**3. Probiotics**

Bacterial concentrations in HBM range between 102 and 104 ufc/mL. This means that an infant ingesting over 800 ml of milk a day would receive 105 to 107 ufc [14]. Therefore, HBM is a primary source of commensal and probiotic bacteria to the infant and plays a key role in the initial colonization of the gut. Some bacteria isolated from HBM have proven to have immunomodulatory and anti-infective effects. Therefore, the protective effects of HBM may be conferred by these bacteria. Supplementation of infant formulae with probiotic bacteria isolated from HBM could help improve gut microbial balance in formula-fed infants, thereby mimicking the beneficial effects of HBM.

Evidence has been published that probiotics modulate mucosal and systemic immune function, improve intestinal barrier function, and exert metabolic effects on the host [4]. Some of the lactobacillus strains isolated from HBM [15] have been reported to compete with enteropathogenic bacteria for nutrients and epithelium

**5**

newborns [28].

months [19].

*Probiotics and Prebiotics in Infant Formulae DOI: http://dx.doi.org/10.5772/intechopen.88609*

supplementation periods.

and no adverse effects were detected [24].

*3.1.2 Prevention and treatment of infant disorders*

*3.1.1 Safety*

adhesion and improve gut barrier functions. The ability of lactobacillus and bifidobacteria strains to stabilize the integrity of gut barrier has been demonstrated [16]. These types of bacteria potentially reduce antigen systemic load and influence immune function via enterocytes, antigen-presenting cells (monocytes and den-

European Society for Pediatric Gastroenterology, Hepatology, and Nutrition (ESPGHAN) Committee on Nutrition [19] published a systematic review of studies assessing the safety and health effects of probiotic-supplemented infant formulae. No conclusive data were obtained from ESPGHAN's analysis of infant and follow-on formulae due to considerable variability in the type and dose of probiotics used and

Formulae supplemented with probiotics do not raise safety concerns with regard to growth and adverse effects [19]. There are sufficient data supporting the safety of probiotics for infants older than 6 months. However, data on the use of probiotic supplementation in infants younger than 4 months are more limited. Studies in breastfed infants younger than 6 months who received a formula supplemented with either *Lactobacillus fermentum* CECT5716 or *Lactobacillus rhamnosus* GG revealed that formulae were well tolerated and had no adverse effects on growth either during the study period or at 3–5 years of age [20–23]. A recent study revealed that growth and food tolerance improved in premature infants >30 weeks of gestational age fed with a formula supplemented with *Saccharomyces boulardii,*

Conflicting results have been obtained regarding the effects of probiotics on the composition of fecal microbiota. A decrease in bifidobacteria and enterobacteria concentrations has been reported with respect to controls [25, 26]. Also, no differences have been observed in lactobacillus and bacteroides. By contrast, Maldonado et al. [27] reported an increase in fecal bifidobacteria and lactobacilli concentrations in infants fed with a formula supplemented with *Lactobacillus fermentum* CECT 5716. Also, no differences were found in other bacteria strains. Evidence has been provided that a formula containing *Bifidobacterium lactis* can influence the composition, stability, and function of gut microbiota in low-weight

The literature reports that probiotic supplementation of formula beyond early infancy can produce a decrease in the use of antibiotics and incidence of diarrhea, colic, and/or irritability. Yet, the variety of methods, type and dose of probiotics, and duration of interventions hinders that conclusive data can be obtained on clear clinical effects of probiotic-supplemented formulae in infants younger than 4

In general, there is no consistent evidence supporting that supplementation of follow-on formula with probiotics has protective effects against infectious diarrhea [19]. Yet, a reduction has been reported in the duration and number of episodes of diarrhea associated with the use of probiotic-supplemented formulae [27, 29–31]. A systematic review conducted by Mugambi et al. [32] of controlled, randomized trials did not reveal that supplementation had any effects on infectious

dritic cells), regulatory T cells, and effector T and B cells [17, 18].

**3.1 Infant formula supplemented with probiotics**

#### *Probiotics and Prebiotics in Infant Formulae DOI: http://dx.doi.org/10.5772/intechopen.88609*

adhesion and improve gut barrier functions. The ability of lactobacillus and bifidobacteria strains to stabilize the integrity of gut barrier has been demonstrated [16]. These types of bacteria potentially reduce antigen systemic load and influence immune function via enterocytes, antigen-presenting cells (monocytes and dendritic cells), regulatory T cells, and effector T and B cells [17, 18].
