Introducing healthybacteria to the gut of newborns appears to decrease their likelihood of developing colic, according to a study published Monday, the latest showing probiotics' beneficial effect on the condition.

The research is thought to be the first to examine whether giving 'good' micro-organisms to infants could prevent the development of what is known as functional gastrointestinal disease, which includes colic, regurgitation and constipation.

Colic, characterized by lengthy crying, is believed to be related to digestive problems and sometimes likened to an infant form of irritable bowel syndrome. The condition has long been a source of anxiety for new parents, who are often driven to try all types of home remedies to soothe their babies in the absence of any medicines indicated for the treatment of colic. A recent study found that as many as 20% of infants suffer from colic in their first three months of life.

In the study published Monday, scientists from Aldo Moro University in Bari, Italy, had parents administer five drops of a solution containing Lactobacillus reuteri, a bacterium well-studied for its health effects, or a placebo to 589 healthy infants daily for the first 90 days of life.

At three months, the babies who received the probiotic exhibited significantly reduced crying time--an average of 38 minutes versus 71 minutes of inconsolable crying per day--fewer spit-ups and more bowel movements, which signaled less constipation, according to Flavia Indrio, a pediatrics professor at the university and the lead author on the study. The research was published Monday in JAMA Pediatrics, a journal of the American Medical Association.

Previous studies, including one of Dr. Indrio's, have found that Lactobacillus reuteri appears to help with colic, but haven't looked at ways to prevent it. Scientists and industry also are studying whether probiotics can be helpful in treating a number of conditions, including allergies, cholesterol and the common cold.

Early intervention in babies' gastrointestinal problems may be important not just for infants' well-being but also health at older ages. Research has found that colic symptoms and development of other gastrointestinal diseases later in life appear to be linked. There have been no reports of adverse events so far in human Lactobacillus reuteri studies.

The latest work, considered the largest human study of probiotics on colic to date, is 'very well done' and the results are encouraging, according to Bruno Chumpitazi, a professor in the department of pediatrics at the Baylor College of Medicine in Houston, who wasn't involved in the research but wrote an editorial to accompany the study. The long-term effects of the bacterium on health are still unknown and need to be studied, he said.

Colonies of Lactobacillus reuteri appear to reduce intestinal inflammation, improve movement in the intestines and lessen sensitivity to pain, according to Dr. Indrio, but more research is needed to understand exactly what the bacterium does in the body, she and other experts say. Dr. Indrio plans to follow the cohort of infants to study their rates of irritable bowel syndrome and gastrointestinal disorders at older ages.

By intervening early or even preventing the start of gastrointestinal distress in infancy, the path of disease development may be changed. 'Maybe the intestine and the brain have a different script to follow,' said Dr. Indrio.