New C. diff treatments
C. difficile is a spore-forming bacteria that is commonly encountered in the soil, water, and even in the air. 3% of adults have it in their intestines and that’s not a problem as long as it is kept in check by an abundance of healthier bacteria.
There are several risk factors for developing an active C. difficile infection. These include being older, sicker, or being in a healthcare setting, like a hospital or nursing facility, where C. Dificile is common in the environment.
Because most of you who follow me are younger people, you’ll also be interested to know that PPIs are a risk factor for C. difficile infection. This is probably because PPI's make the colon less acidic, and good bacteria prefer an acidic environment.
We have a variety of antibiotics that are active against C. dificile, but they don’t address the underlying issue, which is a lack of diversity of existing bacteria in the persons microbiome. And in fact, by treating with antibiotics, we Worsen the situation by killing off whole populations of bacteria, putting the patient at risk for recurrence. We have tried to combat that by developing antibiotics against C diff that have a narrower and narrower spectrum of action, meaning that they are more precisely geared at killing. C. diff. and sparing other bacteria. Still, at present, one in seven patients will have a recurrence of infection.
We also have an antibody that we can use called Bezlotoxumab or Zinplava. It is used during antibiotic treatment of a recurrence of severe C. diff and neutralizes the toxin that the bacteria produces.It is a one hour infusion that is given just once. The benefit is 10% more than seen with placebo. Meh.
The exciting thing I want to tell you about, and the reason for this post, is that there are now two new treatments on the scene. They are a new class of FDA-approved drugs called Live Biotherapeutic Products, or LBPs, and both are aimed at restoring the microbiome so that any C. diff that remain in the colon cannot regain a foothold.
This video from Rebyota does a great job of pictorally demonstrating what these products do in your large intestine.
The development of these products is really, really, really exciting for a MB specialist like me, because it is the first time, and I hope the first of many, that we as doctors can FIX YOUR MICROBIOME!
The first is Rebyota a fecal microbial transplant (FMT), approved in fall 2022, that is done in the comfort of your own home, as an enema. It is administered as a single dose one to three days after completion of antibiotics. 70% of Rebyota recipients had not had a recurrence at 8 weeks.
The second is VOWST, approved in April 2023, an oral capsule containing bacteria that typically populate a healthy, diverse colon. 2-4 days after completing antibiotics, patients take a Mag citrate laxative to clear the colon, then Four capsules are taken orally once a day for three days on an empty stomach. 88% of VOWST recipients had not developed CDI recurrence by 8 weeks.
Rebyota, the enema, is stool that has been isolated and purified from a single donor so that it is traceable, should there be any contamination or infectious episodes (yikes).
VOWST is a capsule of purified spores, akin to the kind of probiotic capsule that we’re all familiar with.
One really interesting thing about both of these is that when they take up residence successfully, they reduce the number if antibiotic-resistant bacteria. A common resistant organism that we see in the hospital is VRE, or vancomycin-resistant enterococcus, and 73% of patients with VRE were cured of this after receiving the transplant. This is big – this means that those patients can be treated in the future with vancomycin IF THEY NEED IT. Vancomycin is one of those core tools in the doctor’s toolkit that we want to be able to use when the stakes are high, if the patient is very sick.
Both are safe, the most common AEs were gas, bloating, abdominal pain, fatigue and constipation. Both of these should be safe in pregnant and lactating mothers.
So, if you’re asking me in clinic which one I recommend, assuming that your insurance will cover either, I would choose VOWST. It DOES require a laxative (and these patients are tired of having diarrhea) but I like the natural route of colonizing the colon orally, the response is better, and there’s no ick factor of an enema.
Rebyota enema VOWST capsules
One time enema 4 capules once a day for 3 days
Effectiveness at 8 weeks 70% 88%
Side effects Abdominal pain, Bloating, fatigue, chills
diarrhea, bloating constipation, diarrhea
Once you do the transplant, of course, you have to listen to me nerd out about why you should be eating plants to keep the bacteria alive, etc., etc. But that’s the topic of another blog 😊
