About SBI
Serum-derived bovine immunoglobulin/protein isolate (a medical-food IgG concentrate) that binds microbial components in the gut lumen. Small pilot RCTs show within-group symptom improvement in diarrhea-predominant IBS at 5-10 g/day, but trials are small and larger confirmation is lacking.
What SBI supports
- May reduce diarrhea-predominant IBS symptoms in small trials at 5-10 g/day
How much SBI to take
The RDA prevents deficiency. The effective range is what clinical trials used to actually move the outcome.
Effective
5–10
g
IBS-D and gut-barrier studies of serum-derived bovine immunoglobulin used 5-10 g/day. Range reflects that clinical use.
Clinical evidence
Limited clinical evidence. Small pilot RCTs in IBS-D; larger confirmation lacking.
NIH Fact Sheet