1. Study suggests social phobia may be affected by genes

    March 14, 2017 by Ashley

    From the University of Bonn press release:

    People with social anxiety avoid situations in which they are exposed to judgment by others. Those affected also lead a withdrawn life and maintain contact above all on the Internet. Around one in ten people is affected by this anxiety disorder over the course of their life. Researchers at the University of Bonn have now found evidence for a gene that is believed to be linked to the illness. It encodes a serotonin transporter in the brain. Interestingly, this messenger suppresses feelings of anxiety and depressiveness. The scientists want to investigate this cause more precisely and are thus looking for more study participants. The results will be published in the journal Psychiatric Genetics.

    Heart palpitations, trembling and shortness of breath: those who suffer from social phobia avoid larger groups. Verbal tests or everyday arrangements are filled with fear — after all, other people could make a negative judgement. Those affected often avoid such situations for this reason. Contact is often easier over social media or anonymously over the Internet. Social phobias are among the psychiatric disorders that are triggered simultaneously by genetic and environmental factors. “There is still a great deal to be done in terms of researching the genetic causes of this illness,” says Dr. Andreas Forstner from the Institute of Human Genetics at the University of Bonn. “Until now, only a few candidate genes have been known that could be linked to this.”

    Individual base pairs can vary in the DNA

    Together with the Clinic and Policlinic for Psychosomatic Medicine and Psychotherapy at the University Hospital Bonn, Dr. Forstner is conducting a study into the genetic causes of social phobia. The research team investigated the DNA of a total of 321 patients and compared it with 804 control individuals. The focus of the scientists lay on what are known as single nucleotide polymorphisms (SNPs). “There are variable positions in the DNA that can exist to various degrees in different people,” explains Dr. Forstner.

    The cause of genetic illnesses often lies in the SNPs. It is estimated that more than thirteen million such changes exist in the human DNA. The scientists investigated a total of 24 SNPs that are suspected in the widest sense of being the cause of social phobias and other mental disorders. “This is the largest association study so far into social phobia,” says associate professor (Privatdozent) Johannes Schumacher from the Institute of Human Genetics at the University of Bonn.

    Patients provided information about their symptoms

    Over the course of the study, scientists at the Clinic and Policlinic for Psychosomatic Medicine and Psychotherapy at the University Hospital Bonn will ask the patients about their symptoms and the severity of their social phobia. Their DNA is also examined using a blood sample. Whether there is a link between the signs of the illness and the genes is being investigated by the scientists using statistical methods. The evaluation of the previously collected data indicated that an SNP in the serotonin transporter gene SLC6A4 is involved in the development of social phobia.

    This gene encodes a mechanism in the brain that is involved in transporting the important messenger serotonin. This substance suppresses, among other things, feelings of fear and depressive moods. “The result substantiates indications from previous studies that serotonin plays an important role in social phobia,” says associate professor (Privatdozent) Dr. Rupert Conrad from the Clinic and Policlinic for Psychosomatic Medicine and Psychotherapy. Medications that block serotonin reuptake and increase the concentration of the messenger in the tissue fluid in the brain have already long been used to treat anxiety disorders and depression.

    Subjects can participate in expanded study

    The scientists now want to investigate more closely what the links are between the DNA and social phobia. “In order to achieve this goal, we need many more study participants who suffer from social anxiety,” says the psychologist and study coordinator Stefanie Rambau from the Clinic and Policlinic for Psychosomatic Medicine and Psychotherapy at University Hospital Bonn. Information about the study is available at http://www.SocialPhobiaResearch.de. “Those who take part will help to research social phobia. This is the basis of better diagnosis and treatment procedures in the future,” says Stefanie Rambau.


  2. Married people have lower levels of stress hormone

    February 15, 2017 by Ashley

    From the Carnegie Mellon University media release:

    couple on dateStudies have suggested that married people are healthier than those who are single, divorced, or widowed. A new Carnegie Mellon University study provides the first biological evidence to explain how marriage impacts health.

    Published in Psychoneuroendocrinology, the researchers found that married individuals had lower levels of the stress hormone cortisol than those who never married or were previously married. These findings support the belief that unmarried people face more psychological stress than married individuals. Prolonged stress is associated with increased levels of cortisol which can interfere with the body’s ability to regulate inflammation, which in turn promotes the development and progression of many diseases.

    “It’s is exciting to discover a physiological pathway that may explain how relationships influence health and disease,” said Brian Chin, a Ph.D. student in the Dietrich College of Humanities and Social Sciences’ Department of Psychology.

    Over three non-consecutive days, the researchers collected saliva samples from 572 healthy adults aged 21-55. Multiple samples were taken during each 24-hour period and tested for cortisol.

    The results showed that the married participants had lower cortisol levels than the never married or previously married people across the three day period. The researchers also compared each person’s daily cortisol rhythm — typically, cortisol levels peak when a person wakes up and decline during the day. Those who were married showed a faster decline, a pattern that has been associated with less heart disease, and longer survival among cancer patients.

    These data provide important insight into the way in which our intimate social relationships can get under the skin to influence our health,” said laboratory director and co-author Sheldon Cohen, the Robert E. Doherty University Professor of Psychology.


  3. ‘Tis better to give, to your spouse

    February 12, 2017 by Ashley

    From the University of Rochester media release:

    presentsWe’ve all heard that it’s better to give than to receive. Now there’s empirical evidence to show that being compassionate to a spouse is rewarding in and of itself.

    Psychologists have found that the emotional benefits of compassionate acts are significant for the giver, whether or not the recipient is even aware of the act. For example, if a husband notices that the windshield on his wife’s car is covered with snow, he may scrape it off before driving to work. That gesture would boost his emotional well-being, regardless of whether his wife notices.

    Harry Reis, a professor of psychology at the University of Rochester, led a research team that studied 175 North American newlywed husbands and wives who were married an average of 7.17 months. The results have been published in the journal Emotion.

    Our study was designed to test a hypothesis put forth by Tenzin Gyatso, the current Dalai Lama,” said Reis, “that compassionate concern for others’ welfare enhances one’s own affective state.”

    The team of psychologists, which included Ronald Rogge of Rochester and Michael Maniaci of Florida Atlantic University, asked participants to keep a two-week daily diary to record those instances in which either spouse put aside personal wishes in order to meet the partner’s needs. But the researchers also needed to assess the emotional well-being of the individuals. To that end, the participants kept track of their daily emotional states for each day based on 14 positive and negative terms — such as enthusiastic, happy, calm, sad, angry, and hurt.

    Over the course of the 14 days, husbands and wives reported giving and receiving an average of .65 and .59 compassionate acts each day — with husbands perceiving more such acts than did their partners. The acts included such things as changing personal plans for the partner’s sake, doing something that showed the partner was valued, and expressing tenderness for the spouse.

    Before the study, the researchers predicted that the greatest impact on the donor would come when the act was recognized by the recipient, because recognition would make the donor feel valued. They also thought the recipient would feel the most benefit when the act was mutually recognized, as opposed to those times when one partner perceived a compassionate act that wasn’t actually intended. While those predictions were confirmed, the researchers discovered something else.

    “Clearly, a recipient needs to notice a compassionate act in order to emotionally benefit from it,” said Reis. “But recognition is much less a factor for the donor.”

    The psychologists discovered that donors benefit from compassionate acts, regardless of whether the recipient explicitly notices the acts. And in those cases, the benefits for the donors was about 45 percent greater than for the recipients, as determined by the self-assessment scales in the daily diaries, with the effect being equally strong for men and women.

    For Reis, the results suggest that “acting compassionately may be its own reward.

    Reis is now working with Rochester alum Peter Caprariello, an assistant professor of marketing at Stony Brook University, to study the emotional benefits of spending money on others. Their work suggests that spending on others can make a person feel better, but only when the goal is to benefit that person. Spending to impress them with generosity or vision doesn’t do the trick.


  4. Depression as hard on the heart as obesity and cholesterol

    January 23, 2017 by Ashley

    From the Helmholtz Zentrum München – German Research Center for Environmental Health media release:

    Depression poses a risk for cardiovascular diseases in men that is just as great as that posed by high cholesterol levels and obesity. This is according to a report recently published in the Atherosclerosis journal by researchers from the Helmholtz Zentrum München, together with colleagues from the Technical University of Munich (TUM) and the German Center for Cardiovascular Disease (DZHK).

    According to the World Health Organisation WHO, 350 million people worldwide are affected by depression. But the mental state is not all that is affected, however, and depression can also compromise the body. “Meanwhile there is little doubt that depression is a risk factor for cardiovascular diseases,” explains Karl-Heinz Ladwig. He is group leader at the Institute of Epidemiology II at the Helmholtz Zentrum München, professor of psychosomatic medicine at TUM’s Klinikum rechts der Isar as well as scientist of DZHK. “The question now is: What is the relationship between depression and other risk factors like tobacco smoke, high cholesterol levels, obesity or hypertension — how big a role does each factor play?”

    In order to examine this question, Ladwig and his team analyzed data from 3,428 male patients between the ages of 45 and 74 years and observed their development over a period of ten years. “The work is based on a prospective population-based data set from the MONICA/KORA study that, with a total term of up to 25 years, is one of the few large studies in Europe that allows such an analysis,” reports the statistician Dr. Jens Baumert of Helmholtz Zentrum München, who was also involved in the publication.

    Investigate depression in high-risk patients

    In their analyses, the scientists compared the impact of depression with the four major risk factors. “Our investigation shows that the risk of a fatal cardiovascular disease due to depression is almost as great as that due to elevated cholesterol levels or obesity,” Ladwig summarizes. The results show that only high blood pressure and smoking are associated with a greater risk. Viewed across the population, depression accounts for roughly 15 percent of the cardiovascular deaths. “That is comparable to the other risk factors, such as hypercholesterolemia, obesity and smoking,” Ladwig states. These factors cause 8.4 to 21.4 percent of the cardiovascular deaths.

    “We invested a great deal of time in this work, just due to the long observation period,” says study leader Ladwig. But the effort paid off: “Our data show that depression has a medium effect size within the range of major, non-congenital risk factors for cardiovascular diseases.” Ladwig accordingly proposes consequences here: “In high risk patients, the diagnostic investigation of co-morbid depression should be standard. This could be registered with simple means.”

     


  5. Increased reaction to stress linked to gastrointestinal issues in children with autism

    January 6, 2017 by Ashley

    From the University of Missouri-Columbia media release:

    One in 45 American children lives with autism spectrum disorder, according to the Centers for Disease Control and Prevention.

    Many of these children also have significant gastrointestinal issues, but the cause of these symptoms is unknown. Now, researchers from the University of Missouri School of Medicine suggest that the gastrointestinal issues in these individuals with autism may be related to an increased reaction to stress. It’s a finding the researchers hope could lead to better treatment options for these patients.

    “We know that it is common for individuals with autism to have a more intense reaction to stress, and some of these patients seem to experience frequent constipation, abdominal pain or other gastrointestinal issues,” said David Beversdorf, M.D., associate professor in the departments of radiology, neurology and psychological sciences at MU and the MU Thompson Center for Autism and Neurodevelopmental Disorders. “To better understand why, we looked for a relationship between gastrointestinal symptoms and the immune markers responsible for stress response. We found a relationship between increased cortisol response to stress and these symptoms.”

    Cortisol is a hormone released by the body in times of stress, and one of its functions is to prevent the release of substances in the body that cause inflammation. These inflammatory substances — known as cytokines — have been associated with autism, gastrointestinal issues and stress. The researchers studied 120 individuals with autism who were treated at MU and Vanderbilt University. The individuals’ parents completed a questionnaire to assess their children’s gastrointestinal symptoms, resulting in 51 patients with symptoms and 69 without gastrointestinal symptoms.

    To elicit a stress response, individuals took a 30-second stress test. Cortisol samples were gathered through participants’ saliva before and after the test. The researchers found that the individuals with gastrointestinal symptoms had greater cortisol in response to the stress than the participants without gastrointestinal symptoms.

    When treating a patient with autism who has constipation and other lower gastrointestinal issues, physicians may give them a laxative to address these issues,” Beversdorf said. “Our findings suggest there may be a subset of patients for which there may be other contributing factors. More research is needed, but anxiety and stress reactivity may be an important factor when treating these patients.”

     


  6. Losing sleep over discrimination? ‘everyday discrimination’ may contribute to sleep problems

    by Ashley

    From the Wolters Kluwer Health: Lippincott Williams and Wilkins media release:

    People who perceive more discrimination in daily life have higher rates of sleep problems, based on both subjective and objective measures, reports a study in Psychosomatic Medicine: Journal of Biobehavioral Medicine, the official journal of the American Psychosomatic Society. The journal is published by Wolters Kluwer.

    “Discrimination is an important factor associated with sleep measures in middle-aged adults,” according to the report by Sherry Owens, PhD, of West Virginia University, Morgantown, and colleagues. The results add to previous research suggesting that discrimination and chronic stress may lead to sleep difficulties and increased health risks.

    Discrimination Related to Both Objective and Subjective Sleep Problems

    The study included 441 adults from a nationwide study of health and well-being in middle age and beyond (the MIDUS Study). The participants’ average age was 47 years; about one-third were of non-white race/ethnicity. Complete data were available for 361 participants.

    Participants wore an activity monitor device for one week to gather data on objective sleep measures — for example, sleep efficiency, calculated as the percentage of time spent in bed that the person was asleep. They also completed subjective sleep ratings — for example, how often they had sleep problems.

    Perceived experiences of discrimination were assessed using a validated “Everyday Discrimination Scale.” For example, subjects were asked how often they were treated with less courtesy or respect than others, or how often they were insulted or harassed.

    Discrimination scores were analyzed for association with the objective and subjective sleep measures. Objective measures indicated that about one-third of participants had poor sleep efficiency. Subjectively, one-half of subjects rated themselves as having poor sleep quality.

    Participants who perceived more discrimination had increased sleep problems, after adjustment for demographic, lifestyle, and health factors. Higher discrimination scores were associated with 12 percent higher odds of poor sleep efficiency and a nine percent increase in the odds of poor sleep quality. Discrimination was also related to (objective) time spent awake after falling asleep and (subjective) overall sleep difficulties.

    Non-white subjects had nearly four times the odds of poor sleep efficiency. Otherwise, all differences in sleep measures between white and non-white subjects were related to discrimination.

    Older participants and men were more likely to have some types of sleep problems. Age, sex, and mental/physical health factors explained only a small proportion of the effects of discrimination.

    Previous studies have suggested that racial/ethnic minorities have worse sleep quality. Inadequate sleep is associated with adverse health outcomes, including increased cardiovascular risks and increased mortality. These consequences of poor sleep may account for some of racial/ethnic variation in health outcomes — possibly reflecting inadequate recovery from chronic daily stressors.

    While poor sleep has previously been linked to higher perceived discrimination, the new study is the first to look at how discrimination affects both objective and subjective sleep measures. “The findings support the model that discrimination acts as a stressor than can disrupt subjective and objective sleep,” Dr. Owens and coauthors write.

    The researchers call for further study to confirm and clarify the implications of their findings. Meanwhile, they believe the study adds a “finer resolution” to previous knowledge the relationship between discrimination and sleep — and suggests a possible “causal pathway” connecting chronic discrimination to sleep problems, and thus to increased health risks.


  7. Childhood poverty can rob adults of psychological health

    January 5, 2017 by Ashley

    From the Cornell University media release:

    childhood depressionA large and growing body of research shows that poor kids grow up to have a host of physical problems as adults.

    Now add poor psychological health to the list, a Cornell University researcher says.

    A sweeping new study, conducted by following participants over a 15-year period, is the first to show that childhood poverty can cause significant psychological damage in adulthood.

    Impoverished children in the study had more antisocial conduct such as aggression and bullying, and increased feeling of helplessness, than kids from middle-income backgrounds, the study said. Poor kids also have more chronic physiological stress and more deficits in short-term spatial memory.

    “What this means is, if you’re born poor, you’re on a trajectory to have more of these kinds of psychological problems,” said Gary Evans, the author of the study and professor of environmental and developmental psychology at Cornell.

    Why?

    In a word, stress.

    “With poverty, you’re exposed to lots of stress. Everybody has stress, but low-income families, low-income children, have a lot more of it,” Evans said. “And the parents are also under a lot of stress. So for kids, there is a cumulative risk exposure.”

    Evans, a child psychologist who specializes in the effects of stress on children, is the author of “Childhood poverty and adult psychological well-being,” published last month in the Proceedings of the National Academy of Sciences.

    The findings are important because kids who grow up in poverty are likely to stay impoverished as adults. For example, there’s a 40 percent chance that a son’s income will be the same as his father’s income.

    People walk around with this idea in their head that if you work hard, play by the rules, you can get ahead,” Evans said. “And that’s just a myth. It’s just not true.

    In his study, Evans tracked 341 participants over a 15-year period, and tested them at ages 9, 13, 17 and 24.

    Short-term spatial memory was tested by asking adult study participants to repeat increasingly complex sequences of lights and sounds by pressing four colored pads in the correct order — similar to the “Simon” game. The adults who grew up in poverty had a diminished ability to recall the sequences, compared to those who did not. “This is an important result because the ability to retain information in short-term memory is fundamental to a host of basic cognitive skills, including language and achievement,” the study said.

    Although the participants were assessed on this measure only when they were adults, this test had the strongest association with childhood poverty of the four measures.

    Helplessness was assessed by asking the participants to solve an impossible puzzle. Adults growing up in poverty gave up 8 percent more quickly than those who weren’t poor as kids. Previous research has shown chronic exposure to uncontrollable stressors — such as family turmoil and substandard housing — tends to induce helplessness.

    Mental health was measured with a well validated, standardized index of mental health with statements including “I argue a lot” and “I am too impatient.” Adults who grew up in poverty were more likely to agree with those questions than adults from a middle-income background.

    Chronic physiological stress was tested by measuring the participants’ blood pressure, stress hormones and body mass index. Adults who grew up in poverty had a higher level of chronic physical stress throughout childhood and into adulthood.

    The study has two implications, Evans said.

    First, early intervention to prevent these problems is more efficient and more likely to work. “If you don’t intervene early, it’s going to be really difficult and is going to cost a lot to intervene later,” he said.

    Second, increasing poor families’ incomes is the most efficient way to reduce a child’s exposure to poverty and, in turn, their risk of developing psychological problems. Evans supports the creation of a safety net, similar to Social Security’s supplemental income for the elderly and disabled. If a family is poor and has children, the federal government should provide them with supplementary income sufficient to participate in society, he said.

    It’s not true you can’t do anything about poverty. It’s just whether there’s the political will, and are people willing to reframe the problem, instead of blaming the person who is poor and — even more preposterous — blaming their children,” he said.

    “This is a societal issue, and if we decide to reallocate resources like we did with the elderly and Social Security, we could change the kind of data this study is showing,” he said.

    “Could we get rid of poverty? Probably not,” Evans said. “But I think we could change it dramatically.”


  8. Yogic breathing helps fight major depression, study shows

    November 28, 2016 by Ashley

    From the Perelman School of Medicine at the University of Pennsylvania media release:

    depressionA breathing-based meditation practice known as Sudarshan Kriya yoga helped alleviate severe depression in people who did not fully respond to antidepressant treatments, reports a new study published in the Journal of Clinical Psychiatry from researchers in the Perelman School of Medicine at the University of Pennsylvania. The study bolsters the science behind the use of controlled yogic breathing to help battle depression.

    In a randomized, controlled pilot study, led by Anup Sharma, MD, PhD, a Neuropsychiatry research fellow in the department of Psychiatry at Penn, researchers found significant improvement in symptoms of depression and anxiety in medicated patients with major depressive disorder (MDD) who participated in the breathing technique compared to medicated patients who did not partake. After two months, the yoga group cut its mean Hamilton Depression Rating Scale (HDRS) score by several points, while the control group showed no improvements. HDRS is the most widely used clinician-administered depression assessment that scores mood, interest in activities, energy, suicidal thoughts, and feelings of guilt, among other symptoms.

    More than half of the 41 million Americans who take antidepressants do not fully respond. Add-on therapies are often prescribed to enhance the effects of the drugs in these patients, but they typically offer limited additional benefits and come with side effects that can curb use, prolonging the depressive episode. What’s more, patients who don’t fully respond to antidepressants are especially at risk of relapse.

    With such a large portion of patients who do not fully respond to antidepressants, it’s important we find new avenues that work best for each person to beat their depression,” Sharma said. “Here, we have a promising, lower-cost therapy that could potentially serve as an effective, non-drug approach for patients battling this disease.”

    The meditation technique, which is practiced in both a group setting and at home, includes a series of sequential, rhythm-specific breathing exercises that bring people into a deep, restful, and meditative state: slow and calm breaths alternated with fast and stimulating breaths.

    Sudarshan Kriya yoga gives people an active method to experience a deep meditative state that’s easy to learn and incorporate in diverse settings,” Sharma said.

    In past studies, the practice has demonstrated a positive response in patients with milder forms of depression, depression due to alcohol dependence, and in patients with MDD; however, there are no clinical studies investigating its use for depression in an outpatient setting. Past studies suggest that yoga and other controlled breathing techniques can potentially adjust the nervous system to reduce stress hormones. Overall, the authors also note, well-designed studies that evaluate the benefits of yoga to treat depression are lacking, despite increased interest in the ancient Indian practice. Millions of Americans participate in some form of yoga every year.

    In the study, researchers enrolled 25 patients suffering from MDD who were depressed, despite more than eight weeks of antidepressant medication treatment. The medicated patients were randomized to either the breathing intervention group or the “waitlist” control group for eight weeks. (The waitlist group was offered the yoga intervention after the study). During the first week, participants completed a six-session program, which featured Sudarshan Kriya yoga in addition to yoga postures, sitting meditation, and stress education. For weeks two through eight, participants attended weekly Sudarshan Kriya yoga follow-up sessions and completed a home practice version of the technique.

    Patients in the Sudarshan Kriya yoga group showed a significantly greater improvement in HDRS scores compared to patients in the waitlist group. With a mean baseline HDRS score of 22.0 (indicating severe depression at the beginning of the study), the group that completed the breathing technique for the full two months improved scores by 10.27 points on average, compared to the waitlist group, which showed no improvements. Patients in the yoga group also showed significant mean reductions in total scores of the self-reported Beck Depression (15.48 point improvement) and Beck Anxiety Inventories (5.19 point improvement), versus the waitlist control group.

    Results of the pilot study suggest the feasibility and promise of Sudarshan Kriya as an add-on intervention for MDD patients who have not responded to antidepressants, the authors wrote. “The next step in this research is to conduct a larger study evaluating how this intervention impacts brain structure and function in patients who have major depression,” Sharma said.

     


  9. Depression in young people affects the stomach, anxiety the skin

    by Ashley

    From the Universität Basel media release:

    DepressedGirlMental disorders and physical diseases frequently go hand in hand. For the first time, psychologists at the University of Basel and Ruhr University Bochum have identified temporal patterns in young people: arthritis and diseases of the digestive system are more common after depression, while anxiety disorders tend to be followed by skin diseases.

    Physical diseases and mental disorders affect a person’s quality of life and present a huge challenge for the healthcare system. If physical and mental disorders systematically co-occur from an early age, there is a risk that the sick child or adolescent will suffer from untoward developments.

    Data from 6,500 teenagers

    In a project financed by the Swiss National Science Foundation, a research group led by PD Dr. Marion Tegethoff in collaboration with Professor Gunther Meinlschmidt from the University of Basel’s Faculty of Psychology has now examined the temporal pattern and relationship between physical diseases and mental disorders in children and young people. In the journal PLOS ONE, they analyzed data from a representative sample of 6,483 teenagers from the US aged between 13 and 18.

    The researchers noted that some physical diseases tend to occur more frequently in children and adolescents if they have previously suffered from certain mental disorders. Likewise, certain mental disorders tend to occur more frequently after the onset of particular physical diseases. Affective disorders such as depression were frequently followed by arthritis and diseases of the digestive system, while the same relationship existed between anxiety disorders and skin diseases. Anxiety disorders were more common if the person had already suffered from heart disease. A close association was also established for the first time between epileptic disorders and subsequent eating disorders.

    Epilepsy and eating disorders

    The results offer important insights into the causal relationship between mental disorders and physical diseases. The newly identified temporal associations draw attention to processes that could be relevant both to the origins of physical diseases and mental disorders and to their treatment. In an earlier study, the same authors had already provided evidence for the relationship between mental disorders and physical diseases in young people.

    For the first time, we have established that epilepsy is followed by an increased risk of eating disorders — a phenomenon, that had previously been described only in single case reports. This suggests that approaches to epilepsy treatment could also have potential in the context of eating disorders,” explains Marion Tegethoff, the study’s lead author. From a health policy perspective, the findings underscore that the treatment of mental disorders and physical diseases should be closely interlinked from an early age on.

     


  10. Common probiotics can reduce stress levels, lessen anxiety

    by Ashley

    From the University of Missouri media release:

    probiotics gut floraProbiotics, or beneficial live bacteria that are introduced into the body, have become increasingly popular as a way to improve health and well-being.

    Previous studies have shown a direct correlation between gut microbes and the central nervous system. Now, researchers at the University of Missouri, using a zebrafish model, determined that a common probiotic sold in supplements and yogurt can decrease stress-related behavior and anxiety. Studying how gut bacteria affect behavior in zebrafish could lead to a better understanding of how probiotics may affect the central nervous system in humans. Their results recently were published in Scientific Reports a journal of Nature.

    “Zebrafish are an emerging model species for neurobehavioral studies and their use is well-established in drug-screening,” said Aaron Ericsson, director of the MU Metagenomics Center and a research assistant professor in the Department of Veterinary Pathobiology. “Our study has shown that simple probiotics that we normally use to keep our digestive tract in sync, could be beneficial to reducing our stress levels as well.”

    In a series of studies, researchers tested how zebrafish behaved after doses of Lactobacillus plantarum, a common bacteria found in yogurt and probiotic supplements. In the first study, scientists added the bacteria to certain tanks housing zebrafish; other tanks of zebrafish received no probiotics. Then, the researchers introduced environmental stressors to both groups, such as draining small amounts of water from the tank and overcrowding.

    “Each day we introduced a different stressor — tests that are validated by other researchers and cause higher anxiety among zebrafish,” said Elizabeth Bryda, professor of veterinary pathobiology in the MU College of Veterinary Medicine. “These are common environmental stress patterns, such as isolation stress and temperature change, so it made the tests relevant to humans as well.”

    By analyzing the gene pathways of both groups of fish, the research team found that zebrafish that were given the supplements showed a reduction in the metabolic pathways associated with stress.

    “By measuring the genes associated with stress and anxiety, our tests were able to predict how this common probiotic is able to benefit behavioral responses in these fish,” said Daniel Davis, assistant director of the MU Animal Modeling Core. “Essentially, bacteria in the gut altered the gene expression associated with stress- and anxiety-related pathways in the fish allowing for increased signaling of particular neurotransmitters.”

    To test their theory further, the researchers measured the movements of fish in their tanks using sophisticated computer measuring and imaging tools. Previous studies of fish behavior have found that fish that are stressed tend to spend more time at the bottom of their tanks. Once the fish were administered probiotics, they tended to spend more time toward the top of the tanks — the change in behavior indicating they were less stressed or less anxious.

    “Using zebrafish, we’ve developed a relatively inexpensive platform for testing of other species of bacteria and probiotics and their potential benefit on different systems of the body,” Ericsson said.