Background:
The consumption of High Fructose Syrup (HFS) was reported to increase in the nearly
future. HFS can cause dysbiosis through a shift of the microbiota abundance in the
gastrointestinal tract which may result in adverse health effects including increase
permeability of the gut barrier and further metabolic diseases. The direction of the
microbiota shift induced by a short-term high fructose diet in humans is largely unknown.
Methods:
To examine the role of a high fructose consumption on the human intestinal microbiota
we performed a crossover intervention study, in which the microbiota of 12 young (age
24 – 35 years) and healthy women (6 lean and 6 obese) was analyzed by 16S rRNA amplicon
sequencing. The volunteers followed three different diets; a low fructose (< 10 g/day
fructose), a fruit (100 g/day fructose from complex food sources) and a HFS (100 g/day
fructose from syrup) diet.
Results:
Although we did not find any difference in alpha-diversity (Shannon-Index) we found
a shift in the bacterial abundances after high-fructose diets. The Firmicutes abundance of all subjects decreased when they switched from the fruit to the lowf2
and HFS diet (FDR adjusted p < 0.05). In comparison, at the same time, the Bacteroidetes abundance increased (FDR adjusted p < 0.05). Analyzing bacteria abundance on genus
level of all subjects, 10 genera were identified to be significantly different between
the diet phases, if no correction for multiple comparisons was applied. Ruminococcus (genus of Firmicutes) was the only genus, which changed between the low fructose diet and HFS diet phase
(p < 0.05). The relative abundance of Ruminococcus and Erysipelatoclostridium were lower (p < 0.05), whereby relative abundance of Barnesiella (genus ofBacteroidetes) was higher after the HFS diet compared to the fruit diet which is characterized
by a high fiber intake (p < 0.05). Alistipes and Sutterella were different between the low fructose and the high fructose diet (p < 0.05).
Conclusion:
Our findings suggest that diets, which differ in the amount of fructose content and
the source of fructose mediate alterations of the gut microbiota differently.