Identification of bacteria with β-galactosidase activity in faeces from lactase non-persistent subjects

• Published in: FEMS microbiology ecology Vol. 54; no. 3; pp. 463 - 469
• Main Authors: He, Tao, Priebe, Marion G., Vonk, Roel J., Welling, Gjalt W.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Elsevier B.V 01.11.2005; Blackwell Publishing Ltd; Blackwell; Oxford University Press
• Subjects: Adult; Asian Continental Ancestry Group; Bacteria; Bacteria, Anaerobic - enzymology; Bacteria, Anaerobic - genetics; Bacteriology; beta-Galactosidase - metabolism; Biological and medical sciences; Colon; Composition; Ecology; Faecal microbiota; Feces; Feces - microbiology; Female; Fermentation; FISH; Fluorescence; Fluorescence in situ hybridization; Fundamental and applied biological sciences. Psychology; Galactosidase; Galactosides; Humans; In Situ Hybridization, Fluorescence; Indoles; Intestine; Intolerance; Lactase; Lactose; Lactose intolerance; Lactose Intolerance - enzymology; Male; Microbiology; Miscellaneous; Small intestine; Statistics, Nonparametric; Substrates; X-gal; β-Galactosidase; Faecal microbiota; FISH; X-gal; Lactose intolerance; β-Galactosidase; Molecular hybridization; Digestive system; Enzyme; Lactase; In situ; Gut; Galactosidase; Identification; Method; Fermentation; Lactose; Glycosidases; Hydrolases; Bacteria; Colon; O-Glycosidases
• ISSN: 0168-6496; 1574-6941
• DOI: 10.1016/j.femsec.2005.06.001

Previous studies suggest that, besides the maldigestion of lactose in the small intestine, the colonic processing of lactose might play a role in lactose intolerance. β-Galactosidase is the bacterial enzyme which catalyzes the first step of lactose fermentation in the colon. We propose a practical method to differentiate and identify bacteria with β-galactosidase activity in faeces which combines a colony-lift filter assay with X-gal (5-bromo-4-chloro-3-indolyl-β- d-galactopyranoside) as substrate for differentiation and the fluorescent in situ hybridization technique for identification. The method was applied to faeces from lactase non-persistent subjects. After 28 subjects had undergone one glucose and two lactose challenges, consistent intolerant ( n = 5) and tolerant ( n = 7) groups were defined according to their symptom scores. Of the 28 faecal samples, 80.6% (mean, SD: 12.1, range: 47.8–100%) of the total cultured bacteria were found to possess β-galactosidase activity, which indicates that the bacterial β-galactosidase is abundant in the colon. The tolerant and intolerant groups did not differ in the percentage or composition of the bacteria with β-galactosidase activity or β-galactosidase activity in faeces. Results suggest that the percentage or composition of the bacteria with β-galactosidase activity in faeces do not play a role in lactose intolerance.