Serum proteins of gnotobiotic rats.

Cellulose-acetate and agar gel immunoelectrophoresis were used to study the serum protein patterns of germfree rats before and after monoassociation with a pure culture of Staphylococcus aureus (phage type 80/81), Streptococcus faecalis, Lactobacillus acidophilus, Bacteroides fragilis, Pseudomonas aeruginosa, or Proteus vulgaris. All six bacteria quickly established themselves in the gastrointestinal tract of the germfree rat, and all six increased the animals' total serum proteins. Only S. aureus and P. aeruginosa caused a noticeable rise in gamma globulins. L. acidophilus, S. faecalis, and B. fragilis multiplied readily in the gastrointestinal tract but caused only minimal alterations in the serum proteins. P. vulgaris caused a marked increase in the alpha and beta, but not the gamma globulins.