Intestinal Bacteria Can Worsen Health of HIV-Infected Patients

Study evaluates how antiretroviral therapy effects gut microbiota.

The altered metabolism in gut microbiota was found to negatively impact the health of HIV-infected patients during a recent study.

The study, which was published in Mucosal Immunology, sought to evaluate the gene and taxonomic composition of intestinal microbiota in HIV-infected patients who had a positive response to antiviral therapy to determine how these changes impacted their health. The study revealed that during treatment, there was both a change in the species of intestinal bacterial communities and a change to their metabolic capacity.

"These functional changes in the microbiota include increased potentially pathogenic metabolic pathways, pathways of resistance to oxidative stress and an increased production pathway of lipopolysaccharides, a key component of the membrane of gram-negative bacteria which is highly inflammatory," first author Jorge Francisco Vázquez Castellanos said in a press release.

The researchers compared HIV-infected patients who had a positive response to antiretroviral therapy with a control group of healthy subjects who were the same age and gender as the infected patients. Investigators measured clinical variables relating to immune system, atherosclerosis, inflammation, and cardiovascular risk, before conducting a metagenomic analysis of the patients’ intestinal bacterial communities.

Following that, the researchers established correlations between altered bacterial communities with health and immune system indicators.

While antiretroviral therapy has significantly improved the life expectancy of HIV-infected patients, the life expectancy is still approximately 10 years less than the general population, the study noted. Cardiovascular diseases related to atherosclerosis are among the most common causes of death in patients with HIV.

"Although the causes of this systemic inflammation may be varied, it is thought that one of the main could be the translocation of bacterial metabolites into the bloodstream due to damage caused by the virus to the intestinal mucosa,” researcher Andrés Moya said in a press release. “That is why it is important to characterize the microbiota in HIV-infected patients and to study the relationship between these changes and the deterioration of their health.”

Investigators will next analyze patient groups with different responses to antiretroviral treatment to evaluate fundamental changes that can cause aberrant bacterial communities.

The research will help to evaluate whether the application of prebiotics or probiotics to the altered bacterial community "could be of great help to prevent chronic damage of patients on antiretroviral therapy and, certainly, a very promising field of study," Vázquez concluded.