Abundant sialylated oligosaccharides in breastmilk may impair infant nutrition

Elevated levels of sialylated human milk oligosaccharides (HMO) in mothers’ breastmilk appears to worsen infant nutritional status, reports a Bangladesh study.

Researchers conducted a nested study within a single-blind, randomized, pilot clinical trial. They obtained 45 breastmilk samples from mothers whose infants had severe acute malnutrition (n=26) or had adequate nutrition status (n=19). HMO analysis was conducted using high-performance liquid chromatography coupled to quadrupole-time of flight mass spectrometry.

Firth logistic regression analysis, adjusted for age, sex, and mother’s secretor status, showed that exposure to sialylated HMOs was a significant indicator of SAM in infants, increasing such likelihood by 96 percent (odds ratio [OR], 1.96, 90 percent confidence interval [CI], 1.29–2.98; p=0.008). This effect remained true when focusing on infants born to nonsecretor mothers (OR, 2.86, 90 percent CI, 1.07–7.62; p=0.078).

Secretor status was determined according to the strength of the mass spectrometry signal associated with α(1,2)-Fuc linkage-containing oligosaccharides present in the mother’s breastmilk. These signal strengths were tested against a previously established and validated threshold.

Meanwhile, no such effect was reported for exposure to fucosylated and undecorated HMOs, regardless of the mother’s secretor status.

“To our knowledge, ours is the first study to assess the relation of different HMOs with malnutrition status among Bangladeshi infant-mother dyads without any supplementation of HMOs,” the researchers said.