The Relationship Between Feeding Type And Infants Gut Flora And Development

Backgrounds:The nutrition and health status of infancy may influence the health in coming days. Human milk is the best natural food for infants, which is beneficial for the development, physiology functions, and mentality of the infants. The feeding type is related to the development of the infants. Furthermore the feeding type is related to the ecosystem colonized in the gastrointestinal tract. The gut flora related to many physiological functions and diseases. There are some reported studies suggesting that changing the gut flora to a healthy mode may improve the development of the infants, but there is little study on the relationship between infant gut flora and development. Infancy is a key period for the development of gut flora. Many factors may influence the establishment of gut flora. Feeding type is among the most important ones. There are much knowledge gaps in the gut flora of infants. The reported studies have obtained different results. The related study in our country is limited.Objectives:To study the composition of the gut flora of infants and assay the relationship between feeding type and gut flora. To evaluate the relationship between development and infants feeding type and gut flora.Methods:Healthy infants of less than 4 month-age were followed for 90 days. The information of birth, feeding, and use of antibiotics was collected by questionnaire. The anthropometry measurement was carried out and Z scores were calculated as the indexes of infant development. The gut flora was assayed at the beginning and the end. The ratios of different organisms were calculated, named mode indexes. The relationship between gut flora and feeding type was analyzed, with correction of other possible factors. The influence of feeding type and gut flora to development was evaluated.Results:Three hundred and eleven infants were followed up, including 61 infants of breast fed and 250 infants of bottle fed. Six classes of organisms were detected. All infants were colonized with lactobacillus, bifidobacteria, enterococcus, and Escherichia coli. All samples except one were positive for bacteroides. The staphycoccus was positive in 45.9% of infants.Infants of breast fed had higher number of lactobacilli, lower prevalence of staphylococcus (P<0.05). The relationship of gut flora and age days, birth weight, and use of antibiotics were different for breast fed infants and bottle fed infants.The numbers of lactobacilli, bifidobacteria, enterococcus, and E. coli at the end were higher than those at the beginning. The mode indexes except the ratio of probiotics were lower at the end than those at the beginning. The E. coli and mode indexes of bottle fed infants at the beginning were different between groups of age, E. coli descending from 1 month of age to 3 month of age and ascending from 3 month of age to 4 month of age, mode indexes ascending from 1 month of age to 3 month of age and descending from 3 month of age to 4 month of age.Bottle fed infants with normal birth weight had higher level of bifidobacteria, higher mode indexes, and lower E. coli than infants with abnormal birth weight for bottle fed infants at the beginning (P<0.05). The birth weight of breast fed infants were positively correlated to the mode indexes except the ratio of probiotics at the end (P<0.05). Bottle fed infants with antibiotics exposure had higher number of E. coli, lower mode indexes at the beginning and higher number of staphycoccus at the end.There was some difference in the Z scores of infants of different feeding types. WAZ of breast fed infants was significant higher than bottle fed infants in adjusted analyses at the beginning of the following. The influence of gut flora to infants development was different for breast fed infants and bottle fed infants. The number of lactobacilli was negatively related to WHZ, WAZ, and BAZ for the bottle fed infants at the beginning. The ratio of probiotics was positively related to WHZ, WAZ, and BAZ for breast fed infants.Conclusions:The gut flora of infants is related to feeding type. The infants of breast fed have higher lactobacilli lower prevelance of staphyloccus than those of bottle fed. The gut flora of infants may be related to birth weight, age, and use of antibiotics. The relationship may be different for breast fed infants and bottle fed infants. The breasts fed infants has higher Z scores than bottle fed infants.The gut flora is related to infants development, with difference for breast fed infants and bottled fed infants.