I left a list of useful UK B12 (and folate/iron) documents I think are worth reading in one of my replies in thread below healthunlocked.com/pasoc/po
A lower Firmicutes/Bacteroidetes ratio ( Lactobacillaceae ( Eggerthella , Klebsiella , Flavonifractor , Lachnospiraceae ( Prevotella , Eubacterium, and Rhodococcus were significantly enriched, whereas Pseudobutyrivibrio and Dialister were decreased in SLE patients ( Clostridium , exhibits a negative correlation with the SLE disease activity index (SLEDAI) ( Clostridium has declined dramatically, including CB , FP , Clostridium cluster XIVa , and Clostridium leptum ( Clostridium leptum (150) and Clostridium cluster XI ( Clostridium leptum and Clostridium cluster XI , classified as potential conditional beneficial bacteria, which align with the principle of dynamic gut microbial balance and may not be directly linked to therapeutic efficacy
When B12 levels are borderline, clinical suspicion remains high, or total B12 is unreliable (as in chronic liver disease), additional tests can provide clarity
The free cobalamin attaches to an R protein which is removed when passing into the duodenum, allowing the cobalamin to bind to the IF allowing its active absorption