Document Detail

Differential impact of lactose/lactase phenotype on colonic microflora.
MedLine Citation:
PMID:  20559580     Owner:  NLM     Status:  MEDLINE    
BACKGROUND: The ability to digest lactose divides the world's population into two phenotypes that may be risk variability markers for several diseases. Prebiotic effects likely favour lactose maldigesters who experience lactose spilling into their colon.
OBJECTIVE: To evaluate the effects of fixed-dose lactose solutions on fecal bifidobacteria and lactobacilli in digesters and maldigesters, and to determine whether the concept of a difference in ability to digest lactose is supported.
METHODS: A four-week study was performed in 23 lactose maldigesters and 18 digesters. Following two weeks of dairy food withdrawal, subjects ingested 25 g of lactose twice a day for two weeks. Stool bifidobacteria and lactobacilli counts pre- and postintervention were measured as the primary outcome. For secondary outcomes, total anaerobes, Enterobacteriaceae, beta-galactosidase and N-acetyl-beta-D-glucosaminidase activity in stool, as well as breath hydrogen and symptoms following lactose challenge tests, were measured.
RESULTS: Lactose maldigesters had a mean change difference (0.72 log10 colony forming unitsg stool; P=0.04) in bifidobacteria counts compared with lactose digesters. Lactobacilli counts were increased, but not significantly. Nevertheless, reduced breath hydrogen after lactose ingestion correlated with lactobacilli (r=-0.5; P<0.001). Reduced total breath hydrogen and symptom scorestogether, with a rise in fecal enzymes after intervention, were appropriate, but not significant.
CONCLUSIONS: Despite failure to achieve full colonic adaptation, the present study provided evidence for a differential impact of lactose on microflora depending on genetic lactase status. A prebiotic effect was evident in lactose maldigesters but not in lactose digesters. This may play a role in modifying the mechanisms of certain disease risks related to dairy food consumption between the two phenotypes.
Andrew Szilagyi; Ian Shrier; Debra Heilpern; Jung Je; Sunghoon Park; George Chong; Catherine Lalonde; Louis-Francois Cote; Byong Lee
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Canadian journal of gastroenterology = Journal canadien de gastroenterologie     Volume:  24     ISSN:  0835-7900     ISO Abbreviation:  Can. J. Gastroenterol.     Publication Date:  2010 Jun 
Date Detail:
Created Date:  2010-06-18     Completed Date:  2010-08-16     Revised Date:  2014-01-17    
Medline Journal Info:
Nlm Unique ID:  8807867     Medline TA:  Can J Gastroenterol     Country:  Canada    
Other Details:
Languages:  eng     Pagination:  373-9     Citation Subset:  IM    
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MeSH Terms
Bifidobacterium / growth & development
Breath Tests
Colon / microbiology*
Colony Count, Microbial
Feces / enzymology
Lactase / genetics*
Lactobacillus / growth & development
Lactose / genetics*,  metabolism
Lactose Intolerance / diagnosis*,  therapy
Pilot Projects
Young Adult
beta-Galactosidase / metabolism
Reg. No./Substance:
EC; EC; J2B2A4N98G/Lactose

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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