ABSTRACT
Obesity results from a complex interplay between biological and environmental factors. The term “obesities” may more aptly describe its multifactorial etiology. Obesity increases susceptibility to microbial infection and may lead to poor outcomes. For example, patients with obesity have a poor prognosis and greater mortality following influenza or COVID-19 infection. Conversely, several viruses, bacteria, parasites, and scrapie agents can contribute to obesity. Among the adipogenic microbes, human adenovirus-36 (Ad36) is extensively investigated for its correlative or causative links with obesity in humans and animal models. Natural or experimental exposure to Ad36 is also linked with lower serum lipids and better glycemic control. The E4orf1 gene of Ad36 is responsible for improving glycemic control and shows strong therapeutic potential. Identifying the contributions of various pathogens in obesity may lead to effective treatment of subtypes of obesity through the development of respective vaccines or other treatments. Finally, for individuals suffering from the stigma of obesity, the possibility that a microbe can cause some types of obesity provides strong assurance that obesity is not a choice or a moral failure, but a serious disease.
