Evaluation of a Plant-Based Infant Formula Containing Almonds and Buckwheat on Gut Microbiota Composition, Intestine Morphology, Metabolic and Immune Markers in a Neonatal Piglet Model.

A controlled-neonatal piglet trial was conducted to evaluate the impact of a plant-based infant formula containing buckwheat and almonds as the main source of protein compared to a commercially available dairy-based formula on the gut health parameters. Two day old piglets were fed either a plant-based or a dairy-based formula until day 21. Gut microbiome, cytokines, growth and metabolism related outcomes, and intestinal morphology were evaluated to determine the safety of the plant-based infant formula. This study reported that the plant-based formula-fed piglets had a similar intestinal microbiota composition relative to the dairy-based formula-fed group. However, differential abundance of specific microbiota species was detected within each diet group in the small and large intestinal regions and fecal samples. Lactobacillus delbrueckii, Lactobacillus crispatus, and Fusobacterium sp. had higher abundance in the small intestine of plant-based formula-fed piglets compared to the dairy-based group. Bacteroides nordii, Enterococcus sp., Lactobacillus crispatus, Prevotella sp., Ruminococcus lactaris, Bacteroides nordii, Eisenbergiella sp., Lactobacillus crispatus, Prevotella sp., and Akkermansia muciniphila had greater abundance in the large intestine of the plant based diet fed piglets relative to the dairy-based diet group. In the feces, Clostridiales, Bacteroides uniformis, Butyricimonasvirosa, Cloacibacillus porcorum, Clostridium clostridioforme, and Fusobacterium sp. were abundant in dairy-based group relative to the plant-based group. Lachnospiraceae, Clostridium scindens, Lactobacillus coleohominis, and Prevetolla sp. had greater abundance in the feces of the plant-based group in comparison to the dairy-based group. Gut morphology was similar between the plant and the dairy-based formula-fed piglets. Circulatory cytokines, magnesium, triiodothyronine (T3), thyroxine (T4), thyroid stimulating hormone (TSH), vitamin D, vitamin K, and IgE levels were similar among all piglets independent of dietary group. Overall, the present study demonstrated that a plant-based formula with buckwheat and almonds as the primary source of protein can support similar gut microbiota growth and health outcomes compared to a dairy-based infant formula.

Evaluation of the Safety of a Plant-Based Infant Formula Containing Almonds and Buckwheat in a Neonatal Piglet Model.

A randomized neonatal piglet trial was conducted to evaluate the safety and the effects of a plant-based formula containing almonds and buckwheat as the main ingredients on growth and plasma parameters. From postnatal day (PND) 2 to 21, the piglets were fed a dairy-based milk formula (Similac Advance) or a plant-based formula (Else Nutrition) and all piglets were euthanized at day 21. No diarrhea was observed after PND 8 and all the piglets completed the trial. Body growth, kcal intake, the complete plasma count parameters and hematological parameters were within the reference range in both groups. Organ growth and development was similar between the two groups. Plasma glucose was higher in the dairy-based-fed piglets relative to the plant-based at 2 weeks of age. Liver function biomarkers levels were greater in the plasma of the plant-based compared to the dairy-based fed group. In addition, calcium levels were higher in the plant-based fed piglets at 1 week of age. Thus, the plant-based formula tested in this study was well tolerated by the piglets and supported similar growth compared to dairy-based milk formula. Therefore, the results support the safety of the tested plant-based infant formula during the neonatal period in comparison to the dairy-based formula fed group.

Modulating Sterol Concentrations in Infant Formula Influences Cholesterol Absorption and Synthesis in the Neonatal Piglet.

Formula-fed infants present higher cholesterol synthesis rates and lower circulating cholesterol during the postnatal feeding period compared to breast-fed infants, though the mechanisms underlying this phenotype are not fully understood. Typical infant formulas contain vegetable-based fats, inherently including phytosterols (PS), which are structurally similar to cholesterol and may interfere with their absorption. A seven-day old piglets model was used to test the inhibitory effects of PS on cholesterol absorption during postnatal feeding. Following feeding for 21 days with milk-based formulas containing PS and cholesterol levels resembling those in formulas or human-milk, apparent cholesterol digestibility was analyzed in ileal digesta, and cholesterol, PS, and cholesterol synthesis markers were analyzed in plasma and liver samples. Ileal cholesterol digestibility content was increased in the piglets fed low PS formulas and the rate of the hepatic cholesterol synthesis, as determined by the lathosterol-to-cholesterol ratios (L:C), was decreased in the piglets fed LP-formulas and corresponded to reduced nuclear expression of SREBP2 relative to those fed HP-formulas. These results are consistent with the hypothesis that PS in formula can inhibit cholesterol absorption and enhance cholesterol synthesis. Whether or not this leads to entrainment of cholesterol synthesis later in life via early programming awaits further research.

Beta Palmitate Improves Bone Length and Quality during Catch-Up Growth in Young Rats.

Palmitic acid (PA) is the most abundant saturated fatty acid in human milk, where it is heavily concentrated in the sn-2-position (termed beta palmitate, BPA) and as such is conserved in all women, regardless of their diet or ethnicity, indicating its physiological and metabolic importance. We hypothesized that BPA improves the efficiency of nutrition-induced catch up growth as compared to sn-1,3 PA, which is present in vegetable oil. Pre-pubertal male rats were subjected to a 17 days food restriction followed by re-feeding for nine days with 1,3 PA or BPA-containing diets. We measured bone length, epiphyseal growth plate height (EGP, histology), bone quality (micro-CT and 3-point bending assay), and gene expression (Affymetrix). The BPA-containing diet improved most growth parameters: humeri length and EGP height were greater in the BPA-fed animals. Further analysis of the EGP revealed that the hypertrophic zone was significantly higher in the BPA group. In addition, Affymetrix analysis revealed that the diet affected the expression of several genes in the liver and EGP. Despite the very subtle difference between the diets and the short re-feeding period, we found a small but significant improvement in most growth parameters in the BPA-fed rats. This pre-clinical study may have important implications, especially for children with growth disorders and children with special nutritional needs.

SN2-Palmitate Reduces Fatty Acid Excretion in Chinese Formula-fed Infants.

OBJECTIVES: Palmitic acid (PA) comprises 17% to 25% of human milk fatty acids, of which 70% to 75% are esterified to the SN2 position of the triglyceride (SN2-palmitate). In vegetable oils, which are commonly used in infant formulas, palmitate is primarily esterified to other positions, resulting in reduced calcium and fat absorption and hard stools. The aim of this study was to elucidate the effects of SN2-palmitate on nutrient excretion. METHODS: In total, 171 Chinese infants were included (within 14 days of birth) in this multicenter study. Formula-fed infants were randomly assigned to receive either SN2-palmitate formula (INFAT, n = 57) or control formula (n = 57). The formulas (Biostime, China) differed only in their SN2 PA proportions. Stool was collected at 6 postnatal weeks. RESULTS: The stool dry weight and fat content of the SN2-palmitate group were lower compared with the control group (dry weight 4.25 g vs 7.28 g, P < 0.05; fat 0.8 g vs 1.2 g, P < 0.05). The lipid component was also significantly lower for the SN2-palmitate group (0.79 g vs 1.19 g, P < 0.05). PA, representing ∼50% of the saponified fatty acids, was significantly lower in the SN2-palmitate group compared with the control group (0.3 g vs 0.7 g, P < 0.01). Breast-fed infants had a significantly lower stool dry weight, fat content, and saponified fat excretion compared with formula-fed infants (P < 0.01). CONCLUSIONS: Similar to breast milk, the SN2-palmitate infant formula primarily reduced calcium-saponified fat excretion. The results of this study further emphasize the nutritional importance of SN2-palmitate structured fat for infants.

Reduced crying in term infants fed high beta-palmitate formula: a double-blind randomized clinical trial.

BACKGROUND: Beta-palmitate (sn-2 palmitate) mimics human milk fat, enabling easier digestion.Therefore, we hypothesized that infants consuming high beta-palmitate formula would have more frequent, softer stools and reduced crying compared to infants consuming low beta-palmitate formula. METHODS: Formula-fed infants were randomly assigned to receive either (1) formula with high beta-palmitate (HBP, n = 21) or (2) regular formula with a standard vegetable oil mix (LBP, n = 21). A matched group of breastfed infants served as a reference (BF, n = 21). Crying and stool characteristics data were recorded by the parents for 3 days before the 6- and 12-week visits. RESULTS: We found no significant differences in the stool frequency or consistency between the two formula groups. The percentage of crying infants in the LBP group was significantly higher than that in the HBP and BF groups during the evening at 6 weeks (88.2% vs. 56.3% and 55.6%, p < 0.05) and during the afternoon at 12 weeks (91.7% vs. 50.0% and 40%, p < 0.05). The infants fed HBP had significantly shorter crying durations when compared with infants fed LBP formula (14.90 ± 3.85 vs.63.96 ± 21.76 min/day, respectively; p = 0.047). CONCLUSIONS: Our study indicates that consumption of a high beta-palmitate formula affects infant crying patterns during the first weeks of life. Comparable to breastfeeding, it reduced crying duration and frequency, primarily during the afternoon and evening hours, thereby improving the well-being of formula-fed infants and their parents. TRIAL REGISTRATION: NCT00874068.Registration date March 31, 2009.

High beta-palmitate fat controls the intestinal inflammatory response and limits intestinal damage in mucin Muc2 deficient mice.

BACKGROUND: Palmitic-acid esterified to the sn-1,3 positions of the glycerol backbone (alpha, alpha'-palmitate), the predominant palmitate conformation in regular infant formula fat, is poorly absorbed and might cause abdominal discomfort. In contrast, palmitic-acid esterified to the sn-2 position (beta-palmitate), the main palmitate conformation in human milk fat, is well absorbed. The aim of the present study was to examine the influence of high alpha, alpha'-palmitate fat (HAPF) diet and high beta-palmitate fat (HBPF) diet on colitis development in Muc2 deficient (Muc2(-/-)) mice, a well-described animal model for spontaneous enterocolitis due to the lack of a protective mucus layer. METHODS: Muc2(-/-) mice received AIN-93G reference diet, HAPF diet or HBPF diet for 5 weeks after weaning. Clinical symptoms, intestinal morphology and inflammation in the distal colon were analyzed. RESULTS: Both HBPF diet and AIN-93G diet limited the extent of intestinal erosions and morphological damage in Muc2(-/-) mice compared with HAPF diet. In addition, the immunosuppressive regulatory T (Treg) cell response as demonstrated by the up-regulation of Foxp3, Tgfb1 and Ebi3 gene expression levels was enhanced by HBPF diet compared with AIN-93G and HAPF diets. HBPF diet also increased the gene expression of Pparg and enzymatic antioxidants (Sod1, Sod3 and Gpx1), genes all reported to be involved in promoting an immunosuppressive Treg cell response and to protect against colitis. CONCLUSIONS: This study shows for the first time that HBPF diet limits the intestinal mucosal damage and controls the inflammatory response in Muc2(-/-) mice by inducing an immunosuppressive Treg cell response.

Review of sn-2 palmitate oil implications for infant health.

Human milk provides the optimal balanced nutrition for the growing infant in the first months after birth. The human mammary gland has evolved with unusual pathways, resulting in a specific positioning of fatty acids at the outer sn-1 and sn-3, and center sn-2 of the triacylglyceride, which is different from the triglycerides in other human tissues and plasma. The development of structured triglycerides enables mimicking the composition as well as structure of human milk fat in infant formulas. Studies conducted two decades ago, together with very recent studies, have provided increasing evidence that this unusual positioning of 16:0 in human milk triglycerides has a significant role for infant health in different directions, such as fat and calcium absorption, bone health, intestinal flora and infant comfort. This review aims to unravel the relevance of human milk triglyceride sn-2 16:0 for intestinal health and inflammatory pathways and for other post-absorption effects.

Effect of high ß-palmitate content in infant formula on the intestinal microbiota of term infants.

OBJECTIVES: Palmitic acid (PA) constitutes 17% to 25% of the human milk fatty acids, and ~70% is esterified in the sn-2 position of triglycerides (ß-palmitate). In the sn-2 position, PA is not hydrolyzed and thus is efficiently absorbed. The PA in palm oils, commonly used in infant formulas, is esterified in the sn-1 and sn-3 positions. In these positions, PA is hydrolyzed and forms poorly absorbed calcium complexes. The present study assessed whether high ß-palmitate in infant formulas affects the intestinal flora. METHODS: Thirty-six term infants were enrolled: 14 breast-fed (BF group) and 22 formula-fed infants who were randomly assigned to receive formula containing high ß-palmitate (HBP group, n=14), or low ß-palmitate (LBP group, n=8), where 44% and 14% of the PA was ß-palmitate, respectively. The total amount of PA in the formulas was 19% and 22% in the LBP and HBP groups, respectively. Neither formula contained pre- or probiotics. Stool samples were collected at enrollment and at 6 weeks for the quantification of bacteria. RESULTS: At 6 weeks, the HBP and BF groups had higher Lactobacillus and bifidobacteria counts than the LBP group (P<0.01). The Lactobacillus counts at 6 weeks were not significantly different between the HBP and BF groups. Lactobacillus counts were 1.2×10¹°, 1.2×10¹¹, and 5.6×10¹° CFU/g for LBP, HBP, and BF groups, respectively. Bifidobacteria counts were 5.1×109, 1.2×10¹¹, and 3.9×10¹° CFU/g for LBP, HBP, and BF groups, respectively. CONCLUSIONS: HBP formula beneficially affected infant gut microbiota by increasing the Lactobacillus and bifidobacteria counts in fecal stools.

High Beta-palmitate formula and bone strength in term infants: a randomized, double-blind, controlled trial.

We aimed to compare the effect of 12-week feeding of commercially available infant formulas with different percentages of palmitic acid at sn-2 (beta-palmitate) on anthropometric measures and bone strength of term infants. It was hypothesized that feeding infants with high beta-palmitate (HBP) formula will enhance their bone speed of sound (SOS). Eighty-three infants appropriate for gestational age participated in the study; of these, 58 were formula-fed and 25 breast-fed infants, serving as a reference group. The formula-fed infants were randomly assigned to receive HBP formula (43 % of the palmitic acid is esterified to the middle position of the glycerol backbone, study group; n = 30) or regular formula with low-beta palmitate (LBP, 14 % of the palmitic acid is esterified to the middle position of the glycerol backbone, n = 28). Sixty-six infants completed the 12-week study. Anthropometric and quantitative ultrasound measurements of bone SOS for assessment of bone strength were performed at randomization and at 6 and 12 weeks postnatal age. At randomization, gestational age, birth weight, and bone SOS were comparable between the three groups. At 12 weeks postnatal age, the mean bone SOS of the HBP group was significantly higher than that of the LBP group (2,896 ± 133 vs. 2,825 ± 79 m/s respectively, P = 0.049) and comparable with that of the breast-fed group (2,875 ± 85 m/s). We concluded that infants consuming HBP formula had changes in bone SOS that were comparable to those of infants consuming breast milk and favorable compared to infants consuming LBP formula.

FOXO1 represses peroxisome proliferator-activated receptor-gamma1 and -gamma2 gene promoters in primary adipocytes. A novel paradigm to increase insulin sensitivity.

FOXO1 and peroxisome proliferator-activated receptor-gamma (PPARgamma) are crucial transcription factors that regulate glucose metabolism and insulin responsiveness in insulin target tissues. We have shown that, in primary rat adipocytes, both factors regulate transcription of the insulin-responsive GLUT4 gene and that PPARgamma2 detachment from the GLUT4 promoter upon thiazolidinedione binding up-regulates GLUT4 gene expression, thus increasing insulin sensitivity (Armoni, M., Kritz, N., Harel, C., Bar-Yoseph, F., Chen, H., Quon, M. J., and Karnieli, E. (2003) J. Biol. Chem. 278, 30614-30623). However, the mechanisms regulating PPARgamma gene transcription are largely unknown. We studied the effects of FOXO1 on human PPARgamma gene expression in primary rat adipocytes and found that both genes are endogenously expressed. FOXO1 coexpression dose-dependently repressed transcription from either the PPARgamma 1 or PPARgamma2 promoter reporter by 65%, whereas insulin (100 nm, 20-24 h) either partially or completely reversed this effect. Phosphorylation-defective FOXO1 mutants T24A, S256A, S319A, and T24A/S256A/S319A still repressed the PPARgamma1 promoter and partially lost their effects on the PPARgamma2 promoter in either basal or insulin-stimulated cells. Use of DNA binding-defective FOXO1 (H215R) indicated that this domain is crucial for FOXO1 repression of the PPARgamma2 (but not PPARgamma1) promoter. Progressive 5'-deletion and gel retardation analyses revealed that this repression involves direct and specific binding of FOXO1 to the PPARgamma2 promoter; chromatin immunoprecipitation analysis confirmed that this binding occurs in cellulo. We suggest a novel paradigm to increase insulin sensitivity in adipocytes in which FOXO1 repression of PPARgamma, the latter being a repressor of the GLUT4 promoter, consequently leads to GLUT4 derepression/up-regulation, thus enhancing cellular insulin sensitivity. The newly identified FOXO1-binding site on the PPARgamma2 promoter may serve as a therapeutic target for type 2 diabetes.

Free fatty acids repress the GLUT4 gene expression in cardiac muscle via novel response elements.

Hyperlipidemia (HL) impairs cardiac glucose homeostasis, but the molecular mechanisms involved are yet unclear. We examined HL-regulated GLUT4 and peroxisome proliferator-activated receptor (PPAR) gamma gene expression in human cardiac muscle. Compared with control patients, GLUT4 protein levels were 30% lower in human cardiac muscle biopsies from patients with HL and/or type 2 diabetes mellitus, whereas GLUT4 mRNA levels were unchanged. PPARgamma mRNA levels were 30-50% lower in patients with HL and/or diabetes mellitus type 2 than in controls. Reporter studies in H9C2 cardiomyotubes showed that HL in vitro, induced by high levels of arachidonic (AA) stearic, linoleic, and oleic acids (24 h, 200 mum) repressed transcription from the GLUT4 promoter; AA also repressed transcription from the PPARgamma1 and PPARgamma2 promoters. Co-expression of PPARgamma2 repressed GLUT4 promoter activity, and the addition of AA further enhanced this effect. 5'-Deletion analysis revealed three GLUT4 promoter regions that accounted for AA-mediated effects: two repression-mediating sequences at -443/-423 bp and -222/-197 bp, the deletion of either or both of which led to a partial derepression of promoter activity, and a third derepression-mediating sequence at -612/-587 bp that was required for sustaining this derepression effect. Electromobility shift assay further shows that AA enhanced binding to two of the three regions of cardiac nuclear protein(s), the nature of which is still unknown. We propose that HL, exhibited as a high free fatty acid level, modulates GLUT4 gene expression in cardiac muscle via a complex mechanism that includes: (a) binding of AA mediator proteins to three newly identified response elements on the GLUT4 promoter gene and (b) repression of GLUT4 and the PPARgamma genes by AA.

The tumor suppressor p53 down-regulates glucose transporters GLUT1 and GLUT4 gene expression.

Tumorigenesis is associated with enhanced cellular glucose uptake and increased metabolism. Because the p53 tumor suppressor is mutated in a large number of cancers, we evaluated whether p53 regulates expression of the GLUT1 and GLUT4 glucose transporter genes. Transient cotransfection of osteosarcoma-derived SaOS-2 cells, rhabdomyosarcoma-derived RD cells, and C2C12 myotubes with GLUT1-P-Luc or GLUT4-P-Luc promoter-reporter constructs and wild-type p53 expression vectors dose dependently decreased both GLUT1 and GLUT4 promoter activity to approximately 50% of their basal levels. PG(13)-Luc activity, which was used as a positive control for functional p53 expression, was increased up to approximately 250-fold by coexpression of wild-type p53. The inhibitory effect of wild-type p53 was greatly reduced or abolished when cells were transfected with p53 with mutations in amino acids 143, 248, or 273. A region spanning -66/+163 bp of the GLUT4 promoter was both necessary and sufficient to mediate the inhibitory effects of p53. Furthermore, in vitro translated p53 protein was found to bind directly to two sequences in that region. p53-DNA binding was completely abolished by excess unlabeled probe but not by nonspecific DNA and was super-shifted by the addition of an anti-p53 antibody. Taken together, our data strongly suggest that wild-type p53 represses GLUT1 and GLUT4 gene transcription in a tissue-specific manner. Mutations within the DNA-binding domain of p53, which are usually associated with malignancy, were found to impair the repressive effect of p53 on transcriptional activity of the GLUT1 and GLUT4 gene promoters, thereby resulting in increased glucose metabolism and cell energy supply. This, in turn, would be predicted to facilitate tumor growth.

Peroxisome proliferator-activated receptor-gamma represses GLUT4 promoter activity in primary adipocytes, and rosiglitazone alleviates this effect.

The synthetic thiazolidinedione ligands of peroxisome proliferator-activated receptor-gamma (PPARgamma) improve insulin sensitivity in type II diabetes and induce GLUT4 mRNA expression in fat and muscle. However, the molecular mechanisms involved are still unclear. We studied the regulatory effects of PPARgamma and its ligands on GLUT4 gene expression in primary rat adipocytes and CHO-K1 cells cotransfected with PPARgamma and the GLUT4 promoter reporter. PPARgamma1 and PPARgamma2 repressed the activity of the GLUT4 promoter in a dose-dependent manner. Whereas this repression was augmented by the natural ligand 15Delta-prostaglandin J2, it was completely alleviated by rosiglitazone (Rg). Ligand binding-defective mutants PPARgamma1-L468A/E471A and PPARgamma2-L496A/E499A retained the repression effect, which was unaffected by Rg, whereas the PPARgamma2-S112A mutant exhibited a 50% reduced capacity to repress GLUT4 promoter activity. The -66/+163 bp GLUT4 promoter region was sufficient to mediate PPARgamma inhibitory effects. The PPARgamma/retinoid X receptor-alpha heterodimer directly bound to this region, whereas binding was abolished in the presence of Rg. Thus, we show that PPARgamma represses transcriptional activity of the GLUT4 promoter via direct and specific binding of PPARgamma/retinoid X receptor-alpha to the GLUT4 promoter. This effect requires an intact Ser112 phosphorylation site on PPARgamma and is completely alleviated by Rg, acting via its ligand-binding domain. These data suggest a novel mechanism by which Rg exerts its antidiabetic effects via detaching PPARgamma from the GLUT4 gene promoter, thus leading to increased GLUT4 expression and enhanced insulin sensitivity.