Absorption and safety of serum-derived bovine immunoglobulin/protein isolate in healthy adults.

Previous studies have shown that oral administration of bovine immunoglobulin protein preparations is safe and provides nutritional and intestinal health benefits. The purpose of this study was to evaluate the plasma amino acid response following a single dose of serum-derived bovine immunoglobulin/protein isolate (SBI) and whether bovine immunoglobulin G (IgG) is present in stool or in blood following multiple doses of SBI in healthy volunteers. A total of 42 healthy adults were administered a single dose of placebo or SBI at one of three doses (5 g, 10 g, or 20 g) in blinded fashion and then continued on SBI (2.5 g, 5 g, or 10 g) twice daily (BID) for an additional 2 weeks. Serial blood samples were collected for amino acid analysis following a single dose of placebo or SBI. Stool and blood samples were collected to assess bovine IgG levels. The area under the curve from time 0 minute to 180 minutes for essential and total amino acids as well as tryptophan increased following ingestion of 5 g, 10 g, or 20 g of SBI, with a significant difference between placebo and all doses of SBI (p<0.05) for essential amino acids and tryptophan but only the 10 g and 20 g doses for total amino acids. Bovine IgG was detected in the stool following multiple doses of SBI. No quantifiable levels of bovine IgG were determined in plasma samples 90 minutes following administration of a single dose or multiple doses of SBI. Oral administration of SBI leads to increases in plasma essential amino acids during transit through the gastrointestinal tract and is safe at levels as high as 20 g/day.