Four weeks of feeding with Danone’s Activia fermented milk product was associated with a reduction in intestinal inflammation in mice with colitis, according to results published in the Proceedings of the National Academy of Sciences of the United States of America (PNAS).
The probiotic product was said to produce an environment in the intestine that protected against colonisation by bacteria called Enterobacteriaceae, which have recently been identified as a promoting the development of colitis.
The researchers also analysed sequencing of rRNA and real time quantitative polymerase chain reaction (RT-qPCR) techniques to measure bacterial concentrations, and found that “the structure of a host’s gut microbiota influences response to probiotics”.
“Thus, the development of gut microbe-based biomarkers for both identification of those individuals likely to benefit from probiotics and for monitoring response to probiotics seems an attainable goal,” wrote researchers led by Wendy Garrett from Harvard School of Public Health.
The researchers also note that the study provides a “gut microbe-based framework for evaluating responses to probiotic interventions in IBD”.
According to the FAO/WHO, probiotics are defined as "live microorganisms which when administered in adequate amounts confer a health benefit on the host".
Study details
The researchers used a specially bred mouse called a T-bet−/−Rag2−/− mice which is known to develop colitis. The disease in the mouse is, in part, driven by Enterobacteriaceae strains, said the researchers.
Mice were fed either the fermented drink containing Bifidobacterium animalis subsp. lactis DN-173 010 or non-fermented milk drink for four weeks. The fermented milk product used in this study is described as a “complex mixture of live bacterial strains, bacterial products, and fermentation products that exert effects on gut microbes as well as host cells”.
At the end of the study the researchers noted that the Activia-fed animals had a decrease in the pH of their cecum. This was accompanied by increases in the abundance of select lactate-consuming and butyrate-producing bacteria, said Dr Garrett and her co-workers.
“These metabolic shifts created a nonpermissive environment for the Enterobacteriaceae recently identified as colitogenic in a T-bet−/−Rag2−/− ulcerative colitis mouse model,” they added.
“We have identified features of the gut microbiota, at the membership and functional level, associated with response to this B. lactis-containing fermented milk product, and therefore this model provides a framework for evaluating and optimizing probiotic-based functional foods,” they concluded.
One of the researchers - Laurie Glimcher – is noted as being a member of the board of directors of and holds equity in the Bristol Myers Squibb, while four of the other researchers are listed as employees of Groupe Danone.
Source: Proceedings of the National Academy of Sciences
Published online ahead of print, doi: 10.1073/pnas.1011737107
“Bifidobacterium animalis subsp. lactis fermented milk product reduces inflammation by altering a niche for colitogenic microbes”
Authors: P. Veiga, C.A. Gallini, C. Beal, M. Michaud, et al.
The full study can be read here.