UCLA: Gut bacteria may cause susceptibility to HIV infection

A new UCLA-led study shows that certain gut bacteria — including one that is critical to a healthy gut microbiome — differs
between people living with and uninfected with HIV.

Dr.
Jennifer Fulcher Fellcher, assistant professor of medicine in the Department of Infectious Diseases at the University of California, Los Angeles, David Geffen School of Medicine, said the findings, published in the peer-reviewed journal EBioMedicine, suggest that the gut microbiota may increase a person's risk of
contracting HIV.

"This is an important area that needs further research to better understand whether and how these bacteria affect the spread
of HIV," Fulcher said.
Fulcher also made an appointment for the veterans' Grand Los Angeles Health System
.
"Microbial-based therapies are becoming a hot area
of research with great potential.
With further research, this could be a new way
to help prevent AIDS.
”

Fulcher said there is a well-known link
between chronic HIV and changes in gut bacteria.
The researchers hope to better understand when these changes began to occur
after HIV infection.
To do so, they examined gut microbiome samples from 27 men who had sex with men who were both sampled before and after infection
.
They then compared
the sample to 28 men who had a similar risk of behavioural infection but did not carry HIV.
The samples came from UCLA-led NIDA Opportunities Cooperative Alliance (C3PNO), a resource and data center containing millions of studies, laboratory samples, statistics, and other data designed to facilitate investigations
into the impact of substance abuse on HIV/AIDS.

The researchers found that in the first year, there was little change
in the gut bacteria of the infected men.
However, they found that men infected with HIV already had differences in gut bacteria compared to men who were not infected, even before
they were infected.

Specifically, these men had decreased levels of Bacteroides, a bacteroides ubiquitous bacteria in the lower digestive tract that have important metabolic functions in the gut environment that maintains health, compared to the uninfected, high-risk control group, while macrophages (Megasphaera elsdenii) levels have risen, and their role in the human gut is unclear
。 The researchers also found that men infected with HIV had elevated inflammatory cytokines and biologically active lipids prior to infection, both of which were linked to systemic inflammation, suggesting that their bodies had been in a state
of resistance to infection or damage compared to a matched control group.

Limitations of the study include a relatively small sample size and a focus on only young men who have sex with men, most of whom use drugs, which may reduce their prevalence to other populations
.

Gut dysbiosis and inflammatory blood markers precede HIV with limited changes after early seroconversion