**6. Probiotics and premature infants**

Prematurity compromises the anatomical and functional development of all organs, in inverse proportion to the gestational age. Some peculiarities of the preterm are the high incidence of respiratory diseases, the multi-systemic immaturity, even if nutrition constitutes one of the major actual problem to afford.

The preterm infant lacks of the sucking reflex, has a restricted gastric and intestinal capacity, insufficient absorption of the main food, that contribute to both quantitative and qualitative nutritional deficiencies.

The lack of an adequate nutrition decreases the synthesis of surfactant and anti-oxidant molecules, thus causing a delayed lung maturation and both cellular and humoral immune response, responsible for an increase of the catabolism, promoting the use of endogenous proteins. Therefore, the goal of the nutrition of the ELBW infant is the manteinance of his post-natal growth, similarly of what happens in utero, preventing the protein catabolism (through the use of endogenous proteins: lean body mass), avoid the weight loss during the first 2 weeks after birth, assuring a high energetic rate since his first day of life, thus reducing the percentage of preterms with a weight less than 10° percentile at discharge.

Nowadays the first approach to ELBW preterms is the parenteral nutrition since their first day of life (with the prompt introduction of glucose as it is the main source of energy and it reduces the catabolism of endogenous proteins since the first 2 hours after birth, and the introduction of lipids since the first 24 hours after birth). It is also important the introduction of low quantities of milk (minimal enteral feeding) via oral or nasal-gastric way in order to promote the feeding tolerance and the increase of enteral production of cholecystokinin that stimulates the bile function, protecting the liver from hepatic steatosis due to parenteral nutrition.

It is important that these procedures are managed in a gradual way in order to avoid the tiredness of the infant and the aspiration of milk with regurgites. For this reason it is conceivable using a fortified maternal formula for premature infants, with a daily increase of the feeding, paying attention to abdominal distension, vomit, gastric stagnation, apneas, and diarrhea.

It is conceivable to stop the parenteral nutrition when the energetic rate reach a quote of 80cal/Kg/die and the daily increase of milk must not be more than 10ml/Kg/die, and

environmental factors such as geographic region and diet, and study variables including

In an RCT, 53 Australian infants with moderate-to-severe atopic dermatitis were given either Lactobacillus fermentum or placebo for 8 weeks. At final assessment at 16 weeks, significantly more children who received the probiotic had improved extent and severity of atopic dermatitis as measured by the Severity of Scoring of Atopic Dermatitis (SCORAD) index over time compared with those who received placebo (P = .01) (Weston et al, 2005; Viljanen et al, 2005). These results are encouraging, but as summarized in a 2008 Cochrane review (Boyle et al, 2008), probiotics have not yet been proven to be effective in the treatment of eczema.

Prematurity compromises the anatomical and functional development of all organs, in inverse proportion to the gestational age. Some peculiarities of the preterm are the high incidence of respiratory diseases, the multi-systemic immaturity, even if nutrition

The preterm infant lacks of the sucking reflex, has a restricted gastric and intestinal capacity, insufficient absorption of the main food, that contribute to both quantitative and qualitative

The lack of an adequate nutrition decreases the synthesis of surfactant and anti-oxidant molecules, thus causing a delayed lung maturation and both cellular and humoral immune response, responsible for an increase of the catabolism, promoting the use of endogenous proteins. Therefore, the goal of the nutrition of the ELBW infant is the manteinance of his post-natal growth, similarly of what happens in utero, preventing the protein catabolism (through the use of endogenous proteins: lean body mass), avoid the weight loss during the first 2 weeks after birth, assuring a high energetic rate since his first day of life, thus reducing the percentage of preterms with a weight less than 10° percentile at discharge.

Nowadays the first approach to ELBW preterms is the parenteral nutrition since their first day of life (with the prompt introduction of glucose as it is the main source of energy and it reduces the catabolism of endogenous proteins since the first 2 hours after birth, and the introduction of lipids since the first 24 hours after birth). It is also important the introduction of low quantities of milk (minimal enteral feeding) via oral or nasal-gastric way in order to promote the feeding tolerance and the increase of enteral production of cholecystokinin that stimulates the bile function, protecting the liver from hepatic steatosis due to parenteral

It is important that these procedures are managed in a gradual way in order to avoid the tiredness of the infant and the aspiration of milk with regurgites. For this reason it is conceivable using a fortified maternal formula for premature infants, with a daily increase of the feeding, paying attention to abdominal distension, vomit, gastric stagnation, apneas,

It is conceivable to stop the parenteral nutrition when the energetic rate reach a quote of 80cal/Kg/die and the daily increase of milk must not be more than 10ml/Kg/die, and

probiotic strains and doses used (Prescott & Björkstén, 2007; Penders, 2007).

**5.2 Use of probiotics in the treatment of atopic diseases** 

**6. Probiotics and premature infants** 

nutritional deficiencies.

nutrition.

and diarrhea.

constitutes one of the major actual problem to afford.

sometimes it is necessary the continuous or discontinuous enteral feeding, via nasal-gastric tube, in order to suspend the parenteral nutrition.

The passage from enteral nutrition to nursing depends on the acquisition of sucking, deglutition, epiglottis and larynx closure ability and on the nasal passage, as well as the esophageal motility and a synchronized process is usually absent before 34 weeks of gestation. The sucking ability is usually reached when the infant has a weight over 1500 gr even if sometimes it is necessary to proceed with the tactile stimulation of the infant tongue (Tsang et al, 2005).

Enzymatic digestive functions in preterm more than 28 weeks of gestation are mature enough to allow the adequate digestion and absorption of proteins and carbohydrates. Lipids are well adsorbed and unsaturated fatty acids and lipids in maternal milk are better adsorbed than the components of the formula milk.

The weight gain in infants with a birth weight less than 2000 gr should be adequate when the mother shows a protein intake of 2.25-2.75/Kg/die, because they should provide a good intake of essential aminoacids, in particular tryptophan and threonine, that are important for the cerebral development.

The maternal milk, through specific immunologic factors, can potentiate the defensive mechanisms of preterms, contributing to ameliorate the immune defense against infectious agents. Recent studies highlighted that the maternal milk not only promote a passive protection, but can directly modify the immunologic development of the infant.

The maternal milk contains immunologic and non-immunologic factors, and immunemodulant factors, such as the bifidogenic factor, that promotes the development of the *Lactobacillus Bifidus,* that by competition promotes the decrease of the intestinal pH and inhibits the growth of *Escherichia Coli.* The maternal milk must be fortified, while the formula for preterm infants do not contain the bifidogenic factor (Heiman & Schanler, 2007) **.**

It is also well established that the composition of the intestinal microbiota is aberrant and its establishment delays in neonates who require intensive care, with an increased risk of developing NEC. As discussed above, probiotics have been shown to enhance the intestinal barrier, inhibit the growth and adherence of pathogenic bacteria and to improve altered gut micro-ecology In preterm infants, administration of the probiotic *Lactobacillus* GG has been shown to affect colonisation patterns. Data from experimental animal models suggest that bifidobacteria reduce the risk of NEC in rats. Consequently, it could be hypothesised that probiotics might have potential in reducing the risk of NEC in premature infants.

The supplementation of probiotics since the first day of life represents a valid help in influencing the growth of a favourable intestinal ecosystem, decreasing the quote of Clostridium, Bacillus and Bacteroides Fragilis and increasing the rate of bifidobacteria, also improving the intestinal barrier with a way of action similar to that of the maternal milk, protecting the gut from bacteria and fungal colonization, avoiding the development of NEC.
