Groundbreaking Israeli study shows gut bacteria could strengthen immune system among HIV patients

Israeli researchers at the Weizmann Institute of Science and the Hadassah AIDS Center have discovered that gut bacteria could strengthen the immune system of HIV patients. The groundbreaking study was carried out in Israel and Ethiopia, and the findings were released on Thursday.

Researchers found that the gut microbiome may improve immune responses among people living with early-stage HIV. The study was led by Prof. Eran Elinav of the Weizmann Institute of Science in Rehovot together with his wife, Prof. Hila Elinav, head of the Hadassah AIDS Center in Jerusalem. It examined the gut microbiome in 70 HIV patients in Israel and a similar number in Ethiopia.

“Our study provides strong evidence in humans that the microbiome and the immune system causally affect one another,” Eran Elinav explained in an interview with The Times of Israel. “In fact, the microbiome acts as a kind of an immune organ – it both shapes and responds to immunity."

“The gut serves as a kind of reservoir for HIV, and T cells in its lining remain damaged even when the immune system in the rest of the body recovers as a result of antiviral therapy,” Hila Elinav explained.

HIV, or human immunodeficiency virus, attacks the body’s immune system and weakens its ability to fight infections.

The study was published in the prominent scientific journal Nature Microbiology and was carried out despite significant challenges. The lead researcher’s lab at the Weizmann Institute was destroyed by an Iranian missile during the 12-day war between Israel and Iran in June 2025. Meanwhile, civil war in Ethiopia forced another study author to flee his home.

Proper treatment can prevent HIV from developing into AIDS, a serious issue in many developing countries. According to the Israel Health Ministry, about 9,064 people are living with HIV in Israel. By contrast, Ethiopia has roughly 600,000 people with the virus. Globally, the World Health Organization reports that over 40 million people are living with HIV.

“We believe the virus is not affecting the bacteria directly,” Eran assessed. The study instead indicates that HIV impacts the immune system, which under normal circumstances secretes “natural antibiotic molecules.”

“Much work remains to identify the exact microbes and molecules involved,” Hila admitted. “But our study suggests that, in the future, altering the microbiome might help support immunity and lower the risk of life-threatening infections in people living with HIV."

Eran volunteered by working in a clinic in the war-torn and poor Ethiopian Tigray region where the treatment is “especially critical in places where advanced antiviral therapies are still out of reach, or in patients whose immune systems are not sufficiently restored by antiviral treatment.”

Despite its comparatively small size, Israel has emerged as an important global center for medical research. Assistant Professor Shady Farah from the Technion Institute in Haifa is leading an international team that has developed a device that could potentially remove the need for future insulin shots among diabetes patients.