Mode of delivery - effects on gut microbiota and humoral immunity.

BACKGROUND: The rate of caesarean deliveries has increased 10-fold worldwide during the past decades. OBJECTIVE: To evaluate differences in the establishment of gut microbiota in infants born by vaginal or caesarean delivery and its impact on mucosal immunity. METHODS: Altogether, 165 consecutive children, prospectively followed from birth at our clinic in Turku, Finland, were gathered; 141 (85%) were born by vaginal delivery and 24 (15%) by caesarean section. Blood was drawn at physician visits for indirect evaluation of mucosal immunity by ELISPOT assay. Faecal samples were obtained for determination of the gut microbiota by fluorescence in situ hybridization of bacterial cells. RESULTS: Infants delivered by caesarean section harboured fewer bifidobacteria at an early age and were shown to mount a stronger humoral immune response. At 1 month of age, the total gut bacterial cell counts per 1 g faeces were higher in vaginally delivered infants (9.9 x 10(9), 95% CI 7.9 x 10(9)-1.2 x 10(10)) as compared to caesarean section delivered (3.1 x 10(9), 95% CI 1.1 x 10(9)-8.6 x 10(9)) (p = 0.001). This distinction was mainly due to the greater number of bifidobacteria in vaginally delivered infants (1.9 x 10(9), 95% CI 6.3 x 10(8)-5.6 x 10(9) vs. 1.5 x 10(6), 95% CI 4.1 x 10(2)-5.7 x 10(9), respectively) (p = 0.001). During the first year of life, the total number of IgA-, IgG- and IgM-secreting cells was lower (p = 0.03, p = 0.02, p = 0.11, respectively) in infants born by vaginal delivery than in those born by caesarean section, possibly reflecting excessive antigen exposure across the vulnerable gut barrier. CONCLUSIONS: Our findings demonstrate that the mode of delivery may have, possibly via gut microbiota development, significant effects on immunological functions in the infant (http://www.clinicaltrials.gov/ct/gui/show/NCT00167700).

Probiotic intervention in the first months of life: short-term effects on gastrointestinal symptoms and long-term effects on gut microbiota.

OBJECTIVES: To determine whether probiotics administered for 6 months postnatally affect gastrointestinal symptoms, crying and the compositional development of the gut microbiota through infancy. METHODS: The study comprised of 132 newborns whose mothers were randomized to receive placebo or Lactobacillus rhamnosus GG (ATCC 53103) before delivery. The treatments of mothers/infants continued for 6 months postnatally. A specific symptom chart was used to monitor gastrointestinal symptoms and infant's crying during the 7th and the 12th weeks of life. Fluorescent in situ hybridization was used to establish the Bifidobacterium, Lactobacillus/Enterococcus, Bacteroides and Clostridium counts in fecal samples at 6, 12, 18 and 24 months of age. RESULTS: Numbers of different types of stools, vomits and crying time were comparable between the groups during the 7th and the 12th weeks of life. Dominant microbiota consisted of bifidobacteria throughout the study. At 6 months, there were less clostridia in faeces in the placebo compared with the probiotic group (P = 0.026), whereas after long-term follow-up at 2 years, there were less lactobacilli/enterococci and clostridia in faeces in the probiotic group than in the placebo group (P = 0.011 and P = 0.032, respectively), reflecting the impact of clostridia as a marker of microbiota succession in healthy infants. CONCLUSIONS: Probiotic administration in the first months of life was well tolerated and did not significantly interfere with long-term composition or quantity of gut microbiota.

Breast milk fatty acid composition is associated with development of atopic dermatitis in the infant.

OBJECTIVE: Breast milk fatty acids may have immunomodulatory properties related to the development of atopic disease. The aim of this study was to assess the impact of the breast milk fatty acid composition on the development of atopic dermatitis (AD) in high-risk infants. METHODS: Mothers with atopic disease were recruited at the end of gestation. Maternal food records and breast milk samples were collected at the infants' age of one month. Infants were clinically examined and AD diagnosed at one, three, six, and 12 months. RESULTS: Altogether 13 of 34 (38%) infants were diagnosed with AD during the first year of life. Infants developing AD had consumed breast milk with a higher ratio of saturated to polyunsaturated fatty acids and less n-3 fatty acids compared to infants not developing AD. Specifically, breast milk consumed by infants with AD contained more stearic acid, 8.9% of total fatty acids (95% confidence interval 7.9-10.0) in comparison to those without AD, 7.1% (95% CI 6.6-7.7). CONCLUSION: Breast milk rich in saturated and low in n-3 fatty acids may be a risk factor for atopic dermatitis in the infant.

Effect of probiotics and breastfeeding on the bifidobacterium and lactobacillus/enterococcus microbiota and humoral immune responses.

OBJECTIVE: To assess impact of probiotics and breastfeeding on gut microecology. STUDY DESIGN: Mothers were randomized to receive placebo or Lactobacillus rhamnosus GG before delivery, with treatment of the infants after delivery. We assessed gut microbiota, humoral immune responses, and measured soluble cluster of differentiation 14 (sCD14) in colostrum in 96 infants. RESULTS: Fecal Bifidobacterium and Lactobacillus/Enterococcus counts were higher in breastfed than formula-fed infants at 6 months; P <.0001 and P=.01, respectively. At 3 months, total number of immunoglobulin (Ig)G-secreting cells in breastfed infants supplemented with probiotics exceeded those in breastfed infants receiving placebo; P=.05, and their number correlated with concentration of sCD14 in colostrum. Total numbers of IgM-, IgA-, and IgG-secreting cells at 12 months were higher in infants breastfed exclusively for at least for 3 months and supplemented with probiotics as compared with breastfed infants receiving placebo; P=.005, P=.03 and P=.04, respectively. Again, sCD14 in colostrum correlated with numbers of IgM and IgA cells; P=.05 in both. CONCLUSIONS: We found an interaction between probiotics and breastfeeding on number of Ig-secreting cells, suggesting that probiotics during breastfeeding may positively influence gut immunity.

Similar bifidogenic effects of prebiotic-supplemented partially hydrolyzed infant formula and breastfeeding on infant gut microbiota.

The aim of the study was to assess the quantitative and qualitative differences of the gut microbiota in infants. We evaluated gut microbiota at the age of 6 months in 32 infants who were either exclusively breast-fed, formula-fed, nursed by a formula supplemented with prebiotics (a mixture of fructo- and galacto-oligosaccharides) or breast-fed by mothers who had been given probiotics. The Bifidobacterium, Bacteroides, Clostridium and Lactobacillus/Enterococcus microbiota were assessed by the fluorescence in situ hybridization, and Bifidobacterium species were further characterized by PCR. Total number of bifidobacteria was lower among the formula-fed group than in other groups (P=0.044). Total amounts of the other bacteria were comparable between the groups. The specific Bifidobacterium microbiota composition of the breast-fed infants was achieved in infants receiving prebiotic supplemented formula. This would suggest that early gut Bifidobacterium microbiota can be modified by special diets up to the age of 6 months.