Infection and obesity: Two sides of the same coin

Obesity is a chronic disease exceeding epidemic proportions whose multifactorial etiology constrains available treatment options. Obesity therapies have focused on lifestyle interventions targeting food intake and/or physical activity but neglect the potential of microbial causal factors. With rising obesity rates, the need for accelerated therapies may be achieved through microbe-specific vaccines targeting cause-specific etiologies. Obesity is a risk factor for increased susceptibility to numerous infectious diseases. This chapter aims to address the bidirectional relationship between obesity and such microbes by investigating the mechanisms and causality of this relationship through correlationally linked infections of microbial origins like influenza and COVID-19. Additionally, this chapter captures how several microbes contribute to obesity through variable transmission mechanisms as well as the cascade of their effects across host biochemistries known as “Infectobesity.” Identifying contributory roles of pathogens in obesity will assist the development of vaccinations against a growing yet underestimated subtype of obesity.