Neonatology. 2017;111(3):260-266. doi: 10.1159/000450883.

Smell and Taste to Improve Nutrition in Very Preterm Infants: A Randomized Controlled Pilot Trial.

Beker F1, Opie G, Noble E, Jiang Y, Bloomfield FH.

Neonatal Services, Mercy Hospital for Women, Melbourne, VIC, Australia.

Department of Newborn Services, Mater Mothers Hospital, Brisbane, QLD, Australia.




The perception of smell and taste, though present early in development, is not routinely considered in the care of preterm infants. Smell and taste are known to increase gut motility, insulin secretion, and the release of appetite, digestive and metabolic hormones.


We aimed to investigate the effect of regular smell and taste on the time from birth to full enteral feeds, and the feasibility of the study protocol in very preterm infants.


In a randomized controlled trial, infants <29 weeks’ postmenstrual age (PA) were assigned to receive either the smell and taste of milk before each feed or to have no exposure to the smell and taste of milk (control).


Infants in the treatment group (n = 28) and control group (n = 23) were born at a mean (SD) PA of 26.7 (1.5) and 27.2 (1.4) weeks, respectively. They reached full enteral feeds at a median (IQR) of 13.5 (10.0-19.0) and 15.5 (11.0-22.0) days, respectively. Survival analysis showed an adjusted hazard ratio of 1.63 (95% confidence interval 0.91-2.91; p = 0.10) for the effect on the time to establish full enteral feeds. Repeated-measures analysis indicated significant group differences in weight z scores at 36 weeks’ PA and at discharge in favor of the intervention (p < 0.05).


These data indicate that the smell and taste of milk may improve milk tolerance and weight in preterm infants. The role of regular smell and taste in promoting enteral nutrition and growth in preterm infants merits a larger trial powered to detect important outcomes.©2016 S. Karger AG, Basel.

PMID: 27902988


Very premature babies face specific problems related to feeding: they cannot coordinate suck and swallow and are therefore tube fed; they have a premature gut causing poor milk tolerance, days to weeks of parenteral nutrition; they are at risk of potentially lethal gut inflammation (necrotizing enterocolitis); they have an extremely high caloric need (often over 140 kcal/kg/day) and if that is not met they are exposed to global growth failure and an increased risk of impaired neurodevelopment.

The appreciation of food is extremely important for our own quality of life. Significant amount of time and energy is spent every day to source, prepare, appreciate, talk about and eat food. Hardly anyone would choose a clear and tasteless fluid with the same nutritional value over a well prepared favorite meal.

Very preterm babies can smell and taste, but they are routinely fed over a nasogastric tube with no opportunity to appreciate their milk or even be aware of their feed. Over one hundred years ago, Professor Pavlov has famously discovered, experimenting on his dogs, that anticipation of food, elicited by the sight of food, timing, a bell or by the smell and taste (facilitated by sham feeding) starts the digestive process. This is now called the “cephalic phase response” and describes increased salivation, increased gut motility, release of gastric hormones and even improved blood glucose control. Pavlov also did the reverse experiment and placed bread in the stomach of his dogs through a tube, without the dog being aware and discovered that digestion was significantly impaired with the bread remaining undigested in the stomach for up to one hour.

The here presented randomized controlled pilot trial investigated if in very preterm infants, the exposure to the smell and taste of milk with tube feeding versus routine care would improve milk tolerance in tube fed infants. The results are promising and there is now a larger multicenter clinical trial underway. The attached video shows a ventilated 10 day old baby boy, born at 23 weeks of gestation with a birthweight of 648g, holding onto a cotton bud that has been dipped in breast milk.

Food tolerance is a significant issue not only in very preterm infants, but also in tube fed adults and children in intensive care and beyond. A range of medications such as prokinetics and antacids as well as non physiological feeding regimes, such as continues feeds, are prescribed with the aim to improve enteral food tolerance. However, often patients are not aware that they are even fed and providing smell and taste with food intake may improve nutritional outcomes beyond the neonatal intensive care unit.

Taste video 2017