Gut Bacteria May Assist in Immune System Recovery in HIV Patients

Researchers from the University of Valencia have taken part in a recent international study, published in eBioMedince journal, that set out to further examine the role that gut bacteria play in immune system recovery of HIV-positive patients who are receiving antiretroviral treatment (ART). The researchers found that a certain fraction of the gut microbiome can potentially cause immune system recovery.

According to a press release, these findings could lead to the development of new therapies that are designed to specifically target gut bacteria as a means to make ART an even more successful treatment option for patients with HIV. In addition, researchers may be able to use these bacteria to prevent complications that are typically associated with HIV, a virus that continues to pose a problem, according to the Centers for Disease Control and Prevention, who estimate that 1.2 million people in the United States are HIV-positive.

One of the study's authors, Manuel Ferrer, Consejo Superior de Investigaciones Científicas researcher of the Catalysis Institute, commented, “HIV patients suffer from persistent immune deficiencies and chronic intestinal inflammation caused, in part, by the very toxins released by the cells to fight off the HIV infection. In this study we have found that, in some patients, certain gut bacteria become activated during ART and begin to amass anti-inflammatory molecules.” In addition, the researchers found that those who were not receiving ART did not experience the same level of immune recovery as those who did.

Using fecal samples from 8 healthy controls and 29 patients who were infected with the virus and were receiving different levels of treatment, the researchers took a closer look at the gut bacteria, specifically the bacteria’s molecular agents: proteins and metabolites, according to the study. The study authors write, “We found that HIV infection is associated to dramatic changes in the active set of gut bacteria simultaneously altering the metabolic outcomes. Effects were accentuated among immunological ART responders, regardless of diet, subject characteristics, clinical variables other than immune recovery, the duration and type of ART, and sexual preferences.”

The researchers noted that the gut bacteria in those infected with the virus, who were also receiving treatment, impacted the response of their immune systems.

Lead author of the study, Sergio Serrano-Villar, MD, PhD, a researcher at Hospital Ramón y Cajal, added, “The make-up and behavior of those gut bacteria of HIV patients whose body responds adequately to antiretrovirals are different to those who respond less well to treatment. It is possible that the reason why some subjects respond better to antiretrovirals is because their immune system is predisposed to these beneficial, recovery-enabling bacteria.”

The study authors concede that some of the changes may be due to “a random consequence of the disease status,” but their findings suggest that gut bacteria do provoke immune recovery and play a role in the reduction of inflammation in HIV-positive individuals. According to the press release, if new therapies were developed to specifically target these bacteria, then a combination of the new therapy and ART can be an even more effective means of treatment for those infected by the virus.