Structural and functional abnormalities of the small intestine due to nutritional folic acid deficiency in infancy

Effects of folic acid and riboflavin on growth performance, nutrient digestion and rumen fermentation in Angus bulls

This study examined the influences of coated folic acid (CFA) and coated riboflavin (CRF) on bull performance, nutrients digestion and ruminal fermentation. Forty-eight Angus bulls based on a randomised block and 2 × 2 factorial design were assigned to four treatments. The CFA of 0 or 6 mg of folic acid/kg DM was supplemented in diets with CRF 0 or 60 mg riboflavin (RF)/kg DM. Supplementation of CRF in diets with CFA had greater increase in daily weight gain and feed efficiency than in diets without CFA. Supplementation with CFA or CRF enhanced digestibility of DM, organic matter, crude protein, neutral-detergent fibre and non-fibre carbohydrate. Ruminal pH and ammonia N content decreased and total volatile fatty acids concentration and acetate to propionate ratio elevated for CFA or CRF addition. Supplement of CFA or CRF increased the activities of fibrolytic enzymes and the numbers of total bacteria, protozoa, fungi, dominant fibrolytic bacteria and Prevotella ruminicola. The activities of α-amylase, protease and pectinase and the numbers of Butyrivibrio fibrisolvens and Ruminobacter amylophilus were increased by CFA but were unaffected by CRF. Blood concentration of folate elevated and homocysteine decreased for CFA addition. The CRF supplementation elevated blood concentrations of folate and RF. These findings suggested that CFA or CRF inclusion had facilitating effects on performance and ruminal fermentation, and combined addition of CFA and CRF had greater increase in performance than CFA or CRF addition alone in bulls.

Effects of maternal and post-weaned rumen-protected folic acid supplementation on slaughter performance and meat quality in offspring lambs

The present study was undertaken to evaluate the influence of rumen-protected folic acid (RPFA) on slaughter performance, visceral organ and gastrointestinal tract coefficients, and meat quality in lambs. Sixty-six lambs from 120 Hu ewes were selected based on body weight and maternal diets and then assigned to six groups using a randomised block experimental design in a 3 × 2 factorial arrangement. The first factor was folic acid (FA) as RPFA in the maternal diet (0 mg/kg (M0F), 16 mg/kg (M16F) or 32 mg/kg (M32F) on DM basis). The second factor was FA in the lambs' diet from weaning until slaughter (0 mg/kg (OC) or 4·0 mg/kg (OF)). The results indicated that the addition of 16 mg/kg FA to the maternal diet increased pre-slaughter weight (PSW), dressing and meat percentage, the reticulum and omasum coefficients, length of the jejunum and ileum, tail fat and perirenal fat coefficient and a* value of the meat colour. The addition of RPFA to the lambs' diet increased PSW, dressing and meat percentage, eye muscle area, abomasum weight, weight and length of the small intestine, but reduced the coefficients of tail fat. An M × O interaction was observed for the weights of heart, lungs, rumen and total stomach, weight and coefficient of omental fat and the girth rib value. Collectively, RPFA in the maternal and lambs' diet improved slaughter performance and meat quality by stimulating the morphological development of the gastrointestinal tract and the distribution of fat in the body.

Effects of varying dietary folic acid during weaning stress of piglets

The present study was conducted to evaluate the effect of dietary folic acid on the growth performance, intestinal morphology, and intestinal epithelial cells renewal in post-weaning piglets. Twenty-eight piglets (weaned at day 21, initial body weight of 6.73 ± 0.62 kg) were randomly allotted to 4 treatments with 7 pens per diet and 1 piglet per pen. The piglets were fed the same antibiotic-free and zinc oxide-free basal diets supplemented with folic acid at 0, 3, 9, and 18 mg/kg for 14 days. The results showed that dietary supplementation with folic acid increased villus height (VH) (P = 0.003; linear, P = 0.001), VH-to-crypt depth (VH:CD) ratio (P = 0.002; linear, P = 0.001), villus surface area (VSA) (P = 0.026; linear, P = 0.010). The analyzed parameters ADG, serum urea nitrogen (BUN) content, VH, VSA, and serum folate (SF) concentration responded linearly to the dietary folic acid concentration when the dietary folic acid concentration was below 4.42, 5.26, 4.79, 3.47, and 3.53 mg/kg respectively (R² = 0.995, 0.995, 0.999, 0.999, 0.872, P = 0.09, 0.07, 0.09, 0.09, 0.36, respectively), as assessed by a two-linear broken-line regression. Above these breakpoints, the response of ADG, VH, VSA, and SF plateaued in response to changes in dietary folic acid concentration. Moreover, dietary supplementation with folic acid significantly increased the lactase (P = 0.001; linear, P = 0.001) and sucrase activities (P = 0.021; linear, P = 0.010) in the jejunal mucosa of weaned piglets. The mRNA expression of solute carrier family 6 member 19 (SLC6a19), solute carrier family 1 member 1 (SLC7a1), tumor necrosis factor-α (TNF-α), the number of Ki67 positive cells, and cell shedding rate had a significant linear contrast (P = 0.023, 0.021, 0.038, 0.049, and 0.008, respectively) in dietary folic acid groups. In conclusion, our results indicate that folic acid supplementation can improve the growth performance and intestinal morphology of weaned piglets by maintaining the balance of epithelial cell renewal.

Maternal Folic Acid Supplementation Differently Affects the Small Intestinal Phenotype and Gene Expression of Newborn Lambs from Differing Litter Sizes

The purpose of this study was to investigate the effect of maternal dietary folic acid (FA) supplementation during gestation on small intestinal development of newborn lambs of different litter sizes, focusing on the intestinal morphology and development-, apoptosis- and digestion-related genes expression. One hundred and twenty Hu ewes (Ovis aries) were inseminated and randomly allotted to three groups. One group received a control diet [without FA supplementation, control (CON)] and the other two groups received control diets supplemented with different amount of FA [16 or 32 mg FA per kg dry matter (DM), i.e., F16 and F32] during pregnancy. After lambing, according to the dietary FA levels and litter size (twins, TW; triplets, TR), the neonatal lambs were divided into 6 (TW-CON, TW-F16, TW-F32, TR-CON, TR-F16, TR-F32) treatment groups. The results showed that the ratio of small intestinal weight to live body weight and the thickness of the intestinal muscle layer in the offspring was enhanced significantly with increasing maternal FA supplementation (p < 0.05). Meanwhile, the expression levels of insulin-like growth factor I (IGF-I), B-cell lymphoma-2 (BCL-2) and sodium/glucose co-transporter-1 (SGLT1) in the small intestines of the newborn lambs were increased, while the opposite was true for Bcl2-associated × (BAX) in response to FA supplementation (p < 0.05). Moreover, the small intestinal weights of twins were significantly higher than those of triplets (p < 0.01), and the expression levels of IGF-I (p < 0.05), sucrase-isomaltase (SI) (p < 0.05) and solute carrier family 2 member 5 (SLC2A5) (p < 0.01) were significantly lower than those in triplets. These findings suggest that maternal FA supplementation could improve the offspring's small intestinal phenotype and the expression of development-, apoptosis- and digestion-related genes, so it could promote the small intestinal development of newborn lambs. Furthermore, the small intestine phenotypic development of twins was generally better than that of triplets, while the expression levels of the above genes of twins were lower than those of triplets.

A 100-Year Review: Advances in goat milk research

In the century of research chronicled between 1917 and 2017, dairy goats have gone from simply serving as surrogates to cows to serving as transgenic carriers of human enzymes. Goat milk has been an important part of human nutrition for millennia, in part because of the greater similarity of goat milk to human milk, softer curd formation, higher proportion of small milk fat globules, and different allergenic properties compared with cow milk; however, key nutritional deficiencies limit its suitability for infants. Great attention has been given not only to protein differences between goat and cow milk, but also to fat and enzyme differences, and their effect on the physical and sensory properties of goat milk and milk products. Physiological differences between the species necessitate different techniques for analysis of somatic cell counts, which are naturally higher in goat milk. The high value of goat milk throughout the world has generated a need for a variety of techniques to detect adulteration of goat milk products with cow milk. Advances in all of these areas have been largely documented in the Journal of Dairy Science (JDS), and this review summarizes such advances.

The Importance of Milk and other Animal-Source Foods for Children in Low-Income Countries

Background

Milk and other animal-source foods are concentrated dietary sources of macro- and micronutrients. Despite a global increase in milk production and consumption over the past decades, milk and other animal-source foods are often lacking in the diets of children in developing countries.

Objective

To evaluate the importance of milk and other animal-source food intake in promoting the growth, development, and health of children in low-income countries.

Methods

Original research articles describing observational and intervention studies with unfortified milk, fortified milk, and other animal-source foods in children were identified by searching the PubMed database.

Results

Consumption of milk and other animal-source foods by undernourished children improves anthropometric indices and cognitive function and reduces the prevalence of biochemical and functional nutritional deficiencies, reducing morbidity and mortality. Unfortified and fortified milk used in supplementation trials has been well tolerated and widely accepted by parents and children.

Conclusions

To improve the dietary quality of children in low-income countries and further the effort to eradicate extreme poverty and hunger in accordance with the United Nations Millennium Development Goals, additional research is necessary to identify and implement programs and policy supporting increased intake of milk and other animal-source foods.

Folate and colorectal cancer: an evidence-based critical review

Currently available evidence from epidemiologic, animal, and intervention studies does not unequivocally support the role of folate, a water-soluble B vitamin and important cofactor in one-carbon transfer, in the development and progression of colorectal cancer (CRC). However, when the portfolio of evidence from these studies is analyzed critically, the overall conclusion supports the inverse association between folate status and CRC risk. It is becoming increasingly evident that folate possesses dual modulatory effects on colorectal carcinogenesis depending on the timing and dose of folate intervention. Folate deficiency has an inhibitory effect whereas folate supplementation has a promoting effect on the progression of established colorectal neoplasms. In contrast, folate deficiency in normal colorectal mucosa appears to predispose it to neoplastic transformation, and modest levels of folic acid supplementation suppress, whereas supraphysiologic supplemental doses enhance, the development of cancer in normal colorectal mucosa. Several potential mechanisms relating to the disruption of one-carbon transfer reactions exist to support the dual modulatory role of folate in colorectal carcinogenesis. Based on the lack of compelling supportive evidence and on the potential tumor-promoting effect, routine folic acid supplementation should not be recommended as a chemopreventive measure against CRC at present.

Níveis de ácido fólico sérico em lactentes eutróficos, alimentados com leite materno, leite de vaca ou fórmula modificada

OBJETIVO: Verificar os níveis de ácido fólico em três grupos de lactentes e comparar os valores encontrados; avaliar a necessidade de suplementação dessa vitamina aos quatro meses, quando as reservas teciduais são escassas e as fontes dietéticas pobres em folatos, em um período no qual a alimentação é exclusivamente láctea. MÉTODOS: Foram analisados os níveis de ácido fólico sérico, obtidos pelo método de radioimunoensaio, em 120 lactentes eutróficos, aos quatro meses, com alimentação láctea exclusiva, sendo 40 com aleitamento materno, 40 com leite de vaca pasteurizado e fervido e 40 com fórmula láctea industrializada e enriquecida com ácido fólico. RESULTADOS: Os níveis de ácido fólico sérico nos lactentes alimentados exclusivamente com leite de vaca pasteurizado e fervido foram significativamente menores do que os dos lactentes alimentados com leite materno e os alimentados com fórmula láctea modificada, enriquecida com folatos. Estes dois últimos grupos não mostraram diferenças entre si. CONCLUSÕES: O estudo ressalta a necessidade de suplementação de ácido fólico nos lactentes aos quatro meses alimentados exclusivamente com leite de vaca. A pasteurização e a fervura do leite de vaca, habitualmente utilizadas, levam à deficiência dessa vitamina, tão importante na nutrição humana.

Folate Deficiency Results in Alteration in Intestinal Brush Border Membrane Composition and Enzyme Activities in Weanling Rats

Folic acid deficiency is the most prevalent vitamin deficiency throughout the world and its effect on brush border membrane composition has not been studied earlier. We investigated the effect of folate deficiency on the structure and function of the intestinal brush border membrane. Various brush border enzyme activities, membrane sugars and lipids were evaluated in two groups of weanling male albino rats after 3 mo of feeding control and folate deficient diets. Except sucrase, all the other three enzymes, viz., alkaline phosphatase, leucine amino peptidase and y-glutamyl transpeptidase showed decrease in activity in rats fed folate-deficient diets. Among sugars, hexoses and hexosamines showed significant decline in amount whereas sialic acid content showed great increase in brush border membrane of folate-deficient rats as compared to controls. Furthermore, there was a significant reduction in cholesterol, phospholipids, triglycerides, cerebrosides and fucolipids in the group fed the folate-deficient diet. Our study suggests that folate deficiency results in altered enzyme activities, lipid and sugar composition of intestinal brush border membrane. Such changes might reflect the underlying cause of the gastrointestinal disturbances observed in folate deficiency.

Severe folate deficiency impairs natural killer cell-mediated cytotoxicity in rats

Dietary folate deficiency enhances, whereas folate supplementation suppresses, the development of several cancers. This study investigated the effect of folate deficiency on natural killer cell (NK)-mediated cytotoxicity, which is important in immune surveillance against tumor cells. In Experiment 1, severe folate deficiency was induced in rats by feeding an amino acid-defined diet containing 0 mg folate and 10 g succinylsulfathiazole/kg diet. Control and folate-supplemented rats were fed the same diet containing 2 (basal requirement) and 8 mg folate/kg diet, respectively. Severe folate deficiency at the end of wk 5 was associated with 20% growth retardation, a 60% reduction in lymphocyte counts and significantly impaired NK-mediated cytotoxicity compared with the control and folate-supplemented groups (P < 0.02). The lesser degree of severe folate deficiency achieved by wk 4 was not associated with impaired NK-mediated cytotoxicity. Folate supplementation at 4x the basal requirement did not significantly enhance NK-mediated cytotoxicity at either time point. In Experiment 2, moderate folate deficiency was induced in rats by feeding the same diet without succinylsulfathiazole. NK-mediated cytotoxicity in the moderately folate-deficient rats (without growth retardation or lymphopenia) was not significantly different from that in controls. Although severe folate deficiency may have adverse effects on NK-mediated cytotoxicity, moderate folate deficiency, a degree of depletion associated with an increased risk of several cancers, appears not to affect NK-mediated cytotoxicity in rats. Furthermore, a modest level of folate supplementation above the basal requirement does not enhance NK-mediated cytotoxicity. These data collectively suggest that NK-mediated cytotoxicity is not a likely mechanism by which folate status modulates carcinogenesis.

Morphometric analysis of small intestinal mucosa. IV. Determining cell volumes

This study was concerned with the measurement of volumes of surface epithelial cells in human small intestine, both in disease-control subjects and, for comparison, in patients with gluten sensitivity. Four procedures were employed, of which two were geometrical, based on cylindrical or truncated conoid models. The third method evolved from the proportionality of area to volume, and required determination of cellular and nuclear profile areas, and an estimation of nuclear volume based on models conforming to (1) a prolate spheroid, or (2) a cylinder with hemispherical caps. This procedure appeared to underestimate enterocyte volumes and failed to reveal volume differences between controls and gluten-sensitive individuals. Finally, a fourth method was devised, based on traditional intraepithelial profile counts per hundred enterocyte nuclei, calculation of surface epithelial volume and of the absolute number of lymphocytes contained therein. Enterocyte volumes appeared to be overestimated twofold by this procedure compared with the first two geometric methods. The results of this study indicate that the cuboidal-type enterocyte profiles typical of the untreated mucosa in gluten sensitivity are a reflection of cells with a reduced volume. From the number of enterocytes and the absolute lymphocyte population present within a morphometrically defined volume of surface epithelium, the ratios of intraepithelial lymphocytes to enterocytes were found to be 50% less than conventional density-profile counts.

Goat's milk and infant feeding

As goat's milk becomes more popular in Australia, clinicians are being asked about its suitability as an infant feed. The popularity of goat's milk in part comes from unsubstantiated claims that it is less allergenic and more digestible than is cow's milk. Raw goat's milk is used by those who believe that pasteurization is detrimental, although the risks of consuming unpasteurized milk have been well documented and recent reports have warned about the dangers of feeding unmodified goat's milk to infants. If goat's milk is to be fed to infants it should be pasteurized or boiled, diluted to reduce solute load, and then fortified with vitamins. Although these modifications do not produce an ideal milk, they do minimize the risks of using goat's milk as an infant feed.

Plasma and red cell folate values and folate requirements in formula-fed premature infants

Plasma and red cell folate concentrations (lactobacillus casei activity) and other pertinent blood values have been studied during the 1st year of life in 41 premature infants (mean gestational age 31.6, range 26-35 weeks). They were formula-fed, 48.5 nmol (21 micrograms) folate per 1, from 1 month of age. The infants were divided into two groups according to their birth weights (BW): group A, BW less than or equal to 1750 g and group B, BW greater than 1750 g, respectively. One-half of the infants in each group received an extra 113.5 nmol (50 micrograms) folic acid daily. The premature infants were compared with 35 breast-fed term infants considered to have an optimal folate status. The infants not receiving folic acid supplementation had low plasma and red cell folate concentrations during the first months of life, while those receiving supplementation had values comparable to the breast-fed infants. No significant differences in the gain in weight and increase in length were observed when the folic acid supplemented infants in group A were compared with the non-supplemented infants. However, in the case of group B a significant increase in length and a somewhat greater weight gain were observed for infants with folic acid supplementation in comparison with those not given extra folate. No significant differences were observed between the haemoglobin, RBC and VPRC values in the folic acid supplemented and non-supplemented infants. It is estimated that the optimal folate intake during the first months of life in formula-fed premature infants is about 150 nmol (65 micrograms) per day. This amount is higher than previously recommended. The infants from all groups had a folate intake similar to, or above, the minimal daily requirement needed for erythropoiesis.

Small bowel function in acute lymphoblastic leukaemia

Small bowel function before, during, and after treatment for acute lymphoblastic leukaemia was studied in 26 children. A significant impairment of D-xylose absorption was found during treatment. Permeability studies showed a significant decrease in mannitol and a significant increase in lactulose concentrations; five of 20 children tested had evidence of lactose malabsorption, three of whom were symptomatic. Intestinal function abnormalities were greater in children whose methotrexate treatments were separated by 7 day than by 16 day intervals. Only five (19%) children had no abnormal tests. Abnormalities of small bowel function may be treatment induced and this has implications for morbidity from gastrointestinal symptoms, impairment of the mucosal barrier, and malabsorption of both nutrients and drugs leading to malnutrition and suboptimal drug concentrations.

Enteropathy complicating maintenance therapy in acute lymphoblastic leukaemia

Seven patients being treated for acute lymphoblastic leukaemia between March 1976 and March 1981, in accordance with Medical Research Council protocols, developed clinical malabsorption while on maintenance chemotherapy. All of them received weekly methotrexate and 6 of the 7 were given co-trimoxazole. Five patients had folate deficiency. Stopping the anti-leukaemic therapy led to a resolution of gastrointestinal symptoms. A combined effect of methotrexate and co-trimoxazole is postulated.

Plasma and red cell folate values and folate requirements in formula-fed term infants

Plasma and red cell folate concentrations (L. casei activity) and other pertinent blood values have been studied during the first year of life in 64 term infants. After weaning and until 6 months of age, 33 infants were given milk formula I (88 nmole [39 micrograms] folate per liter) and 31 infants MF II (178 nmole [78 micrograms] folate per liter). These infants were compared with 35 breast-fed term infants, considered to have an optimal folate status. The mean folate concentration in the human milk consumed at 3 months of age was 124 nmole (55 micrograms) per liter. The infants fed MF I had low plasma and red cell folate concentrations during the first months of life. The infants fed MF II had folate values almost comparable to those of the breast-fed infants. The weight gain in the infants fed MF II was significantly higher than observed in the infants fed MF I during the first 6 months of life. No significant differences related to folate deficiency were observed between the hemoglobin, RBC, and VPRC values in the formula-fed infants and those recorded in the breast-fed infants. It is estimated that the optimal folate intake during the first months of life in formula-fed infants is about 170 nmole (75 micrograms) per day. This amount is higher than previously recommended. Infants from all groups had folate intake similar to, or above, the minimal daily requirement needed for the erythropoiesis.

Plasma and red blood cell folate in breastfed infants

We have studied growth, red blood cell status and folate concentrations in plasma and red cells in a group of 35 breastfed infants during the first year of life. Folic acid supplementation was not given to the mothers during pregnancy or lactation, and none of them developed megaloblastic anaemia. The growth and red blood cell status of the infants were both normal. At birth, and throughout the period of observation, the folate concentrations in plasma and red cells were significantly higher than in the adult reference material. A positive correlation between plasma and red cell folate was demonstrated. During the latter part of pregnancy and lactation the foetuses and infants seem to be protected against folate deficiency. We regard the folate status of normal breastfed infants as optimal. The optimal supply of the vitamin in artificial nutrition should be the amount of folate necessary to maintain plasma and red cell folate concentrations similar to those found in breastfed infants.