HIV launches an immediate assault on the gut after infection, spurring harmful inflammation and causing other damage that even very early antiretroviral (ARV) treatment may not fully reverse. Researchers followed 78 people who were diagnosed with the virus an estimated 12 to 22 days after infection and who then began ARVs within five days, as well as 109 HIV-negative people who served as controls. At the start of the study, various indicators of damage to the gut were higher in the HIV-positive participants, regardless of how soon after infection they were diagnosed, when compared with the control group. Even after two years, the levels of all but one of these damage barometers stayed higher in the HIV-positive group. On the upside, the researchers found that most of the gut-damage gauges among the HIV-positive participants did drop below levels seen in people on ARVs in other studies who began treatment after the acute period of infection.