The cost side of a good result
26 October 2026
My book names preterm probiotics as the strongest evidence in the field. A trial in 693 premature babies has now measured what else happens when you give them
Read on Gut CheckGut Check · the newsletter
One claim, the actual papers, an honest read
An MD and biostatistician on how the gut microbiome shapes health and disease, and how to tell real evidence from hype. Free, and the sources are always linked so you can check the work.
Athletic performance under scrutiny
19 October 2026
A probiotic trial in elite volleyball players measured dozens of things and found plenty. Then the authors corrected their own statistics, and a lot of it disappeared
Read on Gut CheckThe same product, three weeks later
12 October 2026
Three weeks ago I wrote that VSL#3 failed in childhood arthritis, and that evidence does not travel between diseases. A second trial has now tested the same product in long COVID. It worked!
Read on Gut CheckA probiotic result that holds up
28 September 2026
Nine issues of this newsletter have mostly reported trials that failed. This week, 32 randomized trials and 4,010 patients say a probiotic works. Here is how much
Read on Gut CheckThe same product, a different disease
21 September 2026
VSL3 is one of the few probiotics with real trial evidence behind it. A French team has now tested it in a different illness, and the result runs the other way
Read on Gut CheckRead the second half of the sentence
14 September 2026
A trial found nothing, then found something in a slice of its participants. Both halves are true. Only one will travel
Read on Gut CheckThe newsletter grew out of the book. Half Human is the long version: seventeen chapters, every claim anchored to a paper, and where the evidence stops, the book stops.