Milk protein-based infant formula containing rice starch and low lactose reduces common regurgitation in healthy term infants: a randomized, blinded, and prospective trial.

OBJECTIVE: Spit-up (regurgitation) reduction with prethickened milk protein-based infant formulas containing rice starch has been clinically demonstrated in infants with heavy spit-ups but not in otherwise healthy normal infants with common spit-ups. The objective of this study was to evaluate growth, gastrointestinal tolerance, and efficacy to reduce common spit-up in normal, healthy term infants fed an investigational rice starch prethickened lactose-free milk protein-based infant formula. METHODS: This double-blind, randomized, parallel study evaluated the investigational rice starch prethickened lactose-free (low lactose < 100 mg/L) milk protein-based infant formula compared to a standard, commercially available, iso-nutrient, lactose-containing (100% of carbohydrate) milk-based infant formula (control) for growth and gastrointestinal tolerance in healthy term infants (n = 132/group) fed from 14 ± 3 days to 112 days of age. Data were classified and analyzed as evaluable (EV; subjects completing study per protocol) or intent-to-treat data (ITT; all subjects with available data). RESULTS: Growth as indicated by weight gain (primary variable) and formula intake were not significantly different (p > 0.05) between feeding groups (EV or ITT). Though both formulas were well tolerated, spit-up frequency was significantly lower (p < 0.05) in the rice versus control group by 53% at 28 days of age, 54% at 56 days, 48% at 84 days, and 32% at 112 days (EV). Importantly, infants in the rice group were 1.6 to 1.8 times more likely to report zero spit-up than infants in the control group. The rice group also had higher percentages of soft and yellow stools. CONCLUSIONS: The rice starch prethickened lactose-free milk protein-based formula (rice) supported normal growth and safe use as the sole source of feeding for normal infants over the first 4 months of life. The rice formula was efficacious in providing a clinically relevant reduction of spit-up frequency in otherwise healthy term infants.

Fucosylated but not sialylated milk oligosaccharides diminish colon motor contractions.

Human milk oligosaccharides (HMO) are being studied by different groups exploring a broad range of potential beneficial effects to the breastfed infant. Many of these effects have been attributed to a growth promotion effect on certain gut organisms such as bifidobacteria. Additionally, evidence indicates that HMO are able to directly promote positive changes in gut epithelium and immune responses under certain conditions. This study utilizes a standardized ex vivo murine colon preparation to examine the effects of sialylated, fucosylated and other HMO on gut motor contractions. Only the fucosylated molecules, 2'FL and 3'FL, decreased contractility in a concentration dependent fashion. On the basis of IC50 determinations 3'FL was greater than 2 times more effective than 2'FL. The HMO 3'SL and 6'SL, lacto-N-neotetraose (LNnT), and galactooligosaccharides (GOS) elicited no effects. Lactose was used as a negative control. Fucosylation seems to underlie this functional regulation of gut contractility by oligosaccharides, and L-fucose, while it was also capable of reducing contractility, was substantially less effective than 3'FL and 2'FL. These results suggest that specific HMO are unlikely to be having these effects via bifidogenesis, but though direct action on neuronally dependent gut migrating motor complexes is likely and fucosylation is important in providing this function, we cannot conclusively shown that this is not indirectly mediated. Furthermore they support the possibility that fucosylated sugars and fucose might be useful as therapeutic or preventative adjuncts in disorders of gut motility, and possibly also have beneficial central nervous system effects.

Identification and characterization of a regulatory domain on the carboxyl terminus of the measles virus nucleocapsid protein.

The paramyxovirus template for transcription and genome replication consists of the RNA genome encapsidated by the nucleocapsid protein (N protein). The activity of the complex, consisting of viral polymerase plus template, can be measured with minireplicons in which the genomic coding sequence is replaced by chloramphenical acetyltransferase (CAT) antisense RNA. Using this approach, we showed that the C-terminal 24 amino acids of the measles virus N protein are dispensable for transcription and replication, based upon the truncation of N proteins used to support minireplicon reporter gene expression. Truncation at the C-terminal or penultimate amino acid 524 resulted in no change in CAT expression, whereas larger truncations spanning residues 523 to 502 were accompanied by an approximately twofold increase in basal activity. Reporter gene expression was enhanced by supplementation with the major inducible 70-kDa heat shock protein (Hsp72) for minireplicons with the N protein or the N protein truncated at position 525 or 524 but not in systems with a truncation at position 523 or 522. Naturally occurring sequence variants of the N protein with variations at positions 522 and 523 were also shown to lack Hsp72 responsiveness independent of changes in basal activity. Since these residues lie within a linear sequence predicting a direct Hsp72 interaction, N protein-Hsp72 binding reactions were analyzed by using surface plasmon resonance technology. Truncation of the C-terminal portion of the N protein by protease digestion resulted in a reduced binding affinity between Hsp72 and the N protein. Furthermore, with synthetic peptides, we established a correlation between the functional responsiveness and the binding affinity for Hsp72 of C-terminal N protein sequences. Collectively, these results show that the C-terminal 24 amino acids of the N protein represent a regulatory domain containing a functional motif that mediates a direct interaction with Hsp72.