Association between westernized diets, gut microbiome, and obesity and related disorders

corresponding

SUMAN AHUJA1, PADMINI SHANKAR2*
*Corresponding author
1. Lincoln University, MO, USA
2. School of Health & Kinesiology, College of Health & Human Sciences, Georgia Southern University, Statesboro, GA, USA

Abstract

Obesity is a major health concern and primary cause for most chronic diseases such as hypertension, cardiovascular disease, insulin resistance, type 2 diabetes, and certain cancers. Amongst the many causes of obesity, one that stands out the most is consumption of energy dense processed foods and therefore, a lower consumption of nutrient dense foods. Such consumption of high caloric processed foods can have a strong impact on the gut microbiome, resulting in development of inflammation and thus establishing a potential link between obesity and aberrations of the gut microflora. Recent studies have indicated a strong link between gut microbiome, lowered energy metabolism, and thus development of obesity. Lately, developments within the medical field have shown that overweight and obese individuals show many alterations in the composition of their gut bacteria as compared to their lean counterparts. The main question to investigate is if and how diet might be the governing factor, and how dietary choices can play a significant role in the composition of the gut microbiome. Research has also shown that fat metabolism is encouraged and preferred in those with an altered gut microbiome via a multifaceted mechanism. Most recent research has shown that both pre- and probiotics have the most advanced abilities to modulate gut microflora and stimulate growth of key microorganisms involved in modulating both systemic and mucosal immunity, thus allowing a reduction in inflammation, especially the kind associated with presence of visceral fat and central obesity. Therefore, the aim of this review is to discuss the various mechanisms generated by an imbalance in energy homeostasis affecting the gut microbiome. Literature has confirmed that gut microbiome or lack thereof can result in health issues including but not limited to obesity, type 2 diabetes, metabolic syndrome, non alcoholic fatty liver, cardiovascular diseases, cancers, brain and nervous system disorders, asthma, and allergies. Therefore, in this study, we will outline the various mechanisms to identify the correlations between gut microbiome and obesity related health disorders such as metabolic syndrome, type 2 diabetes, non alcoholic fatty liver, and insulin resistance. We will aim to briefly discuss the gut-brain axis and other relevant obesity related health issues as well. We also aim to identify the many dietary factors that may aid in reversal of inflammation of the gut by means of adding certain therapeutic dietary strategies like probiotics and/or prebiotics to combat obesity and related disorders.


INTRODUCTION

Obesity is a major health epidemic affecting both, adults and children. In fact, obesity is now deemed as a major public health concern worldwide and is associated with an increased risk for developing comorbodities such as hypertension, type 2 diabetes, cardiovascular diseases, and cancers (1). While obesity is a multi-factorial health disorder, in part, one of the culprits is the adoption of westernized diet that is high in processed foods (2). Aside from obesity being a result of excess consumption of processed foods, it is evident that surge in obesity has resulted from long term caloric imbalances, that is, intake of energy dense foods exceeding that of nutrient dense choices in addition to reduced physical activity, resulting in decreased energy expenditure (2). Nonetheless, it has become clear over the years that obesity is a far more complex condition and the underlying mechanisms are far more tedious and complicated than just caloric imbalances. The most researched contributors of obesity include but are not limited to genetics, lifestyle, dietary choices, emotional stressors, and other inflammatory conditions both systemic and limi ...