The findings, which come from lab-based work on human gut cells, suggests there is an interaction between the eicosapentaenoic acid (EPA) and colorectal cell response to a commensal bacterial strain.
Writing in Lipid Technology, the research team report on in vitro research assessing whether gut cells respond differently to a commensal bacterium (Lactobacillus gasseri) and two pathogenic bacteria (Escherichia coli and Staphylococcus aureus), and also whether the responses could be altered with PUFAs.
“Our results indicate that L. gasseri could have a way of promoting its own survival in the gut by inducing tolerance towards itself, an effect which pathogenic bacteria do not have,” revealed the research team – who noted that the addition of EPA led to an even bigger increase in the immune signalling protein TGF-β1 (Transforming Growth Factor β1) which promotes tolerance towards commensal bacteria.
“This early research shows the potential of combining fish oil with probiotic bacteria to promote probiotic survival in the gut and/or dampening inflammatory responses,” wrote the team – led by Kerry Bentley-Hewit from the UK Institute of Food Research, and The New Zealand Institute for Plant & Food Research Limited.
Previous research reported in the Journal of functional Foods, suggested that a co-encapsulation of omega-3 fatty acids and probiotic bacteria may have beneficial synergistic effect on health and also on the stability of the co-microencapsulation.
Led by Divya Eratte from Federation University Australia, the research suggested the viability of probiotic bacteria was increased significantly when co-encapsulated with omega-3 rich tuna oil in a whey protein isolate and gum Arabic complex (WPI-GA complex).
In vitro data
In the current study, Bentley-Hewitt and her colleagues used a cell co-culture model containing a layer of colorectal cells, with immune cells in a porous compartment beneath to test the effects of the different bacterial strains and fatty acids on cell responses. They tested the effects of three types of polyunsaturated fatty acid (PUFA) - eicosapentaenoic acid (EPA) and docoasahexaenoic acid (DHA), and arachidonic acid (AA).
“The aim of our study was to test whether PUFAs could modify colorectal cell immune responses to lactobacilli, and potentially to identify a common pathway by which these two components could play a role in maintaining a health immune balance,” said the team, who added that the in vitro model used “represents the outer cell lining of our lower gut and the immune cells that sit underneath in an area called the lamina propria.”
Bentley-Hewitt and her team found that commensal L. gasseri increased the secretion of the immune signalling protein TGF-β1, along with increased expression of its encoding gene signal, while the pathogenic bacteria had no effect on the amount of TGF-β1.
“TGF-β1 has an important role in promoting tolerance towards commensal bacteria and has a role in dampening immune responses following inflammation,” explained the team.
In addition, the authors reported that EPA, but not DHA or AA, resulted in further increases in TGF-β1.
“These preliminary data suggest that EPA may enhance tolerance towards commensal bacteria,” concluded the team – who added that the next step in this research will be testing in living organisms to assess the protection against active inflammation and bacteria survival in vivo.
Source: Lipid Technology
Published online ahead of print, doi: 10.1002/lite.201500035
“How fish oils could support our friendly bacteria”
Authors: Kerry L. Bentley-Hewitt, et al