Can Probiotics Improve the Health of Your Brain?
By Dr. Ruairi Robertson
Did you know that there are roughly 40 trillion bacteria living in and on you?
Most of these bacteria reside in your gut and don't cause any health problems.
In fact, scientists have begun to realize that these bacteria are essential for your physical health.
Now compelling new research has found these bacteria may also be beneficial for your brain and mental health.
This article explains how your brain is affected by gut bacteria and the role probiotics may play.
What Are Probiotics?
The word "probiotic" is derived from the Latin words "pro," meaning to promote and "biotic," meaning life.
Importantly, in order for a certain species of bacteria to be termed "probiotic," it must have a lot of scientific evidence behind it showing a specific health benefit.
Unfortunately, the word probiotic has become overused by food and pharmaceutical companies who were calling some bacteria probiotics even if they had no scientifically proven health benefit.
This led the European Food Safety Authority to ban the word "probiotic" on all foods in the European Union.
However, there is a lot of new scientific evidence showing that some bacterial species have true benefits for health.
Most probiotics belong to one of two types of bacteria: Lactobacillus or Bifidobacteria. There are many different species and strains within these groups and they may have different effects on the body.
Bottom Line: Probiotics are live microorganisms that have a proven health benefit for the body.
How Are Your Intestines and Brain Connected?
The intestines and brain are connected physically and biochemically.
The physical connection between the intestines and brain is through the central nervous system, which controls all of the activities of the body.
The vagus nerve is a large nerve that sends signals between the intestines and brain (7).
The brain is also connected to the intestines through your gut microbes. Molecules that they produce can act as signals that the brain can detect (7).
In the past, scientists have estimated that a person has approximately 100 trillion bacterial cells in their body and only 10 trillion human cells, meaning your own cells are outnumbered by 10 to 1 (8).
However, recent estimates suggest that you have roughly 30 trillion human cells and 40 trillion bacteria. This is still pretty impressive and means that, by number of cells, you are more bacteria than human (9).
The majority of these bacteria are in your gut, so they're in direct contact with the cells that line your intestines and with everything that enters your body. That includes food, medicines and microbes.
Alongside your gut bacteria, there are many other microbes, such as yeasts and fungi. Collectively, these microbes are known as the gut microbiota or gut microbiome (10).
Each of these bacteria can produce different compounds, such as short-chain fatty acids, neurotransmitters and amino acids. Many of these substances have effects on the brain (11).
Bottom Line: There are thousands of different species of bacteria in the human body, mostly in the intestines. In general, these bacteria are good for your health and may even influence brain health.
An Altered Microbiota May Contribute to a Number of Diseases
The term "gut dysbiosis" refers to when the intestines and gut bacteria are in a diseased state. This may be due to the presence of disease-causing bacteria, which may also lead to chronic inflammation.
Interestingly, some studies have shown that people with certain mental disorders also have an altered microbiota. However, it is unclear if this is a cause of such diseases or the result of an altered diet and lifestyle (22, 23, 24, 25).
Since the gut and brain are connected and gut bacteria produce substances that can influence the brain, probiotics may be able to benefit the brain and mental health.
A number of recent studies have investigated this, but most have been in animals. However, a few have shown interesting results in humans.
Bottom Line: A number of diseases, including mental disorders, are associated with higher disease-causing bacteria in the intestines. Some probiotics may be able to restore healthy bacteria to reduce symptoms.
Taking Probiotic Supplements May Reduce Symptoms of Stress, Anxiety and Depression
Only one study has examined how probiotics affect patients with clinically diagnosed depression.
In the study, consuming a mixture of three Lactobacillus and Bifidobacteria strains for eight weeks significantly reduced depressive symptoms. The probiotic also reduced inflammation in the patients (30).
A handful of other studies have examined how probiotics affect depressive symptoms in healthy subjects. In healthy people, certain probiotics may reduce:
- Depressive symptoms (34)
- Psychological distress (35)
- Academic stress (36)
Bottom Line: Certain probiotics may reduce anxiety, stress and depressive symptoms in healthy people. More research is needed about potential benefits for people with clinically diagnosed psychological disorders.
Taking Probiotic Supplements May Reduce Symptoms of Irritable Bowel Syndrome
Bottom Line: IBS is commonly associated with elevated levels of anxiety and depression. Probiotics appear to help reduce IBS symptoms.
Certain Probiotics May Enhance Mood
In healthy people without a psychological disorder, some probiotics may help improve mood.
One study treated participants daily for four weeks with a probiotic mix containing eight different Lactobacillus and Bifidobacteria strains.
The researchers found that taking the supplements reduced participants' negative thoughts associated with a sad mood (45).
Another study showed that consuming a milk drink containing a probiotic called Lactobacillus casei for three weeks improved mood in people who had the lowest mood before the treatment (46).
Interestingly, this study also found that people scored slightly lower on a memory test after taking the probiotic. Further research is needed to validate these results.
Bottom Line: A few studies have shown that taking certain probiotics for a few weeks may slightly improve mood.
Certain Probiotics May Have Benefits After Traumatic Brain Injury
Traumatic brain injury usually involves admission to an intensive care unit. During this time, food is usually administered enterally, meaning through a tube.
In some cases, breathing also has to be assisted with a tube, which can increase the risk of infection. Infections in people with traumatic brain injuries can lead to further complications.
A few studies have found that adding certain probiotics into enteral nutrition can reduce the number of infections in the patients with traumatic brain injury and the length of time they spend in the intensive care unit (47, 48, 49).
The effects of the probiotics on these outcomes may be due to their benefits for the immune system.
Bottom Line: Administering probiotics after traumatic brain injury may reduce patients' rate of infections and length of stay in intensive care.
Other Beneficial Effects of Probiotics on the Brain
A handful of other studies have shown that probiotics may have interesting benefits for the brain.
One intriguing study looked at images of women's brains after they consumed a mix of Bifidobacteria, Streptococcus, Lactobacillus and Lactococcus strains.
Consuming the probiotic affected regions of the brain that control emotion and sensation (50).
Bottom Line: Some probiotics may influence the function of the brain and symptoms of multiple sclerosis and schizophrenia. However, this research is still very new, so the results aren't clear.
Should You Be Taking a Probiotic for Your Brain?
At the moment, there is not enough evidence to definitively say that probiotics benefit the brain. Therefore, they cannot yet be considered a treatment for any brain-related disorders.
If you're looking to treat such disorders, consult a doctor.
Thus far, scientific evidence does show a clear connection between the gut and the brain. It's an exciting area of research that is expanding rapidly.
If necessary, taking probiotic supplements can help you increase the beneficial bacterial species in your intestines. In general, consuming probiotics is safe and causes few side effects.
If you're buying a probiotic, choose one that has scientific evidence behind it. Lactobacillus GG (LGG) and VSL#3 have both been widely studied and shown a number of health benefits.
Bottom Line: Probiotics have been shown to benefit other aspects of health, but not enough research has been done to definitively demonstrate whether probiotics have positive effects on the brain.
Take Home Message
Although the research is promising, it is too soon to recommend any probiotic specifically to boost brain health.
Still, current evidence gives some food for thought about how probiotics may be used to enhance brain health in the future.
Reposted with permission from our media associate Authority Nutrition.
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Farmers are the stewards of our planet's precious soil, one of the least understood and untapped defenses against climate change. Because of its massive potential to store carbon and foundational role in growing our food supply, soil makes farming a solution for both climate change and food security.
Soil can act as a natural "carbon sink." Climate Central, 2019
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By Shelly Miller
The vast majority of SARS-CoV-2 transmission occurs indoors, most of it from the inhalation of airborne particles that contain the coronavirus. The best way to prevent the virus from spreading in a home or business would be to simply keep infected people away. But this is hard to do when an estimated 40% of cases are asymptomatic and asymptomatic people can still spread the coronavirus to others.
It’s All About Fresh, Outside Air<p>The safest indoor space is one that constantly has lots of <a href="https://www.epa.gov/indoor-air-quality-iaq/how-does-outdoor-air-enter-building" target="_blank">outside air</a> replacing the stale air inside.</p><p>In commercial buildings, <a href="https://www.ncbi.nlm.nih.gov/books/NBK143277/" target="_blank">outside air is usually pumped in</a> through heating, ventilating and air-conditioning (HVAC) systems. In <a href="https://www.epa.gov/indoor-air-quality-iaq/how-does-outdoor-air-enter-building" target="_blank">homes, outside air gets in</a> through open windows and doors, in addition to seeping in through various nooks and crannies.</p><p>Simply put, the more fresh, outside air inside a building, the better. Bringing in this air dilutes any contaminant in a building, whether a virus or a something else, and <a href="https://doi.org/10.1111/j.1600-0668.2010.00703.x" target="_blank">reduces the exposure of anyone inside</a>. Environmental engineers like me quantify how much outside air is getting into a building using a measure called the <a href="https://doi.org/10.1038/jes.2013.30" target="_blank">air exchange rate</a>. This number quantifies the number of times the air inside a building gets replaced with air from outside in an hour.</p><p>While the exact rate depends on the number of people and size of the room, most experts consider roughly <a href="https://doi.org/10.1034/j.1600-0668.2002.01145.x" target="_blank">six air changes an hour</a> to be good for a 10-foot-by-10-foot room with three to four people in it. In a pandemic this should be higher, with one study from 2016 suggesting that an exchange rate of nine times per hour <a href="https://doi.org/10.1177%2F1420326X16631596" target="_blank">reduced the spread of SARS, MERS and H1N1</a> in a Hong Kong hospital.</p><p>Many buildings in the U.S., <a href="https://doi.org/10.1111/ina.12403" target="_blank">especially schools</a>, do not meet recommended ventilation rates. Thankfully, it can be pretty easy to get more outside air into a building. Keeping <a href="https://doi.org/10.1016/S0960-1481(99)00012-9" target="_blank">windows and doors open</a> is a good start. Putting a box fan in a window blowing out can greatly increase air exchange too. In buildings that don't have operable windows, you can change the mechanical ventilation system to increase how much air it is pumping. But in any room, the more people inside, the faster the air should be replaced.</p>
Using CO2 to Measure Air Circulation<p>So how do you know if the room you're in has enough air exchange? It's actually a pretty hard number to calculate. But there's an easy-to-measure proxy that can help. Every time you exhale, you <a href="https://doi.org/10.1111/ina.12383" target="_blank">release CO2</a> into the air. Since the coronavirus is most often spread by breathing, coughing or talking, you can use <a href="https://pdfs.semanticscholar.org/dd7e/b2870c38f70e5285e5118ed6f158c091f7cf.pdf" target="_blank">CO2 levels</a> to see if the room is filling up with potentially infectious exhalations. The CO2 level lets you estimate if enough fresh outside air is getting in.</p><p>Outdoors, CO2 levels are just above 400 parts per million (ppm). A well ventilated room will have around <a href="https://doi.org/10.1111/j.1600-0668.1999.00003.x" target="_blank">800 ppm of CO2</a>. Any higher than that and it is a sign the room might need more ventilation.</p><p>Last year, researchers in Taiwan reported on the <a href="https://doi.org/10.1111/ina.12639" target="_blank">effect of ventilation on a tuberculosis outbreak</a> at Taipei University. Many of the rooms in the school were underventilated and had CO2 levels above 3,000 ppm. When engineers improved air circulation and got CO2 levels under 600 ppm, <a href="https://doi.org/10.1111/ina.12639" target="_blank">the outbreak completely stopped</a>. According to the research, the increase in ventilation was responsible for 97% of the decrease in transmission.</p><p>Since the coronavirus is spread through the air, higher CO2 levels in a room likely mean there is a <a href="https://doi.org/10.1111/ina.12639" target="_blank">higher chance of transmission</a> if an infected person is inside. Based on the study above, I recommend trying to keep the CO2 levels below 600 ppm. You can buy <a href="https://doi.org/10.5194/amt-7-3325-2014" target="_blank">good CO2 meters</a> for around $100 online; just make sure that they are accurate to within 50 ppm.</p>
Air Cleaners<p>If you are in a room that can't get enough outside air for dilution, consider an air cleaner, also commonly called air purifiers. These machines remove particles from the air, usually using <a href="https://doi.org/10.1016/j.cap.2005.07.013" target="_blank">a filter</a> made of tightly woven fibers. They can <a href="https://shellym80304.files.wordpress.com/2020/06/miller-leiden-et-al-1996.pdf" target="_blank">capture particles containing bacteria and viruses</a> and can help reduce disease transmission.</p><p>The U.S. Environmental Protection Agency says that <a href="https://www.epa.gov/coronavirus/air-cleaners-hvac-filters-and-coronavirus-covid-19" target="_blank">air cleaners can do this for the coronavirus</a>, but not all air cleaners are equal. Before you go out and buy one, there are few things to keep in mind.</p><p>The first thing to consider is <a href="https://shellym80304.files.wordpress.com/2020/06/air-cleaner-report.pdf" target="_blank">how effective an air cleaner's filter is</a>. Your best option is a cleaner that uses a high-efficiency particulate air (<a href="https://doi.org/10.1016/S0021-8502(05)80214-9" target="_blank">HEPA</a>) filter, as these remove more than <a href="https://doi.org/10.1063/1.2771421" target="_blank">99.97% of all particle sizes</a>.</p><p>The second thing to consider is how powerful the cleaner is. The bigger the room – or the more people in it – the more air needs to be cleaned. I worked with some colleagues at Harvard to put together a tool to help teachers and schools determine <a href="https://docs.google.com/spreadsheets/d/1NEhk1IEdbEi_b3wa6gI_zNs8uBJjlSS-86d4b7bW098/edit#gid=1275403500" target="_blank">how powerful of an air cleaner you need for different classroom sizes</a>.</p><p>The last thing to consider is the validity of the claims made by the company producing the air cleaner.</p><p>The Association of Home Appliance Manufacturers certifies air cleaners, so the AHAM Verifide seal is a good place to start. Additionally, the California Air Resources Board has a <a href="https://ww2.arb.ca.gov/our-work/programs/air-cleaners-ozone-products/california-certified-air-cleaning-devices" target="_blank">list of air cleaners</a> that are certified as safe and effective, though not all of them use HEPA filters.</p>
Keep Air Fresh or Get Outside<p>Both the <a href="https://www.who.int/news-room/commentaries/detail/transmission-of-sars-cov-2-implications-for-infection-prevention-precautions" target="_blank">World Health Organization</a> and <a href="https://www.cdc.gov/coronavirus/2019-ncov/daily-life-coping/deciding-to-go-out.html" target="_blank">U.S. Centers for Disease Control and Prevention</a> say that poor ventilation increases the risk of transmitting the coronavirus.</p><p>If you are in control of your indoor environment, make sure you are getting enough fresh air from outside circulating into the building. A CO2 monitor can help give you a clue if there is enough ventilation, and if CO2 levels start going up, open some windows and <a href="https://www.advisory.com/daily-briefing/2020/07/17/outdoor-gathering" target="_blank">take a break outside</a>. If you can't get enough fresh air into a room, an air cleaner might be a good idea. If you do get an air cleaner, be aware that they don't remove CO2, so even though the air might be safer, CO2 levels could still be high in the room.</p><p>If you walk into a building and it feels hot, stuffy and crowded, chances are that there is not enough ventilation. Turn around and leave.</p><p>By paying attention to air circulation and filtration, improving them where you can and staying away from places where you can't, you can add another powerful tool to your anti-coronavirus toolkit.</p>
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The tiny island nation of Mauritius, known for its turquoise waters, vibrant corals and diverse ecosystem, is in the midst of an environmental catastrophe after a Japanese cargo ship struck a reef off the country's coast two weeks ago. That ship, which is still intact, has since leaked more than 1,000 metric tons of oil into the Indian Ocean. Now, a greater threat looms, as a growing crack in the ship's hull might cause the ship to split in two and release the rest of the ship's oil into the water, NPR reported.
On Friday, Prime Minister Pravind Jugnauth declared a state of environmental emergency.
France has sent a military aircraft carrying pollution control equipment from the nearby island of Reunion to help mitigate the disaster. Additionally, Japan has sent a six-member team to assist as well, the BBC reported.
The teams are working to pump out the remaining oil from the ship, which was believed to be carrying 4,000 metric tons of fuel.
"We are expecting the worst," Mauritian Wildlife Foundation manager Jean Hugues Gardenne said on Monday, The Weather Channel reported. "The ship is showing really big, big cracks. We believe it will break into two at any time, at the maximum within two days. So much oil remains in the ship, so the disaster could become much worse. It's important to remove as much oil as possible. Helicopters are taking out the fuel little by little, ton by ton."
Sunil Dowarkasing, a former strategist for Greenpeace International and former member of parliament in Mauritius, told CNN that the ship contains three oil tanks. The one that ruptured has stopped leaking oil, giving disaster crews time to use a tanker and salvage teams to remove oil from the other two tanks before the ship splits.
By the end of Tuesday, the crew had removed over 1,000 metric tons of oil from the ship, NPR reported, leaving about 1,800 metric tons of oil and diesel, according to the company that owns the ship. So far the frantic efforts are paying off. Earlier today, a local police chief told BBC that there were still 700 metric tons aboard the ship.
The oil spill has already killed marine animals and turned the turquoise water black. It's also threatening the long-term viability of the country's coral reefs, lagoons and shoreline, NBC News reported.
"We are starting to see dead fish. We are starting to see animals like crabs covered in oil, we are starting to see seabirds covered in oil, including some which could not be rescued," said Vikash Tatayah, conservation director at Mauritius Wildlife Foundation, according to The Weather Channel.
While the Mauritian authorities have asked residents to leave the clean-up to officials, locals have organized to help.
"People have realized that they need to take things into their hands. We are here to protect our fauna and flora," environmental activist Ashok Subron said in an AFP story.
Reuters reported that sugar cane leaves, plastic bottles and human hair donated by locals are being sewn into makeshift booms.
Human hair absorbs oil, but not water, so scientists have long suggested it as a material to contain oil spills, Gizmodo reported. Mauritians are currently collecting as much human hair as possible to contribute to the booms, which consist of tubes and nets that float on the water to trap the oil.
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Environmentalists and ornithologists found a friend in a federal court on Tuesday when a judge struck down a Trump administration attempt to allow polluters to kill birds without repercussions through rewriting the Migratory Treaty Bird Act (MBTA).
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By Elizabeth Claire Alberts
There are trillions of microplastics in the ocean — they bob on the surface, float through the water column, and accumulate in clusters on the seafloor. With plastic being so ubiquitous, it's inevitable that marine organisms, such as sharks, will ingest them.
Polyproylene fibers found in one of the sampled sharks. Kristian Parton
Spiny dogfish. NOAA / Wikimedia Commons<p>"There appear to be two routes for these particles to end up in the sharks," Parton said. "The first through their food source [such as] crustaceans. Their prey may already contain these fibers, and consequently it's passed to the shark through bioaccumulation up the food chain. The second pathway is direct ingestion from the sediment. As these sharks feed, they'll often suck up sediment into their mouths, some of this is expelled straight away, although some is swallowed, therefore fibers and particles that may have sunk down into the seabed may be directly ingested from the surrounding sediment as these sharks feed."</p><p>Some sharks only contained a few plastic particles, but others contained dozens. The larger the shark, the more plastic was in it, the findings suggested. The highest number of microplastics was found in an individual bull huss, which had 154 polypropylene fibers inside its stomach and intestines.</p><p>"It's perhaps likely this individual shark had swallowed a larger piece of fishing rope/netting and this has broken down during digestive processes within the shark, and also broken down into smaller pieces during our analysis," Parton said.</p>
Lesser-spotted dogfish caught as bycatch. Kristian Parton<p>While this study only examined the stomach and digestive tracts of demersal sharks, Parton says it's possible that plastic would be present in other parts of the sharks' bodies, such as the liver and muscle tissue. However, more research would be needed to prove this.</p><p>At the moment, there is also limited understanding of how microplastic ingestion would impact a shark's health, although microplastics are known to negatively influence feeding behavior, development, reproduction and life span of zooplankton and crustaceans.</p><p>"If we can show that these fibers contain inorganic pollutants attached to them, then that could have real consequences for these shark species at a cellular level, impacting various internal body systems," Parton said.</p>
Parton in the lab. Kristian Parton<p>This new study demonstrates how pervasive and destructive plastic pollution can be in the marine environment, according to Will McCallum, head of oceans for Greenpeace U.K.</p><p>"Our addiction to plastics combined with the lack of mechanisms to protect our oceans is suffocating marine life," McCallum said in a statement. "Sharks sit on top of the marine food web and play a vital role in ocean ecosystems. Yet, they are completely exposed to pollutants and other human impactful activities. We need to stop producing so much plastic and create a network of ocean sanctuaries to give wildlife space to recover. The ocean is not our dump, marine life deserves better than plastic."</p>
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By Loveday Wright and Stuart Braun
After a Japanese-owned oil tanker struck a reef off Mauritius on July 25, a prolonged period of inaction is threatening to become an ecological disaster.
<div id="bb0a7" class="rm-shortcode" data-rm-shortcode-id="e5aefc0fff61ab1aea2f4b03c5399864"><blockquote class="twitter-tweet twitter-custom-tweet" data-twitter-tweet-id="1291765757013983238" data-partner="rebelmouse"><div style="margin:1em 0">The #oilspill is devastating but I want to honour the community mobilisation at the Mahebourg waterfront today (to… https://t.co/UWFkZFdjdi</div> — Fabiola Monty (@Fabiola Monty)<a href="https://twitter.com/LFabiolaMonty/statuses/1291765757013983238">1596815930.0</a></blockquote></div><p>"Booms are made of nylon mesh filled with #sugarcane straws all hand-stitched by Mauritian volunteers, empty plastic bottles used as buoys," described Mauritian journalist Zeenat Hansrod in a tweet. </p>
How to Tackle Oil Spills<p>The method for tackling oil spills depends on several factors, including the type and amount of oil in question, location and weather conditions.</p><p>"Once the oil comes to shore, the more intensive the cleaning technique. You can risk causing further damage," said Nicky Cariglia, an independent consultant at Marittima, who specializes in marine pollution. </p><p>"If you wanted to remove all traces of oil, the techniques available become increasingly aggressive the less oil that remains. In mangroves, you would have the added risk of causing damage by trampling," Cariglia told DW. Highly sensitive mangrove ecosystems line the Mauritius east coast that is threatened by the current spill.</p><p>Because oil normally has a lower density than water, it floats on the surface of the ocean. This means that for clean-up action to be most effective, it should happen very quickly after a spill, before the oil disperses. </p>
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