Synbiotic effects of β-glucans from cauliflower mushroom and Lactobacillus fermentum on metabolic changes and gut microbiome in estrogen-deficient rats
Jeong et al. Genes & Nutrition
Synbiotic effects of β-glucans from cauliflower mushroom and Lactobacillus fermentum on metabolic changes and gut microbiome in estrogen-deficient rats
Seong-Yeop Jeong 1
Suna Kang 0
Cao Shi Hua 0
Zhang Ting 0
Sunmin Park 0
0 Department of Food & Nutrition, Obesity/Diabetes Center, Hoseo University , 165 Sechul-Ri, BaeBang-Yup, Asan-Si, ChungNam-Do 336-795 , South Korea
1 Department of R&D, Microbial Institute for Fermentation Industry , Sunchang , South Korea
Background: We investigated whether the long-term consumption of a symbiotic formulation with Lactobacillus fermentum (probiotic) and β-glucan from cauliflower mushroom (prebiotic) would delay the progression of post-menopausal symptoms in ovariectomized (OVX) rats and explored their mechanisms of action, including changes in gut microbiota. Methods: OVX rats were fed with high-fat diets containing 1% dextrin (control), 1% lyophilized cauliflower mushroom extract (CFM), 0.1% L. fermentum JS (LFE), 1% CFM plus 0.1% LFE (CFLF), or 30 μg 17β-estradiol/kg body weight (positive-control) for 8 weeks. Results: CFM contained 95.8% β-glucans. OVX increased the ratio of Firmicutes and Bacteroidetes in the large intestines. Only CFLF lowered tail skin temperature without increasing serum 17β-estradiol and uterine index. Visceral fat mass was lower in CFLF and positive-control groups by increasing daily energy expenditure and fat oxidation. Dyslipidemia induced by OVX was improved by CFM and CFLF as much as in the positive-control group. Homeostasis model assessment estimate of insulin resistance was lower in CFLF than in the positive-control. Hepatic insulin signaling (pAkt➔GSK-3β) was potentiated in the ascending order of the control, LFE, CFM, CFLF, and positive-control. AMPK phosphorylation showed similar patterns of hepatic insulin signaling but LFE increased it more than CFM. The changes in gut microbiota were prevented by CFLF in OVX rats, and the ratio of Firmicutes and Bacteroidetes in the CFLF was similar to the positive-control group. Conclusion: OVX changed gut microbiota and was associated with menopausal symptoms; however, the synbiotics, CFM and LFE, prevented menopausal symptoms and improved the gut microbiota in estrogen-deficient rats.
Cauliflower mushroom; β-Glucan; Lactobacillus fermentum; Gut microbiota; Ovariectomy; Synbiotics
Background
Estrogen deficiency causes disturbances of energy, lipid,
glucose, and bone metabolism and induces vasomotor
symptoms such as daytime hot flushes, night sweats,
sleep and mood disorder, and difficulty in concentration.
These menopausal symptoms result in a lower quality of
life and increase the incidence of metabolic disease.
Although hormone replacement therapy ultimately
prevents menopausal symptoms and improves quality of
life, hormone replacement therapy is often not
recommended due to its risk of adverse side-effects [
1
].
Alternative therapies with less adverse effects have been
suggested for the treatment of menopausal symptoms.
Firmicutes among the gut microbiota is associated
with obesity and its progression towards metabolic
disease [
2
], and dietary interventions to modulate the
gut microbiota can alleviate metabolic diseases [
3
]. Sex
hormones including estrogen and testosterone have been
reported to modulate microbial communities [
4
], and
gut microbiota influence systemic levels of sex hormones
[
5, 6
]. Intestinal tissues mainly contain estrogen receptor
(ER)-β. ER-β affects the composition of gut microbiota
in female mice [7]. Cox-York et al. [
8
] have
demonstrated that ovariectomized (OVX) rats with higher
aerobic capacity increase microbial diversity and the
number of the Bacteroidetes phylum in the gut. In
addition, equol production in the gut produces the
beneficial effects of soy and isoflavones on menopausal
symptoms and gut microbiota is associated with equol
production in the gut from soy-isoflavone concentrates
in post-menopausal women [
9
]. Thus, the changes of
gut microbiota composition can prevent the
menopausal symptoms.
Diets including prebiotics and probiotics can modulate gut
microbiota [
7, 10
]. Probiotics consumption seems to be a
feasible approach to modulate the intestinal microbiota and
to maintain or restore human health [11]. Bifidobacterium
and Lactobacillus, natural components of the colon
microbiota, are the most commonly used probiotics in many
functional foods and dietary supplements. Various Lactobacillus
species such as Lactobacillus fermentum, Lactobacillus
plantarium, and Lactobacillus reuteri are naturally present in
fermented foods and milk products [
12
] and especially,
L. fermentum, which was isolated from human milk,
can inhibit pathogens, decrease cholesterol synthesis,
and change gut microbiota [
13, 14
]. Dietary
supplementation with prebiotics, including lactulose,
galactooligosaccharides, and fructo-oligosaccharides, increases
the contents and proportion of bifidobacteria in the
intest (...truncated)