Baby colic: the role of the microbiota has been confirmed
Although baby colic affects between 20% and 25% of newborns, its causes remain largely unknown. For the first time, researchers from Toulouse (France) and Lausanne (Switzerland) have tried to establish a link between colic and intestinal hyperactivity, which causes pain.
Crying is the main sign
Infants with colic cry excessively and unsoothably, in a recurring manner and with no apparent reason. It is a benign condition, but it can cause frustration for the parents who try to relieve their babies’ pain however they can: heat, massages, herbal medicines. Although all babies cry, those who have colic experience episodes of crying for more than three hours a day, more than three days a week for a duration of over one week.
Intestinal hypersensitivity is believed to play a major part in functional gastrointestinal disorders (FGID) such as irritable bowel syndrome and it might also be the cause of colic. Several hypotheses have been suggested to explain gastrointestinal disorders in infants and an imbalance in the gut flora has been observed in several scientific studies. The authors showed that there are significant differences in the stool of colicky and non-colicky infants. In order to avoid any invasive procedure on babies and assess whether the stool composition of colicky infants is directly involved in intestinal hypersensitivity, the researchers transplanted a sample of human stool into mice intestine (fecal microbiota transplant).
The involved compounds still have to be identified
Mice received stool extracts from breastfed babies aged 1 to 4 months who either had colic or not. Several parameters of their gastrointestinal function were then measured. The results indicated that fecal transplants from colicky infants led to gastrointestinal hypersensitivity characterized by an increase of abdominal muscle contractions. Moreover, the severity of gastrointestinal hypersensitivity is correlated to crying time, as well as to the presence of some bacteria from the Bacteroides group (which are more abundant in colicky infants). Nevertheless, researchers still not agree on the exact role of Bacteroides in visceral hypersensitivity. “Additional studies are necessary to determine the involved compounds, their mechanism of action and their link with intestinal microbiota disruptions” said Emmanuel Mas, researcher at the INRA of Toulouse and co-author of these studies.
Eutamène H, Garcia-Rodenas CL, Yvon S et al. Luminal coontents from the gut of colicky infants induce visceral hypersensitivity. Neurogastroenterol Motil 2017 ; 29 : e12994.