April 08, 2011

Diet is important for gut bacteria in newborns

It is one thing to check a newborn for 10 fingers and 10 toes, but what about checking for healthy gut bacteria? Unhealthy populations of gut bacteria are associated with bowel diseases in all mammalian infants and allergies in children and adults. Scientists from the University of Memphis and the University of Copenhagen are researching how to encourage healthy bacterial colonization in the gastrointestinal tracts (GIT) of newborn babies.

“Colonization of the GIT after birth triggers a series of events that influence the pattern of immune system development,” said Randal Buddington (University of Memphis), co-author of the paper published in January by the Journal of Animal Science. The team, lead by Buddington and Per Sangild (University of Copenhagen), is looking for answers in the field of epigenetics. Epigenetics decodes how genes and environment work together. “Genetics establishes the basic patterns of gut structure and functions within a range of possibilities, with diet influencing the specific patterns that occur within that range,” Buddington said in an interview. The development of the immune system in reaction to gut bacteria can influence life-long immune response.

The process of gut colonization is deceptively simple. When an infant is born, the lining of its GIT is sterile. With its first meal come bacteria, fungi, protozoa, viruses, and bacteriophages. The human GIT has co-evolved with many helpful species of microbes, and the newborn GIT must differentiate between good and bad species. Unfortunately, controlling the selection process is difficult.

Unhealthy gut bacteria are associated with necrotizing entercolitis (NEC), a bowel disease that causes death of intestinal tissue. “NEC is the most common and serious GI health issue among infants born preterm,” said Buddington. “NEC is uncommon among term infants who are born with a more mature GIT prepared for and capable of facing the challenges expected at birth.” Buddington and Sangild cited a clinical trial suggesting that probiotics can reduce the risk of NEC.

By studying how genes and diet interact, Buddington and Sangild have developed suggestions for raising healthy infants. Whereas many new parents know that first breast milk, called colostrum, is very important for immune system development in the early days of life, few realize that colostrum is also an important source of healthy gut bacteria. “Provision of colostrum is beneficial during the neonatal period and should be encouraged,” Buddington said.

Buddington suggested that future researchers look at how bacteria and diet influence GIT functions, like osmoregulation and detoxification. He said nutritional studies could be used to improve the value of infant formulas. “Formula manufacturers will agree they can be better,” said Buddington.

The paper is titled “Development of the mammalian gastrointestinal tract, the resident microbiota, and the role of diet in early life.” It can be read in full at jas.fass.org.

Media Contact: Madeline McCurry-Schmidt

619-438-2382 / memschmidt@ucdavis.edu