Magic Bacteria I

I try to be logical about which health charities I support (those that make the greatest difference to the most people) and which research excites me (useful, high quality) but my brain snags on Alzheimer’s.

Alzheimer’s is a big deal. Dementia (including Alzheimer’s) currently affects approximately 48 million people. It can affect “memory, thinking, orientation, comprehension, calculation, learning capacity, language, and judgement”, which is basically everything that makes you, you. There’s no cure, no treatment, and we don’t really know why some people get it and others don’t.

So a bit more clarity and the hope of any treatment would be a wonderful thing.




The Mail gets in a little bit of fear-based selling on the side…

A quick look, and you might be considering taking probiotic supplements.

So why does this report make me grumpy? Not because I used critical appraisal tools to carefully consider the paper. I got bored half-way through. Instead, here are some pet peeves.

A 12-week study is NOT LONG ENOUGH. People can have Alzheimer’s for over a decade. I need to know what happens to people who have Alzheimer’s for more than 12 weeks.

60 patients is NOT ENOUGH PARTICIPANTS, especially as 8 of them died before the study finished. The trialists managed to get some statistically significant stats – but having lost 13% of their participants, perhaps you would expect some variation between baseline and end of study results? How did they know 60 people was enough to detect the difference they hypothesised? How applicable are these results of these 60 people to the other 48 million?

15 different biomarkers, WHO CARES. Might be useful for mechanistic proof of concept. But are they outcomes relevant to patients? Or have they be stuck in post-hoc to ramp up the number of significant outcomes? Outcome switching.

Mini-mental state examination (MMSE) started at 8.47 (±1.10) and decreased to 8.00 (±1.08) in the control group. MMSE started at 8.67 (±1.44) and increased to 10.57 (±1.64) in the probiotic group. The numbers are statistically significantly different. But are the patient’s symptoms clinically significantly different? NHS Choices says probably not (they already thought of the things I wrote). So WHAT IS THE BENEFIT FOR PEOPLE WITH ALZHEIMER’S?

This trial does not show a benefit (or show lack of benefit) of probiotics in reducing symptoms of Alzheimer’s – because the trial hasn’t been well enough designed. And the reporting was crappy. THIS MAKES ME GRUMPY.


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