine supplementation influenced some morphofunctional characteristics of piglet ileal mucosa. These data corroborate the nutraceutical role of glutamine as a trophic agent for mucosal repair, improvement of barrier function and gut adaptation in the swine per se and as an animal model.

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.

The long-term effects of breastfeeding on asthma and atopic disease

In this review, the primary objective is to assess the evidence of whether breastfeeding protects against asthma and atopic disease for the long-term (long-term is defined here as >5 years of age). Two main types of observational epidemiological studies have been used to test this hypothesis. These are cohort studies of random samples of children and cohort studies of children with a family history of asthma or atopy. In each study type, exposure and outcome data are collected either prospectively or retrospectively. The 12 criteria for assessing the adequate measurement of exposure, outcome and statistics of cohort studies in this context are given in Table 17-1.

Effects of nucleotide supplementation in milk replacer on small intestinal absorptive capacity in dairy calves

Milk replacer was supplemented with nucleotides and fed to dairy calves from birth through weaning to examine the potential for enhancing recovery of small intestinal function after enteric infection. Three treatments of 23 calves each were fed milk replacer (10% body weight/d) supplemented with no nucleotides (C), purified nucleotides (N), or nucleotides from an extract of Saccharomyces cerevisiae (S). Average daily gain, health scores, fecal dry matter, and fecal bacteria were monitored, and blood was analyzed for packed cell volume, glucose, blood urea nitrogen (BUN), and creatinine. Calves were monitored twice daily for fecal score, and 48 h after increased fecal fluidity was recorded, intestinal function was evaluated by measuring absorption of orally administered xylose (0.5 g/kg of body weight). Packed cell volume of blood was greater for treatment N for wk 2 and 5 compared with other treatment groups. Four calves per treatment were killed, and intestinal tissue was evaluated for morphology, enzyme activities, and nucleoside transporter mRNA expression. Treatment S calves had increased abundance of nucleoside transporter mRNA, numerically longer villi, and lower alkaline phosphatase than other groups. Growth measurements and plasma concentrations of glucose, BUN, creatinine, and IgG were not different between treatments; however, BUN-to-creatinine ratio was higher for treatment N, possibly indicating decreased kidney function. There were also no treatment effects on fecal dry matter and fecal bacteria population. However, N-treated calves had the highest detrimental and lowest beneficial bacteria overall, indicating an unfavorable intestinal environment. Supplementation of purified nucleotides did not improve intestinal morphology or function and resulted in higher fecal water loss and calf dehydration. Supplementation of nucleotides derived from yeast tended to increase calf intestinal function, provide a more beneficial intestinal environment, and improve intestinal morphology.

Nutritional factors influencing infections in preterm infants

In contrast with clinical studies in term infants or older children, it is very difficult to investigate possible immunoregulatory effects of a novel infant formula composition in preterm infants. This is mainly because of the multicausal origin of infections in this high-risk population that is usually admitted to the neonatal intensive care unit. Possible effects of nutrition composition on onset and incidence of nosocomial infections in these very small infants have to be compared with infections that may have originated in utero. The development of the gastrointestinal tract may be inhibited after severe intrauterine growth retardation, leading to functional impairment of the gut shortly after birth. This may be related to the onset of necrotizing enterocolitis of the newborn. However, this disease in very small preterm infants is possibly also related to the initiation of oral feeding and/or the amount of feeding. Specific infection risks of neonatal intensive care as a result of invasive techniques such as artificial ventilation or total parenteral nutrition using indwelling umbilical and/or Silastic lines and so-called "all-in-one" mixtures may influence the incidence of infections. Widespread use of intravenous antibiotics in the neonatal intensive care unit may create an even larger infection risk. Investigation of possible immunomodulatory effects of factors such as prebiotics and probiotics added to the nutrition of preterm infants should always be considered along with other nutritional factors known to influence the immature immune system.