Visbiome and immune activation

As mentioned earlier in this issue of TreatmentUpdate, experiments with animals suggest that bacteria living in the gut can affect several aspects of health, including inflammation in the gut, general inflammation, the health of the immune system and perhaps even the brain.

Researchers in Rome and Bologna, Italy, conducted a sub-study of a slightly larger study, with eight HIV-positive participants and supplements with a sophisticated mix of friendly bacteria (called Visbiome in North America or Vivomixx in the European Union). The bacteria were taken for six months. Researchers found increased levels of the neurotransmitter serotonin in the blood of participants. Other blood tests found reduced levels of activation of CD4+ cells in the blood. Levels of an enzyme in the blood that can weaken the immune system were also reduced.

This pilot study suggests that Visbiome holds promise. A more robustly designed clinical trial of Visbiome is underway in Toronto.

Study details

The average profile of participants was similar to that in the previous reported study in this issue of TreatmentUpdate. Participants took Visbiome twice daily for six months.

Results—Immune activation

Over the course of the study, researchers found that there was a decrease in the proportion of activated CD4+ cells in the blood. This decrease approached statistical significance.

The researchers found significantly decreased levels of an enzyme called IDO-1 (indoleamine 2,3-dioxygenase-1) in the blood. In many lab experiments with cell cultures, IDO-1 can weaken the immune system, particularly in cancer and HIV infection.

Bear in mind

This sub-study suggests that Visbiome may be able to reduce levels of immune activation and levels of an important enzyme that can weaken the immune system. However, due to design issues, firm conclusions cannot be drawn from this study. But it has provided the foundation for a more robustly designed study underway in Toronto. In this study, researchers hope to better understand Visbiome’s potential to reduce excess immunological activation.

—Sean R. Hosein


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  2. d’Ettorre G, Rossi G, Scagnolari C, et al. Probiotic supplementation promotes a reduction in T-cell activation, an increase in Th17 frequencies, and a recovery of intestinal epithelium integrity and mitochondrial morphology in ART-treated HIV-1-positive patients. Immunity, Inflammation and Disease. 2017 Sep;5(3):244-260.
  3. Prendergast GC, Malachowski WP, DuHadaway JB, et al. Discovery of IDO1 inhibitors: From bench to bedside. Cancer Research. 2017 Dec 15;77(24):6795-6811.