Viability of Lactobacillus casei Strain Shirota (LcS) from Feces of Thai Healthy Subjects Regularly Taking Milk Product Containing LcS
Surapee Tiengrim MSc*, Amornrut Leelaporn PhD**, Sathaporn Manatsathit MD***, Visanu Thamlikitkul MD*
Affiliation : * Division of Infectious Diseases and Tropical Medicine, Department of Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand ** Department of Microbiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand *** Division of Gastroenterology, Department of Medicine, Faculty of Medicine Siriraj Hospital, Bangkok, Thailand
Objective : To demonstrate the recovery of Lactobacillus casei strain Shirota (LcS) from feces of Thai subjects who regularly
took LcS containing milk product for 1 week and demonstrate the disappearance of LcS after stopped taking milk product.
Material and Method: First fecal samples were collected from 20 healthy adults at 10 days after they abstained from all
lactobacillus containing milk products. Second specimens taken after the subjects ingested LcS containing milk product for 7
days and third specimens at 7 days after they stopped taking LcS containing milk product. All the fecal specimens were culture
for LcS using LLV-FOS culture medium and enumeration of LcS was calculated. All stool samples were also tested for the
presence of LcS by using nested PCR to confirm the presence of LcS obtained from culture method.
Results : Both culture and nested PCR method showed that all the stools samples obtained from subjects prior to the
administration of LcS containing milk product were devoid of LcS, except for 3 specimens which showed weakly positive test
for PCR. At 7 days after ingesting LcS containing milk product, all stool specimens were positive for LcS on both culture and
PCR method. At 7 days after stopped taking LcS containing milk product, 1/19 specimens were positive from culture and 6/
19 specimens were positive for PCR method.
Conclusion : LcS could survive in the gastrointestinal tract of Thai subjects and could be recovered from the feces after
ingestion.
Keywords : Lactobacillus, L. casei, Enteric flora, Probiotics, Probiotic survival, Normal host, Healthy volunteer
