Assessing the role of dietary interventions on the gut microbiome: a potential therapeutic for IBD
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Citation
Abstract
The gut microbiome consists of a wide diversity of bacteria that play a role in maintaining homeostasis and regulating inflammation. Therefore, in recent years, there has been an increased focus in sequencing the microbiome through new metagenomic advancements to better understand the functions of the bacteria. Through sequencing, it was discovered that the microbiome is composed of four main phyla, each with a different primary function. Many studies have been conducted investigating the impact of diets on the microbiome and they have shown its composition can change depending on the dietary patterns of a particular individual. For example, in a high animal-based protein diet there is an increase in microbiota processing of L-carnitine and phosphatidylcholine, which leads to increased levels of Trimethylamine N-oxide (TMAO). In a carbohydrate diet, there is an increase in microbiota accessible carbohydrates (MAC), which leads to an increase in bacteria that convert the MAC to short chain fatty acids (SCFA). In a high fat diet, more bacteria are needed to alter the bile acids in order to enhance their binding to receptors. When consuming a plant-based diet, it has been well demonstrated that there is an increase in Prevotella bacteria. Gluten free (GFD) and low Fermentable Oligosaccharides, Disaccharides, Monosaccharides and Polyols (FODMAP) diets also show a differing composition of the microbiome, when compared to a normal diet. While dietary changes allow for alteration of the microbiome without disrupting the symbiotic nature of the microbiota with the gastrointestinal system, dysbiosis of the microbiome can occur which can lead to the pathogenesis of many diseases, including Inflammatory Bowel Disease (IBD). IBD is an autoimmune condition characterized by persistent intestinal inflammation. While the development of IBD is largely multifactorial, there is strong evidence that alteration of the composition of the microbiome is a core component of the pathogenesis. Current treatments center around managing the inflammation through prolonged steroid use, Tumor Necrosis Factor (TNF) inhibitors, and other maintenance medications. However, emerging treatment options have explored utilizing dietary interventions to attempt to restore the symbiotic nature of the microbiome. Many of these dietary interventions, such as exclusive enteral nutrition (EEN) and Crohn’s Disease exclusion diet (CDED) have been proven to lead to remission in Crohn’s Disease (CD) patients. By understanding the complexity of the microbiome and its relationship to the digestive system, new advancements can be made in treating chronic diseases such as IBD through dietary interventions.