Dont expect weight-loss or a big energy boost from B12 unless you were deficient (Mayo Clinic)
A lower Firmicutes/Bacteroidetes ratio (142), reduced counts of Lactobacillaceae (143), and altered abundance of several genera have been reported (144) including Eggerthella , Klebsiella , Flavonifractor , Lachnospiraceae (145, 146), Prevotella , Eubacterium, and Rhodococcus were significantly enriched, whereas Pseudobutyrivibrio and Dialister were decreased in SLE patients (147)
Monitor for Allergic Reactions: Observe for signs of an allergic reaction, such as hives, itching, swelling, or difficulty breathing
In support, recently BPC 157 increased the survival rate of cultured enteric neurons and the proliferation rate of cultured enteric glial cells (Wang et al., 2019)