Irritable bowel syndrome (IBS) is a highly prevalent gastrointestinal disorder that affects 8.8% of the general population (1). Diagnosis of IBS continues to be challenging as there is a lack of clinical biomarkers associated with the disorder. Recent evidence implicates a wide range of factors potentially associated with IBS, such as gut immune activation, intestinal permeability, and the gut microbiome.
The gut microbiome develops early in infancy and plays an essential role in the development of the immune system in the gut. Recent studies have highlighted the role of gut microbiota in the progression of IBS. There is an increased risk of developing IBS after infections that target the gut, like gastroenteritis. Dysbiosis stemming from the infection can activate the gut immune system leading to low grade inflammation.
Although bacterial colonization of the fetal intestine begins during pregnancy, much of the baby’s microbiome develops after birth and is heavily influenced by the environment in which they are raised. The early development of an infant’s microbiome can be affected by many different factors such as birth mode (cesarean delivery vs. vaginal delivery), breastmilk vs. formula feeding, antibiotic use, the timing of the transition to solid foods, and even the presence of pets in the household. Development of the gut microbiota in infancy occurs during a critical window, and any disturbances in the natural process are sometimes linked to immune diseases such as food allergies and asthma.
Multiple studies have shown differences in the gut microbiome in children with IBS when compared to healthy controls. The diversity and stability of microbiota is often reduced in children with IBS. Recent efforts have been focused towards utilizing therapeutic approaches to influence the gut microbiome and alleviate symptoms associated with IBS. The most common approaches include prebiotics, probiotics, antibiotics, diet, and even fecal transplants. The field of evidence for the use of prebiotics and probiotics in these cases continues to grow, but further research is necessary to identify the optimal dosage and treatment duration to encourage the desired effects, as overuse of prebiotics and probiotics can sometimes lead to increased severity of IBS symptoms.
The use of antibiotics is primarily associated with decreased microbiome health, but some studies have shown that IBS patients respond well to antibiotic treatment. The use of antibiotics may be beneficial for the purpose of reducing the abundance of undesirable species in the gut. While many patients show reductions in symptoms when given antibiotic therapies, recurrence of IBS symptoms is fairly common, and more work must be done to further understand the mechanisms of antibiotic therapy.
Although we are far from fully understanding the mechanisms underlying IBS, it is essential to take steps to promote the development of a healthy microbiome in the early stages of children’s lives. While sanitization is crucial to reduce the risk of infection from environmental pathogens and viruses, over-sanitization can hinder microbiome development by limiting the abundance of beneficial microbes. From owning pets to playing in dirt, exposing the body to a diverse microbial environment promotes a diverse and healthy ecosystem in the gut. In fact, some studies have shown that owning a pet and exposing it to the family and home can enhance microbial diversity in newborns. Exposure to furry animals increases a type of bacteria (Bifidobacterium) that is beneficial to the gut ecosystem. On top of that, there is a wide range of evidence supporting the belief that children that are allowed to play freely in their environment tend to develop more robust microbial health and display a reduced incidence of immune disorders such as asthma and allergies.
It is still important to take steps to limit our exposure to disease causing pathogens and harmful environmental chemicals, but it’s also important to consider that many environmental microbes are essential for the development of a healthy microbiome and the wide range of health benefits that are associated with it.
Dr. Rohan Bissoondath,
Medical Director