Although it may not be pleasant for your kitty, it does tell us that our cats immune system has responded to the vaccine
(jofem.org) The best-case signal: modest weight loss in a shorter trial A frequently cited 12-week randomized trial result (as summarized in reviews) reported: ~2.6 kg average loss with AOD-9604 1 mg/day vs ~0.8 kg with placebo (PMC) This is the kind of result that can be statistically meaningful, clinically modest, and very sensitive to study design (diet, activity, baseline metabolic status, adherence)
Malabsorption (inadequate intake of vitamin B12 in the intestine) Insufficient production of intrinsic factor (a protein that is produced in the gastric mucosa and is required for the absorption of vitamin B12), Diseases in the terminal part of the ileum (part of the small intestine), eg
This has become a very popular area in the last year, crossing over from biohacker communities into more normie circles
Benefaction of probiotics for human health: A review