Not Curing Obesity with Fecal Microbiota Transplantation & More on Remdesivir

A recent pilot (n=22) double-blind study (JR Allegrett et al. Clin Gastroenterol Hepatol 2020; 18: 855-63) pours cold water on the idea that repopulating one’s microbiome would be helpful in treating obesity.

In this study, the authors examined obese patients without diabetes, nonalcoholic steatohepatitis, or metabolic syndrome.  In the treatment group, patients received FMT by capsules: 30 capsules at week 4 and then a maintenance dose of 12 capsules at week 8.  All FMT was derived from a single lean donor.

Key findings:

  • There were no significant changes in mean BMI at week 12 in either group.
  • Patients in the FMT group had sustained shifts in microbiomes associated with obesity toward those of the donor (P<.001).  In addition, bile acid profiles became more similar to the donor.

My take: Though this was a small study, it suggests that changing the microbiome by itself is likely insufficient to result in significant weight loss.

Related blog posts:

JH Beigel et al. NEJM DOI: 10.1056/NEJMoa2007764 (May 22, 2020): Full text: Remdesivir for the Treatment of Covid-19 — Preliminary Report

This was a a double-blind, randomized, placebo-controlled trial of intravenous remdesivir in adults hospitalized with Covid-19 with evidence of lower respiratory tract involvement (n=1063).

Key findings:

  • Faster recovery for remdesivir recipients: 11 days vs 15 days
  • Lower mortality rate: 7.1% with remdesivir and 11.9% with placebo (hazard ratio for death, 0.70, 95% CI, 0.47 to 1.04) (mortality difference did not reach statistical significance)

 

 

Two Studies: 1. COVID-19 Transmissibility 2.Fecal Microbiota Transplantation in 372 Children

A study in Nature suggests that more than 40% of SARS-CoV-2 infections (COVID-19 viral infections) are spread in the presymptomatic stage: Temporal dynamics in viral shedding andtransmissibility of COVID-19 (Thanks to Steven Liu for this reference).

An excerpt:
We report temporal patterns of viral shedding in 94 patients with laboratory-confirmed COVID-19 and modeled COVID-19 infectiousness profiles from a separate sample of 77 infector–infectee transmission pairs. We observed the highest viral load in throat swabs at the time of symptom onset, and inferred that infectiousness peaked on or before symptom onset. We estimated that 44% (95% confidence interval, 25–69%) of secondary cases were infected during the index cases’ presymptomatic stage, in settings with substantial household clustering, active case finding and quarantine outside the home. Disease control measures should be adjusted to account for probable substantial presymptomatic transmission.

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A recent retrospective multi-center study (MR Nicholson et al. Clin Gastroenterol Hepatol 2020; 18: 612-9) provides data on fecal microbiota transplantation (FMT) for Clostridium difficile infection (CDI). Congratulations to one of my partners, Jeffery Lewis, who is one of the coauthors. This paper’s abstract is noted in a separate blog: Large Study Show FMT Efficacy/Safety in Children.

Though this is a pediatric study, the authors included patients up to 23 years.  335 of the patients had followup for at least 2 months following FMT.

Key findings:

  • 81% of patients had a successful outcome after a single FMT and 86.6% after single or repeated FMT
  • Higher success rates were associated with fresh donor stool (OR 2.66), FMT via colonoscopy (OR 2.41), and with not having a feeding tube (OR 2.08)
  • Though not reaching statistical significance, patients with inflammatory bowel disease had a high failure rate of 23% (26/111).  Short bowel syndrome patients had a 50% failure rate (5/10), solid organ transplant recipients had a 56% failure rate (5/9), and patients with feeding tubes had a 32% failure rate (21/65).
  • Seventeen patients (4.7%) had a severe adverse event during the 3-month follow-up period, including 10 hospitalizations; however, the majority were unrelated to FMT. Specific adverse reactions that were related or may have been included aspiration pneumonia on day of procedure (n=1), IBD flare/colectomy (n=5), and vomiting/dehydration (n=1)
  • Common adverse reactions included diarrhea, abdominal pain, and bloating. (These symptoms have been reported in up to 70% of adults following FMT.)

The authors note that a prior systematic review had indicated that delivery of FMT via colonoscopy was more successful in adults (95% vs 88%), though there are some additional risks with colonoscopy.

It is worth considering that the failure rate in some patients could be due to misdiagnosis, particularly in certain populations like patients with IBD and or organ transplant recipients.  In these populations, PCR assays may result in false-positive diagnosis and should be confirmed with an ELISA assay.   While eradication of CDI with FMT improves clinical symptoms and reduces the use of antibiotics the true benefit and risks will not be known for a long time.  Does FMT increase or reduce the risk of downstream infections, autoimmune disease, and metabolic syndrome?

My take: Many of the concerns with FMT can only be adequately addressed with prospective studies (with strict definitions of CDI) and longer followup.

Related blog posts:

Island Ford, Sandy Springs

More Details on Drug-Resistant E coli Transmitted by Fecal Microbiota Transplant

In June 2019, the FDA delivered a warning about the potential danger of transmitting drug-resistant E coli with fecal microbiota tranplantaion (FMT).  (FDA Warning for FMT)

A report on this issue has now been published: Z DeFilipp et al. NEJM 381: 2043-50, editorial M Blaser pgs 264-6.

The authors describe two patients, a 69 year-old with cirrhosis and a 73 year-old sp stem cell transplantation, who developed bacteremia due to transmission of a drug-resistant (extended-spectrum beta-lactamase [ESBL]) E coli following FMT which was delivered by oral capsules. The latter patient died from sepsis. The two patients had a genomicly-identical strain isolated that was also found in the donated aliquot.

In the commentary, a couple of important points:

  • “Up to now, the complications have been infrequent [from FMT], and for recurrent C difficile infection, the benefits of FMT clearly outweigh the risks; however, as the use of FMT is broadened and more compromised patients are treated, complications may be more frequently observed.”
  • “In the short term, improved and uniform screening of FMT material is needed to reduce the risks.”

My take: Both of these patients who became developed bacteremia were at risk for more severe infections.  However, we need to remain aware that severe complications can and do occur with FMT.  In context, though, there are risks of severe complications from routine use of antibiotics as well.

Frontenac Hotel, Quebec City

Only 3% Make It Through the Donor Screening Process for Fecal Microbiota Transplantation

A recent letter (Z Kassam et al. NEJM 2019; 381: 2070-2) describes the arduous process involved in being selected as a stool donor for fecal microbiota transplantation (FMT).

In a previous blog (2015), it appeared that 17% of donors were accepted for FMT: Rejected! Most Stool is Not Good Enough for FMT This current review of the donor program from a stool bank (OpenBiome) prospectively evaluated 15,317 donor candidates from 2014-2018.

Key finding:

  • Only 3% (n=386) made it through all the steps to become donors

Reasons for exclusion:

Stage 1: common reasons for exclusion:

  • geographical -living too far away to donate regularly
  • BMI >30
  • social history
  • travel history
  • not in age range

Stage 2: “failing” the 200-item clinical assessment –common reasons for exclusion:

  • lost to followup
  • allergic disorders/asthma
  • receiving medications/supplements
  • mental health concerns
  • infectious disease history
  • social history/sexual history/other reasons

Stage 3: “failing” the stool and nasal screening which included (in 2016) carbapenem-resistant Enterobacteriacea (CRE), extended-spectrum beta-lactamase-producing organisms (ESBL) and MRSA. –common reasons for exclusion:

  • lost to followup
  • infectious disorders (including C diff in 7 patients)

Stage 4: “failing” serological screening

  • lost to followup
  • abnormal LFTs, CBC or infection

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Island Ford, Sandy Springs, GA

Fecal Microbial Transplantation -Evidence for Use Beyond Recurrent Clostridium Difficile

Briefly noted: GR D’Haens, C Jobin. Gastroenterol 2019; 157: 624-36. This review sums up the emerging evidence for use of fecal microbial transplantation for conditions besides recurrent Clostridium difficile infection.

Table 2 succinctly provides list of disease, types of study/evidence, and potential effect.

  • Among gastrointestinal diseases, the authors note that there is an “overall positive” effect for ulcerative colitis, “suggestive” benefits for IBS, GVHD, post-antibiotic diarrhea, constipation, and hepatic encephalopathy.  No effect has been evident with Crohn’s disease or pouchitis.
  • Among nongastrointestinal diseases, the authors note a “suggestive” benefit in autism and metabolic syndrome and “unknown” effect with psoriasis and multiple sclerosis.

My take: The review indicates a need for more studies and the need to define which factors in fecal material mediate the therapeutic effects.

Related article: OC Aroniadis. Lancet Gastroenterology and Hepatology; 2019. https://doi.org/10.1016/S2468-1253(19)30198-0. In this double-blind, randomized, placebo-controlled crossover trial in patients aged 18–65 years with moderate-to-severe IBS-D with 48 patients, FMT (capsule study) was safe, but did not induce symptom relief at 12 weeks compared with placebo.

Related blog posts:

“Intestinal Microbiota Transplant” -New Terminology for Fecal Transplant

A recent letter to the editor (A Khoruts, LJ Brandt, Am J Gastroenterol 114: 1176) suggests that the terms “Fecal Transplant” or “Fecal Microbiota Transplantation” (FMT) should be abandoned in favor of “intestinal microbiota transplant.”

  • First of all, the authors argue that the word “fecal” is no longer accurate as some transplants occur by swallowing capsules of purified microbiota and the days of “blending raw stool near the bedside are largely over.”
  • Secondly, the term “fecal” is highly problematic.  “We are hard-wired to perceive feces to be disgusting.”
  • Third, the media sensation from the terms FMT or fecal transplant “has not translated into substantial positive consequences, such as funding research…[or] philanthropic fundraising.”

Thus, the authors advocate “Intestinal Microbiota Transplant” or IMT.

My take: (borrowed from authors) It is time to “abandon the scatologic humor that is arguably threatening further development of this promising therapeutic approach.”

Related blog posts:

Sunrise at Crater Lake, OR

NY Times: The Battle Over Fecal Transplantation

NY Times: Drug Companies and Doctors Battle Over the Future of Fecal Transplants

This article highlights a concern that pharmaceutical companies may persuade the FDA to regulate fecal transplants similar to medications.  This will exponentially increase the cost and limit the access to beneficial human excrement. Thanks to one of my sons for pointing out this commentary to me.

An excerpt:

As pharmaceutical companies seek to profit from the curative wonders of human feces, doctors worry about new regulations, higher prices and patients attempting DIY cures…

The clash is over the future of fecal microbiota transplants, or F.M.T., a revolutionary treatment that has proved remarkably effective in treating Clostridioides difficile, a debilitating bacterial infection that strikes 500,000 Americans a year and kills 30,000…

At the heart of the controversy is a question of classification: Are the fecal microbiota that cure C. diff a drug, or are they more akin to organs, tissues and blood products that are transferred from the healthy to treat the sick? The answer will determine how the Food and Drug Administration regulates the procedure, how much it costs and who gets to profit…

Human feces, it turns out, are a potential gold mine, for both medical researchers and drug makers…

Inspired by the success of fecal transplants for C. diff, scientists are racing to develop similar treatments for an array of ailments and disorders, among them obesityautismulcerative colitis, and Alzheimer’s and Parkinson’s diseases…

For now, most of the material used in fecal transplants comes from OpenBiome, the public stool bank in Cambridge …The material comes from donors who earn $40 a pop and must pass intensive screenings and regular medical checkups. “It’s harder to become a stool donor than it is to get into M.I.T.,” said Carolyn Edelstein, who runs the organization…The F.D.A. has ramped up oversight of OpenBiome’s production, leading to more rigorous testing and higher prices, which will double to $1,600 this month.

Related blog posts:

From NY Times Twitter Feed

Experimental Use of FMT for Ulcerative Colitis

In a recent randomized, double-blind study (SP Costello et al. JAMA. 2019;321(2):156-164. doi:10.1001/jama.2018.20046), the use of fecal microbiota transplantation (FMT) was effective in 32% in inducing remission in adult patients with ulcerative colitis (UC).

Key Finding:  In this randomized clinical trial that included 73 adults with mild to moderately active ulcerative colitis, the proportion achieving steroid-free remission at 8 weeks was 32% with donor FMT vs 9% with autologous FMT, a significant difference

Abstract:

Importance  High-intensity, aerobically prepared fecal microbiota transplantation (FMT) has demonstrated efficacy in treating active ulcerative colitis (UC). FMT protocols involving anaerobic stool processing methods may enhance microbial viability and allow efficacy with a lower treatment intensity.

Objective  To assess the efficacy of a short duration of FMT therapy to induce remission in UC using anaerobically prepared stool.

Design, Setting, and Participants  A total of 73 adults with mild to moderately active UC were enrolled in a multicenter, randomized, double-blind clinical trial in 3 Australian tertiary referral centers between June 2013 and June 2016, with 12-month follow-up until June 2017.

Interventions  Patients were randomized to receive either anaerobically prepared pooled donor FMT (n = 38) or autologous FMT (n = 35) via colonoscopy followed by 2 enemas over 7 days. Open-label therapy was offered to autologous FMT participants at 8 weeks and they were followed up for 12 months.

Main Outcomes and Measures  The primary outcome was steroid-free remission of UC, defined as a total Mayo score of ≤2 with an endoscopic Mayo score of 1 or less at week 8. Total Mayo score ranges from 0 to 12 (0 = no disease and 12 = most severe disease). Steroid-free remission of UC was reassessed at 12 months. Secondary clinical outcomes included adverse events.

Results  Among 73 patients who were randomized (mean age, 39 years; women, 33 [45%]), 69 (95%) completed the trial. The primary outcome was achieved in 12 of the 38 participants (32%) receiving pooled donor FMT compared with 3 of the 35 (9%) receiving autologous FMT (difference, 23% [95% CI, 4%-42%]; odds ratio, 5.0 [95% CI, 1.2-20.1]; P = .03). Five of the 12 participants (42%) who achieved the primary end point at week 8 following donor FMT maintained remission at 12 months. There were 3 serious adverse events in the donor FMT group and 2 in the autologous FMT group.

Conclusions and Relevance  In this preliminary study of adults with mild to moderate UC, 1-week treatment with anaerobically prepared donor FMT compared with autologous FMT resulted in a higher likelihood of remission at 8 weeks. Further research is needed to assess longer-term maintenance of remission and safety.

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Fecal Microbioata Transplantation for Recurrent Clostridium difficile — Position Paper

A recent position paper (ZH Davidovics et al. JPGN 2019; 68: 130-43) from NASPGHAN/ESPGHAN on Fecal Microbioata Transplantation (FMT) for Recurrent Clostridium difficile infection (CDI) provides a pretty good review. Though, I think a summary table of recommendations would have made this publication much more helpful.

Here is a full-text link: Fecal Microbiota Transplantation for Recurrent Clostridium difficile Infection and Other Conditions in Children: A Joint Position Paper

A couple key points/excerpts:

In general, we concur with current adult guidelines  when considering FMT for the treatment of rCDI in children and propose FMT be considered in children with one of the following:
1. rCDI (recurrence of symptoms within 8 weeks of treatment for CDI) (either a or b)
a. At least 3 episodes of mild to moderate CDI and failure of a 6- to 8-week taper with vancomycin with or without an alternative antibiotic (eg, rifaximin, nitazoxanide).
b. At least 2 episodes of severe CDI resulting in hospitalization and associated with significant morbidity.

2. Moderate CDI not responding to standard therapy (including vancomycin) for at least 1 week. We recommend caution, however, in such cases, with repeated testing for etiologies other than CDI such as IBD.

3. Severe CDI or fulminant C difficile colitis with no response to standard therapy after 48 hours.

My take:  I think the IDSA 2017 guidelines are more useful: Clostridium difficile Guidelines (2017 IDSA/SHEA)

More related blog posts:

Fecal Microbiota Transplantation: How important is the BMI of the stool donor?

Currently fecal microbiota transplantation (FMT) “best practices” exclude obese stool donors based on a report of germ-free mice gaining weight after FMT from mice with obesity and based on a case report of an individual with 34 pound weight gain after FMT.

A recent report (M Fischer et al. Clin Gastroenterol Hepatol 2018; 16: 1351-3) suggests that the the BMI of the stool donor does not affect recipient weight after a single FMT procedure for C difficile infection.

This analysis included 173 patients with a mean age of 57 years.  One group of 103 were from a randomized control trial; in this group, 66 (64%) received FMT from a normal weight (BMI 18-24.9) donor and 37 (36%) received FMT from an overweight (BMI 25-29.9) donor. Among an additional 70 individuals from an observational cohort, 25 received FMT from normal weight donor, 30 received FMT from overweight donor, and 15 received FMT from an obese donor.

Key finding:

  • There was no significant difference in BMI among the FMT recipients up to 48 weeks after a single FMT.  Based on data from Figure 1, patients who received FMT from normal weight donor had slightly higher mean weight gain at 48 weeks afterwards (not statistically-significant)

The authors caution that a prospective study is required to confirm these findings and in the interim, they recommend exclusion of obese/overweight FMT donors.

My take: There are plenty of willing stool donors –so who knows if this will ever be examined adequately.  This study challenges the idea that FMT from an obese donor will result in recipient obesity, presumably via changes in the microbiome.

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