Small study shows probiotics can beat back depression


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


Baanbrekend onderzoek onthult reden voor agressief en asociaal gedrag


boze man -

(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.

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.

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


Healthier gut bacteria and weight loss achieved through magnetic brain stimulation


For several years now, researchers have been building on a series of studies that have displayed links between non-invasive, deep Transcranial Magnetic Stimulation (dTMS) and reduced food cravings. Now, for the first time, research has shown that dTMS can fundamentally alter the composition of gut microbiota, resulting in both weight loss and general improvements in other metabolic and hormonal factors.

Transcranial Magnetic Stimulation has shown promise in recent years for a variety of applications, from boosting memory function to treating migraines. The technique involves firing magnetic pulses into particular regions of the brain to alter the activity of certain neurons. The process is currently approved for use in the United States to treat major depression.

Following on from studies that showed how an imbalance in gut bacteria altered the brain signals for appetite, a team at the IRCCS Policlinico San Donato and University of Milan set out to examine how dTMS could effect the composition of a subject’s gut microbiota.

The study involved 14 subjects split into two groups. One group received 15 dTMS sessions over five weeks, targeting the insula and prefrontal cortex, while the other group was the control, receiving a sham simulation.

As well as analyzing the subjects’ gut microbiota through stool samples both before and after the trial, the team measured blood levels of insulin, pituitary gland hormones, glucose and a neurotransmitter called norepinephrine, which is known to affect microbiota composition.

The research team noted significant differences between the dTMS subjects and the control group after five weeks, with the dTMS subjects losing more than three percent of their total body weight and more than four percent of their fat.

Most interestingly, the stool samples showed that the dTMS subjects had greatly altered gut microbiota composition, including higher levels of several beneficial bacteria associated with anti-inflammatory properties and a general improvement in certain hormonal parameters. The control group receiving the sham stimulations were noted as having no clinically relevant changes in any of these areas.

“These changes suggest a beneficial effect of dTMS on both weight loss and change in microbiota composition,” says Professor Livio Luzi, head of the research. “Our research shows the innovative ability of dTMS in exerting anti-obesity effects through alteration of the gut-brain axis.”

The “gut-brain axis” is hot area of research at the moment, with scientists discovering the degree of interaction between brain function and gut bacteria to be significantly more complex and comprehensive than previously known. This is the first time researchers have shown that the gut microbiota can be altered through magnetic brain stimulation and it paves the way for fascinating new therapeutic interventions to battle obesity in the future.

The research will be presented on Sunday April 9th at ENDO 2017, the Endocrine Society’s 99th annual meeting.

Source: The Endocrine Society

Onze bron:

Can microbes make us better people?


Why did human beings evolve to be nice to one another? From a scientific standpoint, it doesn’t make much sense for us to go out of our way to help others, especially when we don’t receive any direct benefit. But new research suggests there may be an evolutionary reason that kindness exists, and it may have more to do with microbes than genetics.

Most theories that attempt to explain the evolution of altruism focus on the individual; some people see the benefit of helping the community to help their own species. These theories assume that altruism is genetically encoded — that some people just have bigger hearts than others, and that quality is determined by the genes passed down to them. But a new study has found that altruism may have less to do with the kindness in someone’s heart and more to do with the number of microbes in their gut.

Researchers at Tel-Aviv University in Israel recently took a look at the role that microbes play in human behavior to determine the evolutionary benefit of altruistic behavior. We already know that viruses and bacteria can change a host’s behavior. Rabies, for example, can make an individual more aggressive. There are certain parasites that can cause their insect hosts to commit suicide, and there are types of plasma that can manipulate their bacterial hosts into cooperating with one another.

The new study, which was published in a recent issue of Nature, proposed that microbes could make humans act altruistically, meaning it’s microbes that explain and determine the evolution of human kindness.

How the researchers reached this conclusion

Using a series of computer models, researchers tested a number of scenarios involving interactions between humans, some with altruism-inducing microbes and others without. They found that humans could not only be influenced by microbes to act altruistically, but that doing so would help promote the transfer of these microbes from one individual to another. In other words, microbes may make their human hosts act altruistically to give the microbe a better chance of spreading to the new host. That’s evolution.

Researchers also compared the altruism-inducing microbe theory with the possibility that niceness is simply encoded in our genes. In these models, they found that genetically-encoded altruism would not evolve over time as it would with a microbial influence. They also noted that while genetic kindness could persist from generation to generation, microbe-induced niceness is much more likely to spread to the next generation.

“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,” Dr. Lilach Hadany, a researcher of population genetics and evolution theory at Tel Aviv University and a lead researcher for the study, told

The microbial theory explains why altruism tends to “spread” within a community. One act of kindness often causes a snowballing of such acts within a population. That wouldn’t be caused by genetics, but it does make sense when you consider the possibility that altruism is caused by microbes.

Can microbes make us better people? It’s certainly possible. And if we have to “catch” something while interacting with another human being, wouldn’t it be nice if that something was a dose of kindness?


Microbes may encourage altruistic behavior


(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

(—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

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.



Zeer geslaagd eerste internationaal congres over invloed darmbacteriën op hersenaandoeningen

Cyber brain

Cyber brain

Darmbacteriën hebben de potentie om een rol te spelen bij de behandeling van verschillende hersenaandoeningen en de klachten die ermee samenhangen. Dat is een van de conclusies van de eerste editie van het Mind, Mood & Microbes congres dat op 1 en 2 december in Koninklijk Instituut voor de Tropen plaats vond. Meer dan 250 internationale en Nederlandse specialisten kwamen samen om kennis uit te wisselen over de connectie tussen de darm en de hersenen.Er was veel animo voor het Mind, Mood & Microbes congres. Meer dan 250 neurowetenschappers, gastro-enterologen, microbiologen, psychiaters, psychologen, immunologen en scheikundigen kwamen samen om de laatste stand van zaken te bespreken op het gebied van de invloed van de darmbacteriën (darmmicrobiota) op de mentale gezondheid. Op donderdag en vrijdag waren er lezingen en posterpresentaties en op vrijdag was er een interactieve brainstormsessie over de potentie van micro-organismen bij de behandeling van depressie, autisme en Parkinson.

Prof dr. Sommer (UMC Utrecht) gaf tijdens haar lezing aan dat mensen met Parkinson, bipolaire stoornis, Multiple sclerose, Alzheimer, Gilles de la Tourette, Schizofrenie, Huntington’s disease, hersenschade door trauma, obsessieve compulsieve stoornissen (OCD) en andere neurologische en psychiatrische aandoeningen vaak kampen met gemeenschappelijke klachten. Moeheid, stemmingsproblemen, sociale isolatie, problemen in de omgang en cognitieve problemen hebben voor patiënten een grote impact op het functioneren en de kwaliteit van leven. Gemeenschappelijke klachten die door preventie en interventies mogelijk zijn te voorkomen en behandelen. Een belangrijke rol kan daarbij zijn weggelegd voor de zogeheten ‘psychobiotica’, probiotische bacteriën met een effect op het gedrag en de hersenfunctie.

Prof. dr. Cryan (Cork, Ierland) vertelde tijdens zijn lezing hoe de bacteriën in onze darm mogelijk een deel van de klachten veroorzaakt. Deze gedachte wordt ondersteund door verschillende muisstudies waaruit blijkt dat het toevoegen of weglaten van bepaalde bacteriën invloed heeft op het gedrag en de gemoedstoestand van de muis.

Dat bacteriën in onze darm rechtstreeks de hersenen kunnen beïnvloeden, werd duidelijk tijdens de lezingen van Dr. Chevalier uit Parijs en Dr. Wolf uit Duitsland. Zij zagen binnen hun onderzoek dat stoffen die darmbacteriën produceren een direct effect hebben op de aanmaak van hersencellen bij de behandeling en het ontstaan van depressie. Sarah Dash van de IMPACT-studie in Melbourne (Australië) haakte hierop in door toe te lichten hoe belangrijk het juiste dieet is bij het behandelen van depressie. Uit een interventiestudie kwamen de eerste positieve resultaten dat een weinig bewerkt, mediterraan dieet met veel groente zou kunnen helpen bij de behandeling van major depressie.

Prof dr. Dinan (Cork, Ierland) opende de vrijdagochtendsessie door te melden dat er een verminderde rijkheid en diversiteit aan darmbacteriën gevonden wordt bij mensen met een depressie. Gezonde bacteriën, probiotica zullen volgens hem vooral een toevoeging zijn op de behandeling en zullen medicijnen niet volledig kunnen vervangen. Dinan: “Je zou met speciale probiotica de darmmicrobiota kunnen manipuleren zodat iemand met een hersenziekte beter reageert op medicatie.” Dr. Laura Steenbergen liet tot slot zien, dat er bij een studie in Leiden met gezonde vrijwilligers een verbetering te zien was op de vatbaarheid voor depressie na het toedienen van vier weken met een specifiek probioticum.

Tijdens de brainstormsessies, een zogenaamd World Café waarbij acht verschillende specialisten aan een ronde tafel met elkaar in dialoog gaan, bleek hoe verbindend het Mind, Mood & Microbes congres was. Het congres bracht verschillende wetenschappelijke en klinische disciplines dichter bij elkaar, wat uiteindelijk zou kunnen leiden nieuwe mogelijkheden voor de toepassing van voeding, probiotica en prebiotica bij verschillende hersenaandoeningen. De eerste stap is gezet!