Talk:BGDB Gastrointestinal - Postnatal

BGD Internal Links 2009 6. Postnatal

The early settlers: intestinal microbiology in early life

Annu Rev Food Sci Technol. 2012;3:425-47. doi: 10.1146/annurev-food-022811-101120. Epub 2012 Jan 3.

Scholtens PA, Oozeer R, Martin R, Amor KB, Knol J. Source Danone Research, Centre for Specialised Nutrition, 6700 CA, Wageningen, Netherlands. petra.scholtens@danone.com

Abstract

The human intestinal microbiota forms an integral part of normal human physiology, and disturbances of the normal gut microbiology have been implicated in many health and disease issues. Because newborns are essentially sterile, their microbiota must establish and develop from the very first days of life. The first colonizers play an important role in the development of the ecosystem and may impact the long-term composition and activity of the microbiota. These first settlers obviously develop and proliferate dependent on host characteristics and diet, but other factors can also significantly contribute to this vital biological process. Considering the importance of the microbiota for the human immune, metabolic, and neurological systems, it is important to understand the dynamics and driving determinants of this development. This review gives a global overview of our current understanding of the different factors impacting the intestinal microbiology in early life.

PMID 22224552

http://www.annualreviews.org/doi/full/10.1146/annurev-food-022811-101120

Neural regulation of intestinal nutrient absorption

Prog Neurobiol. 2011 Oct;95(2):149-62. doi: 10.1016/j.pneurobio.2011.07.010. Epub 2011 Jul 27.

Mourad FH, Saadé NE. Source Department of Internal Medicine, Faculty of Medicine, American University of Beirut, Beirut, Lebanon. fmourad@aub.edu.lb

Abstract

The nervous system and the gastrointestinal (GI) tract share several common features including reciprocal interconnections and several neurotransmitters and peptides known as gut peptides, neuropeptides or hormones. The processes of digestion, secretion of digestive enzymes and then absorption are regulated by the neuro-endocrine system. Luminal glucose enhances its own absorption through a neuronal reflex that involves capsaicin sensitive primary afferent (CSPA) fibres. Absorbed glucose stimulates insulin release that activates hepatoenteric neural pathways leading to an increase in the expression of glucose transporters. Adrenergic innervation increases glucose absorption through α1 and β receptors and decreases absorption through activation of α2 receptors. The vagus nerve plays an important role in the regulation of diurnal variation in transporter expression and in anticipation to food intake. Vagal CSPAs exert tonic inhibitory effects on amino acid absorption. It also plays an important role in the mediation of the inhibitory effect of intestinal amino acids on their own absorption at the level of proximal or distal segment. However, chronic extrinsic denervation leads to a decrease in intestinal amino acid absorption. Conversely, adrenergic agonists as well as activation of CSPA fibres enhance peptides uptake through the peptide transporter PEPT1. Finally, intestinal innervation plays a minimal role in the absorption of fat digestion products. Intestinal absorption of nutrients is a basic vital mechanism that depends essentially on the function of intestinal mucosa. However, intrinsic and extrinsic neural mechanisms that rely on several redundant loops are involved in immediate and long-term control of the outcome of intestinal function. Copyright © 2011 Elsevier Ltd. All rights reserved.

PMID 21854830

Antiinfective properties of human milk

J Nutr. 2008 Sep;138(9):1801S-1806S.

Chirico G, Marzollo R, Cortinovis S, Fonte C, Gasparoni A.

Department of Neonatology and Neonatal Intensive Care, Spedali Civili, 25123 Brescia, Italy. gaechirico@alice.it Abstract The unfavorable effects of neonatal immunodeficiency are limited by some naturally occurring compensatory mechanisms, such as the introduction of protective and immunological components of human milk in the infant. Breast-feeding maintains the maternal-fetal immunological link after birth, may favor the transmission of immunocompetence from the mother to her infant, and is considered an important contributory factor to the neonatal immune defense system during a delicate and crucial period for immune development. Several studies have reported that breast-feeding, because of the antimicrobial activity against several viruses, bacteria, and protozoa, may reduce the incidence of infection in infants. The protection from infections may be ensured either passively by factors with antiinfective, hormonal, enzymatic, trophic, and bioactive activity present in breast milk, or through a modulator effect on the neonatal immune system exerted by cells, cytokines, and other immune agents in human milk.

PMID: 18716190 http://www.ncbi.nlm.nih.gov/pubmed/18716190

Reevaluation of the DHA requirement for the premature infant

Prostaglandins Leukot Essent Fatty Acids. 2009 Aug-Sep;81(2-3):143-50. Epub 2009 Jul 5

Lapillonne A, Jensen CL.

APHP, Paris Descartes University, Paris, France. alexandre.lapillonne@svp.aphp.fr

Abstract

The long-chain polyunsaturated fatty acid (LC-PUFA) intake in preterm infants is crucial for normal central nervous system development and has the potential for long-lasting effects that extend beyond the period of dietary insufficiency. While much attention has focused on improving their nutritional intake, many premature infants do not receive an adequate DHA supply. We demonstrate that enterally fed premature infants exhibit daily DHA deficit of 20mg/kg.d, representing 44% of the DHA that should have been accumulated. Furthermore, the DHA content of human milk and current preterm formulas cannot compensate for an early DHA deficit which may occur during the first month of life. We recommend breast-feeding, which supplies preformed LC-PUFA, as the preferred method of feeding for preterm infants. However, to fulfill the specific DHA requirement of these infants, we recommend increasing the DHA content of human milk either by providing the mothers with a DHA supplement or by adding DHA directly to the milk. Increasing the DHA content above 1% total fatty acids appears to be safe and may enhance neurological development particularly that of infants with a birth weight below 1250 g. We estimate that human milk and preterm formula should contain approximately 1.5% of fatty acid as DHA to prevent the appearance of a DHA deficit and to compensate for the early DHA deficit.

• LC-PUFA, particularly docosahexaenoic acid (DHA) and arachidonic acid (AA), accumulate rapidly during the brain growth spurt
• During the last trimester of pregnancy, the placenta provides the fetus with AA and DHA.
• highly concentrated in cell membranes of the retina and brain
• have important effects on membrane function, neurogenesis, photoreceptor differentiation, activation of the visual pigment rhodopsin, protection against oxidative stress, the activity of several enzymes, the function of ion channels, and the levels and metabolism of neurotransmitters and eicosanoids

PMID: 19577914 http://www.ncbi.nlm.nih.gov/pubmed/19577914