All probiotics are not the same in protecting premature infants from common, life-threatening illness

October 17, 2013

Treating premature infants with probiotics, the dietary supplements containing live bacteria that many adults take to help maintain their natural intestinal balance, may be effective for preventing a common and life-threatening bowel disease among premature infants, researchers at UC Davis Children's Hospital have found.

The study, "A comparison of two probiotic strains of in premature infants," recently was published online in the Journal of Pediatrics. The bowel disease, necrotizing enterocolitis (NEC), is the second most common cause of death among premature infants, said Mark Underwood, lead study author, neonatologist and professor in the Department of Pediatrics at UC Davis Children's Hospital. It affects 3 to 10 percent of premature infants; about 25 percent of those with the severe form of this NEC succumb to the infection.

Underwood and his collaborators evaluated the effectiveness and safety of two types of probiotics of known purity and composition in a clinical trial that included nine breastmilk- and 12 formula-fed premature infants in the Neonatal Intensive Care Unit (NICU) at UC Davis Children's Hospital.

The products tested in the study were two genetically different strains of bifidobacteria, normal inhabitants of the gastroentestinal tract that inhibit the growth of harmful pathogens and bacteria, Bifidobacterium longum subspecies infantis (B. infantis); and Bifidobacterium animalis lactis (B. lactis).

Laboratory analysis of the bacterial contents of fecal samples from the infants, B. infantis was more effective at colonizing bifidobacteria, the healthy bacteria, in the newborns' gastrointestinal tracts than was B. lactis. The highest fecal levels of bifidobacteria were found in the infants who were breastmilk-fed and received the B. infantis probiotic, Underwood said.

No side effects were identified from administration of the two probiotic strains, Underwood said. One of the breast milk-fed infants treated with B. lactis developed NEC early in the trial, Underwood said, "indicating that B. lactis may not be as effective as B. infantis in protecting against NEC, though the study was not designed to answer that question."

Because earlier research conducted in Europe, Japan, and Australia has demonstrated the potential benefits of probiotic therapy in preventing NEC, many NICUs in the United States treat premature infants with the supplements, said Underwood. Probiotic therapy is not, however, the standard of care for premature infants in the United States. The American Academy of Pediatrics has not established a policy about using the products in newborns, and the U.S. Food and Drug Administration (FDA) currently regards probiotics as food supplements, not drugs.

The study was conducted in premature infants born between 24 to 33 weeks gestation and weighing less than 1,500 grams, or three pounds. It was conducted in two phases. In the first, the formula-fed infants were randomly assigned to receive either B. infantis or B. lactis in increasing doses over a five-week period. The second-phase evaluated the probiotics in breastmilk-fed premature infants. Each infant was treated with one strain for two weeks and after a one-week break, received the other strain for two weeks.

In both the formula-fed and breast milk-fed newborns, greater increases in fecal bifidobacteria occurred in the B. infantis groups than in the B. lactis groups.

"B. lactis colonization was not sustained in the infants," Underwood said.

"The highest total numbers and percentages of bifidobacteria were found after two weeks of B. infantis treatment in the breast milk-fed babies," said Underwood. "In addition, during the one week break in the phase of the study that involved the breast milk-fed infants, the relative abundance of bifidobacteria was significantly greater for those treated with B. infantis."

During periods of administration of B. infantis, the diversity of the beneficial microbes inhabiting the breast milk-fed babies' GI tract increased. In addition, the harmful bacteria known as γ-Proteobacteria decreased in the breast milk-fed babies who received B. infantis.

However, the formula-fed infants treated with B. infantis and B. lactis did not experience a decline in the γ-Proteobacteria, which typically increases at the onset of NEC and can cause serious tissue-damaging infections in the gastrointestinal system, lungs and other organs of the body.

The two strains of bifidobacteria used in the study were grown for UC Davis by a food-grade commercial facility, to insure that the infants in the study would receive of known purity and composition, Underwood said.

Specimens were obtained from the stool of the formula-fed infants at baseline, the beginning of the study, and then weekly for five weeks. In the breast milk-fed babies, the stool specimens were collected at baseline and following the first probiotic course, the one-week break and the second probiotic course.

Underwood is submitting an application for a new investigational drug to the FDA for a multi-centered second phase clinical trial to evaluate the safety and effectiveness of the B. infantis probiotic in preventing NEC in . If the application is approved and funded by the National Institues of Health, Underwood and his colleagues will conduct a larger trial involving more babies.

Explore further: Study examines probiotics to prevent or treat excessive infant crying

Related Stories

Study examines probiotics to prevent or treat excessive infant crying

October 7, 2013
There still appears to be insufficient evidence to support using probiotics (Lactobacillus reuteri) to manage colic or to prevent crying in infants, especially in formula-fed babies, but it may be an effective treatment for ...

New infant formula ingredients boost babies' immunity by feeding their gut bacteria

February 29, 2012
Adding prebiotic ingredients to infant formula helps colonize the newborn's gut with a stable population of beneficial bacteria, and probiotics enhance immunity in formula-fed infants, two University of Illinois studies report.

Probiotic-derived treatment offers new hope for premature babies

February 13, 2013
Study in the American Journal of Physiology-Gastrointestinal and Liver Physiology addresses critical component of problem affecting infants with necrotizing enterocolitis.

Formula-fed babies may be more susceptible to chronic disease, study finds

August 9, 2013
(Medical Xpress)—Formula-fed infants experience metabolic stress that could make them more susceptible than breast-fed infants to a wide range of health issues such as obesity, diabetes, liver problems and cardiovascular ...

Formula-fed preemies at higher risk for dangerous GI condition than babies who get donor milk

May 1, 2011
Extremely premature babies fed human donor milk are less likely to develop the dangerous intestinal condition necrotizing enterocolitis (NEC) than babies fed a standard premature infant formula derived from cow's milk, according ...

Recommended for you

At the cellular level, a child's loss of a father is associated with increased stress

July 18, 2017
The absence of a father—due to incarceration, death, separation or divorce—has adverse physical and behavioral consequences for a growing child. But little is known about the biological processes that underlie this link ...

New comparison chart sheds light on babies' tears

July 10, 2017
A chart that enables parents and clinicians to calculate if a baby is crying more than it should in the first three months of its life has been created by a Kingston University London researcher, following a study of colic ...

Blood of SIDS infants contains high levels of serotonin

July 3, 2017
Blood samples from infants who died of Sudden Infant Death Syndrome (SIDS) had high levels of serotonin, a chemical that carries signals along and between nerves, according to a study funded in part by the National Institutes ...

Is your child's 'penicillin allergy' real?

July 3, 2017
(HealthDay)—Many children suspected of being allergic to the inexpensive, first-line antibiotic penicillin actually aren't, new research indicates.

Probiotic supplements failed to prevent babies' infections

July 3, 2017
(HealthDay)—Probiotic supplements may not protect babies from catching colds or stomach bugs in day care, a new clinical trial suggests.

Starting school young can put child wellbeing at risk

June 22, 2017
New research has shown that the youngest pupils in each school year group could be at risk of worse mental health than their older classmates.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.