A low body mass index reduces Human Milk Oligosaccharide concentration in breast milk of Bangladeshi women

Abstract

Human Milk Oligosaccharides (HMO), complex glycans highly abundant in human milk, are thought to protect the breast‐fed infant from infectious diseases and diarrhea. For example, the concentration of alpha1‐2‐fucosylated HMO in human milk is inversely correlated to the incidence of infant diarrhea. Diarrhea poses a particular threat to infants in developing countries, where mothers are also often malnourished. Here, we studied whether a low body mass index (BMI) in mothers had any effect on the HMO concentration in their milk. As part of the MINIMat project, milk samples from mothers in rural Bangladesh with a BMI of either 14–18 (n=8) or 24–28 (n=8) were collected at 8 weeks post‐partum. All milk samples were spiked with raffinose as internal standard. Oligosaccharides were isolated as described before, tagged with 2‐aminobenzamide, and analyzed by HPLC with fluorescence detection. Milk from mothers with a BMI of 14–18 contained 42.4% less total HMO than milk from mothers with a BMI of 24–28 (P<0.001), which may put the infant at higher risk of developing infectious diseases and diarrhea. Most intriguingly, 50% of all Bangladeshi samples were from Secretor‐negative mothers (lacking alpha1–2‐fucosylated HMO), which exceeds the 23% average reported for American/European mothers. This study is the first to show a correlation between the mother's nutritional status and the oligosaccharide concentration in her milk.