Microbes and the Developing Gastrointestinal Tract

Pediatrics, College of Medicine, University of Florida, Gainesville, FL 32510, USA.
Nutrition in Clinical Practice (Impact Factor: 2.4). 05/2007; 22(2):174-82. DOI: 10.1177/0115426507022002174
Source: PubMed


During the course of mammalian evolution, there has been a close relationship between microbes residing in the gastrointestinal (GI) tract and the mammalian host. Although the host provides the microbes with a warm environment and nutrients, they, in turn, undergo various metabolic processes that aid the host. The host has developed weapons against microbes that are considered foreign, as well as mechanisms to tolerate and live synergistically with most of the microbes in the GI tract. This relationship is proving to be important not only in the neonatal period and during infancy, but it is becoming increasingly evident that microbial colonization in early life may affect the individual's health throughout life. Here we will review this relationship in terms of health and disease, with a focus on the aspects of this relationship during maturation of the host.

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    • "Given their gastrointestinal introduction of mutualistic or commensal symbiotic bacteria, probiotics have the potential to confer many beneficial effects to the host at the cellular level. For example, such symbionts can promote maturation of the intestinal barrier function, reduce growth of potentially pathogenic organisms, enhance the production of anti-inflammatory cytokines, increase antioxidant activities, and regulate apoptosis (4,5). From a macroscopic perspective, many clinical studies included in this meta-analysis also showed a positive impact of probiotics in the prevention of NEC and its complications. "
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    ABSTRACT: Necrotizing enterocolitis (NEC) is one of the most common acquired diseases of the gastrointestinal tract in preterm infants. Some randomized, controlled trials (RCTs) have indicated that probiotics may potentially lower the incidence of NEC and mortality. However, debate still remains about the safety of probiotics and their influence on normal infant growth. We performed this meta-analysis to assess the safety and benefits of probiotic supplementation in preterm infants. We searched in PubMed, Embase, and Cochrane databases for English references, and in Wanfang, VIP, and CNKI databases for Chinese references. Ultimately, 27 RCTs (including 9 Chinese articles) were incorporated into this meta-analysis. Relative risk (RR) and weighted mean difference (WMD) were calculated using a random-effects or fixed-effects model, depending on the data type and heterogeneity. A total of 6655 preterm infants, including the probiotic group (n=3298) and the placebo group (n=3357), were eligible for inclusion in this meta-analysis. For Bell stage ≥I and gestational age <37 weeks, risk of NEC incidence was significantly lower in the probiotic group [RR=0.35, 95% confidence interval (CI)=0.27-0.44, P<0.00001]. For Bell stage ≥II or gestational age <34 weeks, there were likewise significant differences between the probiotic and placebo groups concerning NEC incidence (RR=0.34, 95%CI=0.25-0.48, P<0.00001; and RR=0.39, 95%CI=0.27-0.56, P<0.00001). Risk of death was significantly reduced in the probiotic group (RR=0.58, 95%CI=0.46-0.75, P<0.0001). In contrast, there was no significant difference concerning the risk of sepsis (RR=0.94, 95%CI=0.83-1.06, P=0.31). With respect to weight gain and the age at which infants reached full feeds, no significant differences were found between the probiotic and placebo groups (WMD=1.07, 95%CI=-0.21-2.34, P=0.10; and WMD=-1.66, 95%CI=-3.6-0.27, P=0.09). This meta-analysis has shown that, regardless of gestational age and NEC stage, probiotic supplementation could significantly reduce the risk of NEC in preterm infants. Analysis also indicated that such supplementation did not increase the incidence risk of sepsis or of mortality. Finally, the study showed that probiotic supplementation may have no adverse effect on normal feeding and growth.
    Brazilian journal of medical and biological research = Revista brasileira de pesquisas medicas e biologicas / Sociedade Brasileira de Biofisica ... [et al.] 08/2014; DOI:10.1590/1414-431X20143857 · 1.01 Impact Factor
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    ABSTRACT: The mammalian gastrointestinal (GI) tract harbors a complex micro-ecosystem consisting of countless bacteria. As an essential 'organ', the gut microbiota plays an important role in host nutrition and health by promoting supply, digestion and absorption of nutrient, preventing pathogen's colonization, and shaping and maintaining normal mucosal immunity. Antibiotics used as dietary additive not only interrupt the commensal microbiota in animal GI tract, but also lead to microbial resistance and antibiotics residues in animal products, which has become a worldwide problem to the health of human being and animals. So antibiotics have been banned as feed additives in many countries. Therefore, animal nutritionists and feed manufacturers are becoming increasingly interested in the topic. This paper mainly focuses on the development and important functions of microbes in monogastric GI tract as well as the factors affecting them. Applications of some novel alternatives in practice to keep GI tract ecosystem healthy, such as probiotics, prebiotics, Chinese herbal additives and exogenous enzymes, and their mechanisms were also introduced. The new alternatives to keep health of GI tract have great ecological, environmental issues and economic social effects. It may lead to the rational design of supplementation for animal production to study the functions of the microbiota, which has profound implications to support continuous development in livestock production in the future.
    Journal of Food Agriculture and Environment 04/2010; 8(2). · 0.44 Impact Factor
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