“Probiotic” Baby Formula Deemed Safe in Study

Infant formula fortified with “good” bacteria appears safe, and may help ease babies’ irritability, new research suggests.

Infant formula fortified with “good” bacteria appears safe, and may help ease babies’ irritability, new research suggests. The study, funded by Nestle USA, a maker of infant formula, adds to evidence that so-called probiotic foods may have digestive and immune system benefits, according to the authors. These are, however, benefits that breast feeding has already been shown to have, an expert not involved in the study pointed out. Beneficial bacteria dwell by the trillions in the human body, helping to defend it from disease-causing bugs. People have long gotten an added boost of good bacteria from foods such as yogurt and other fermented dairy products. Though not approved in the U.S., probiotic infant formulas have been marketed in Europe, Asia and South America for a number of years, with no apparent ill effects. Still, there’s been little study of the products’ long-term safety, according to the authors of the new study. Their investigation of formula supplemented with two types of bacteria — Bifidobacterium lactis and Streptococcus thermophilus — found it to be safe among 78 infants who consumed it for seven months, on average. In a key measure of safety, the infants’ growth was no different from that of 40 babies on regular formula. In addition, parents of babies on the designer formula reported less colic or irritability, and less antibiotic use than those whose babies were on regular formula, Dr. Jose M. Saavedra and his colleagues at Johns Hopkins University in Baltimore found. Saavedra, who is also medical director of Nestle USA’s nutrition division, and his team report the results in the American Journal of Clinical Nutrition. Friendly bacteria that reside in the gut are thought to promote health in a number of ways. They compete with illness-causing bacteria for space and nutrients, helping to crowd the bad bugs out. They also secrete enzymes that aid in digestion, and may affect the workings of immune-system cells in the gut. Some studies have shown probiotics help treat or prevent diarrhea caused by rotavirus infection, which is a common cause of diarrhea in children. There’s also some evidence that probiotics might cut the risk of certain allergies. However, breast feeding — the preferred source of infant nutrition — has already been linked to better digestion, less diarrhea and a lower risk of allergies and certain infections. And one of the things breast milk does is promote the growth of beneficial bacteria in the digestive tract, Dr. Frank Greer of the University of Wisconsin in Madison said in an interview. According to Greer, who is on the American Academy of Pediatrics’ nutrition committee, it would have been helpful to have a comparison group of breast-fed babies in this study. “Because ultimately,” he said, “what they’re trying to do is make formula more like breast milk.” And Greer said that while he liked the fact that the study looked at infant growth, he was unimpressed by the small differences between groups in parents’ reports of irritability and antibiotic use. Antibiotic use, which Saavedra’s team says could be a marker of the fortified formula’s immune system benefits, was actually higher among babies who got a high level of probiotic supplements in the formula compared with those on a low probiotic dose, Greer noted. (Source: Reuters Health, American Journal of Clinical Nutrition, Feb 2004)