Why I Don't Recommend Rebyota for Conditions Beyond C. difficile

As fecal microbiota transplantation (FMT) gains traction in treating various conditions, we're seeing an increase in off-label use of patented FMT products like Rebyota. While Rebyota is FDA-approved for preventing recurrent Clostridioides difficile infections, its use for other conditions raises concerns. Here is why I  cannot recommend Rebyota off label for conditions such as IBS, IBD, bipolar, depression, etc.

Limited Microbial Diversity and Screening Process

Rebyota's primary selling point is its guaranteed Bacteroides content. According to the product description:

"REBYOTA is manufactured from human fecal matter sourced from qualified donors. The human fecal matter is tested for a panel of transmissible pathogens. Donors do not have dietary restrictions with respect to potential food allergens. Each 150mL dose of REBYOTA contains between 1×108 and 5×1010 colony forming units (CFU) per mL of fecal microbes including >1×105 CFU/mL of Bacteroides."

While this may be sufficient for C. difficile treatment, it falls short for addressing other conditions:

• Bacteroides dominance has been linked to various health issues, including bipolar disorder, depression, chronic fatigue syndrome, inflammatory bowel disease, OCD, Parkinson's, and chronic constipation.

• Some Bacteroides strains are innately pathogenic. For which Rebyota does not screen.

Narrow Definition of Success

In clinical trials, success in preventing recurrent CDI was defined as the absence of CDI diarrhea within 8 weeks of administration of Rebyota or placebo. However, this definition doesn't account for other potential issues:

• 55% of patients note IBS-like symptoms after treatment.

• Mental health parameters are not tracked in the donors nor the recipients, leaving a significant gap in understanding the treatment's full impact.

Lack of Targeted Beneficial Microbes

Many conditions we treat require a more nuanced approach to microbiome restoration. For example,

• Depression often benefits from increased levels of Coprococcus, Faecalibacterium, Eubacterium, Bifidobacterium, and Lactobacillus.

• Bipolar disorder treatment may involve boosting Bifidobacterium, Faecalibacterium, and Eubacterium while reducing Clostridium and Alistipes.

Rebyota's limited microbial profile may not provide the specific strains needed for these conditions.

Screening and Transparency Concerns

While Rebyota is tested for transmissible pathogens, the screening standards and lack of detailed information about the full microbial composition are concerning for off-label use. When treating complex conditions, we need a more comprehensive understanding of the transplanted microbiome.

Personalized Approach is Key

Effective microbiome-based treatments often require a tailored approach:

• Patient-specific factors like diet, immune system, environment, and lifestyle significantly impact microbial colonization.

• A one-size-fits-all product may not address individual needs effectively.

Conclusion

While Rebyota has its place in treating C. difficile infections, its use for other conditions requires caution. As we continue to unravel the complexities of the human microbiome, targeted, personalized approaches remain crucial for addressing diverse health issues effectively.

Remember, successful microbiome modulation goes beyond simply introducing new microbes – it's about creating the right environment for beneficial bacteria to thrive and contribute to overall health. The limited microbial profile, broad donor criteria, and narrow definition of success in Rebyota's clinical trials may not be suitable for the nuanced needs of conditions beyond C. difficile infections.