One Way Fecal Microbiota Transplant May Work: Changing Bile Acids

Breifly Noted:

From MedPage Today: Fecal transplant success may depend on bile acid metabolism

An excerpt:

the transplants change patterns of bile acid metabolism in the gut, making the environment inhospitable to C. diff colonization.

In three studies reported at Digestive Disease Week (DDW) 2017, it was demonstrated that individuals with C. diff who respond to fecal transplant showed a different pattern of microbiota species composition compared with baseline and/or with those who fail to respond. But that’s not all: the responders also showed distinct, altered profiles of those elements involved in bile acid metabolism.

Vincent Van Gogh; Hopital Saint-Paul (1889)

 

Another Shady Pharmaceutical Business Practice: Citizen’s Pathway to Delay Competition

First, a comment regarding yesterday’s post: The Truth About Probiotics: Constipation Version

Some readers took issue with my pessimism with probiotics in terms of their effectiveness for several conditions, their safety and the number needed to treat (NNT). It is noted that the number needed to treat (NNT) with probiotics is better than with many other conditions.  For example, the NNT for benefit with the influenza vaccine, Tamiflu for influenza, and mammography for preventing breast cancer are much worse than the NNT for benefit with probiotics for conditions like NEC, antibiotic-associated diarrhea, Clostridium difficile infection, and ulcerative colitis (with VSL#3). If one looks at multiple posts from this blog, there are plenty of posts supporting the use of probiotics (see some of the links yesterday or search “probiotics” on this blog.  Thus, it is important to not overlook the benefits of probiotics for many conditions and to not take a single study and extrapolate too much.

Now for today’s post -perhaps it will stir as much interest:

I must admit I’m fascinated with the way pharmaceutical companies operate and the creative ways they find to magnify their profits.  In previous posts, I’ve detailed how pharmaceutical companies will try to corner the generic market, increase the cost of liquid medicines, and package drugs in a way to force the purchase of additional vials of medicine among other tactics.  Now, a commentary (R Feldman, C Wang. NEJM 2017; 376: 1499-1501) details how pharmaceutical companies have increasingly used “the citizen-petition process that the Food and Drug Administration (FDA) implemented in the 1970s.”  This process was designed as “a way to voice concerns” by individual citizens.

Yet, this pathway is now being used to delay competition/entrance of generic drugs, mainly with frivolous claims.  In most cases, companies file these claims at the end of the approval process, almost always as a delaying tactic.  Approximately 80% of these actions by competitor drug companies are denied by the FDA.

Ultimately, these actions could be countered with antitrust actions; this, in fact, has occurred with Shire ViroPharma.  On February 7, 2017, the Federal Trade Commission filed an antitrust action “alleging that the company abused regulatory processes by filing 43 submissions with the FDA (including 24 meritless citizen-petition filings within one docket) in an effort to hold off generic competition for its gastrointestinal drug Vancocin (vancomycin).”  However, antitrust actions are typically difficult to pursue and expensive.

My take: I think these tactics (and others) will undermine the relationship of pharmaceutical companies with consumers. While their stock holders may see benefits in the short term, I expect that other stake holders will fight back.  There are several targets in that endeavor, including ending limits on Medicare negotiating for better prices.

Related blog posts:

Two for the PPI Team

Medicine safety is not nearly as straight-forward as most people would expect.  Virtually all medicines have the potential for adverse reactions.  In addition, there are often conflicting reports on how frequent adverse reactions occur; furthermore, negative studies demonstrating safety may be published less frequently due to publication bias.

This problem is compounded by the frequent misunderstanding of statistics.  Frequently, risks of medications are expressed as an odds ratio.  So, if an adverse reaction occurs twice as often with the medication than without the medication, the odds ratio would 2.0.  Yet, if the adverse reaction is rare (eg. one in a million), then the absolute increase in risk remains minuscule.

Proton pump inhibitors have received a lot of press, often about rare increases in adverse reactions. But, there are many potential benefits to these medications and numerous studies demonstrating fairly good safety profiles.  A few more studies (thanks to Ben Gold for these references) on their safety have recently been published:

  • 1. “Long-term Proton Pump Inhibitor Use is Not Associated with Changes in Bone Strength and Structure” LE Targownik et al. Am J Gastroenterol 2017; 112: 95: 101.
  • 2. “Proton Pump Inhibitors Do Not Increase Risk for Clostridium difficile Infection in the Intensive Care Unit.” DM Faleck et al. Am J Gastroenterol 2016; 111: 1641-8.

In the first study, the authors examined 52 PPI-users (>5 yrs) and 52 non-PPI users with mean age of 65 years.  They underwent quantitative CT , DXA, and markers of bone metabolism. “There were no differences detected..between the two groups.”  The conclude that PPIs were not associated with changes that increase a risk of fracture and “provide further evidence that the association between PPI use and fracture is not causal.”

In the second study, the authors analyzed data from 14 ICUs 2010-2013 and identified 18,134 patients (mean age 66-67 yrs) who met inclusion criteria.  271 (1.5%) developed Clostridium difficile infection (CDI) in the ICU.  The main risk factor for CDI was antibiotics with adjusted Hazard Ratio (aHR) of 2.79.  “There was no significant increase in risk for CDI associated with PPIs in those who did not receive antibiotics (aHR 1.56; 95% CI, 0.72-3.35).”  “PPIs were actually associated with a decreased risk for CDI in those who received antibiotics (aHR 0.64; 95% CI 0.48-0.83).”  The authors also noted that even those who received the highest doses of PPIs, “there was no risk for health-care facility-onset CDI.”

My take: PPIs can be life-saving medications and can alleviate a lot of suffering.  These studies pushback on some of the concerns about PPI risk.

Related blog posts:

The Coronation of Napoleon (Louvre); Jacques-Louise David

How Much Do We Really Know About Fecal Microbiota Transplantation?

A recent study (SJ Ott et al. Gastroenterol 2017; 152: 799-811) followed 5 patients who were treated with a sterile fecal filtrate (via nasojejunal tube) for recurrent Clostridium difficile infection (CDI) for a minimum of 6 months.  This open-label study noted that this fecal filtrate transfer eliminated the symptoms of CDI in all 5 patients.

A summary of this important study is available in the AGA blog:

Here’s an excerpt: What is the Active Ingredient in FMT for CDI?

Stool was collected from 5 donors selected by the patients and fully characterized according to FMT standards. The stool was then sterile filtered to remove small particles and bacteria, and the filtrate was transferred to patients in a single administration via nasojejunal tube.

Fecal samples were collected from patients before and at 1 week and 6 weeks after FFT. Microbiome, virome, and proteome profiles of donors and patients were compared….

They identified about 300 different proteins in each of the filtrates they analyzed—most proteins were of human origin, but the filtrates also contained 20–60 bacterial and fungal proteins. The major human proteins in the filtrate proteome were human enzymes such as intestinal-type alkaline phosphatase, chymotrypsin-like elastases, and α amylases. Bacterial proteins included metabolic enzymes and redox proteins without obvious microbiome-modifying properties, such as glyceraldehyde-3-phosphate dehydrogenase, phosphoenolpyruvate carboxykinase, glutaredoxin-1, or thioredoxin-1…

Ott et al propose that the active component of FMT therapy might not be living bacteria, but bacterial components, antimicrobial compounds of bacterial origin (bacteriocins), or bacteriophages that contribute to a healthy intestinal microenvironment. These could be common to all successful FMT therapies and even rather unspecific regarding the bacterial strain(s) used for therapies. They propose that bacteriophages affect community dynamics of gut microbiota to resolve dysbiosis.

My take: This is a provocative study that challenges us to rethink how FMT works. Ultimately, treating CDI needs to be more precise.

Related blog posts:

 

Clostridium difficile Infection in Inflammatory Bowel Disease: Expert Updates

A recent clinical practice update (S Khanna et al. Clin Gastroenterol Hepatol; 2017; 15: 166-74) provides some succinct recommendations regarding Clostridium difficile infection (CDI) in Inflammatory Bowel Disease (IBD).

Background: In 2011, the authors note that CDI was associated with 29,000 deaths and is now the most lethal enteric pathogen in the U.S.

Differences in pathogenesis of C diff in IBD compared to those without IBD:

  • Younger age
  • Less frequent antibiotic exposure
  • More often community onset (rather than hospital onset)
  • Higher recurrence (may be related to dysbiosis)

Key recommendations:

  • In patients with IBD flare, test for CDI
  • In patients with CDI and IBD, clinicians should consider “using vancomycin instead of metronidazole.”
  • In patients with recurrent CDI and IBD, consider fecal microbiota transplantation

Figure 4 proposes a management algorithm (for adults).  If uncomplicated CDI, recommended dose of vancomycin was 125 mg q6h. If no improvement in 3-4 days, then “consider escalation of immunosuppression.” For complicated CDI, consider oral vancomycin at 500 mg q6h and IV metronidazole 500 mg q8.  In addition, consider rectal vancomycin and surgery consult.

Complicated CDI includes ICU admission, hypotension, T >38.5, ileus/megacolon, mental status changes, leukocyte count >35,000  or < 2000, or lactate >2.2 mmol/L

Another review article (Y Chen et al. Inflamm Bowel Dis 2017; 23: 200-07) is a meta-analysis that identified six studies.  One of these studies was a case-control study with nearly 400,000 patients (and about 7000 cases of C diff). Key finding: CDI results in nearly a doubling of the risk of colectomy (OR 1.90), mainly in patients with ulcerative colitis.

Related blog posts

Disclaimer: These blog posts are for educational purposes only. Specific dosing of medications (along with potential adverse effects) should be confirmed by prescribing physician.  This content is not a substitute for medical advice, diagnosis or treatment provided by a qualified healthcare provider. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a condition.

 

Expert Advice on Clostridium difficile and Inflammatory Bowel Disease

Link: Management of Clostridium difficile Infection in Inflammatory Bowel Disease: Expert Review from the Clinical Practice Updates Committee of the AGA Institute

Abstract: The purpose of this expert review is to synthesize the existing evidence on the management of Clostridium difficile infection in patients with underlying inflammatory bowel disease. The evidence reviewed in this article is a summation of relevant scientific publications, expert opinion statements, and current practice guidelines. This review is a summary of expert opinion in the field without a formal systematic review of evidence.

Best Practice Advice 1: Clinicians should test patients who present with a flare of underlying inflammatory bowel disease for Clostridium difficile infection.

Best Practice Advice 2: Clinicians should screen for recurrent C difficile infection if diarrhea or other symptoms of colitis persist or return after antibiotic treatment for C difficile infection.

Best Practice Advice 3: Clinicians should consider treating C difficile infection in inflammatory bowel disease patients with vancomycin instead of metronidazole.

Best Practice Advice 4: Clinicians strongly should consider hospitalization for close monitoring and aggressive management for inflammatory bowel disease patients with C difficile infection who have profuse diarrhea, severe abdominal pain, a markedly increased peripheral blood leukocyte count, or other evidence of sepsis.

Best Practice Advice 5: Clinicians may postpone escalation of steroids and other immunosuppression agents during acute C difficile infection until therapy for C difficile infection has been initiated. However, the decision to withhold or continue immunosuppression in inflammatory bowel disease patients with C difficile infection should be individualized because there is insufficient existing robust literature on which to develop firm recommendations.

Best Practice Advice 6: Clinicians should offer a referral for fecal microbiota transplantation to inflammatory bowel disease patients with recurrent C difficile infection.

 

Related blog posts:

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Quick Take: Preventing Recurrent Clostridium difficile Infection with Bezlotoxumab

A recent study on a new monoclonal antibody to prevent Clostridium difficile infection is available from the NEJM.  Here’s the link: Preventing Clostridium difficile Infection Recurrence

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My take: In Modify I and Modify II, Bezlotoxumab reduced the rate of Clostridium difficile recurrence in elderly patients (median age 66 years). In a high risk patients, the likely hefty cost of this medication may be warranted.

These studies were likely pivotal in receiving FDA approval: FDA Approves Merck’s ZINPLAVA™ (bezlotoxumab) to Reduce Recurrence of Clostridium difficile Infection