Adherence of probiotic bacteria to human intestinal mucus in healthy infants and during rotavirus infection

The concentration of fecal mucin and the adhesion of specific probiotics and their combinations in the intestinal mucus of infants during and after rotavirus diarrhea and in healthy children were determined. Mucus was prepared from fecal samples from 20 infants during and after rotavirus diarrhea and from 10 healthy age-matched children. Mucin concentration was determined, and the adhesion of five probiotics-Lactobacillus rhamnosus GG, Lactobacillus casei Shirota, Lactobacillus paracasei F19, Lactobacillus acidophilus LA5, and Bifidobacterium lactis Bb12-and their combinations was tested in vitro. The mean concentrations of fecal mucin during and after rotavirus diarrhea, 15.2 and 14.1 mg/g, were comparable to that in healthy children, 14.9 mg/g. The adherence of probiotics ranged from 1 to 34% in healthy subjects as indicated for the following strains: L. rhamnosus GG, 34%; B. lactis Bb12, 31%; L. acidophilus LA5, 4%; L. paracasei F19, 3%; and L. casei Shirota, 1% (P = 0.0001). The distinctive pattern of probiotic adherence was not influenced by rotavirus diarrhea. The adhesion of Bb12 in the presence of GG increased from 31 to 39% in healthy infants (P = 0.018) and in episodes of diarrhea increased from 26 to 44% (P = 0.001). Rotavirus diarrhea does not decrease the production of fecal mucin or with respect to the adhesion of probiotic bacteria tested in vitro. Combination of specific probiotic strains may enhance adherence in a synergistic manner. Optimal clinical application of these interactions may offer novel therapeutic guidelines for the treatment and prevention of gastrointestinal infections.