A review of the evidence on the use of complementary and alternative (CAM) therapies to treat babies with colic has shown some that some treatments—including probiotics, fennel extract and spinal manipulation—do appear to help, but that overall the evidence on the use of these therapies is limited so should be treated with caution.

Researchers from the National Institute for Health Research (NIHR) at the University of Bristol and the University of Manchester reviewed published "systematic reviews" on the use of CAM therapies to treat babies with colic. Systematic Reviews bring together all the studies on a topic, to understand the totality of the evidence available.

Colic can be distressing for both babies and parents, but it's not clear what causes it. This makes treating it difficult, and many parents resort to CAM therapies because of this lack of conventional treatments.

The review included 16 systematic reviews on a variety of therapies, including probiotics, herbal medicine, acupuncture, and manipulation such as chiropractic massage. The researchers found that while probiotics, fennel extract, and spinal manipulation all showed promise as treatments, these results should be treated with caution because of issues with the studies. These issues included small sample sizes, possible bias in the findings, the measurement of outcomes through parent diaries which are highly subjective, and the inability to "blind" therapists for many treatments, especially those that involved manipulation of the baby. Research into the use of probiotics for babies who are formula-fed was also lacking, which is significant as formula already contains probiotics.

The team, which included researchers from the NIHR Bristol Biomedical Research Centre (BRC) and NIHR Applied Research Collaboration West (ARC West), also concluded that acupuncture and soy are not recommended to treat colic.

Dr. Rachel Perry, senior research associate in the NIHR Bristol BRC's nutrition theme at the University of Bristol, said: "Many parents will know how distressing looking after a colicky baby can be. But doctors don't really understand what causes it, which makes it difficult to treat. This gap in conventional medical knowledge leads many parents to try complementary and alternative therapies.

"Our review does show that some treatments—probiotics, fennel extract and spinal manipulation—do appear to help, though the studies that showed this weren't big enough or well-designed enough to be sure of the results. This is especially true for probiotics, where some of the findings from earlier, poor quality studies were rather oversold. But our findings do point to where future research efforts should be focused."