INFANT FORMUA PRODUCTS

Introduction Human milk is most physiologically suited to infants Optimal source for feeding infants till 12 months Human milk is the only source of nutrition till 6 months of life. For infants whose mother cannot or will not breast feed them, alternatives are needed

Infant physiology and growth: GI and renal systems GI maturation Infant Formula Products: Introduction Infant physiology and growth: GI and renal systems GI maturation Second trimester of pregnancy: all segments of GIT are formed Third trimester; maximal GI growth and differentiation. Preterm infants (before 32 weeks of gestation) Transition from intrauterine to extra uterine feeding requires maturation of many physiologic processes, e.g…. Nutritive sucking: 33-34 weeks of gestation. No problem in term infants, but in premature,,,,, Preterm (before 34 weeks) cannot coordinate sucking, swallowing and breathing

Definition of Premature Birth 􀂃 The WHO and AAP define premature birth as the delivery of an infant before 37 weeks of gestation. A full term infant: 37-42 weeks of gestation 􀂃 The NCHS of the CDC generally reports data on three categories of preterm birth: 1. Overall preterm, less than 37 weeks 2. Moderately preterm, 32 and 36 weeks 3. Very preterm births, less than 32 weeks

Early infancy: Liquid nutrition only: poor coordination of complex tongue movements and swallowing Frequent feeding: limited stomach capacity: 20-90 ml at birth, 90-150 ml at 1 month Term infants: gastric and pepsin secretion peaks at 10 days, in preterm basal acid output is low Milk in the stomach increases pH, poor pepsin activity

CHO digestion: lactase, sucrase, maltase, isomaltase, glucoamylase are mature. Lactase activity may be immature in premature infants. Pancreatic amylase is low in full term infants, till 1 year of life. Salivary amylase may compensate for that Low pancreatic lipase concentration, bile salt synthesis is low, lingual and gastric lipases compensate Protein digestion and absorption are mature

Kidney maturation: Ability of the kidney to excrete solute load Glomerular filtration starts in the 9th week of fetal life GFR increases after birth and reaches adult level at age of 3

Growth: Average birth weight: 3.5 Kg Premature infants: LBW: less than 2500 gm VLBW: less than 1500 gm 6-10% weight loss after birth Weight gain: 20-25gm daily till 4th month, 12gm/day for the coming 8 months Double the weight by 4 months and triple by 12 months Changes in body composition occurs as well: at birth, total boy water is 70% and decreases to 60% at 1 year. Adipose tissue increases Normal values are expressed as percentiles: see growth charts

Introduction, cont. Nutritional standards Acceptable growth needs a balance between adequate intake: absorption and utilization of energy. Recommended Dietary Allowance (RDA), energy requirements Components of a healthy infant diet Fluid:100ml/kg per day for the first 10 kg + 50ml/kg for each additional kg. Water intake in the first 6 months is derived from breast milk or formula CHO: 40-50% of total calories. Should be balanced with fat intake to allow better development. Lactose is the primary source. Lactose intolerance: lactase deficiency Congenital lactase deficiency is rare Secondary lactase deficiency: in some cases of gastroenteritis

Introduction, cont. 3. Protein and amino acids: 2.2gm/kg/day (birth-6 months), 1.6gm/kg/day (6-12 months) Composition Essential a.a.: isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, valine Conditionally essential a.a.:cystein, taurine, tyrosine, histidine 4. Fat and essential fatty acids Most dense source of calories in the diet Supplies 40-50% of the energy intake of infants Essential PUFA: Linoliec acid, linolenic acid: precursors for LCPUFA: DHA and ARA 5. Micronutrients -Vitamins Biotin, choline, inositol Minerals: calcium, phosphorous, Iron, zinc, copper, manganese

Milk production Lactating mammary gland: Branching network of ducts formed of epithelial cells ending in extensive lobulo alveolar clusters that are the site of milk secretion Alveoli are surrounded by myoepithelial cells that function in milk ejection, and a vascularized connective tissue containing adipocytes and fibroblasts Ejection of milk requires contraction of the myoepithelial cells stimulated by oxytocin Lactating alveolar cell: highly active secretory cell numerous mitochondria Extensive rough endoplasmic reticulum Well developed Golgi apparatus Epithelium is connected by tight junctions Basal side contacts myoepithelial cells and the basement mem