Although the health benefits of fermented foods have been acknowledged for centuries, an emerging interest in understanding the science supporting that understanding has witnessed a huge rise over the last decade.
Within fermented foods, the health properties of fermented dairy products such as yogurt have mainly been studied in large populations. As such, epidemiological data has linked yogurt consumption with greater adherence to the Mediterranean Diet and protection against the risk factors of type 2 diabetes. However, the mechanisms of action that explain yogurt’s health benefits are multiple and presumably driven by different components (e.g. probiotic bacteria, nutrients, and the beneficial byproducts derived from fermentation).
A new cross-sectional study, led by Xuehong Zhang from the Harvard T.H. Chan School of Public Health, shows that the consumption of 2 cups of yogurt a week may confer a benefit on gut barrier function, as suggested by reduced plasma soluble CD14 concentrations.
Diet is a major factor that shapes gut barrier structure and function. When it comes to the effects of fermented milks on immune-related markers, for instance, previous research has shown the effects of fermented dairy milks on modulating the number of lymphocytes and CD56 cells in students under examination stress.
The consumption of 2 cups of yogurt a week may confer a benefit on gut barrier function, as suggested by reduced plasma soluble CD14 concentrations
In the new study, the authors explored the impact of yogurt consumption on plasma soluble CD14 concentrations – a surrogate marker of gut barrier dysfunction. Specifically, plasma sCD14 is a receptor molecule released by macrophages and hepatocytes as part of the innate immune response to lipopolysaccharide and has been used as a marker of gut hyperpermeability.
The authors conducted a cross-sectional study in 1,076 men and women using datasets from two prospective US cohorts (i.e. the Nurses’ Health Study and Health Professionals Follow-up Study). After adjusting for potential confounding demographic, lifestyle and medical factors, higher yogurt consumption (at least 2 cups/week) was associated with lower plasma sCD14 concentrations compared to non-consumers, especially in men.
On the whole, this is the first study showing the effect of high levels of yogurt consumption on improving gut barrier function, which separates the intestinal lumen and the underlying lamina propria. In the light of current findings, strengthening the gut barrier could mediate the health benefits of yogurt in adults, thus warranting further research in order to elucidate which yogurt-based components are involved.
This is the first study showing the effect of high levels of yogurt consumption on improving gut barrier function
Luo X, Sui J, Birmann BM, et al. Association between yogurt consumption and plasma soluble CD14 in two prospective cohorts of US adults. Eur J Nutr. 2020. doi: 10.1007/s00394-020-02303-3.