These probiotics raise histamine levels
Some probiotic strains (note: some strains, not entire species) can increase histamine levels in some people.
This is because they contain bacterial strains that feature histidine decarboxylase activity, an enzyme involved in histamine production.
probiotic species and strains that can increase histamine levels
Lactobacillus casei eg Shirota (LcS)
Lactobacillus bulgaricus eg DSM 20081
Lactobacillus reuteri eg DSM 17938
Lactobacillus helveticus eg R0052
Lactobacillus fermentum eg CECT 5716
Lactobacillus delbrueckii, subsp bulgaricus ATCC 11842
Streptococcus thermophilus (potentially, used in yoghurt/found in fermented foods) STY-31
other factors
Factors like someone's gut microbiome composition, genetics, underlying health conditions and dietary habits can all impact this sensitivity too.
People should not have to be on a low histamine diet for good, only while finding the cause and dealing with it.