Treating infant colic with the probiotic Lactobacillus reuteri

A study investigates the effectiveness of the probiotic Lactobacillus reuteri in treating infant colic.

Infant colic, or excessive crying of unknown cause, affects up to 20% of infants and is a major burden to families and health services. Infant colic is often defined by the Wessel's criteria of crying or fussing for three hours or more a day for three days or more per week for three weeks in infants aged less than 3 months. Although infant colic spontaneously resolves after the first three to four months after birth, it is associated with maternal depression, early breastfeeding cessation, and shaken baby syndrome. Infant distress is one of the most common presenting problems to primary, secondary, and tertiary healthcare sectors, costing the UK healthcare system millions of pounds annually. The cause of infant colic remains elusive despite decades of research. Psychosocial hypotheses include poor maternal-infant interactions, maternal anxiety and depression, and difficult infant temperament. Gastrointestinal theories include increased intra-abdominal gas, hyperperistalsis, and visceral pain. One study has suggested that infants with colic may have increased faecal calprotectin levels, suggesting a possible role for gut inflammation; however, another study suggested no differences in faecal calprotectin levels between infants with and infants without colic. No single effective treatment for colic exists, and most clinical guidelines recommend support and reassurance as the mainstay of management. The use of hypoallergenic formulas or elimination of cow's milk protein from the diet of mothers who are breast feeding may possibly be effective, yet not all irritable infants respond. Anticholinergic drugs, for example, dicycloverine, are effective but have potentially dangerous side effects, including breathing difficulties and coma. An effective, practical, and acceptable intervention for infant colic would represent a major advance in clinical and public health. Recently, research into the use of probiotics for colic has been rapidly gaining momentum. Infants with colic are reported to have increased concentrations of gas forming organisms and proteobacteria such as Escherichia coli in their gut. Colonisation with certain intestinal micro-organisms, such as Bifidobacterium and Lactobacillus species, along with increased intestinal microbial diversity, may protect against infant distress. Probiotics enhance the mucosal barrier and promote microbial diversity in the gut. They may reduce concentrations of proteobacteria and gas forming coliform and reduce intestinal inflammation. A recent meta-analysis of three small, randomised controlled trials of breastfed infants with colic reported that Lactobacillus reuteri noticeably reduced crying time at 21 days post supplementation. However, one trial was unblinded, two included only infants with mothers on dairy-free diets, and none used validated measures of infant distress. No trials have included formula fed infants, which is relevant because colic is associated with early breastfeeding cessation. Desp