Letters in Applied Microbiology 1997, 24, 361–364 Recovery of Lactobacillus rhamnosus GG from human colonic biopsies M. Alander, R. Korpela 1 , M. Saxelin 1 , T. Vilpponen-Salmela 2 , T. Mattila-Sandholm and A. von Wright VTT Biotechnology and Food Research, Espoo, 1 Valio Ltd, Helsinki, and 2 Harjula Hospital, Kuopio, Finland 1281/96: received 3 September 1996 and accepted 23 September 1996 M. ALANDER, R. KORPELA, M. SAXELIN, T. VILPPONEN-SALMELA, T. MATTILA-SANDHOLM AND A. VON WRIGHT. 1997. The colonization of Lactobacillus rhamnosus GG (ATCC 53103, henceforth L.GG) in five human colonoscopy patients was studied. The test subjects consumed whey drink fermented with the bacterium for 12 d before the colonoscopy. The presence of L.GG was subsequently checked both in the faecal samples and in the colonic biopsies obtained from various locations in the large intestine. In all patients L.GG was the dominant faecal lactic acid bacterium as a result of the administration. In four patients L.GG could also be recovered from the biopsies, while with one patient (suffering from ulcerative colitis diagnosed during the colonoscopy) no L.GG was detected in the biopsy samples. The results suggest that L.GG is able to adhere in vivo to the colon. Study of the faecal samples alone is apparently not sufficient for elucidation of the gastrointestinal ecology of probiotic bacteria. INTRODUCTION stated that it is essential for several targeted functions that a probiotic should remain viable within the gastrointestinal During recent years a major worldwide increase has occurred tract (Kaila et al. 1995). For immunostimulatory functions, in the sales of cultured products containing viable probiotic however, this might not always be necessary (Miettinen et al. bacteria. Numerous studies have been undertaken to obtain 1996). Survival studies have usually been undertaken in the scientific evidence for the beneficial effects of human pro- laboratory only, thus providing simulated environmental con- biotics (Fuller 1992; Donohue and Salminen 1996). The pro- ditions of the stomach and pylorus using gastric juices and posed health-promoting effects of probiotics include bile salts. Furthermore, several gastrointestinal models have alleviation of lactose intolerance, maintenance of normal been applied as more sophisticated tools, including par- intestinal flora, prevention and treatment of diarrhoea, ameters such as transit time (which may be crucially impor- increased nutritional value of foods, stimulation of the tant for survival) to study the viability of the probiotic immune system, anticarcinogenic activity and reduction of (Rumney and Rowland 1992). Human clinical trials, however, serum cholesterol levels (Marteau and Rambaud 1993). Tra- are presently required as a basis of credible market claims ditionally, there are several specified criteria that a probiotic to provide evidence even of the survival of the probiotic should meet to fulfil the desirable functions. The probiotic strain. should be acid- and bile-tolerant, be adhesive to epithelial Lactobacillus rhamnosus GG (ATCC 53103, henceforth surfaces of the gastrointestinal tract, be non-invasive, non- L.GG) is one of the most thoroughly studied probiotic strains pathogenic, immunostimulatory yet not proinflammatory and (Salminen et al. 1993). The ability of L.GG to survive and preferably antagonistic against specific pathogens such as colonize the gastrointestinal tract has been shown for both Helicobacter pylori, Salmonella, Listeria or Clostridium. adults and children (Goldin et al. 1992; Millar et al. 1993; Extensive debate has occurred on the importance of the Saxelin et al. 1993); however, these studies have been per- viability and colonization capacity of probiotics. It has been formed using faecal material only. Consequently, the aim of the present study was to demonstrate the in vivo attachment Correspondence to: Minna Alander, Research Scientist, VTT of L.GG to human intestinal mucosae using biopsies obtained Biotechnology and Food Research, PO Box 1501, FIN-02044 VTT, Finland. from the various parts of the colon. © 1997 The Society for Applied Bacteriology