David Henry, MD: Here we are in COVID. We’re recording this the first week in November. Sadly, cases are spiking in the country. And I understand you’ve got some information that you might share about how manipulating ... the microbiome that we all exist with inside our gut might somehow play into doing better or worse with COVID.
Anthony Sung, MD: Absolutely. So, as associate director of the Duke Microbiome Center, I was approached by one of my colleagues, Paul Wischmeyer, who is a professor of anesthesiology and critical care medicine at Duke. Paul had previously done some very nice murine studies with the probiotic Lactobacillus rhamnosus GG, or LGG.
He showed, in a murine model of pseudomonas pneumonia, that giving LGG to mice would help modulate their microbiome and, in turn, their immune system, leading to decreased inflammation, decreased TNF-alpha, IL [interleukin]-2, and IL-6, [and] increased Treg cells . This also helped prevent lung injury, and it actually significantly improved survival in mice receiving LGG [ ].
In addition, there has been a randomized clinical trial of LGG showing that its administration would help prevent ventilator-associated pneumonia, or VAP .
And a few years ago, there was another RCT [randomized, controlled trial], published in Nature, showing that another Lactobacillus product significantly decreased the combined endpoint of sepsis and mortality, primarily by reducing lower respiratory tract infection [
Dr. Henry: And how is that working? What is the bacillus doing to help us?
Dr. Sung: We think it’s through modulating the immune system. As mentioned in Paul’s studies, we saw significantly decreased amounts of TNF-alpha, IL-2, and IL-6, which are the same cytokines that have been implicated in COVID-19 and associated with increased lung injury in patients during this pandemic.
And we believe that by giving individuals this probiotic, LGG, we may help modulate the immune system, decrease lung injury and symptoms, and maybe even prevent COVID-19.
So with support from the Duke Microbiome Center, as well as private donations and philanthropy, we are conducting a randomized clinical trial of LGG to prevent COVID-19 in household contacts who’ve been exposed to the disease. In other words, if someone in the house gets COVID-19, we want to try to prophylax everybody else living in that house and prevent them from coming down with the same infection.
Dr. Henry: And this is an oral administration?
Dr. Sung: Correct. This is an oral pill, two pills once a day.
Dr. Henry: And it’s an ongoing study, of course, in COVID right now?
Dr. Sung: Correct. So we have an IND [investigational new drug application] from the FDA [Food and Drug Administration], and we are actively recruiting subjects both at Duke University, but also due to the unique study design, we can enroll patients anywhere across the country. Because of the importance of social distancing, everything is done remotely.
So a household contact can hear about us, either through your podcast or one of our Facebook ads or through other media. They can reach out to our study website, which is, or reach out to us at our study email, .
And we can go ahead and screen them for eligibility in our trial. And if they are eligible and they consent to participate, we will mail them a package basically overnight, FedEx, containing either LGG or placebo, as well as kits so that they can self-collect their stool and nasal swabs so we can test it for SARS-CoV-2 by PCR [polymerase chain reaction] and look at the microbiome.
Dr. Sung and Dr. Henry have no relevant disclosures. Funding for the trial is provided by the Duke Microbiome Center and philanthropic giving. The LGG and placebo used in the trial are provided by DSM.