To start with, the researchers wanted to find out whether the tryptophan metabolic pathways could be changed.
Why the tryptophan metabolic pathway?
Because tryptophan is a needed component of the human diet that is found in many protein based food. If this pathway is disrupted it is thought to produce metabolites that are toxic to the cells, like quinolinic acid, which may, in turn, be the source of inflammation in the nervous system in HIV patients.
Then, if the tryptophan metabolic pathway could be changed, they wanted to see if this would lead to a lessening of neurological inflammation in the HIV patients.
So, HIV-positive patients on ART were given a high dose of Visbiome probiotic on a daily basis. The dose consisted of 1800 billion live bacteria strains. They were given this regimen for 6 months.
Sample tissue from the colon and cerebrospinal fluid were assessed both before and after the start of them using Visbiome probiotics on a dialy basis.
What they found was that both biomarkers that they used, were reduced by statistically significant amounts.
What scientists have discovered is that in patients with HIV, even those who control their disease with antiretroviral drugs i.e. ART, their gut microbiome is extremely different from those people who are uninfected with HIV. They call this condition 'dysbiosis'.
The scientists postulate that in HIV patients dysbiois can result in a breakdown in the digestive system's ability to protect the body from any kind of immunological invasion. This would permit disease causing bacteria and other types of toxins to move across into the blood stream.
They think that it is this bacterial "invasion" that results in a body-wide inflammatory response, including the central nervous system (CNS), which is where inflammation is a root cause of a many different HIV-related neuro-cognitive dysfunctions.
The researchers think that taking Visbiome helps normalize the gut microbiome in HIV patients and so improves the normal barrier function in the gut. This research adds to the growing science that acknowledges the importance of the gut-brain connection in basic bodily function.
What's really exciting is that a number of studies are currently underway in the U.S.A., Europe, and Canada to assess the possible positive influence of probiotics in gut function of HIV patients. You can learn more about these trials by going to ClinicalTrials.gov