Modifiable Risk Factors for Dementia: The Role of Gut Microbiota

2021 ◽  
Vol 18 ◽  
Author(s):  
Cristian Cabrera ◽  
Paloma Vicens ◽  
Margarita Torrente

: Dementia is a syndrome resulting from chronic or progressive brain disease. Around 40% of worldwide dementia can be prevented or delayed by modifying 12 risk factors: low educational attainment in early life, mid-life hypertension, mid-life obesity, hearing loss, traumatic brain injury, excessive alcohol consumption, smoking, depression, physical inactivity, social isolation, diabetes mellitus, and air pollution. There is growing evidence that gastrointestinal tract microbiota may significantly contribute to dementia pathogenesis. In particular, gut dysbiosis can trigger metabolic diseases and the progression of low-grade systemic inflammation, being involved in much of the major modifiable risk factors. In this review, we focus on studies that have evaluated the association between modifiable risk factors for dementia and the role of gut microbiota. We also suggest clinical implications for researchers in dementia-gut microbiota related fields.

2015 ◽  
Vol 172 (4) ◽  
pp. R167-R177 ◽  
Author(s):  
Kristine H Allin ◽  
Trine Nielsen ◽  
Oluf Pedersen

Perturbations of the composition and function of the gut microbiota have been associated with metabolic disorders including obesity, insulin resistance and type 2 diabetes. Studies on mice have demonstrated several underlying mechanisms including host signalling through bacterial lipopolysaccharides derived from the outer membranes of Gram-negative bacteria, bacterial fermentation of dietary fibres to short-chain fatty acids and bacterial modulation of bile acids. On top of this, an increased permeability of the intestinal epithelium may lead to increased absorption of macromolecules from the intestinal content resulting in systemic immune responses, low-grade inflammation and altered signalling pathways influencing lipid and glucose metabolism. While mechanistic studies on mice collectively support a causal role of the gut microbiota in metabolic diseases, the majority of studies in humans are correlative of nature and thus hinder causal inferences. Importantly, several factors known to influence the risk of type 2 diabetes, e.g. diet and age, have also been linked to alterations in the gut microbiota complicating the interpretation of correlative studies. However, based upon the available evidence, it is hypothesised that the gut microbiota may mediate or modulate the influence of lifestyle factors triggering development of type 2 diabetes. Thus, the aim of this review is to critically discuss the potential role of the gut microbiota in the pathophysiology and pathogenesis of type 2 diabetes.


Nutrients ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 117 ◽  
Author(s):  
Paul J. Wisniewski ◽  
Robert A. Dowden ◽  
Sara C. Campbell

Inflammation and its resolution is a tenuous balance that is under constant contest. Though several regulatory mechanisms are employed to maintain homeostasis, disruptions in the regulation of inflammation can lead to detrimental effects for the host. Of note, the gut and microbial dysbiosis are implicated in the pathology of systemic chronic low-grade inflammation which has been linked to several metabolic diseases. What remains to be described is the extent to which dietary fat and concomitant changes in the gut microbiota contribute to, or arise from, the onset of metabolic disorders. The present review will highlight the role of microorganisms in host energy regulation and several mechanisms that contribute to inflammatory pathways. This review will also discuss the immunomodulatory effects of the endocannabinoid system and its link with the gut microbiota. Finally, a brief discussion arguing for improved taxonomic resolution (at the species and strain level) is needed to deepen our current knowledge of the microbiota and host inflammatory state.


BMJ Open ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. e042006
Author(s):  
Xiang Feng ◽  
Zhao-Lai Hua ◽  
Qin Zhou ◽  
Ai-Wu Shi ◽  
Tong-Qiu Song ◽  
...  

ObjectivesTo describe the prevalence of modifiable risk factors for upper digestive tract cancer (UDTC) and its coprevalence, and investigate relevant influencing factors of modifiable UDTC risk factors coprevalence among residents aged 40–69 years in Yangzhong city, China.DesignCross-sectional study.ParticipantsA total of 21 175 participants aged 40–69 years were enrolled in the study. 1962 subjects were excluded due to missing age, marital status or some other selected information. Eventually, 19 213 participants were available for the present analysis.Main outcomes measuresPrevalence and coprevalence of eight modifiable UDTC risk factors (overweight or obesity, current smoking, excessive alcohol consumption, insufficient vegetables intake, insufficient fruit intake and the consumption of pickled, fried and hot food) were analysed.ResultsThe prevalence of overweight/obesity, current smoking, excessive alcohol consumption, insufficient vegetables intake, insufficient fruit intake and the consumption of pickled, fried and hot food in this study was 45.3%, 24.1%, 16.2%, 66.1%, 94.5%, 68.1%, 36.0% and 88.4%, respectively. Nearly all (99.9%) participants showed one or more UDTC risk factors, 98.6% of the participants showed at least two risk factors, 92.2% of the participants had at least three risk factors and 69.7% of the participants had four or more risk factors. Multivariate logistic regression analysis revealed that men, younger age, single, higher education, higher annual family income and smaller household size were more likely to present modifiable UDTC risk factors coprevalence.ConclusionsThe prevalence and coprevalence of modifiable UDTC risk factors are high among participants in Yangzhong city. Extra attention must be paid to these groups who are susceptible to risk factors coprevalence during screening progress. Relative departments also need to make significant public health programmes that aim to decrease modifiable UDTC risk factors coprevalence among residents aged 40–69 years from high-risk areas of UDTC.


2017 ◽  
Vol 69 (2) ◽  
pp. 125-143 ◽  
Author(s):  
Flávia Galvão Cândido ◽  
Flávia Xavier Valente ◽  
Łukasz Marcin Grześkowiak ◽  
Ana Paula Boroni Moreira ◽  
Daniela Mayumi Usuda Prado Rocha ◽  
...  

2021 ◽  
Vol 11 (9) ◽  
pp. 544-549
Author(s):  
Paulina Trojanowska ◽  
Magdalena Chrościńska-Krawczyk ◽  
Alina Trojanowska ◽  
Ewa Tywanek ◽  
Jakub Wronecki ◽  
...  

Understanding the important role of the non-specific immune response in protecting the body against the development of numerous diseases has become partially possible after the discovery of several classes of pattern recognition receptors (PRR), such as Toll-like or NOD-like receptors. A group of cytoplasmic proteins called the inflammasome, which detect PAMP and DAMP through the PRR receptors, is able to activate pro-inflammatory cytokines and trigger an acute inflammatory reaction both in the extracellular and intracellular space. Low-grade systemic and local inflammation contributes to the development and progression of various conditions, including autoimmune and metabolic diseases, such as diabetes, metabolic syndrome and atherosclerosis, which until recently were not even considered inflammatory diseases. This review will discuss the role of innate immunity in the development of type 1 and type 2 diabetes, focusing on the role of specific innate immunity receptors and insulin resistance involved in these diseases pathogenesis.


2020 ◽  
Vol 111 (4) ◽  
pp. 864-876
Author(s):  
Anne K Eriksen ◽  
Carl Brunius ◽  
Mohsen Mazidi ◽  
Per M Hellström ◽  
Ulf Risérus ◽  
...  

ABSTRACT Background A whole-grain (WG)–rich diet has shown to have potential for both prevention and treatment of the metabolic syndrome (MetS), which is a cluster of risk factors that increase the risk of type 2 diabetes and cardiovascular disease. Different WGs may have different health effects. WG rye, in particular, may improve glucose homeostasis and blood lipids, possibly mediated through fermentable dietary fiber and lignans. Recent studies have also suggested a crucial role of the gut microbiota in response to WG. Objectives The aim was to investigate WG rye, alone and with lignan supplements [secoisolariciresinol diglucoside (SDG)], and WG wheat diets on glucose tolerance [oral-glucose-tolerance test (OGTT)], other cardiometabolic outcomes, enterolignans, and microbiota composition. Moreover, we exploratively evaluated the role of gut microbiota enterotypes in response to intervention diets. Methods Forty men with MetS risk profile were randomly assigned to WG diets in an 8-wk crossover study. The rye diet was supplemented with 280 mg SDG at weeks 4–8. Effects of treatment were evaluated by mixed-effects modeling, and effects on microbiota composition and the role of gut microbiota as a predictor of response to treatment were analyzed by random forest plots. Results The WG rye diet (± SDG supplements) did not affect the OGTT compared with WG wheat. Total and LDL cholesterol were lowered (−0.06 and −0.09 mmol/L, respectively; P < 0.05) after WG rye compared with WG wheat after 4 wk but not after 8 wk. WG rye resulted in higher abundance of Bifidobacterium [fold-change (FC) = 2.58, P < 0.001] compared with baseline and lower abundance of Clostridium genus compared with WG wheat (FC = 0.54, P = 0.02). The explorative analyses suggest that baseline enterotype is associated with total and LDL-cholesterol response to diet. Conclusions WG rye, alone or with SDG supplementation, compared with WG wheat did not affect glucose metabolism but caused transient LDL-cholesterol reduction. The effect of WG diets appeared to differ according to enterotype. This trial was registered at www.clinicaltrials.gov as NCT02987595.


2018 ◽  
Vol 25 (3) ◽  
pp. 231 ◽  
Author(s):  
J. Tung ◽  
C.E. Politis ◽  
J. Chadder ◽  
J. Han ◽  
J. Niu ◽  
...  

Colorectal cancer (crc) is the 2nd most common cancer in Canada and the 2nd leading cause of cancer death. That heavy burden can be mitigated given the preventability of crc through lifestyle changes and screening. Here, we describe the extent of the variation in crc incidence rates across Canada and the disparities, by jurisdiction, in the prevalence of modifiable risk factors known to contribute to the crc burden.Findings suggest that there is a north–south and east–west gradient in crc modifiable risk factors, including excess weight, physical inactivity, excessive alcohol consumption, and low fruit and vegetable consumption, with the highest prevalence of risk factors typically found in the territories and Atlantic provinces. In general, that pattern reflects the crc incidence rates seen across Canada. Given the substantial interjurisdictional variation, more work is needed to increase prevention efforts, including promoting a healthier diet and lifestyle, especially in jurisdictions facing disproportionately higher burdens of crc.Based on current knowledge, the most effective approaches to reduce the burden of crc include adopting public policies that create healthier environments in which people live, work, learn, and play; making healthy choices easier; and continuing to emphasize screening and early detection. Strategic approaches to modifiable risk factors and mechanisms for early cancer detection have the potential to translate into positive effects for population health and fewer Canadians developing and dying from cancer.


2020 ◽  
Vol 52 (12) ◽  
pp. 1959-1975
Author(s):  
Yu Wang ◽  
Weifan Yao ◽  
Bo Li ◽  
Shiyun Qian ◽  
Binbin Wei ◽  
...  

AbstractGut microbiota dysbiosis has a significant role in the pathogenesis of metabolic diseases, including obesity. Nuciferine (NUC) is a main bioactive component in the lotus leaf that has been used as food in China since ancient times. Here, we examined whether the anti-obesity effects of NUC are related to modulations in the gut microbiota. Using an obese rat model fed a HFD for 8 weeks, we show that NUC supplementation of HFD rats prevents weight gain, reduces fat accumulation, and ameliorates lipid metabolic disorders. Furthermore, 16S rRNA gene sequencing of the fecal microbiota suggested that NUC changed the diversity and composition of the gut microbiota in HFD-fed rats. In particular, NUC decreased the ratio of the phyla Firmicutes/Bacteroidetes, the relative abundance of the LPS-producing genus Desulfovibrio and bacteria involved in lipid metabolism, whereas it increased the relative abundance of SCFA-producing bacteria in HFD-fed rats. Predicted functional analysis of microbial communities showed that NUC modified genes involved in LPS biosynthesis and lipid metabolism. In addition, serum metabolomics analysis revealed that NUC effectively improved HFD-induced disorders of endogenous metabolism, especially lipid metabolism. Notably, NUC promoted SCFA production and enhanced intestinal integrity, leading to lower blood endotoxemia to reduce inflammation in HFD-fed rats. Together, the anti-obesity effects of NUC may be related to modulations in the composition and potential function of gut microbiota, improvement in intestinal barrier integrity and prevention of chronic low-grade inflammation. This research may provide support for the application of NUC in the prevention and treatment of obesity.


2019 ◽  
Vol 29 ◽  
pp. S132
Author(s):  
Jodie Lord ◽  
Rebecca Green ◽  
Christopher Hübel ◽  
Marcus Richards ◽  
Pak Sham ◽  
...  

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