The incidence of inflammatory bowel disease has increased substantially among children in Canada over the past decade. This increase, which is particularly worrying given the fact that these diseases predispose to colorectal cancer, could be explained by various environmental factors, such as the intake of antibiotics, a diet low in fiber and high in meat, as well as lifestyle. urban, which is generally more sanitized and sedentary.
At CHU Sainte-Justine, the register in which all new cases of Crohn’s disease and ulcerative colitis are collected annually has shown a 65% increase in the number of new cases of these two diseases between 2009 and 2020. So 80 new cases were diagnosed in 2009, 132 were detected in 2020. “This increase is similar to that reported in several other studies. A survey conducted in Canada indicates that it is mainly seen in children, ”notes Dr.r Prévost Jantchou, researcher in pediatric gastroenterology at CHU Sainte-Justine.
In the pediatric cohort of 700 patients monitored by gastroenterologists at Sainte-Justine, 25% were under 11 years old at the time of diagnosis, 25% were over 16 years old and 50% between 11 and 16 years old. “We diagnose the disease in younger and younger children,” says Dr.r Jantchou.
Environmental factors are clearly involved in the increase of these diseases in children, as the majority of cases do not have a genetic predisposition. “Out of about 130 cases, we only found a family history in 10 to 20%,” he says.
Antibiotics and diet
The repeated intake of antibiotics during the first years of life is a major factor that increases the risk of developing these diseases. It is “during the first three years of life that the microbiome is created and consolidated,” recalls Dr.r Jantchou. However, antibiotics can unbalance the microbiome for several months.
Until a few years ago, children could receive antibiotics for banal viral infections, such as nasopharyngitis, for which they are however not indicated. “Children who have recurrent ear infections in the eardrum and tonsils may justify antibiotic treatment, agrees the doctor. But we can act upstream by implementing strategies to reduce these infections. Breastfeeding helps reduce the risk of a baby getting sick during the first years of life. The vaccine againstHaemophilus influenzae, which is part of the vaccination program for the first year of life, also helps reduce ENT infections, which are generally treated with antibiotics. And the pneumococcal vaccine can help too. “
Out of about 130 cases, a family history was only found in 10 to 20%
Food also plays a central role. A diet low in fiber and high in fat, animal protein and processed products, in which there are lots of added emulsifiers, has been shown to be associated with a higher risk of inflammatory bowel disease. “We should focus on foods that are enriched with seeds and fiber, such as brown bread rather than white bread, as well as fruits and vegetables, which are important for fiber intake. All these changes can improve the intestinal microbiota, which has the function of protecting the intestinal barrier and constituting an antimicrobial barrier ”, indicates the researcher.
Sunshine
Living in latitudes like those of Quebec, where the sunshine is less than further south, also seems to increase the risk of these diseases, because they are much less frequent in the southern hemisphere, especially in Africa and in Latin America. “There really is a north-south gradient. In countries where there is strong sunshine, there are fewer cases. We deduced that vitamin D seems to have a protective role ”, indicates the Dr Prévost Jantchou, who is conducting a study on the role of vitamin D in these diseases.
But the emergence of cases and their increase in some African countries which have become westernized suggests that lifestyle also has an influence on the risk of suffering from these diseases. Urban life, which involves less contact with farm animals, less play outside and in the land, and less physical activity, would predispose more than rural life. The fact that children who live in cities are less exposed to germs and are more sedentary would make them more fragile, says the specialist.
The deterioration of the intestinal microbiota contributes to the emergence of these diseases which, before causing symptoms, first lead to an increase in the permeability of the intestinal mucosa. The intestine becomes “porous”, that is to say that “the junctions between the cells which make up the intestinal barrier are less close together than normally, and thus allow food antigens to pass through which are then found in the vascular system, where they will trigger an immune reaction. By attacking the cells of the intestinal mucosa, this immune reaction induces ulcers, cracks, cuts in the wall of the intestine. In some severe cases of Crohn’s disease, these ulcers can even lead to perforations, ”explains the gastroenterologist, adding that this damage leads to very characteristic clinical signs, such as stomach aches, diarrhea and blood in the stool or even vomiting, weight loss, fever and fatigue.
Treatments
“The sooner these diseases are detected, the less aggressive the treatments will be, and the faster the clinical remission will be,” says Dr.r Jantchou. The aim of the treatments is to decrease the activity of the disease to the point that there are no more symptoms and signs of ulcers and cracks on the intestinal wall. But scarring of the intestinal wall does not mean that the person is cured, as studies have shown that more than half of the patients who stop their treatment relapse. “
Adherence to treatment is therefore particularly important in adolescents who sometimes show little concern for their treatment. However, since Crohn’s disease and ulcerative colitis predispose to colorectal cancer and the risk of cancer is directly linked to the activity of the disease – the more silent the disease, the lower the probability of cancer – we follow very close to the patients. “The prevention of colorectal cancer involves putting it into remission, followed by rigorous monitoring and colonoscopy checks. When our patients become adults, we make sure that they will not be lost to follow-up even if they are well, because if an 18-year-old young adult stops his treatments, he can end up with cancer at 27 ” , warns the Dr Jantchou.
The first treatment proposed consists of enteral nutrition which aims to put the intestine at rest for 8 to 12 weeks. It is a liquid mixture that looks like milk but contains all the necessary calories and nutrients. Immunomodulators or monoclonal antibodies are then prescribed, which act on the immune system so that it is less reactive and does not damage the intestinal mucosa.
Watch video
–
