Ribonucleotides: conditionally essential nutrients shown to enhance immune function and reduce diarrheal disease in infants

[Expert consensus on the nutritional aspects of initial and follow-on infant formulas]

INTRODUCTION

Infant feeding in the first months/years of life affects the health in the short and long term. Breastfeeding is the perfect food due to its many benefits. However, when breastfeeding is not possible, infant formulas are the best alternative. The aim of this study is to define the role of the supplemented formulas in infant nutrition using the opinion of a panel of experts in infant gastroenterology and nutrition.

MATERIAL AND METHODS

A survey, using 62 items, stratified into 5 blocks, was performed by 48 panelists using the Delphi method to achieve a professional criteria consensus on nutritional aspects of infant formulas.

RESULTS

A consensus was reached in 64.6% of the items, with a non-unified agreement being established as regards the nutritional aspects of infant formulas, and their influence in body and brain development and immune maturity.

CONCLUSIONS

According to the experts surveyed, there is consensus as regards the suitable composition of lipids, lactose, calcium, vitamin D, and prebiotics in infant formulas, for a correct cerebral, immune and somatic development. There was no consensus on the not yet well-defined subjects, such as nutritional quality of proteins, use of thickeners, taurine supplementation, probiotic, and symbiotic aspects. More studies are necessary to confirm these subjects.

Developmental effects of dietary nucleotides in second-generation weaned rats

The aim of the present study was to evaluate dietary effects of dietary nucleotides (NTs) on developmental parameters in second-generation Sprague-Dawley rats. Experimental design was set up as six groups, including one control and five nucleotide administered groups, doses ranged from 0.01% to 1.28% nucleotides. First-generation (F0) rats were divided into two terms: (1) fed for 90-day study; (2) mated for offspring (F1). After weaning, each group of second-generation F1 rats was fed the control diet. Evaluating parameters were weight gain and food utilization ratios of rats, hematological and biochemical parameters, and organ pathology. The results showed that there was a greater weight gain and food utilization ratio in weaned rats (F0 and F1). Furthermore, weight gain and food utilization ratios were increased in the first 2 weeks of F1 male and the first week of F1 female rats. There were no significant changes in blood indicators of NT groups with the exception of decrease in aspartate aminotransferase and serum uric acid levels. Overall, it was demonstrated that NT supplements could promote the early growth and development at a 0.01% dose. Although NTs may have cumulative reproductive effects, they were safe even at a high-dose supplementation. Additionally, NT supplementation could promote restoration and optimize liver function.

Biotechnological utilization of biodiesel-derived glycerol for the production of ribonucleotides and microbial biomass

Ten yeast strains were evaluated concerning their capabilities to assimilate biodiesel-derived glycerol in batch cultivation. The influence of glycerol concentration, temperature, pH and yeast extract concentration on biomass production was studied for the yeast selected. Further, the effect of agitation on glycerol utilization by the yeast Hansenula anomala was also studied. The yeast H. anomala CCT 2648 showed the highest biomass yield (0.30 g g(-1)) and productivity (0.19 g L(-1) h(-1)). Citric acid, succinic acid, acetic acid and ethanol were found as the main metabolites produced. The increase of yeast extract concentration from 1 to 3 g L(-1) resulted in high biomass production. The highest biomass concentration (21 g L(-1)), yield (0.45 g g(-1)) and productivity (0.31 g L(-1) h(-1)), as well as ribonucleotide production (13.13 mg g(-1)), were observed at 700 rpm and 0.5 vvm. These results demonstrated that glycerol from biodiesel production process showed to be a feasible substrate for producing biomass and ribonucleotides by yeast species.

Short-term effect of dietary yeast nucleotide supplementation on small intestinal enzyme activities, bacterial populations and metabolites and ileal nutrient digestibilities in newly weaned pigs

In previous studies, dietary nucleotides have been shown to improve performance in single-stomached animals by promoting the renewal of small intestine epithelial cells and by influencing the activity and composition of the microbial community in the digestive tract. The present experiment was carried out with 12 barrows weaned at the age of 18 days and fitted with a simple T-cannula at the distal ileum. To determine short-term effects of dietary yeast nucleotides, the piglets received a grain-soybean meal-based basal diet with or without supplementation of 1 g/kg of a dried yeast product containing free nucleotides. Dietary supplementation with yeast did not affect bacterial numbers in the ileum as well as ileal concentrations of individual short-chain fatty acids (SCFA), total SCFA and total lactic acid (p > 0.05). Moreover, there was no effect of supplemental yeast nucleotides on ileal α-amylase, leucine amino peptidase, maltase and lactase activities (p > 0.05), as well as on ileal dry matter, crude protein and crude fibre digestibilities (p > 0.05). In conclusion, short-term supplementation with dietary yeast nucleotides did not affect microbial metabolite concentrations, bacterial numbers and enzyme activities in the ileal digesta as well as ileal nutrient digestibilities of newly weaned pigs.

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.

Dietary nucleotides and fecal microbiota in formula-fed infants: a randomized controlled trial

BACKGROUND

Dietary nucleotides are nonprotein nitrogenous compounds that are thought to be important for growth, repair, and differentiation of the gastrointestinal tract. A higher nucleotide intake may also have favorable effects on the fecal microbial composition and incidence of diarrhea in infancy. However, few studies have tested this hypothesis with an experimental study design.

OBJECTIVE

We tested the hypothesis that nucleotide supplementation of infant formula has beneficial effects on fecal bacteriology.

DESIGN

Oligonucleotide probes were used to measure bacterial genus-specific 16S ribosomal RNA in stools of a subset of infants (mean age: 20.4 wk) who were randomly assigned to nucleotide-supplemented (31 mg/L; n = 35) or control formula (n = 37) from birth until age 20 wk or were breastfed (reference group; n = 44). The microbial pattern was assessed as the ratio of Bacteroides-Porphyromonas-Prevotella group (BPP) to Bifidobacterium species.

RESULTS

The ratio of BPP to Bifidobacterium spp. rRNA in infants randomly assigned to the nucleotide-supplemented formula was lower than in infants receiving the control formula (mean difference: -118%; 95% CI: -203%, -34%; P = 0.007), but it did not differ in infants who were breastfed. The difference between randomized formula-fed groups was independent of potential confounding factors (P = 0.003).

CONCLUSIONS

Our data support the hypothesis that nucleotide supplementation improves the composition of the gut microbiota in formula-fed infants. Because this effect could contribute to previously described benefits of nucleotide supplementation for gastrointestinal tract and immune function, these findings have important implications for optimizing the diet of formula-fed infants.

Milk lipoprotein membranes and their imperative enzymes

There are two main sources of lipoprotein membranes in milk: the relatively well-defined milk fat globule membrane (MFGM) that covers the milk fat globules, and the much less attended lipoprotein source, in the form of vesicles floating in the milk serum. We challenge the common view that the milk serum lipoprotein membrane (MSLM) is secondly derived from the MFGM and present a different view suggesting that it represents Golgi-derived vesicles that are released intact to milk. The potential role of enzymes attached to the MSLM and MFGM is considered in detail for select ubiquitously expressed enzymes.