The cross-sectional study, published in the journal Nutrients, analyzed the influence of lifestyle factors (diet, physical activity, sleep) on the concentration of fecal short-chain fatty acids (SCFAs) as well as the potential of SCFAs to modulate cardiometabolic disease risk.
The researchers from the Medical University of Warsaw, Poland (which funded the study) concluded that SCFAs may protect healthy individuals against overweight and obesity, in addition to modulating cardiometabolic disease risk by interacting with adiposity parameters and diet, namely dietary fiber. They also postulated that SCFA concentration could impact sleep.
"We concluded that a potential direct link between diet and SCFAs—indicated in our study—may at least partly contribute to sleep mechanisms and sleep improvement, which was shown in the case of women enrolled in the study," they wrote.
As limitation, the study noted its small sample size and inconsistent findings regarding biochemical outcomes in men which require further investigation.
SCFAs and their impact on health
SCFAs are produced by fermenting non-digestible polysaccharides and play a regulatory role in improving gut health by enhancing intestinal barrier integrity, mucus production and serotonin release.
Human intervention studies have shown that fiber-enriched diets can significantly improve the composition of gut microbiota, resulting in increased SCFA production. This evidence suggests a beneficial role of SCFAs in the regulation of blood glucose, blood lipids and energy homeostasis, however robust conclusions about causality are still lacking, the researchers noted.
The present study therefore aimed to analyze the stool concentration of SCFAs in healthy non-obese men and women and the association with diet, physical activity, sleep and cardiometabolic disease risk.
Links with weight and sleep
The study comprised 77 healthy, non-obese individuals between the ages of 30 and 45 years who were assessed for the concentration of SCFAs in stool, diet, physical activity level and sleep duration. Body composition measurement and patients’ biochemical parameters were also evaluated.
The researchers reported that the resulting data correlations reflect the fact that diet shapes the composition of the gut microbiota, and SCFAs are synthesized from dietary fiber.
"We noticed significant negative associations between energy and fat intake and some SCFAs in males (IBA, IVA, VA, isocaproic acid (ICA)," they wrote. "Further, we indicated that a high intake of fiber (insoluble and soluble) in both males and females results in an elevated concentration of the vast majority of SCFAs and the amount of SCFAs in total. This effect was particularly noticeable in the case of the soluble fraction of fiber."
The data further indicated a significant negative correlation between several SCFAs (especially acetic acid, isobutyric acid, butyric acid, propionic acid, isovaleric acid and valeric acid) with BMI, VAT/SAT ratio (visceral to subcutaneous fat ratio) and percentage of fat mass in the females. There was also a negative correlation between several SCFAs and waist circumference in both sexes.
In addition, the study noted a significant positive association between the concentration of AA, PA and ICA, as well as the total concentration of SCFAs, with sleep duration in a group of women in the sample.
SCFAs may have a potential role in modulating cardiometabolic disease risk by interacting with adiposity parameters and diet, and this potential direct link between diet and SCFAs "may at least partly contribute to sleep improvement", the researchers concluded.
Source: Nutrients
doi: 10.3390/nu16020266
"The Potential Role of SCFAs in Modulating Cardiometabolic Risk by Interacting with Adiposity Parameters and Diet"
Authors: Ostrowska, J. et al.