Letter: A step forward towards a standard FMT protocol for IBS (Oct 2023) Magdy El-Salhy et al compare their procedure to a recent RCT that got poor results FMT

[Michael Harrop]

https://onlinelibrary.wiley.com/doi/10.1111/apt.17749

TABLE 1. Handling of the donor's faecal transplant.

	Yau et al	El-Salhy et al	Comments
Handling of the donor faeces	Exposed to ambient air 2 h before delivery	Froze immediately and kept frozen until transplantation	Exposing faecal samples to ambient air reduces the abundance of important commensal taxa. Freeze–thaw faecal samples does not affect the viable bacterial composition of stool9
Transplant preparation	Mixed in a laboratory blender	Mixed manually	The increased air flow by high-speed blending may result in increasing oxygen exposure and be more detrimental to oxygen sensitive species than manual homogenisation9

The issues discussed above could explain the difference between FMT without effect and FMT with high efficacy according to the stringent EMA/FDA composite responder endpoints.

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I think it's more likely to be a donor quality issue.