Calorie-restricted oat diet is associated with zonulin and short-chain fatty acid response in metabolic syndrome: a randomized controlled trial.
A short-term calorie-restricted oat diet may reduce gut permeability markers in metabolic syndrome, but the clinical significance of these changes is uncertain.
Where it sits
this study against the rest of the dihexa corpusSummary and findings
This study measured the effects of two different oat diets on gut permeability markers in individuals with metabolic syndrome. Participants consumed either 3 × 100 g oatmeal/d for 2 days or integrated 1 × 80 g oatmeal/d into their habitual diet for 6 weeks. Serum zonulin decreased and plasma butyric acid increased in the short-term oat diet group compared to controls.
Abstract
Oats are associated with positive effects on gut health, but human studies are largely lacking. Therefore, we investigated the effects of two different oat diets on gut permeability makers in individuals with metabolic syndrome, each in a randomized, controlled parallel design. Participants either consumed 3 × 100 g oatmeal/d for 2 d or an adapted control diet, or they integrated 1 × 80 g oatmeal/d into their habitual diet for 6 weeks or maintained it unchanged. Serum zonulin decreased upon 2-d calorie-restricted oat diet compared to baseline, while plasma butyric acid increased compared to the control (<i>n</i> = 27). Zonulin reduction correlated inversely with changes in short-chain fatty acids (SCFAs), particularly valeric and butyric acids, which were associated with shifts in microbial composition. During the 6-week isocaloric oat diet, these parameters remained stable (<i>n</i> = 22). Our data suggests that alterations in microbiome and related effects on SCFAs upon a short-term calorie-restricted diet with high-dose oats are contributing factors to changes in gut permeability markers. Thus, an intense oat intake might be a suitable and feasible approach to improve obesity-related intestinal barrier dysfunction in metabolic syndrome.German Clinical Trials Register: 07/28/2020, identifier: DRKS00022169.
Background
This paper addresses the relationship between oat consumption and gut health, specifically in individuals with metabolic syndrome. Previous studies have suggested that oats may positively impact gut permeability, but human data are limited. Understanding these effects is important for developing dietary interventions for metabolic syndrome.
Methods
The study employed a randomized controlled parallel design with participants consuming either 3 × 100 g oatmeal/d for 2 days or integrating 1 × 80 g oatmeal/d into their habitual diet for 6 weeks. The primary outcome measures included serum zonulin and plasma short-chain fatty acids. The sample sizes were 27 for the short-term diet and 22 for the long-term diet.
Results
Serum zonulin decreased upon 2-d calorie-restricted oat diet compared to baseline, n=27. Plasma butyric acid increased compared to the control, n=27. Zonulin reduction correlated inversely with changes in short-chain fatty acids, particularly valeric and butyric acids.
Interpretation
The findings suggest that a short-term calorie-restricted oat diet may influence gut permeability markers through changes in short-chain fatty acids. However, the effect sizes are not quantified in the abstract, and the clinical significance of these changes remains unclear. Limitations such as small sample sizes and short follow-up periods may confound the conclusions.
Key findings
- Serum zonulin decreased upon 2-d calorie-restricted oat diet compared to baseline, n=27.
- Plasma butyric acid increased compared to the control, n=27.
- Zonulin reduction correlated inversely with changes in short-chain fatty acids, particularly valeric and butyric acids.
- During the 6-week isocaloric oat diet, these parameters remained stable, n=22.
Limitations
- small n=27 for the short-term diet and n=22 for the long-term diet
- short follow-up of 6 weeks for the isocaloric diet
- no long-term data on the effects of oat consumption