FOR THE FIRST TIME, GUT BACTERIA HAS BEEN SPOTTED EATING CHEMICALS IN THE BRAIN

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Scientists are finally starting to understand the gut and brain connection, and this understanding can lead to huge breakthroughs in regard to various mental disorders, and how what’s going on in the gut could actually be a culprit for many of these illnesses. Many are surprised to learn that an estimated 90% of the serotonin produced by the body actually comes from the gut! This may lead us to believe that proper nutrition, gut microbiome, and digestion might be a key component to a healthy mind.

 Recently, bacteria have been discovered in the gut that depends solely on one of the chemicals in our brains for survival. These bacteria consume a molecule known as GABA; this molecule is crucial for calming the brain. This shows directly how gut bacteria can affect our mood.

Philip Strandawitz and his colleagues from Northeastern University in Boston have recently discovered that a species of recently discovered gut bacteria, called KLE1738 could only be grown if it was provided with GABA molecules. While announcing his findings at the annual meeting of the American Society of Microbiology in Boston last month, Strandawitz said, “Nothing made is grown, except GABA.”

GABA acts by inhibiting signals from nerve cells, which calms down the activity of the brain. This is why it’s so surprising that a bacteria in the gut needs it in order to grow and reproduce. Interestingly enough, low levels of GABA are directly linked to depression and other mood disorders. The findings of this study just provide further evidence that the bacteria in our gut are directly affecting the function of our brains.

What Does This Mean For Treatment Of Depression?

An experiment performed in 2011 showed how a type of gut bacteria called Lactobacillus rhamnosus can actually alter the GABA activity in the brains of mice, as well as directly influencing how the mice are responding from stress. Researchers involved in this study found that this effect disappeared when they surgically removed the vagus nerve, linking the gut to the brain, in the mice. This suggests that it plays a role in the influence that gut bacteria have on the brain.

Now, Strandawitz is looking for other gut bacteria that consume, or alternatively produce GABA. This way he can test their effects on the brains and behavior of animals. This research may eventually lead to alternative treatments for various mood disorders including depression and anxiety.

Is It Really As Simple As Diet?

Perhaps. We can’t really say for sure, but having a healthy gut can relate to having a healthy mind. There are more and more instances being documented from people who have completely changed their diets, and the impact it has had on their mood, symptoms of depression and, believe it or not, on autism as well.

There are many different contributing factors leading to an imbalance of gut flora, which in turn can lead to various mental and physical issues. Overuse of antibiotics without taking probiotics can cause this, not being breastfed as a baby could lead to gut issues down the road, also, being born from a C-section can also cause issues later on, as the beneficial bacteria that would normally be passed to the baby during birth is bypassed. These factors and more can lead to many different ailments and allergies.

After all our guts go through, it is no surprise that many of us are struggling with so many health disorders and allergies, but having this awareness – that so much is dependent on an optimal functioning gut and digestive system – is the first step towards taking back our health!

I highly suggest the book, Medical Medium by Anthony William, where these topics are explored on a much deeper level.

Have you changed your life by changing your diet and bringing balance to your gut flora? Let us know your story!

Much Love

BRON: http://www.collective-evolution.com/2017/09/05/for-the-first-time-gut-bacteria-has-been-spotted-eating-chemicals-in-the-brain/

EM- Verenging: EM-Actief (zoals Microferm) wordt gebruikt als probiotica. Er zijn mensen die merken dat ze bij het drinken van EM-Actief minder tot geen negatieve hebben!

Your Gut Can Help Fight Depression and High Blood Pressure

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By Dr. Mercola

Trillions of bacteria live in your gut, influencing your body’s homeostasis daily. Far from being restricted to the confines of your intestinal tract, your gut microbiota is intricately tied to other body systems via a number of complex pathways, including the gut-brain axis and a recently revealed gut-brain-bone marrow axis, the latter of which may influence your blood pressure, mood and more.

It’s becoming increasingly clear that your brain, your immune system and your gut microbes are intricately linked, so it’s not a stretch to add bone marrow to the list of connections. Immune cells stem from bone marrow, and bone marrow inflammation, which may result from high blood pressure, is known to be caused by a signal from the brain. In a study published in the journal Frontiers in Physiology, researchers further revealed that immune cells in bone marrow play an important role in signaling between the brain and gut.1,2

Gut-Brain-Bone Marrow Connection Revealed

In an animal study, researchers replaced natural bone marrow in mice with bone marrow cells from genetically engineered (GE) mice. The marrow had been modified to be deficient in adrenergic receptor beta, making it less responsive to messages from the brain.

“In this way,” researchers wrote in The Conversation, “we could investigate how the host brain-immune communication will modify gut microbiota. Indeed, by studying this new mouse model, we determined that our nervous system — directed by our brain — can modify the composition of gut microbiota by communicating directly with the bone marrow immune cells. The brain, therefore, can change our gut microbiota indirectly by talking to the bone.”3

In short, when bone marrow was less able to communicate with the brain, a “muted inflammatory response” was observed in the gut, which in turn led to a more diverse (i.e., healthier) microbiome. The study shed light on one of the complex ways your gut health may be implicated in that of your heart and brain, with researchers noting:4

“In the context of cardiovascular disease, this muted inflammatory response appears to be beneficial, as it leads to beneficial lowering of blood pressure in our experimental mice.

Most interestingly, a link between gut microbiota and our mental health has recently become clearer. In particular, some have suggested that gut microbiota influence the stress and anxiety pathways in the brain in a way that can alter mood and behavior both positively and negatively, giving a whole new meaning to the term ‘gut feeling.'”

Imbalanced Gut Microbes Play a Role in High Blood Pressure

Imbalanced gut microbes, known as gut dysbiosis, have been previously linked to heart disease and high blood pressure, but a recent animal study shed further light on the unique connection.5 Researchers gave rats antibiotics for 10 days to wipe out their natural microbiota, then transplanted hypertensive microbiota into rats with normal blood pressure. Rats with high blood pressure, in turn, were transplanted with normal microbiota.6

The results were surprising in that the rats treated with hypertensive microbiota developed high blood pressure, while the transplantation of normal microbiota led to only a slight reduction in blood pressure among the hypertensive rats. “We conclude that gut dysbiosis can directly affect SBP [systolic blood pressure],” the researchers wrote, adding that manipulating gut microbiota, such as via the use of probiotics or eating fermented foods, may be an “innovative treatment for hypertension.”7

However, it’s not the first time such a link has been revealed. A systematic review and meta-analysis of nine randomized, controlled studies found significant benefits among people with high blood pressure who consumed probiotics in products like yogurt and milk.8 On average, compared to a placebo, the probiotic consumption lowered systolic blood pressure (the top number) by 3.56 mm Hg and diastolic blood pressure (the bottom number) by 2.38 mm Hg.

It appeared that at least 100 billion colony-forming units of probiotics a day were necessary to trigger such improvements, and the benefit was only seen in those who consumed probiotics for eight weeks or more. In 2015, meanwhile, certain gut microbes, namely firmicutes and bacteroidetes, were associated with increased blood pressure in rats.

“Products of the fermentation of nutrients by gut microbiota can influence blood pressure by regulating expenditure of energy, intestinal metabolism of catecholamines, and gastrointestinal and renal ion transport, and thus, salt sensitivity,” according to research published in the journal Current Opinion in Nephrology and Hypertension.9

Probiotics Found to Benefit Gut Diseases, Mental Health

The addition of beneficial microbes has been found to benefit people struggling with serious gut diseases, including necrotizing enterocolitis (NEC), which often occurs in premature infants and can be fatal. An Australian study revealed that probiotic supplementation significantly reduced NEC risk and mortality in preterm neonates, lowering the incidence of NEC in premature babies by at least 30 percent.10

Probiotics have also been found to benefit irritable bowel syndrome (IBS), of which disturbances in the gut microbiota are often seen.11Compared to placebo, probiotic therapy was found to reduce pain and symptom severity among people with IBS,12 and probiotics are also known to prevent antibiotic-associated diarrhea in children.13

On the mental front, a small study involving adults diagnosed with IBS and depression found the probiotic Bifidobacterium longum provided depression relief. At six weeks, 64 percent of the treatment group had reduced depression scores compared to 32 percent of the control group that received a placebo.14

Those receiving the probiotic also reported fewer symptoms of IBS and improved overall quality of life. At the end of 10 weeks, approximately twice as many in the treatment group were still reporting lower levels of depression.

Interestingly, functional MRI scans revealed a link between reductions in depression score and actual changes in brain activity, specifically in areas involved in mood regulation, such as the amygdala. As noted by Dr. Roger McIntyre, professor of psychiatry and pharmacology at the University of Toronto, who was not involved in the study:15

“We know that one part of the brain, the amygdala, tends to be red-hot in people with depression, and it seemed to cool down with this intervention. It provides more scientific believability that something in the brain, at a very biological level, seems to be affected by this probiotic.”

Are Personalized Probiotics the Answer?

As for which strains of probiotic are best, the answer may be harder to come by. Emma Allen-Vercoe, a microbiologist at the University of Guelph in Ontario, told Scientific American, “Bacterial strains are so genetically different from one another, and everybody has a different gut microbiota … There will probably never be a one-size-fits-all probiotic.”16

Studies suggest, for instance, that some people may benefit more from probiotics than others if they’re “low” in a certain variety that is then added to their diet. As Scientific American reported:17

“In other words, their gut ecosystems had a vacancy that the probiotic filled. That is exactly the kind of insight that clinicians need to create and recommend more effective probiotics. If a doctor knows that an individual with severe diarrhea has an undersized population of a particular beneficial microbe, for example, then prescribing the missing strain should increase the chance of a successful treatment.”

Other research has looked into the benefits of certain strains of bacteria, such as Bifidobacteria, which tend to be abundant in babies’ intestines but typically make up less than 10 percent of the gut microbiome bacteria in adults.18 Low levels of Bifidobacteria, in turn, are linked to chronic diseases like celiac disease, diabetes, allergic asthma and even obesity, while supplementing with them has been found to benefit IBS, inflammatory bowel disease, chronic fatigue syndrome, psoriasis, depression and more.19

Another type of bacteria, lactobacillus, has been shown to reduce anxiety in animal studies,20 while taking a probiotic with eight different bacterial strains reduced aggressive and ruminative thoughts in a study of adult volunteers.21,22

The Lectin Connection and How Leaky Gut Can Destroy Your Health

It’s important to be aware that gut dysbiosis, also known as leaky gut, is not only a major gut disrupter linked to digestive disorders, but may also contribute to other chronic diseases like Alzheimer’s and possibly cancer. If your gut is leaky, your blood-brain barrier is also leaky, which means toxins can go right into your brain, affecting your cognitive and mental health.

Further, leaky gut can be triggered by a number of factors, including imbalanced gut microbiota that result from dietary factors, such as the consumption of sugar as well as lectins. This latter component is very important. Lectins are plant proteins, sometimes called sticky proteins or glycan-binding proteins, because they seek out and bind to certain sugar molecules on the surface of cells. There are many types of lectins, and the main difference between them is the type of sugar each prefers and binds to.

Some — including wheat germ agglutinin (WGA), found in wheat and other grass-family seeds — bind to specific receptor sites on your intestinal mucosal cells and interfere with the absorption of nutrients across your intestinal wall.

As such, they act as “antinutrients,” and can have a detrimental effect on your gut microbiome by shifting the balance of your bacterial flora — a common precursor to leaky gut. Dr. Steven Gundry, author of “The Plant Paradox: The Hidden Dangers in ‘Healthy’ Foods That Cause Disease and Weight Gain,” makes a strong case for a lectin-free diet, stating:

“Our microbiome is, I think, our early warning system, because about 99 percent of all the genes that make up [the human body] are actually nonhuman, they’re bacterial, viral and fungal … [from which] we’ve uploaded most of the information about interacting with our environment … because the microbiome is capable of almost instantaneous changing and information processing that we actually don’t have the ability to do.

We’re beginning to realize … that the microbiome is not only how we interact with plant materials … like lectins, but probably more importantly, our microbiome teaches our immune system whether a particular plant compound is a friend or foe [based on] how long we’ve known that plant compound. There are lectins in everything.

But the longer we’ve interacted with lectins and the longer our microbiome has interacted with them, the more our microbiome kind of tells our immune system, ‘Hey, guys, it’s cool. We’ve known these guys for 40 million years. Chill out. They’re a pain, but we can handle them.’

From an evolutionary perspective, if you look at modern foods — say the grains and the beans, which we started interacting with 10,000 years ago, which is a blink of time — our microbiome [regards them as] foreign substances … [T]here’s no lectin speed dating in evolution.”

Lectins are strongly associated with autoimmune disorders of all kinds, primarily by triggering leaky gut. They’re found in many of our most cherished foods, such as:

Potatoes Eggplants Tomatoes Peppers Goji berries Lima beans
Cashews Peanuts Sunflower seeds Chia seeds Pumpkin seeds Kidney beans
Squash Corn Quinoa Soybeans Wheat Lentils

In addition, according to Gundry, glyphosate, which is not only sprayed on GE crops via Roundup but also is used to desiccate wheat in the U.S., is also highly problematic, decimating your microbiome and increasing leaky gut. It’s yet another reason to eat organic as much as possible.

To learn more, I highly recommend picking up a copy of “The Plant Paradox,” especially if you’ve already cleaned up your diet and still struggle with excess weight and/or health problems. Certainly, anyone with an autoimmune disorder would also be wise to take a closer look at lectins.

How to Support a Healthy Microbiota

Supporting your microbiome isn’t very complicated, but you do need to take proactive steps to encourage its health while avoiding factors known to cause harm. In addition to the lectin information above, consider the following recommendations to optimize your microbiome:

Do Avoid
Eat plenty of fermented foods. Healthy choices include lassi, fermented grass fed kefir, natto (fermented soy) and fermented vegetables. Antibiotics, unless absolutely necessary, and when you do, make sure to reseed your gut with fermented foods and/or a high-quality probiotic supplement.
Take a probiotic supplement. Although I’m not a major proponent of taking many supplements (as I believe the majority of your nutrients need to come from food), probiotics are an exception if you don’t eat fermented foods on a regular basis Conventionally-raised meats and other animal products, as CAFO animals are routinely fed low-dose antibiotics plus GE grains loaded with glyphosate, which is widely known to kill many bacteria.
Boost your soluble and insoluble fiber intake, focusing on vegetables, nuts and seeds, including sprouted seeds. Chlorinated and/or fluoridated water. Especially in your bathing such as showers, which are worse than drinking it.
Get your hands dirty in the garden. Exposure to bacteria and viruses can help to strengthen your immune system and provide long-lasting immunity against disease.

Getting your hands dirty in the garden can help reacquaint your immune system with beneficial microorganisms on the plants and in the soil.

Processed foods. Excessive sugars, along with otherwise “dead” nutrients, feed pathogenic bacteria.

Food emulsifiers such as polysorbate 80, lecithin, carrageenan, polyglycerols and xanthan gum also appear to have an adverse effect on your gut flora.

Unless 100 percent organic, they may also contain GMOs that tend to be heavily contaminated with pesticides such as glyphosate. Artificial sweeteners have also been found to alter gut bacteria in adverse ways.23

Open your windows. For the vast majority of human history, the outside was always part of the inside, and at no moment during our day were we ever really separated from nature.

Today, we spend 90 percent of our lives indoors. And, although keeping the outside out does have its advantages it has also changed the microbiome of your home.

Research shows that opening a window and increasing natural airflow can improve the diversity and health of the microbes in your home, which in turn benefit you.24

Agricultural chemicals, glyphosate (Roundup) in particular is a known antibiotic and will actively kill many of your beneficial gut microbes if you eat foods contaminated with it.
Wash your dishes by hand instead of in the dishwasher. Research has shown that washing your dishes by hand leaves more bacteria on the dishes than dishwashers do, and eating off these less-than-sterile dishes may actually decrease your risk of allergies by stimulating your immune system. Antibacterial soap, as it too kills off both good and bad bacteria and contributes to the development of antibiotic resistance.

Bron:  http://wakingtimesmedia.com/gut-can-help-fight-depression-high-blood-pressure/

Small study shows probiotics can beat back depression

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In March of this year, researchers showed that a probiotic found in yogurt was able to reverse symptoms of anxiety and depression in mice. Now, in a small study involving 44 adults, investigators at McMaster University in Canada have shown a different probiotic can have the same effect in humans.

Increasingly, scientists are exploring the link between our guts and our brains, and finding that the two are very much linked. Earlier this year, researchers found that they could alter the gut microbiota by beaming people’s’ brains with magnetism, and last year, a study indicated that certain molecules in the gut can inhibit inflammation it the brain.

The McMaster research focussed on individuals with irritable bowel syndrome (IBS) which, the university says, is the most common gastrointestinal disorder in the world. The study split 44 adults into two groups. One group took the probiotic Bifidobacterium longum every day for ten weeks, while the other group took a placebo.

At six weeks, in the group taking the probiotic, 14 out of 22 participants (64 percent) had a lower depression score than the group taking the placebo. What’s more, the researchers saw changes in brain areas associated with depression in the probiotic group when they observed them using functional MRI (fMRI) scans.

“The fMRI study showed decreased activity in the amygdala and other fronto–limbic regions of the brain, which are known to be involved in the control of mood, in the patients taking with probiotics compared to those taking placebo,” Premysl Bercik told us. Bercik is an associate professor of medicine at McMaster and senior author on the study.

Of course, one theory is that the symptoms of depression went away in the study subjects taking the probiotic because their IBS symptoms also improved. So we asked Bercik about that, and he said that the effects of the probiotic treatment on mood lasted longer than the effects on the IBS symptoms – longer than the treatment was carried out, in fact.

“You are right,” he told us, “the patients on probiotics also reported improvement in their IBS symptoms (adequate relief of symptoms) at the end of the probiotic treatment, but not four weeks later when the beneficial effect on depression was still present. So one can argue that the primary effect of this probiotic is on depression. Also, the amygdala is one of the important centers in processing abdominal pain so if the probiotic altered the function of this brain region, it could also improve the gut symptoms of IBS (the pain is the hallmark symptom of IBS).”

The study, which was carried out in conjunction with scientists from food giant Nestlé, has been published in the journal Gastroenterology.

Source: McMaster University

BRON: http://newatlas.com/probiotics-fight-depression/49693/

Baanbrekend onderzoek onthult reden voor agressief en asociaal gedrag

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boze man - pixabay.com

(Nine for news) Canadese onderzoekers hebben een baanbrekende studie gepubliceerd waaruit blijkt dat lage doses penicilline kunnen resulteren in gedragsveranderingen.

Muizenbaby’s die tijdens de laatste week van de zwangerschap en de eerste weken na de geboorte penicilline kregen, vertoonden op latere leeftijd agressief gedrag en waren minder sociaal en minder angstig.

Toen de muizen de melkzuurbacterie Lactobacillus kregen, had het antibioticum geen invloed op hun gedrag.

Probiotica
Er zijn steeds meer zorgen over de langetermijneffecten van antibiotica, aldus hoofdonderzoeker John Bienenstock van de McMaster University.

“Uit ons onderzoek blijkt dat probiotica de nadelige effecten van penicilline kunnen voorkomen,” zei hij.

Andere studies hebben al aangetoond dat antibiotica het gedrag van dieren kunnen beïnvloeden.

Vrijwel geen
“Er zijn vrijwel geen baby’s in Noord-Amerika die in hun eerste levensjaar nog geen antibioticakuur hebben gehad,” zei dr. Bienenstock.

“Antibiotica worden niet alleen voorgeschreven, maar ook gevonden in vlees en zuivelproducten,” vervolgde hij.

Als moeders de effecten van deze medicijnen overdragen op hun kinderen, kunnen we ons afvragen wat de langetermijneffecten van de consumptie van antibiotica zijn, aldus Bienenstock.

Obesitas
Na een studie uit 2014 werden er ook al zorgen geuit over het gebruik van antibiotica toen bleek dat muizen die penicilline kregen vatbaarder waren voor obesitas.

Het onderzoeksteam gaat nu kijken wat de effecten zijn als enkel de zwangere muizen penicilline krijgen toegediend.

De onderzoekers gaan ook bestuderen welke bacteriën de muizenbaby’s kunnen beschermen tegen gedragsveranderingen als gevolg van antibioticagebruik.

Het onderzoek is gepubliceerd in het tijdschrift Nature Communications.
Bron: EarthmattersNine for NewsNewswise

 

Microbes may encourage altruistic behavior

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(Left) The payoff matrix and (right) an illustration of horizontal transmission probability of microbes between hosts. Using this model, researchers have found that microbes may induce their hosts to help other hosts, benefitting the microbes and the other hosts, but not always the original hosts. Credit: Lewin-Epstein et al. Nature Communications

(Phys.org)—Why do people commonly go out of their way to do something nice for another person, even when it comes at a cost to themselves—and how could such altruistic behavior have evolved? The answer may not just be in our genes, but also in our microbes.

In a new paper, researchers Ohad Lewin-Epstein, Ranit Aharonov, and Lilach Hadany at Tel-Aviv University in Israel have theoretically shown that could influence their hosts to act altruistically. And this influence could be surprisingly effective, with simulations showing that microbes may promote the evolution of altruistic behavior in a population to an even greater extent than do.

“I believe the most important aspect of the work is that it changes the way we think about altruism from centering on the animals (or humans) performing the altruistic acts to their microbes,” Hadany told Phys.org.

It’s already well-known that microbes can affect the behavior of their hosts, with a prime example being how the rabies virus increases aggressive behavior in infected individuals. Research has also shown that the microbiome—the community of microorganisms that inhabit our gut—can even manipulate the hosts’ social behavior by infecting neurons and altering neurotransmitter and hormone activity.

Against this backdrop, the researchers in the new study have proposed that microbes may induce a person to help others because the close physical contact (for example, food-sharing, co-sheltering, and grooming) increases the transmission of the microbes from one person to another. So when someone does something nice for us, we are not just the recipient of a kind act, but also of their microbes.

To show that this idea can have a prevailing effect on a population over time, the researchers designed simulations of interacting individuals, some with altruism-inducing microbes, and some without. Then using a prisoner’s dilemma payoff scheme, the researchers investigated what happens to this population, its microbes, and its altruistic behavior over many generations.

The results showed that, as long as horizontal transmission (between individuals) of microbes is allowed, altruism-inducing microbes can take over the population, leading to microbe-induced altruism. This result occurs even when only a very small percentage of the initially carries these altruism-inducing microbes. The simulations also revealed that the evolution of altruism is successful because the microbes have a chance to either meet genetically related microbes in the recipient or infect and transform some of the recipient’s microbes into relatives.

In a variation of this model in which altruism can also be induced by host genes, the researchers found that genetically encoded altruism does not evolve, but microbe-induced altruism continues to evolve whether or not genetic factors are present. Further simulations showed that, although there are some cases in which altruism encoded in genes can persist, microbe-induced persists more often. Overall, the results suggest that microbes may play a dominant and previously overlooked role in the evolution of altruistic behavior.

If microbes do exert such large sway on altruistic behavior, then it raises other intriguing questions, such as whether antibiotics, probiotics, and foods affecting the microbiome may influence the of their hosts. In the future, the researchers plan to address these possibilities, as well as to test the theory.

“We are now collaborating with experimental biologists in order to empirically validate the predictions of our theory,” Hadany said.

BRON: https://phys.org/news/2017-01-microbes-altruistic-behavior.html

 

Fat or thin: can the bacteria in our gut affect our eating habits and weight?

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Our gut does more than help us digest food; the bacteria that call our intestines home have been implicated in everything from our mental health and sleep, to weight gain and cravings for certain foods. This series examines how far the science has come and whether there’s anything we can do to improve the health of our gut.


When we can’t lose weight, we tend to want to blame something outside our control. Could it be related to the microbiota – the bacteria and other organisms – that colonise your gut?

You are what you eat

Our gut harbours some trillion microorganisms. These are key in harvesting energy from our food, regulating our immune function, and keeping the lining of our gut healthy.

The composition of our gut microbiota is partly determined by our genes but can also be influenced by lifestyle factors such as our diet, alcohol intake and exercise, as well as medications.

What is the human microbiome?

The bacteria in the gut obtain energy for growth when we metabolise nutrients from food. So our diet is a crucial factor in regulating the type of bacteria that colonise our gut.

One key role of the gut microbiota is degrading the carbohydrates we can’t digest into short-chain fatty acids. These help regulate our metabolism and are also important for keeping our colon cells healthy.

Changes in our diet can rapidly change the gut microbiota. Generally, a high-fibre diet which is low in saturated fat and sugar is associated with a healthier gut microbiome, characterised by a greater diversity of organisms.

On the other hand, diets high in saturated fat and refined sugars with low fibre content reduce the microbial diversity, which is bad for our health.

Our animal studies have shown that consuming an unhealthy diet for only three days a week has detrimental effects on the gut microbiota, even when a healthy diet is eaten for the other four days.

This may be because the gut microbiota are under selective pressure to manipulate the hosts’ eating behaviour to increase their own fitness. This may lead to cravings, akin to your system being “hijacked” by your microbiota.

Can gut microbiota changes lead to obesity?

Bacteria in humans fall into two major classifications: bacteroidetes and firmicutes. Obesity is associated with a reduction in the ratio of bacteroidetes to firmicutes but weight loss can reverse this shift.

Many studies have found that the gut of an obese person is more likely to contain bacteria that inflame the gastrointestinal tract and damage its lining. This allows the bacteria in the gut to escape.

The gastrointestinal tract. Christos Georghiou/Shutterstock

We still don’t know definitively if changes in the gut microbiota from an unhealthy diet can contribute to obesity. Most evidence supporting this hypothesis comes from animal studies; for instance, the transfer of faecal material from an obese human can lead to weight gain in a recipient mouse.

One possibility is that the obese microbiota may be more efficient in harvesting energy, in part, by influencing the host to eat foods which favour its growth. This could ultimately contribute to weight gain.

Gut changes after weight-loss surgery

Bariatric surgeries such as gastric bypass, are one of the most effective treatments for obesity because they reduce the size of the stomach. This limits how much food can be eaten and has also been shown to promote the release of hormones which make us feel full.

But other factors may be involved. Intriguingly, some patients report a shift in food preference away from energy-dense foods after surgery. This may contribute to the success of the procedure.

Gastric bypass-induced weight loss has also been associated with increased diversity of the gut microbiota. But how much this contributes to the success of the procedure remains to be determined.

One possibility is that the changes in food preferences reported in bariatric patients may relate to changes in the composition of their gut microbiota.

How gut microbiota affect our behaviour

Apart from regulating gut health, there is compelling experimental evidence that gut microbiota play a role in regulating mood.

Several studies have shown that depression is associated with changes in the gut microbiome of humans.

Depressed patients showed changes in their abundance of firmicutes, actinobacteria and bacteroidetes. When these patients’ gut microbiota was transferred to mice, the mice showed more depressive behaviour than mice that received biota from healthy people.

More work still needs to be done as it is unclear whether this may indicate a causal relationship, or be related to other factors associated with depressive disorders such as a poor diet, changed sleep patterns and drug treatment.

Emerging evidence suggests that gut microbiota can influence other behaviours through the “microbiota-gut-brain axis”. Put simply, the gut and the brain communicate in part via the microbiota, which links the emotional and cognitive centres of the brain with our intestinal functions.

Recent work from our lab showed that rats consuming diets high in saturated fat or sugar, for just two weeks, had impaired spatial memory. These rats consumed the same amount of energy as the control rats (those on a regular diet) and were also a similar body weight.

We found that the memory deficits were associated with changes in the gut microbiota composition and genes related to inflammation in the hippocampus, which is a key brain region for memory and learning.

Similar memory deficits have also been reported when healthy mice were transplanted with microbiota from overweight mice who had been fed a high-fat diet.

Together, studies such as these suggest the gut microbiota could play a causal role in regulating behaviour. This may, in part, be due to the different microbiota profiles influencing the production of key transmitters such as serotonin.

What can you do now?

Further research is needed into the relationship between poor diet, the gut microbiota and behavioural changes. In the long term, such knowledge may be harnessed to develop targeted therapeutic interventions to replace relevant microbiota diminished by an unhealthy lifestyle.

Meanwhile, the good news is that the gut microbiota can change relatively quickly and we have the capacity to promote the growth of beneficial bacteria which may ultimately improve a range of health outcomes. Eating a healthy diet of unprocessed foods, including adequate fibre, avoiding excess alcohol and getting enough exercise are key.

BRON: http://theconversation.com/fat-or-thin-can-the-bacteria-in-our-gut-affect-our-eating-habits-and-weight-65103

Depressed? Anxious? What If Your Bacteria Are Playing a Part?

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unnamed

The fascinating world of the gut-brain axis.

Although we’re used to science advancing at the speed of light these days, it hasn’t always been like this.

Take the Greek physician Hippocrates, for example, born around 460 BC.

He proposed that the human body contained four fluids or “humors”—blood, phlegm, yellow bile, and black bile, usually in balance.

When one of them became more or less present, illness could ensue.

He believed that an excess of black bile, for example, could cause someone to become melancholic.

What we now call depressed.

In fact the term “melancholic” comes from the ancient Greek words “melas” and “kholé”, meaning black bile.

This theory of “humorism,” certainly nothing to do with comedy, stuck around for almost 2,000 years.

Jumping ahead to the 19th century, many scientists argued that a buildup of waste matter in the colon could trigger something they called “auto intoxication”, poisoning the gut and producing infections linked with depression, anxiety and psychosis.

So if you were depressed in those days you might get treated with a colonic purge, which doesn’t exactly sound like something guaranteed to put a smile on your face.

This poisoning idea was eventually dismissed as quackery after direct observation of the colon during surgery and autopsies showed zero evidence for hardened feces accumulating on the walls of the intestine.

However, although it’s clear that both of these schools of thought were distinctly not on the right track, there’s increasing (and exciting) evidence of a very real connection between the gut and the brain.

You see, it’s now widely believed that there is a “gut-brain axis”, which is in fact a two-way street.

Your brain acts on your gut, shaping its microbial makeup, while your gut is busy manufacturing neurotransmitters including dopamine, gamma-aminobutyric acid (GABA) and serotonin.

In fact the vast majority of your serotonin originates in your intestine.

Talk about gut feelings, eh?

There have been many remarkable experiments showing ways in which the function of the brain can be affected by the gut microbiome.

Nobuyki Sudo and colleagues at Japan’s Kyushu University published pioneering work in 2004 by experimenting with mice that had been specially bred to be germ-free giving them, effectively, sterile guts.

When these mice were placed in a tube that restricted their movement, their levels of stress hormones became far higher than those of mice in the same situation whose microbiomes were not germ-free.

Fascinatingly, the scientists were able to re-engineer these germ-free mice, turning them into relaxed rodents simply by adding one species of bacteria to their guts: Bifidobacterium infantis (now viewed as a subspecies of Bifidobacterium longum) which is one of the very first types of bacteria acquired by a baby, particularly one born vaginally.

The amazing studies kept coming.

Researchers at McMaster University in Ontario were able to change the behavior of germ-free mice by colonizing their intestines with bacteria from other mice—giving them what you might call a poop-personality transplant.

This led naturally daring mice to become apprehensive and shy, for example, leading scientists to suggest that microbial interactions with the brain could induce psychological change.

Although some are understandably uncomfortable with experiments such as these, other researchers from McMaster later joined forces with scientists from University College Cork to show that mice fed a broth containing Lactobacillus rhamnosus were far less likely to relapse into “behavioral despair” when dropped into a tall cylinder, from which there was no escape, than mice without these microbes.

The same experiment has been used to test antidepressants, leading one scientist to suggest that the broth-fed mice were behaving as though they were on Prozac.

Lactobacillus rhamnosus is a bacterium commonly found in the human body, and also used in the fermentation of milk as it is turned into yogurt.

It hasn’t all been about mice, however.

A 2013 proof-of-concept study at UCLA showed through fMRI scans that women who ate yogurt containing active probiotics twice a day for a month showed a reduced reflexive response to photos of actors with frightened or angry faces.

The researchers warned that their results were rudimentary, but there was at least an indication that consumption of probiotic bacteria such as Bifidobacterium animalis subsp Lactis, Streptococcus thermophiles, Lactobacillus bulgaricus, and Lactococcus lactis subsp Lactis could have been making the participants less prone to anxiety.

Another study, in Norway in 2014, found significant correlations between bacteria in stool samples and depression, with elevated levels of the order Bacteroidales and a reduced abundance of the family Lachnospiraceae.

Advances in the mental health/microbiota world are certainly moving faster than the science of Hippocrates’ day, but there’s still a lot of work to be done.

It’s an area of great promise, though.

Who knows?

When the bottom’s fallen out of your world, the day may come when microbes, delivered in various ways, are used instead of standard prescription medicines.

Have a great week!
Alexandra 🙂

Alexandra Carmichael
Director of Product, Community, and Growth
uBiome

Bron: uBiome nieuwsbrief