Background: High fat diet can lead to metabolic syndrome and is associated with changes in gut
microbiota and gut permeability, possibly mediated by bile acids. The aim of this
study was to investigate whether patients with MetS show increased gut permeability
and whether this is associated with changes in serum bile acid composition.
Methods: Gut permeability was assessed by a differential sugar absorption method and by determination
of diaminooxidase (DAO) serum levels. Serum bile acids (cholic acid, deoxycholic acid,
chenodeoxycholic acid, lithocholic acid, ursodeoxycholic acid) were determined as
unconjugated acids and as taurine and glycine conjugates using a tandem mass spectrometry
method.
Results: Twenty-eight patients and 11 healthy controls were included. Gut permeability (Saccharose
excretion, Lactulose/Mannitol ratio and DAO serum levels) was significantly increased
in MetS compared to controls but did not differ between patient groups. No difference
in individual bile acids or total bile acids was found between controls and patients
with MetS. Neither gut permeability nor bile acids changed after consumption of a
milk drink over three months. Bile acids did not correlate with markers of gut permeability.
Patients who reported higher fat consumption had significantly lower levels of ursodeoxycholic
acid, glyco-ursodeoxycholic acid and tauro-chenodeoxycholic acid compared to those
with moderate fat consumption.
Discussion: Gut permeability of MetS patients was significantly increased compared to healthy
controls. No association between bile acid levels and gut permeability was found.
Probiotic supplementation did not have any influence on gut permeability or the bile
acid profile possibly due to too short study duration or underdosing. Patients who
reported to eat a high fat diet, had lower levels of less hydrophobic bile acids.
This finding might implicate that a high fat diet reduced protective factors that
are necessary for gut barrier integrity.
