Wednesday, December 15, 2021

Microbiome in Complex Disease

An imbalance between microorganisms in human microbiome is responsible for many complex diseases. The relationship is complex. In a new review article published in the International Journal of Molecular Sciences, researchers analyzed over 24,000 scientific papers on gut microbiome in metabolic (n=6109 papers), immune (n=7434), autoimmune (n=1927), cardiovascular (n=2605), brain diseases (n=4216) and various cancers (n=5564).  Most papers were written about the role of microbiome in obesity (n=5342), while the smallest subset was about heart failure (n=261). 

Complex diseases occur due to interaction of genetic and environmental factors.

Gut microbes and their metabolites play important roles as environmental factors. The metabolites - such as short-chain fatty acids (SCFAs), the end products of fermentation of dietary fibers by the anaerobic microbes in the gut, can protect us from pathogen invasion by activating immune defense. Lactobacillus rhamnose, for example, strengthens the ability of the T cell response. Lactobacillus sakei reduces the level of serum IgE and IL4. Acinetobacter iwoffii improves respiratory hyperresponsiveness by blocking the recruitment of dendritic cells in the lungs. Lactobacillus casei ATCC334 can produce iron pigment, which plays a role in inhibiting tumor progression. Some microorganisms may be also used in the treatment of hypertension, cardiovascular and other diseases. 

Bacterial biofilms (bacterial colonies self-organized in complex structures), on the other hand, can interrupt human immune system in many harmful ways. Bacteroides fragilis biofilms are implicated in destruction of mucosal epithelium, thus promoting migration of harmful species and helping them escape body's defense mechanisms. Small metabolites such as trimethylamine oxide (TMAO) produced by some gut bacteria could induce cardiac hypertrophy and fibrosis. 

Some proteases secreted by microbes are contributing to developing diseases, such as arterial sclerosis, skin disease, enteritis and cardiovascular disease and others. M. globosa (a common skin color fungi), on the other hand, secretes proteinase MgSAP1 that rapidly hydrolyses Staphylococcus protein A (SpA) and prevents S. aureus biofilm formation, helping to maintain a healthy skin. Bacteria can also secrete amino acid-derived antibiotics to fight diseases - e.g., Clostridium scindens and C. sordellii that help to inhibit the growth of C. difficile. 

The new review discusses these and many other mechanisms in complex disease as well as potential cures and dietary interventions.


Yu D, Meng X, de Vos WM, Wu H, Fang X, Maiti AK. Implications of Gut Microbiota in Complex Human Diseases. International Journal of Molecular Sciences. 2021, 22(23):12661.

Friday, December 10, 2021

Gamified Eating

Unhealthy diet is one the most important lifestyle risk factors for metabolic and physiologic changes predisposing to disease. IBS, for example, can be caused by irregular eating, physical inactivity, and quality of sleep, even though  IBS subjects usually eat more healthy foods (such as vegetables and legumes) than others. Gamification approaches to nutrition education offer advantages for preventing disease over traditional persuasion methods. Gamiļ¬cation might provide not only positive emotional feelings, but it also increases sense of immersion, facilitating learning. 

Yet, about half of existing apps don't improve health and wellbeing because they are not developed in a skilled way. 

What makes a diet best? What is the best diet for you? Every year US News calls health experts to rank popular diets and every year there are changes in ranking. 10 years ago,  the DASH diet beat out  AtkinsJenny Craig, Slim-Fast and 15 others to win the crown. It was praised as the best for combating high blood pressure. This year it's number 2, after Mediterranean diet scoring high on weight loss, heart and brain health,  diabetes and cancer prevention. For dropping those extra pounds, 10 years ago Weight Watchers ranked No. 1, followed closely by Jenny Craig and the Raw Food Diet. This year i's the Flexitarean Diet. The database has 39 diets, a small fraction of existing "eating plans" built around various personalities and lifestyles. The EAT-Lancet diet is one of those not included - it tries to balance nutrition with environmental concerns. The FODMAP diet - best for IBS - is not ranked either. 
Click here to find out more!
US News & World Report puts hard numbers on the common-sense belief that no diet is ideal for everybody. But finding out which diet is best for you could be a cumbersome task. Many apps exist but they are not sufficiently engaging or sufficiently good for your health. 
Health gamification research is progressing at a fast pace. Researchers are finding which elements the users of nutrition apps prefer. Food gamers like clear measurable goals, performance graphs, and progress bars, but seem to lack motivating elements found in non-nutrition apps - since digital "rewards",  "levels" and "leaderboards" are not sufficiently appealing.  And neither is counting calories, gameplay narratives and individual competition.  

Gamified nutrition apps show promise. Who'll design the perfect food game?
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