The Roles of Food, Genes and Mind in Functional Gastrointestinal Disorders and IBS
This blog post is related to gut disorders - in fact, a special category of them which are usually referred to as functional GI disorders, which have been increasingly on the rise and affecting a large fraction of the world population. This is a high-level introduction to how those disorders are connected to our brain and nervous system, to our gene expression, and to the food we eat. In later articles, we will do a deep dive into each one of them, but for now, let's just introduce a few terms and the new fields that have emerged around those topics.
Functional gastrointestinal disorders (FGIDs), the most common diagnoses in gastroenterology, are usually recognized by abnormalities in the anatomy and function of the digestive system, often occurring in combination. Those can include motility disturbance (when the nerves or muscles of the gut do not work in a coordinated way), visceral hypersensitivity (a general increase in pain sensation experienced in internal organs), altered mucosal and immune function, altered gut microbiota, and altered central nervous system processing . I have chosen this topic because as such, they can benefit from a more integrative treatment approach.
Irritable bowel syndrome (IBS) is an example of FGID, and another widely prevalent gastrointestinal disorder, affecting about 5% to 11% of the general population. It is a complex condition characterized by alterations of bidirectional brain-gut interactions affecting GI function. Surprisingly, the pathophysiology of IBS is not yet completely understood. As such, this is a diagnosis that often leads to frustration in patients, since there is no standardized treatment procedure and many of them end up trying many different approaches, some without success. It drastically interferes with quality of life and well-being.
The presence of emotional and psychological factors and of food intolerance contribute to the clinical presentation and can exacerbate IBS symptoms . Interestingly, genes can play a role in that. Environmental factors including (1) stress and psychological factors at the central nervous system (CNS) level, and (2) dietary factors at the gastrointestinal level, can induce changes in gene expression mediated by epigenetic or non-genetic factors and can have a direct influence on CNS and gut function. Peripheral or gut factors, including GI infection or other host or microbial factors, can potentially modify the function of genes and influence the CNS and gut functions (such as pain modulation, sensation, immunity, barrier function, colonic transit, and secretion) to manifest the symptoms of IBS.
It is not only stress and environment that can affect the gene expression in IBS, but also food. Nutrigenomics, the study of the interaction of diet and genomic factors, is an emerging topic in the context of IBS, with most IBS patients reporting meal-related symptoms. Dietary modification is an increasing treatment intervention used in IBS, with a low FODMAP (fermentable oligo-, di-, and mono-saccharides and polyols) diet having been associated with the alleviation of IBS symptoms.
Psychiatric comorbidities are usually present in patients suffering from gastrointestinal disorders. The growing field of psychogastroenterology focuses on applying scientifically-based psychological principles and techniques to alleviate digestive symptoms . Brain-gut psychotherapies, including cognitive behavioral therapy (CBT) and gut-directed hypnotherapy, are among the techniques used by mental health professionals in this field. Along with psychotherapy, antidepressants have been proposed as treatments for gut-brain disorders, with potential benefits to both psychological and gastrointestinal health .
How we can help
At mind∙body∙food∙pain, we use both dietary interventions (low FODMAP) as well as psychological interventions for addressing IBS symptoms, along with lifestyle medicine principles. Removing the fear around the food and symptoms, finding appropriate lifestyle strategies, and regulating the nervous system through mindfulness and yoga are all tools that we provide in order to address this condition from a more integrative perspective. To learn more, go to https://www.mindbodyfoodpain.com/gut-health
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