Fructose-induced intestinal microbiota shift following two types of short-term high fructose dietary phases: A microbiota analysis of a crossover intervention study in healthy women.

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.