Page 136 - Petelin, Ana. 2020. Ed. Zdravje delovno aktivne populacije / Health of the Working-Age Population. Proceedings. Koper: University of Primorska Press.
P. 136
avje delovno aktivne populacije | health of the working-age population 134 abetes and heart disease (Li et al., 2018). Kefir is a fermented dairy product con-
taining a large number of lactic acid bacteria and yeasts (Kim et al., 2017). The
largest bacterial community in the human body is located in the gastrointesti-
nal tract (Bischoff et al., 2014) and it’s known that a diverse gut microbiota and
increased intestinal permeability plays a key role in inflammation that accom-
panies chronic diseases and in maintaining health (Kim et al., 2017). It mod-
ulates the expression of many genes in the gut that are associated with immu-
nity, nutrient absorption, energy metabolism, and gut barrier function (Bell et
al., 2018). The human gut is surrounded by a layer of epithelial cells that forms
a barrier between the environment and the host. Increased intestinal permea-
bility is thought to be an important element in the pathogenesis of chronic in-
flammatory diseases, in addition to genetic and environmental factors. Zonu-
lin is so far the only known physiological intercellular modulator of intestinal
tight junctions (Sturgeon and Fasano, 2016) and it’s a biomarker showing al-
tered intestinal barrier function in many autoimmune, neurodegenerative and
tumor diseases (Fasano, 2012). The specific pathophysiological role of zonulin
in various diseases is not well known, but elevated zonulin levels are thought
to be a key factor in the onset of the inflammatory process (Sturgeon and Fas-
ano, 2016). Despite the prevalence of dairy products, there has been very little
research done on the effects of kefir and milk intake on the intestine, especial-
ly in humans.
Methods
We performed a longitudinal intervention study, which lasted from March
to June 2018 at the Faculty of Health Sciences in Izola. The study included 28
healthy individuals (13 men and 15 women) aged between 31 and 64 years, with a
BMI between 25 and 30 kg/m2. The exclusion criteria were: any acute or chron-
ic illness, lactose intolerance or milk allergy, taking medication, BMI < 25 kg/
m2 or BMI > 30 kg/m2, pregnancy and lactation, significant body weight change
in the last 3 months. The participants were divided into two groups, each alter-
nately consuming kefir (250 ml daily) or milk (250 ml daily) for 21 days, with
two washout periods in-between. During the washout periods complete absti-
tence from fermented dairy products was required. After each phase venous
blood was sampled (fasted) and was then analyzed with Cobas c 111 analyzer
(Roche Diagnostics) and with enzyme-linked immunosorbent assay (ELISA)
for serum zonulin levels. After each phase participants completed a question-
naire on gastrointestinal symptoms – nausea, bloating, borborygmus, stom-
ach pain, flatulence and heartburn. They also completed a Bristol stool scale.
Participants were instructed to try to keep their diet as normal as possible
throughout the study.
taining a large number of lactic acid bacteria and yeasts (Kim et al., 2017). The
largest bacterial community in the human body is located in the gastrointesti-
nal tract (Bischoff et al., 2014) and it’s known that a diverse gut microbiota and
increased intestinal permeability plays a key role in inflammation that accom-
panies chronic diseases and in maintaining health (Kim et al., 2017). It mod-
ulates the expression of many genes in the gut that are associated with immu-
nity, nutrient absorption, energy metabolism, and gut barrier function (Bell et
al., 2018). The human gut is surrounded by a layer of epithelial cells that forms
a barrier between the environment and the host. Increased intestinal permea-
bility is thought to be an important element in the pathogenesis of chronic in-
flammatory diseases, in addition to genetic and environmental factors. Zonu-
lin is so far the only known physiological intercellular modulator of intestinal
tight junctions (Sturgeon and Fasano, 2016) and it’s a biomarker showing al-
tered intestinal barrier function in many autoimmune, neurodegenerative and
tumor diseases (Fasano, 2012). The specific pathophysiological role of zonulin
in various diseases is not well known, but elevated zonulin levels are thought
to be a key factor in the onset of the inflammatory process (Sturgeon and Fas-
ano, 2016). Despite the prevalence of dairy products, there has been very little
research done on the effects of kefir and milk intake on the intestine, especial-
ly in humans.
Methods
We performed a longitudinal intervention study, which lasted from March
to June 2018 at the Faculty of Health Sciences in Izola. The study included 28
healthy individuals (13 men and 15 women) aged between 31 and 64 years, with a
BMI between 25 and 30 kg/m2. The exclusion criteria were: any acute or chron-
ic illness, lactose intolerance or milk allergy, taking medication, BMI < 25 kg/
m2 or BMI > 30 kg/m2, pregnancy and lactation, significant body weight change
in the last 3 months. The participants were divided into two groups, each alter-
nately consuming kefir (250 ml daily) or milk (250 ml daily) for 21 days, with
two washout periods in-between. During the washout periods complete absti-
tence from fermented dairy products was required. After each phase venous
blood was sampled (fasted) and was then analyzed with Cobas c 111 analyzer
(Roche Diagnostics) and with enzyme-linked immunosorbent assay (ELISA)
for serum zonulin levels. After each phase participants completed a question-
naire on gastrointestinal symptoms – nausea, bloating, borborygmus, stom-
ach pain, flatulence and heartburn. They also completed a Bristol stool scale.
Participants were instructed to try to keep their diet as normal as possible
throughout the study.
