Infectobesity: a New Area for Microbiological and Virological Research

Abstract

Obesity is connected with numerous diseases, such as type 2 diabetes, atherosclerosis, cancer, and nervous system dysfunctions. Obesity is affected by genetic, environmental, and cultural factors. However, numerous studies indicate that several pathogens might cause obesity. This review discusses recent data and the characteristics of pathogens that are implicated in obesity. In particular, human adenovirus 36 (Ad36) is the most clearly implicated virus in human obesity. It was recently shown that obese groups from the USA, Korea, and Italy have a higher prevalence of serum antibodies against Ad36. The mechanisms of Ad36-induced obesity remain unclear. However, glucose uptake and inflammation are possible mechanisms of Ad36-induced obesity. Overall, this new understanding of causes of obesity has developed into the concept of 'infectobesity' and the possibility of developing a 'vaccine' or 'therapeutic agents' for obesity. million women were considered to be obese (Fig. 1A and 1B). Thus, more than one in ten of the world's adult population was obese. Close to 35 million overweight children live in developing countries and eight million in developed countries, which means that overweight children are a problem in all countries. Overweight and obesity also account for 44% of the diabetes burden, 23% of the ischemic heart disease burden, and between 7% and 41% of certain cancer burdens. Recently, the obesity rate among Koreans has increased drastically (Fig. 1C). In 1995, 11.7% of women and 18% of men were considered to be obese.However, 29.4% of women and 32.6% of men were considered obese in 2001 and the obese ratio recently increased further. There was also a noticeable increase in the ratio of obese children and adolescents (1).The costs of treating obesity and obesity-related metabolic disease account for 40% of total health expenditure in the USA and this recent trend is dramatically increasing (2).The social and economic cost of obesity therapy is more than 1 billion dollar and diabetes treatments account for 19.2% of the national medical insurance premium in Korea (3). Thus, obesity-related diseases are a severe loss to the national economy.There are many causes for obesity, such as genetics, medical problems, or psychiatric illness. Simply put, obesity is a result of an energy imbalance, where the energy intake is greater than energy expenditure (4) and excess energy accumulates in adipose tissue. Increasing rates of obesity at the societal level are attributed to easy access to a palatable diet, increased dependence on cars, and mechanized manufacturing. However, the recent increase in obesity might be

Central obesity is associated with helicobacter pylori infection: a large-scale cross-sectional retrospective study in West China

“…On the other hand, as virus can lead to infectobesity, H. pylori may be a contributing factor to obesity. The virus induces obesity probably by means of interacting with the hypothalamic-pituitary-adrenal axis [30], while the possible mechanisms of H. pylori-induced obesity include interruption of leptin secretion, glucose uptake, and inflammation [31], H. pylori infection can induce chronic low-grade inflammation, and then prolonged, low-level immune stimulation induces hypertrophy of adipose tissue and increases shunting of energy to host defense mechanisms [32]. Our study found that the FPG, TG, LDL-C, and TC levels were higher in H. pylori-positive subjects than those in H. pylorinegative subjects.…”

The role of adenovirus 36 as a risk factor in obesity: The first clinical study made in the fatty tissues of adults in Turkey

“…Although the triggering role of Ad-36 in the Ad-36-obesity relationship is explained by these mechanisms, considering the replication potential and persistence of the virus in the host cell, other mechanisms may also impact the development and progression of obesity. Chronic inflammation process has been proposed to such a contributing mechanism [24,30].…”

“…Immune cells and macrophages infiltrate the adipocytes and remodeling of adipose tissue develops because of angiogenesis. The infiltrated macrophages secrete IL-6, IL-8, TNF-a and MCP-1 and adipocytes lose homeostasis of the free acid pathway during the inflammatory state [30].…”

Reduction of adenovirus 36‐induced obesity and inflammation by mulberry extract

“…Human adenovirus 36 infection has been shown to increase adiposity in both human and animal model systems . In addition, we have determined that Ad36 infection also increases inflammation in adipose tissues and maintains obesity states .…”

“…In this study, we used Ad36 as a trigger for inflammation and obesity because Ad36 infection induces chronic inflammation that may contribute to increased adiposity in animals and humans (1)(2)(3)(4)(5). However, there are no currently available specific treatments or vaccines for Ad36-induced obesity.…”