Impact of a specialized oral nutritional supplement on quality of life in older adults following hospitalization: Post-hoc analysis of the NOURISH trial

BACKGROUND & AIMS

Both during and after hospitalization, nutritional care with daily intake of oral nutritional supplements (ONS) improves health outcomes and decreases risk of mortality in malnourished older adults. In a post-hoc analysis of data from hospitalized older adults with malnutrition risk, we sought to determine whether consuming a specialized ONS (S-ONS) containing high protein and beta-hydroxy-beta-methylbutyrate (HMB) can also improve Quality of Life (QoL).

METHODS

We analyzed data from the NOURISH trial-a randomized, placebo-controlled, multi-center, double-blind study conducted in patients with congestive heart failure, acute myocardial infarction, pneumonia, or chronic obstructive pulmonary disease. Patients received standard care + S-ONS or placebo beverage (target 2 servings/day) during hospitalization and for 90 days post-discharge. SF-36 and EQ-5D QoL outcomes were assessed at 0-, 30-, 60-, and 90-days post-discharge. To account for the missing QoL observations (27.7%) due to patient dropout, we used multiple imputation. Data represent differences between least squares mean (LSM) values with 95% Confidence Intervals for groups receiving S-ONS or placebo treatments.

RESULTS

The study population consisted of 622 patients of mean age ±standard deviation: 77.9 ± 8.4 years and of whom 52.1% were females. Patients consuming placebo had lower (worse) QoL domain scores than did those consuming S-ONS. Specifically for the SF-36 health domain scores, group differences (placebo vs S-ONS) in LSM were significant for the mental component summary at day 90 (-4.23 [-7.75, -0.71]; p = 0.019), the domains of mental health at days 60 (-3.76 [-7.40, -0.12]; p = 0.043) and 90 (-4.88 [-8.41, -1.34]; p = 0.007), vitality at day 90 (-3.33 [-6.65, -0.01]; p = 0.049) and social functioning at day 90 (-4.02 [-7.48,-0.55]; p = 0.023). Compared to placebo, differences in LSM values for the SF-36 general health domain were significant with improvement in the S-ONS group at hospital discharge and beyond: day 0 (-2.72 [-5.33, -0.11]; p = 0.041), day 30 (-3.08 [-6.09, -0.08]; p = 0.044), day 60 (-3.95 [-7.13, -0.76]; p = 0.015), and day 90 (-4.56 [-7.74, -1.38]; p = 0.005).

CONCLUSIONS

In hospitalized older adults with cardiopulmonary diseases and evidence of poor nutritional status, daily intake of S-ONS compared to placebo improved post-discharge QoL scores for mental health/cognition, vitality, social functioning, and general health. These QoL benefits complement survival benefits found in the original NOURISH trial analysis.

CLINICAL TRIAL REGISTRATION

NCT01626742.

Pilot study on the impact of a carbohydrate loading drink on postprandial glycemic responses and gastric emptying in adults with prediabetes and type 2 diabetes mellitus

BACKGROUND

Preoperative carbohydrate (CHO) loading improves patient outcomes but is not extensively studied in individuals with diabetes mellitus (DM), resulting in limited professional recommendations. This study examined postprandial glycemic responses and gastric emptying rates following consumption of a CHO drink in adults with and without DM.

METHODS

A single-arm, nonrandomized pilot trial was conducted in adults without DM (non-DM) (47.5 ± 2.5 years), with pre-DM (55.8 ± 3.0 years), and with type 2 DM (56.2 ± 2.5 years). Following an overnight fast, participants consumed a 50 g CHO drink followed by 1.5 g liquid paracetamol. Venous blood samples were collected at baseline (ie, t = 0 min) and 15, 30, 45, 60, 90, 120, 150, 180, 210, and 240 min for plasma glucose and serum insulin and paracetamol concentrations to assess gastric emptying.

RESULTS

Participants with DM were older and had a higher body mass index than non-DM participants (31.2 ± 0.9 vs 28.2 ± 0.9). Fasting glucose and hemoglobin A1c levels differed significantly across groups (non-DM: 95.4 ± 3.6 mg/dl and 5.2% ± 0.1%; pre-DM: 111.6 ± 3.6 mg/dl and 5.8% ± 0.1%; DM: 167.4 ± 3.6 mg/dl and 7.2% ± 0.1%). Compared with the non-DM group, DM had increased glucose responses at 30-180 min. Glucose returned to baseline at 150 min in the non-DM and pre-DM groups compared with 210 min in the DM group. Paracetamol concentrations were not significantly different between the non-DM and DM groups.

CONCLUSION

Blood glucose returned to baseline within ~2.5 h in non-DM and pre-DM groups and ~3.5 h in participants with DM following ingestion of a CHO drink. No consistent differences in gastric emptying rates were observed between participants with and without DM.

Optimal Cutoffs for the Diagnosis of Sarcopenia in Older Chinese Adults

Background

The optimal criteria for sarcopenia in the older Chinese population have not been defined. Consequently, this study aims to determine the optimal cutoffs of grip strength, appendicular skeletal muscle index (ASMI) using bioelectrical impedance analysis (BIA), and gait speed, comprising the best definition of sarcopenia for older Chinese populations.

Methods

A total of 2,821 (1,398 men and 1,423 women) community-dwelling older people (≥60 years) and 409 (205 men and 204 women) young healthy adults (25–34 years) were recruited from three big cities in China. Besides gait speed and grip strength, we examined ASMI by BIA and dual-energy X-ray absorptiometry (DXA), comprising the three components of sarcopenia. DXA classification for low ASMI, 20th percentile among older adults in the study sample, was found to be best compared with the other existing classification, 1 SD and 2 SD below the mean for the young population, and was used as the gold standard to determine the optimal cutoffs of BIA using receiver operating characteristic curves (ROC). The cutoffs of handgrip strength and gait speed were determined following the same rule.

Results

Using gender-specific 20th percentiles of DXA (6.53 kg/m² for men and 5.40 kg/m² for women), the cutoffs 7.05 kg/m² for men and 5.85 kg/m² for women were determined as optimal cutoffs of BIA by achieving the largest sensitivity (0.81, 95% CI: 0.63–0.93 for men and 0.90, 95% CI: 0.73–0.98 for women) and specificity greater than 0.80 (0.80, 95% CI: 0.72–0.87 for men and 0.81, 95% CI: 0.72–0.87 for women) in the ROC analysis. The 28.5 kg and 1.05 m/s for men and 18.6 kg and 1.01 m/s for women were determined as the cutoffs for handgrip strength and gait speed, respectively. Based on the derived cutoffs, 14.2% of men and 15.7% of women in the older Chinese study population were classified as sarcopenia.

Conclusion

Notably, 7.05 kg/m², 28.5 kg, and 1.05 m/s for men and 5.85 kg/m², 18.6 kg, and 1.01 m/s for women were selected as the optimal cutoffs for low ASMI by BIA, handgrip strength, and gait speed, respectively. These optimal cutoffs will enhance practicability for screening sarcopenia in primary care and clinical settings.

Efficacy of Soy-Based Formulas in Alleviating Gastrointestinal Symptoms in Infants With Milk-Based Formula Intolerance: A Randomized Clinical Trial

A randomized, blinded pilot clinical study was conducted to assess gastrointestinal (GI) tolerance in healthy, full-term infants (2-9 weeks old), whose pediatricians recommended a formula change due to perceived cow's milk formula intolerance. Infants were randomized and exclusively fed either a commercial control soy formula (SF; n = 22), an experimental partially hydrolyzed SF (10% hydrolyzed, n = 23), or a 5% hydrolyzed SF (n = 26) for 2 weeks. Age-matched reference cohorts (n = 72) with no GI intolerance on milk-based formula were assessed in parallel. Results indicated that all SF-fed groups contributed to reduction (P < .05) in common GI tolerance symptoms to levels not different from the non-symptomatic reference cohort at study end. The control SF group had more reduced fussiness, gas, and crying and higher formed stools versus hydrolyzed SF groups. In conclusion, the study suggests that SFs reduced GI intolerance symptoms in otherwise healthy infants with poor tolerance on milk-based formulas.

Predictor Biomarkers of Nonelective Hospital Readmission and Mortality in Malnourished Hospitalized Older Adults

BACKGROUND

90-day mortality and rehospitalizations are important hospital quality metrics. Biomarkers that predict these outcomes among malnourished hospitalized patients could identify those at risk and help direct care plans.

OBJECTIVES

To identify biomarkers that predict 90-day (primary) and 30-day (secondary) mortality or nonelective rehospitalization.

DESIGN AND PARTICIPANTS

An analysis of the ability of biomarkers to predict 90- and 30-day mortality and rehospitalization among malnourished hospitalized patients.

SETTING

52 blood biomarkers were measured in 193 participants in NOURISH, a randomized trial that determined the effects of a nutritional supplement on 90-day readmission and death in patients >65 years. Composite outcomes were defined as readmission or death over 90-days or 30-days. Univariate Cox Proportional Hazards models were used to select best predictors of outcomes. Markers with the strongest association were included in multivariate stepwise regression. Final model of hospital readmission or death was derived using stepwise selection.

MEASUREMENTS

Nutritional, inflammatory, hormonal and muscle biomarkers.

RESULTS

Mean age was 76 years, 51% were men. In univariate models, 10 biomarkers were significantly associated with 90-day outcomes and 4 biomarkers with 30-day outcomes. In multivariate stepwise selection, glutamate, hydroxyproline, tau-methylhistidine levels, and sex were associated with death and readmission within 90-days. In stepwise selection, age-adjusted model that included sex and these 3 amino-acids demonstrated moderate discriminating ability over 90-days (C-statistic 0.68 (95%CI 0.61, 0.75); age-adjusted model that included sex, hydroxyproline and Charlson Comorbidity Index was predictive of 30-day outcomes (C-statistic 0.76 (95%CI 0.68, 0.85).

CONCLUSIONS

Baseline glutamate, hydroxyproline, and tau-methylhistidine levels, along with sex and age, predict risk of 90-day mortality and nonelective readmission in malnourished hospitalized older patients. This biomarker set should be further validated in prospective studies and could be useful in prognostication of malnourished hospitalized patients and guiding in-hospital care.

Specialized High-Protein Oral Nutrition Supplement Improves Home Nutrient Intake of Malnourished Older Adults Without Decreasing Usual Food Intake

Background

Reduced nutrient intake is common in patients after hospitalization, contributing to increased risk for readmission and mortality. Oral nutrition supplements can improve nutrition status and clinical outcomes, but intake of food is prioritized by clinicians. This study examines the impact of a high‐protein oral nutrition supplement (S‐ONS) on nutrient intake post discharge.

Methods

In a subset of patients (14 S‐ONS and 16 placebo) from the NOURISH (Nutrition effect On Unplanned ReadmIssions and Survival in Hospitalized patients) trial, 24‐hour dietary recalls were conducted on 3 randomly selected days during the weeks of 30, 60, and 90 days post discharge. Nutrient intake was estimated using Nutrition Data System for Research software. Adequate energy and protein intake were defined as 30 kcal/kg/d and 1.2 g/kg/d, respectively. Dietary Reference Intakes (DRIs) were used for other nutrients.

Results

Less than half of patients met the requirements for energy, protein, and 12 micronutrients from food intake alone during the study. Energy and protein intakes from food were not diminished relative to placebo. Considering nutrient intake from both food and S‐ONS, 50% and 71% of patients receiving S‐ONSs met energy and protein goals respectively at 90 days (compared with 29% and 36%, in the placebo group), and 100% met the DRI for total carbohydrate, iron, phosphorus, copper, selenium, thiamin, and riboflavin at all time points, all of which were consumed at higher amounts vs placebo.

Conclusion

Three months of S‐ONS consumption increases intake of numerous nutrients without decreasing nutrient intake from food in older malnourished adults post discharge.

Review of the Clinical Experiences of Feeding Infants Formula Containing the Human Milk Oligosaccharide 2'-Fucosyllactose

Human milk oligosaccharides (HMOs) are the third most abundant solid component in human milk after lactose and lipids. Preclinical research has demonstrated that HMOs and specifically 2′-fucosyllactose (2′-FL) are more than a prebiotic and have multiple functions, including immune, gut, and cognition benefits. Previously, human milk has been the only source for significant levels of HMOs. The most abundant HMO in most mothers’ breast milk is 2′-FL. Recently, 2′-FL has been synthesized and shown to be structurally identical to the 2′-FL found in human milk. 2′-FL HMO is now available in some commercial infant formulas. The purpose of this narrative review was to summarize the clinical experiences of feeding infant formula supplemented with the HMO, 2′-FL. Most of these studies investigated standard intact milk protein-based infant formulas containing 2′-FL, and one evaluated a partially hydrolyzed whey-based formula. Collectively, these clinical experiences demonstrated that 2′-FL being added to infant formula was safe, well-tolerated, and absorbed and excreted with similar efficiency to 2′-FL in human milk. Further, infants that were fed formula with 2′-FL had immune benefits, fewer parent-reported respiratory infections, and improved symptoms of formula intolerance. Ultimately, infant formula with 2′-FL supports immune and gut health and is closer compositionally and functionally to human milk.

Comparison of Growth of Healthy Term Infants Fed Extensively Hydrolyzed Protein- and Amino Acid-Based Infant Formulas

The aim of this narrative review was to assess published growth data for healthy, term, infants consuming extensively hydrolyzed protein-based (EHF), or amino acid-based formulas (AAF). These data may be of use to clinicians managing infants with medical conditions consuming these products. A search was conducted using key terms: amino acid-based, hydrolysate, hydrolyzed, hydrolysed, infant formula, infant formulae or formulas, baby formula, or formulae or formulas, infant, infants, infantile, and growth. Seven controlled, randomized, prospective growth trials of healthy term infants fed EHFs or AAFs at similar time points during the first four months of age met these and other criteria, including that the trial was published in a peer-reviewed journal, subjects were enrolled by ≤14 days of age and were exclusively formula-fed at entry and throughout the duration of the trial, and infants were assessed at regular intervals with weight measures available ideally at 14 days, one, two, three, and four months of age. Results suggested that healthy infants receiving commonly available EHFs and AAFs do not appear to experience accelerated growth as reported for infants fed many standard formulas. Differences in growth patterns were observed with some formulas supporting normative growth patterns during the first four months but others appearing to support markedly lower growth patterns. These observations should be confirmed in well-designed prospective randomized trials. Until that time, it is recommended that EHFs and AAFs be chosen carefully with individual patient needs considered.

A Randomized Controlled Multicenter Trial of an Investigational Liquid Nutritional Formula in Women with Cyclic Breast Pain Associated with Fibrocystic Breast Changes

Objective: A randomized, multicenter, controlled double-blind trial was performed in women with cyclic breast pain (mastalgia) associated with fibrocystic breast changes (FBCs) to determine whether a nutritional formula reduced breast pain and/or nodularity.

Study Design: Women were randomized to receive a specifically designed liquid formulation (n = 93) (1 g gamma-linolenic acid [GLA], 750 μg iodine, and 70 μg selenium) or control formula (n = 95) (without GLA, iodine, and selenium) daily for three cycles. Women recorded breast pain, medications, and menstrual signs daily using interactive voice-response system. Nodularity was determined by physical breast examination.

Results: Breast pain scores decreased similarly in the experimental (−32.2%) and control (−33.1%) groups (p = 0.64). Nodularity was reduced in the experimental, but not the control group (p = 0.03). Among women who continued pain medication, the amount was reduced in the experimental group relative to controls (p = 0.02).

Conclusion: Women with FBC using the formula containing GLA, iodine, and selenium experienced reduced nodularity and in those women who took over-the-counter breast pain medication, a decrease in the quantity of pain medication was observed.

Readmission and mortality in malnourished, older, hospitalized adults treated with a specialized oral nutritional supplement: A randomized clinical trial

BACKGROUND

Hospitalized, malnourished older adults have a high risk of readmission and mortality.

OBJECTIVE

Evaluation of a high-protein oral nutritional supplement (HP-HMB) containing beta-hydroxy-beta-methylbutyrate on postdischarge outcomes of nonelective readmission and mortality in malnourished, hospitalized older adults.

DESIGN

Multicenter, randomized, placebo-controlled, double-blind trial.

SETTING

Inpatient and posthospital discharge.

PATIENTS

Older (≥65 years), malnourished (Subjective Global Assessment [SGA] class B or C) adults hospitalized for congestive heart failure, acute myocardial infarction, pneumonia, or chronic obstructive pulmonary disease.

INTERVENTIONS

Standard-of-care plus HP-HMB (n = 328) or a placebo supplement (n = 324), 2 servings/day.

MEASUREMENTS

Primary composite endpoint was 90-day postdischarge incidence of death or nonelective readmission. Other endpoints included 30- and 60-day postdischarge incidence of death or readmission, length of stay (LOS), SGA class, body weight, and activities of daily living (ADL).

RESULTS

The primary composite endpoint was similar between HP-HMB (26.8%) and placebo (31.1%). No between-group differences were observed for 90-day readmission rate, but 90-day mortality was significantly lower with HP-HMB relative to placebo (4.8% vs. 9.7%; relative risk 0.49, 95% confidence interval [CI], 0.27 to 0.90; p = 0.018). The number-needed-to-treat to prevent 1 death was 20.3 (95% CI: 10.9, 121.4). Compared with placebo, HP-HMB resulted in improved odds of better nutritional status (SGA class, OR, 2.04, 95% CI: 1.28, 3.25, p = 0.009) at day 90, and an increase in body weight at day 30 (p = 0.035). LOS and ADL were similar between treatments.

LIMITATIONS

Limited generalizability; patients represent a selected hospitalized population.

CONCLUSIONS

Although no effects were observed for the primary composite endpoint, compared with placebo HP-HMB decreased mortality and improved indices of nutritional status during the 90-day observation period.

CLINICAL TRIAL REGISTRATION

www.ClinicalTrials.govNCT01626742.

A New Hydrolyzed Formula is Well Tolerated in Infants with Suspected Food Protein Allergy or Intolerance

Background:

Extensively hydrolyzed formulas (eHF) are indicated for infants with food protein allergy. The purpose of the study was to assess the tolerance and compliance of an intended population of infants to a new formulation of a hypoallergenic eHF.

Methods:

A non-random, single-group, multicenter study was conducted. Infants with suspected food protein allergy, persistent feeding intolerance, or presenting conditions where an eHF was deemed appropriate were enrolled in a 15-day feeding trial. Intake, stool patterns, weight (wt), length, and questionnaires were collected. The primary outcome was maintenance of wt for age Z-score during the study.

Results:

25 infants (85 ± 8.9 d of age) were enrolled; 7 were ≥ 4 months; 4 were preterm. At entry, 12 had symptoms of allergic colitis or food protein allergy/intolerance, 12 had persistent formula intolerance, 11 had hematochezia/heme positive stools, and 1 was recovering from necrotizing enterocolitis. Mean wt for age Z-score was -0.62 ± 0.19 at entry and -0.41 ± 0.16 at exit. Mean change in wt for age Z-score was 0.21 ± 0.10. Mean formula intake was 764 ± 48 mL/day. The mean number of stools/day was 1.8 ± 0.4 and the predominant stool consistencies were loose/mushy (48%) or soft (43%).

Conclusion:

The results suggest that this eHF was well accepted and tolerated by an intended use population of infants during the first 6 months of life which enabled adequate volume consumption, maintenance of wt for age Z-scores and a high level of parental satisfaction.

Evaluation of a free amino acid-based formula in infants with presumptive food protein-induced proctocolitis

Objective:

Food protein–induced proctocolitis usually occurs early in life and is characterized by blood-streaked stools and pain during defecation in an otherwise healthy infant. While many infants with food protein–induced proctocolitis respond well to a casein hydrolysate formula, some require an amino acid–based formula. The objective of the study was to measure the change in physician-rated symptom score from enrollment to study completion in infants with presumptive food protein–induced proctocolitis fed with a specific amino acid-based formula.

Methods:

In this study, infants ≤6 months of age diagnosed with presumptive food protein–induced proctocolitis received an amino acid-based formula for 42 days. Intake, stool patterns, weight, stool occult blood, and questionnaires assessing infant feeding and stool patterns and parental formula satisfaction were collected.

Results:

The full analysis set included 43 infants. The mean age at enrollment was 59 ± 5 days. A significant improvement was observed from enrollment to exit in physician-rated symptom score (9.1 ± 0.5 to 4.8 ± 0.5, p < 0.0001), the number of infants with occult blood in stool, and weight-for-age Z-scores during the study. Parental satisfaction with the formula was high.

Conclusion:

The results confirm that the amino acid-based formula studied is efficacious for managing symptoms of presumptive food protein–induced proctocolitis.

Effect of oral nutritional supplementation on wound healing in diabetic foot ulcers: a prospective randomized controlled trial

AIMS

Among people with diabetes, 10-25% will experience a foot ulcer. Research has shown that supplementation with arginine, glutamine and β-hydroxy-β-methylbutyrate may improve wound repair. This study tested whether such supplementation would improve healing of foot ulcers in persons with diabetes.

METHODS

Along with standard of care, 270 subjects received, in a double-blinded fashion, (twice per day) either arginine, glutamine and β-hydroxy-β-methylbutyrate or a control drink for 16 weeks. The proportion of subjects with total wound closure and time to complete healing was assessed. In a post-hoc analysis, the interaction of serum albumin or limb perfusion, as measured by ankle-brachial index, and supplementation on healing was investigated.

RESULTS

Overall, there were no group differences in wound closure or time to wound healing at week 16. However, in subjects with an albumin level of ≤ 40 g/l and/or an ankle-brachial index of < 1.0, a significantly greater proportion of subjects in the arginine, glutamine and β-hydroxy-β-methylbutyrate group healed at week 16 compared with control subjects (P = 0.03 and 0.008, respectively). Those with low albumin or decreased limb perfusion in the supplementation group were 1.70 (95% CI 1.04-2.79) and 1.66 (95% CI 1.15-2.38) times more likely to heal.

CONCLUSIONS

While no differences in healing were identified with supplementation in non-ischaemic patients or those with normal albumin, addition of arginine, glutamine and β-hydroxy-β-methylbutyrate as an adjunct to standard of care may improve healing of diabetic foot ulcers in patients with risk of poor limb perfusion and/or low albumin levels. Further investigation involving arginine, glutamine and β-hydroxy-β-methylbutyrate in these high-risk subgroups might prove clinically valuable.

Growth of healthy term infants fed ready-to-feed and powdered forms of an extensively hydrolyzed casein-based infant formula: a randomized, blinded, controlled trial

Extensively hydrolyzed formulas present a complex matrix subject to adverse conditions during manufacture that could influence growth and tolerance of infants fed these formulas. A masked, randomized, parallel growth study was conducted in infants fed a ready-to-feed (RTF) or powdered (PWD) form of an extensively hydrolyzed casein-based formula. Infants were enrolled between 0 and 9 days and studied to 112 days of age. Growth, formula intake, and stool patterns were assessed. There were no significant differences between groups in weight, length, head circumference, or their respective gains. Tolerance was similar between groups except that the RTF group had greater formula intakes and passed more stools/day compared to the PWD group. This study demonstrates that the PWD formulation of this RTF formula supports similar growth and tolerance in infants during the first 4 months of life.

Effect of dietary ribonucleotides on infant immune status. Part 1: Humoral responses

The objective of this study was to further explore previously identified effects of supplemental ribonucleotides on infant immune status as measured by antibody responses to routine infant immunizations. Infants were randomized to a milk-based formula with (FN, n = 138) or without (F, n = 147) 72 mg ribonucleotides/L. A cohort of human milk-fed (HMF, n = 192) infants was also followed. Subjects were given Haemophilus influenzae type b (Hib), diphtheria tetanus acellular pertussis, and oral poliovirus vaccinations at 2, 4, and 6 mo of age, and specific antibody responses were assessed at 2, 6, 7, and 12 mo. Growth and safety data were also monitored. Using a two-group repeated measures analysis (RMA), FN-fed infants had significantly higher poliovirus type 1 neutralizing antibody (PV-VN1) responses than F-fed infants (p = 0.045). Using three-group RMA, PV-VN1 responses in HMF infants were not different from FN-fed infants, while HMF-fed infant PV-VN1 responses were significantly higher than F-fed infants at 6 (p = 0.0004) and 12 mo (p = 0.0001). FN-fed infants had responses to Hib Farr, diphtheria, tetanus toxoid, oral poliovirus-specific IgA, and PV-VN3 not significantly different from those of F and HMF infants. Growth, gastrointestinal tolerance, and adverse events were equivalent among the three groups. The FN-associated increase in PV-VN1 response and nonstatistically significant trends toward increased Hib and diphtheria antibody responses were consistent with observations from earlier studies, indicating immune benefits of nucleotide supplementation of infant formula.

Effect of dietary ribonucleotides on infant immune status. Part 2: Immune cell development

The objective of this study was to determine whether dietary ribonucleotides alter immune cell phenotypes or function in the first year of life. Newborn term infants in a double-blind, 12-mo, multicenter trial were randomized to cow milk formula groups with (FN, n = 138) or without (F, n = 147) 72 mg/L supplemental ribonucleotides. A nonrandomized HMF cohort (n = 192) was concurrently enrolled. Eighty-eight immune blood cell types were characterized by flow cytometry. Data were analyzed by multivariate ANOVA (MANOVA), ANOVA, and repeated measures analysis (RMA), with adjustments made for multiple comparisons. Ribonucleotide feeding changed subpopulations of T and natural killer (NK) cells. FN had higher numbers and percentages of memory/effector (M/E) cytotoxic/suppressor (CD45R0(+)CD8(+), RMA) T, Fas(+) M/E (CD45R0(+)CD95(+)CD3(+), 6 mo) T, and CD56(+)CD16(-) NK cells (CD56(+)CD16(-)CD3(-)CD8(-), 12 mo), and higher percentages of M/E helper (CD45R0(+)CD4(+), RMA) T, Tc1 (IFN gamma(+)CD4(-)CD3(+), RMA), total interferon (IFN)gamma T (IFN gamma(+)CD4(+/-)CD3(+), RMA), Th2 (IL-4(+)CD4(+)CD3(+), 7 mo), and CD57(+) NK-T cells (CD57(+)CD56(-)CD3(+), 6 mo, 7 mo) compared with F. Percentages of naive helper T (CD45RA(+)CD4(+), 12 mo) and numbers and percentages of CD56(+) NK-T cells (CD56(+)CD16(-)CD3(+)CD8(-), 2 mo, 6 mo) were lower in FN than F. Percentages of M/E cytotoxic/suppressor, Th2, and CD56(+)CD16(-) NK cells in FN were significantly higher than F but were not different from HMF, whereas F was significantly lower than HMF. Ribonucleotide supplementation of infant formula supported increased T-cell maturation and affected immunoregulatory NK cell subsets. These FN-associated immune cell profiles either did not differ from those infants fed HMF or tended to be more like those fed HMF than those fed F.

Formula tolerance in postbreastfed and exclusively formula-fed infants

OBJECTIVE

Perceived intolerance to infant formula is a frequently reported reason for formula switching. Formula intolerance may be related to perceived symptoms of constipation, fussiness, abdominal cramps, and excessive spit-up or vomit. Commercially available formulas differ from each other in processing and in sources and levels of protein, lipids, and micronutrients. These differences may affect tolerance. The objective of this article was to compare the tolerance of two commercially available powder infant formulas that differ in composition. Measures of tolerance in exclusively breastfed infants weaned to an infant formula and exclusively formula-fed infants were evaluated.

METHODS

Two clinical studies were conducted. In study 1, 82 healthy, full-term infants who were exclusively breastfed at the time of enrollment were randomized at weaning to formula A (commercially available Similac With Iron Powder) or formula B (previously available Enfamil With Iron Powder). Parents completed daily records of tolerance during exclusive breast milk feeding, during the weaning period, and for a 2-week exclusive formula-feeding period. In study 2, 87 healthy, full-term infants who were exclusively formula-fed at the time of study enrollment (by 2 weeks of age) were fed a standard cow milk-based formula (previously commercially available Similac With Iron Powder) and then randomized to receive formula A or B for a 2-week period. Parents completed daily records of tolerance throughout the study. Formula A was a cow milk-based formula with a whey:casein ratio of 48:52 and a fat blend of 42% high-oleic safflower, 30% coconut, and 28% soy oils. Formula B was a cow milk-based formula with a whey:casein ratio of 60:40 and a fat blend of 45% palm olein, 20% soy, 20% coconut, and 15% high-oleic sunflower oils. Both formulas had lactose as the source of carbohydrate and contained 12 mg of iron per liter. Only formula A contained nucleotides at the time of the study. Measures of tolerance included volume of each formula feeding, occurrences of spit-up and/or vomit, and the color (yellow, green, brown, or black) and consistency (water, loose/mushy, soft, formed, or hard) of each stool.

RESULTS

In both studies, volume of formula intake, weight gain, and incidence of spit-up or vomit did not differ between feeding groups. In study 1, stool frequency decreased significantly from the exclusive breast milk period to weaning. Stools also became firmer as infants moved from breast milk to weaning and to exclusive formula feeding. When formula was introduced into the diet, stools became less yellow and more green. Infants weaned to formula B had less frequent stools, fewer brown stools, and more yellow stools than did infants fed formula A. In both studies, infants fed formula B experienced significantly firmer stools than did those fed formula A.

CONCLUSIONS

The present clinical studies indicate that the composition and/or processing of milk-based powder iron-fortified infant formulas affect stool characteristics experienced by infants. The inclusion of palm olein oil in formula B may be the reason for the observed differences in stool characteristics. Palm olein is used in infant formulas to provide palmitic acid at a level similar to that found in breast milk. However, palmitic acid from palm olein is arranged differently from that in breast milk triglyceride and is poorly absorbed. Unabsorbed palmitic acid tends to react with calcium to form insoluble soaps, and the level of these soaps is correlated with stool hardness. The pattern of softer stools and greater frequency of stooling associated with formula A is similar to the stool pattern in the exclusively breastfed infant. Thus, the use of formula A may ease the transition from breast milk to formula feeding and ameliorate parents' perception that constipation is associated with iron-fortified formula.