Probiotic’s gut benefits get "omics" boost
The probiotic Lactobacillus rhamnosus GG (LGG) bacteria was associated with decreased levels of lysophosphatidylcholines (LysoGPCho) and sphingomyelins (SM), according to analyses done using the lipidomics technique to study lipid metabolites in human volunteers.
LysoGPCho are reported to be involved in detrimental processes such as oxidative metabolism, angiogenesis, and carcinogenesis. SM have been connected to inflammatory processes that play a role in hardening of the arteries (atherosclerosis).
The researchers, from the University of Helsinki, Valio Ltd, and VTT Technical Research Centre of Finland, report their findings in the World Journal of Gastroenterology.
“This study is the first to apply lipidomic techniques to analyse the global lipidomic profiles of healthy adults after a probiotic intervention,” wrote lead author Riina Kekkonen.
“Lipidomics may provide powerful tools for identifying new biomarkers behind the clinical effects of probiotic intervention trials and for establishing relationships between molecular profiles and other known data from the same individual.”
The study is a necessary addition to our understanding of how probiotics exert beneficial effects in the gastrointestinal tract.
The researchers recruited 26 people (14 women, average age 42, average BMI 24 kg/m2) to take part in the three-week randomised, double-blind, placebo-controlled trial. Subjects were assigned to receive either LGG supplements or placebo.
The lipodomic profiles of the volunteers were measured by analysing blood samples with ultra performance liquid chromatography in combination with mass spectrometry (UPLC/MS). Kekkonen and co-workers report that 407 lipids were identified, and these corresponded to 13 different classes of lipids.
Overall, the results indicated that the probiotic was associated with decreases in LysoGPCho, SM, and certain types of glycerophosphatidylcholines (GPCho).
On the other hand, the triacylglycerols (TAG) type of lipids were increased in the subjects receiving the probiotic bacteria.
LysoGPCho is reportedly a pro-inflammatory lipid, and the researchers noted that compounds associated with inflammation, notably interleukin-6 (IL-6), were also affected by LGG supplementation.
“LysoGPCho, derived from phosphatidylcholines, are mediators that affect numerous functions in many types of cells, from proliferation and survival to migration and secretion,” explained the researchers.
“They are also involved in oxidative metabolism, angiogenesis, and carcinogenesis. LysoGPCho is a major atherogenic lipid of oxidised LDL, and it has been associated with vascular inflammation, endothelial dysfunction and coronary atherosclerosis,” they added.
In terms of SM decreases, the researchers note that these types of lipids have been linked to inflammatory processes that may cause atherosclerosis and inflammatory bowel disease.
“Therefore, the decrease in SM seen after LGG intervention in the present study may also contribute to the beneficial effects on gut barrier function seen in the previous intervention studies with LGG,” they said.
The journal article included the views of the peer-reviewers. The article was described as “interesting, well written and well presented”.
“However, this is a small study. One good point is the randomized cohort. The study population was healthy individuals and the results may not be applicable to a population with lipid-related disease states.
“There were multiple comparisons and one thus cannot exclude the possibility that some of the significant changes were detected by chance,” states the journal.
Source: World Journal of GastroenterologyVolume 14, Issue 20 3188-3194“Effect of probiotic Lactobacillus rhamnosus GG intervention on global serum lipidomics profiles in healthy adults”Authors: R.A. Kekkonen, M. Sysi-Aho, T. Seppanen-Laakso, I. Julkunen, H. Vapaatalo, M. Oresic, R. Korpela