Skip to content

The latest development in treating stubborn cases of Clostridium difficile infections (CDI) are "poop pills" - pills that patients can easily swallow rather than having to go through a fecal microbiota transplant (FMT). The "poop pills" are filled with blenderized fecal matter from healthy donors, are much easier for patients to swallow, and they successfully treat C. difficile at almost the same rate as fecal microbiota transplants - about 91% after 1 or 2 treatments for the pills, and 93 to 96% for FMT. This is an amazing success rate for an infection that debilitates people, is resistant to antibiotics in many cases, and even kills people.

Interestingly, these "poop pills" or "Capsule FMT" containing an entire microbiome (bacteria, viruses, fungi, etc) had fantastic results, as compared to a probiotic for the treatment of C. difficile tested by microbiome therapeutics company Seres Therapeutics Inc. In July 2016 Seres announced very disappointing results (no better than a placebo) with its product known as SER-109, a mix of various strains of bacteria.

So why did the Seres probiotic not work in clinical trails? The answer seems to be that the human gut (and so also human fecal matter) contains an entire community of microbes - hundreds of species of bacteria, as well as fungi, viruses, and archaea, but the Seres probiotic was just a mixture of some types of bacteria. This shows how little we know right now. (NOTE: For those interested, the "poop pills" or Capsule FMT is now offered as standard care for recurrent CDI at Massachusetts General Hospital.) From BioMedCentral:

Oral, frozen fecal microbiota transplant (FMT) capsules for recurrent Clostridium difficile infection

Fecal microbiota transplantation (FMT) has been shown to be safe and effective in treating refractory or relapsing C. difficile infection (CDI), but its use has been limited by practical barriers. We recently reported a small preliminary feasibility study using orally administered frozen fecal capsules. Following these early results, we now report our clinical experience in a large cohort with structured follow-up. We prospectively followed a cohort of patients with recurrent or refractory CDI who were treated with frozen, encapsulated FMT at our institution. The primary endpoint was defined as clinical resolution whilst off antibiotics for CDI at 8 weeks after last capsule ingestion. Safety was defined as any FMT-related adverse event grade 2 or above.

Overall, 180 patients aged 7–95 years with a minimal follow-up of 8 weeks were included in the analysis. CDI resolved in 82 % of patients after a single treatment, rising to a 91 % cure rate with two treatments. Three adverse events Grade 2 or above, deemed related or possibly related to FMT, were observed. We confirm the effectiveness and safety of oral administration of frozen encapsulated fecal material, prepared from unrelated donors, in treating recurrent CDI. Randomized studies and FMT registries are still needed to ascertain long-term safety.

The epidemiology of Clostridium difficile infection (CDI) is evolving. Rates of infection are increasing and response to standard antimicrobial treatment with metronidazole or vancomycin may be suboptimal [1, 2].....Fecal microbiota transplant (FMT) has been shown to be safe and effective in treating refractory or relapsing CDI [4, 5, 6, 7, 8], but its use has been limited by practical barriers. Among other concerns, the administration of FMT by colonoscope or naso-gastric/duodenal tube exposes the patient to some risk and discomfort. We recently reported a preliminary feasibility study using orally administered frozen fecal capsules, prepared from unrelated donors, to treat 20 patients with recurrent CDI [9]. Following these encouraging results, we have continued treating patients with FMT capsules. We report our clinical experience in a large cohort with structured follow-up.

Donated fecal matter was blenderized, sieved, centrifuged, and suspended in concentrated form in sterile saline with 10 % glycerol. The suspension was double-encapsulated in hypromellose capsules (Capsugel, Cambridge, MA) and stored at –80 °C for up to 6 months pending use. Processing was done entirely under ambient air. FMT recipients discontinued any anti-CDI treatment for 24–48 hours prior to FMT, and were given 15 capsules on each of two consecutive days with water or apple sauce. The 30 capsules contained sieved, concentrated material derived from a mean of 48 g of fecal matter.

Of the 180 patients reaching 8 weeks, 147 were cured of CDI after the first administration of fecal capsules (82 %). Twenty six individuals relapsed within 8 weeks and were re-treated, with 17 responding, resulting in an overall cure rate of 91 % with one or two treatments. Six individuals declined re-treatment (our standard procedure in these cases is to offer long-term suppressive oral vancomycin treatment). Three patients were cured after a third administration, but were considered “non-responders” as per protocol definition. One patient received three treatments, relapsed, and was advised to continue suppressive vancomycin.

This is very interesting, and raises all sorts of possibilities for microbial transplants. While it's looking at only one person, this seems to be evidence that microbes are involved with our weight and manipulating them may result in weight gain or loss. From Science Daily:

Rapid and unexpected weight gain after fecal transplant

A woman successfully treated for a recurrent Clostridium difficile infection with stool from an overweight donor rapidly gained weight herself afterwards, becoming obese, according to a case report published in the new journal Open Forum Infectious Diseases.

Fecal microbiota transplant (FMT) is a promising treatment for relapsing C. difficile infections, a common cause of antibiotic-related diarrhea that in severe cases may be life-threatening. The case suggests that clinicians should avoid selecting stool donors who are overweight. The report also raises questions about the role of gut bacteria in metabolism and health.

At the time of the woman's fecal transplant in 2011, her weight was stable at 136 pounds, and her Body Mass Index (BMI) was 26. Then 32 years old, she had always been of normal weight. The transplant used donor stool from the woman's overweight but otherwise healthy teenage daughter, administered via colonoscopy, to restore a healthy balance of bacteria in the woman's gut, curing her C. difficile infection.

Sixteen months later, the woman weighed 170 pounds, and her BMI was 33, meeting medical criteria for obesity. The weight gain persisted despite a medically supervised liquid protein diet and exercise program. Continuing efforts to diet and exercise did not lower her weight: Three years after the transplant, she weighed 177 pounds with a BMI of 34.5, and she remains obese today.

"We're questioning whether there was something in the fecal transplant, whether some of those 'good' bacteria we transferred may have had an impact on her metabolism in a negative way," said Colleen R. Kelly, MD, of the Warren Alpert Medical School of Brown University, who wrote the case report with Neha Alang, MD, of Newport Hospital in Rhode Island. Such a link between bacteria in the gastrointestinal tract and weight is supported by previously published animal studies, where transfer of gut bacteria from obese to normal-weight mice can lead to a marked increase in fat. In light of the case and the animal data, the authors recommend selecting stool donors who are not overweight for fecal transplants.

Importantly, the FMT was not the only possible cause of the woman's weight gain. In addition to treatment for C. difficile, she had also been treated with several antibiotics for Helicobacter pylori infection. Other possible contributing factors in the woman's weight gain include the resolution of her C. difficile infection, genetic factors, aging, and stress related to illness. However, as noted above, she had never been overweight before.