Bovine immunoglobulin concentrate-Clostridium diYcile retains C diYcile toxin neutralising activity after passage through the human stomach and small intestine

Background—Bovine immunoglobulin concentrate (BIC)-Clostridium diYcile is prepared from the colostrum of cows immunised against C diYcile toxins and contains high concentrations of neutralising IgG antitoxin. Aims—To determine the proportion of BIC-C diYcile which survives passage through the human stomach and small intestine. Methods—Six volunteers with an end ileostomy took 5 g of BIC-C diYcile containing 2.1 g of bovine IgG on four occasions: alone, with an antacid, during treatment with omeprazole, and within enteric coated capsules. Results—When BIC-C diYcile was taken alone, a mean (SEM) of 1033 (232) mg of bovine IgG was recovered in the ileal fluid representing 49% of the total ingested dose. Bovine IgG recovery was not significantly increased by antacid (636 (129) mg) or omeprazole (1052 (268) mg). The enteric capsules frequently remained intact or only partially opened in the ileal eZuent and free bovine IgG levels were low in this treatment group (89 (101) mg). Bovine IgG recovery was higher in volunteers with shorter (less than two hours) mouth to ileum transit times (68% versus 36%, p<0.05). Specific bovine IgG against C diYcile toxin A was detected in ileal fluid following oral BIC. Toxin neutralising activity was also present and correlated closely with bovine IgG levels (r=0.95, p<0.001). Conclusion—BIC-C diYcile resists digestion in the human upper gastrointestinal tract and specific anti-C diYcile toxin A binding and neutralising activity was retained. Passive oral immunotherapy with anti-C diYcile BIC may be a useful non-antibiotic approach to the prevention and treatment of C diYcile antibiotic associated diarrhoea and colitis. (Gut 1999;44:212–217)