Differences in the microbiome between HIV-infected and uninfected men among homosexual men
A new study suggests that differences in the trillions of bacteria (microbiome) in the human gut may actually affect human immunodeficiency virus (HIV) infection. The health medicine web magazine ‘Health Day’ reported on the 4th (local time) based on a research paper by University of California, Los Angeles (UCLA) researchers recently published in eBio Medicine, the sister journal of the medical journal The Lancet. content.
Researchers led by Professor Jennifer Fulcher at UCLA’s David Geffen School of Medicine analyzed the microbiome of 55 men who had sex with other men. Of these, 27 were HIV infected and 28 were uninfected.
The researchers found significant differences in the amount of certain bacteria in the two groups. “The results suggest that there is a link between these gut bacteria and the risk of HIV,” said Pulcher.
“We followed up with changes in the microbiome before and after HIV infection,” he said. As a result, it was found that little change was observed in the microbiome of the HIV patient population in the years following infection. The researchers next compared the microbiome of people living with HIV to the microbiome of those who had sex with a person infected with HIV but remained negative. Then the difference was noticed.
First, the HIV-positive group had relatively low levels of gut bacteria, which are known to play an important role in maintaining gut health. In the HIV-positive group, the pre-infection level of the bacterium Megasphaera elsdenii was relatively high, but the role of this bacterium has not yet been identified.
The HIV-positive group also showed high levels of biomarkers for inflammation before infection. Higher levels of these biomarkers, such as cytokines and signaling lipid molecules, suggest that the immune system is already on alert before infection. Higher levels of inflammation “can increase the risk of HIV,” Pulcher said.
He said the study should, however, be considered preliminary only, given that the study was small and included only men who had sex with men, many of whom were drug users. “Although the study was designed to limit differences between groups, it is difficult to completely rule out other factors that may have contributed to an increased risk of HIV in participants, so these limitations need to be kept in mind, ” he said.
This study was supported by the National Institute of Allergy and Infectious Diseases (NIAID), the National Institute on Substance Abuse (NIDA), the National Institute of Mental Health (NIMH), the UCLA AIDS Research Center, the UCLA Center for AIDS Research, and UCLA Childhood AIDS Coalition.
The paper can be found at the following link (https://www.thelancet.com/journals/ebiom/article/PIIS2352-3964(22)00468-6/fulltext).
