Effect of synbiotic supplementation on breast milk IgA level in overweight and obese women,and diarrhea incidence in infants
Background: Human milk is rich in protective proteins which play a part in the prevention of microbial infection in suckling infants. IgA (Immunoglobulin A) is foremost of these in terms of its concentration in human milk,and in the breadth and sophistication of its protective effects. The aim of this study was to determine the effects of synbiotic supplementation on breast milk IgA level in over weight and obese women,and diarrhea incidence in infants. Methods: In this randomized,double-blind,placebocontrolled trial,55 lactating mothers with BMI≥25 were randomly divided into two groups to receive daily supplement of synbiotic (n=25) or a placebo (n=30) for 30 days. Breast milk samples (15 mL) were collected into sterile glass bottles by self-expression before the baby was nursed in the morning and stored at - 70°C until analysis. Breast milk IgA levels were detected by nephelometry according to the manufacturer’s instructions before and after the intervention. The mother᾽s report of ≥ 3 loose or watery stool in a 24-hour period was considered diarrheal illness. On the interview days,mothers provided information on the incidence of diarrhea in the 2 weeks preceding the survey start and end. Paired t-test and independent t test were used to analyze within group and between group comparisons. P value of < 0.05 was considered statistically significant. Results: The mean breast milk IgA level in synbiotic and placebo groups were 0.43 ± 0.1 and 0.45± 0.13 g/l respectively. There was no significant difference in the baseline measures between the supplemented and the placebo group. The IgA of breast milk increased significantly from 0.43 ± 0.1 to 0.49 ± 0.12 g/l in the supplemented group (p = 0.01),whereas it decreased from 0.45± 0.13 to 0.43± 0.13g/l in the placebo group (p = 0.33). Also,the comparison of changes in the breast milk IgA level showed a significant difference (p = 0.03) between the two groups during the study. In addition,diarrhea incidence decreased significantly (P = 0.03) from 22% to 3.7% in the supplemented group while no significant changes (increased from 21% to 25%) were observed in the placebo group after the experimental period. Conclusions: The results showed that administration of synbiotics was preventing breast milk IgA decreases with time and diarrhea incidence in infants. However,further studies using different species of probiotic bacteria and longer duration of supplementation are necessary to make concise conclusions.