Learn how your gut flora strengthens your immunity, protects you from chronic diseases and how to keep it healthy
Did you know that your body comes ‘factory-fitted’ with an army of ‘fighters’ that preserve and protect your health every waking hour of your life? That’s right. They are bacteria (and several other microorganisms, of the good kind) that live in your gut, grow with your body, and are responsible for several vital functions. Let’s get to know our soldiers a little better!
What is gut flora?
Gut means your digestive tract and flora in medical terms refers to the group of microbes that live inside as well as outside humans and other animals. Flora in relation to the human body refers to yeast, bacteria and other fungi. And hence “gut flora” refers to microorganisms that colonize your digestive system (stomach, small intestine and colon, or large intestine). This unique ecosystem is also referred to as “gut microbiota” or “gut microbiome.”
Gut flora consists of bacteria and archaea (single-celled microorganisms that are structurally similar to bacteria). Our entire digestive system is lined with bacteria, and the intestines and colon are the hotspots. An adult can have as many as 100 trillion bacteria (‘good’ as well as ‘bad’) in the gastrointestinal tract.
Our gut microbiome is our most important human organ. The gut microbiome’s role in human biology is so extensive that scientists from nearly every specialty are checking for potential health solutions in the gut. With chronic diseases on the rise across the world, the gut microbiome is now front and center in mankind’s quests for better medicines and healthier outcomes.
How does gut flora develop?
When babies are born, they have a completely or mostly sterile gut. While passing through the mother’s vagina while being born, the baby is exposed to her vaginal microorganisms. This is the baby’s first encounter with microorganisms and these organisms initiate the future colonization of the microbiome. For babies delivered through C-section, this microbiome originates once the baby is exposed to the environment and starts ingesting breast milk, formula and finally food. The gut flora then continues to evolve throughout our lifetime.
What does gut flora do?
Gut microbiome helps us break down food and turn the nutrients into things our body can use. They stop growing when they run out of food, hence the body has only what it needs. The ‘good’ bacteria also help to keep in check the ‘bad’ bacteria. The ‘good’ bacteria multiply quickly so the ‘bad’ bacteria do not have space to grow. You have ‘equilibrium’ when there is a healthy bacterial balance in your gut. The gut flora can be attributed with the following functions:
- Supports the immune system
Since our gut lining is the largest surface that is at risk of being the entry point of infectious organisms, 70 percent of our immune system resides in our gut to protect this most vulnerable entry point. In other words, 70 percent of all our immune cells are present in our gut lining.
Since our whole digestive system is lined with bacteria, and the intestines and colon being their hotspots, the bacteria thereby provide protection of the lining from harmful substances. Along with this, the ‘good’ bacteria work with the immune system at the level of the lining of our intestines to fight against disease-causing bacteria or other substances, thereby protecting our whole body.
When an imbalance of gut microbiota (known as dysbiosis) occurs, it can result in increased weakness of the gut lining, which is more commonly called ‘leaky gut.’ When there are gaps in the gut lining, toxins, bacteria, and food particles can leak into the bloodstream and cause widespread inflammation throughout the body.
Right from the time that we are born, the gut flora “teaches” our immune system how to recognize harmful bacteria and how to produce effective antibodies against them.
- Helps metabolism
Our bodily supply of vitamins and other nutrients needed for our health is provided by the gut flora. In addition, the microbiome also deals with the undigested carbohydrates in the small intestine (e.g., starch which can trigger bloating, gas and stomach pain). This association produces more nutrients, controls fat storage and epithelial cell growth. Epithelial cells are present on the surfaces of your body – skin, urinary tract, blood vessels or organs – and provide protection from viruses, both inside and outside.
- Balances our hormones
The connection between our gut (stomach) and our brain is through the vagus nerve. Changes in the gut microbiome affects your mood, pain tolerance level, happiness, behavior, cognitive health and mental health.
Your gut microbiota influences nearly every hormone in the body, including your thyroid hormones, estrogen, melatonin and stress hormones like cortisol. There is growing evidence that an imbalance in your gut flora will impact the production of certain hormones which may, in turn, lead to disorders.
Serotonin, sometimes called the ‘happy chemical’ is produced by the gut microbiome. So, literally, your happiness lies in your gut!
- Manages skin appearance
Beauty is skin deep… and managed by your gut microbiota. Your gut flora manages inflammation, oxidative stress, tissue lipid levels, glycemic control, neuropeptide levels and opportunistic bacteria. Autoimmune skin conditions like rosacea, eczema and psoriasis, and their worsening conditions are a result of an unhealthy gut. So if you want a healthy, glowing skin, take care of your gut flora first.
Hence, gut microbiome is an essential part of our digestive system as well as helps with our physical and mental health. It is imperative, therefore, to take care of our gut health. But what happens when we don’t or haven’t for a long time?
Chronic diseases: What are they and why do they happen?
A chronic disease means a disease which persists over an extended period of time and has long-lasting effects. The development of chronic diseases, spanning from gastrointestinal disorders, colorectal cancer and metabolic diseases, are all influenced by the gut microbiome. Chronic diseases (more specifically, disorders) are also referred to as “lifestyle disorders” as they usually originate through bad, or unhealthy, lifestyle choices.
For instance, type 2 diabetes, for example, occurs as a result of an unhealthy diet that is rich in simple carbohydrates that puts pressure on the glucose metabolism of the body. Tobacco and alcohol intake, sedentary lifestyle (little or no physical activity) and excessive psychological stress can also put you at risk of a chronic disorder, along with bad diet.
An unhealthy gut microbiome is also responsible for certain chronic disorders. Our body has a gut barrier (or intestinal barrier) that prevents the passage of harmful foreign antigens, microorganisms and toxins. The gut barrier also acts as a selective filter which allows the transfer of electrolytes, necessary dietary nutrients and water from the intestine. A diet high in fat increases the dysfunction of the gut barrier, making the gut ‘leakier’. As a result, bacterial content ends up making their way past the ‘gut gates’. When there are ‘bad’ bacteria more than the ‘good’ ones, you tend to have various diseases. Some of the common chronic diseases that affect the digestive system as well as other systems of the body and very likely caused, or aggravated, by unhealthy gut flora are:
- Crohn’s disease:
This is an inflammatory condition of a part or whole of the digestive tract. The gut lining is damaged in patches. Swelling develops in parts of the digestive tract, and they develop ulcers or deep sores. This results in narrowing of the passageway of the food. Although Crohn’s can develop anywhere in the digestive tract, from the mouth to the anus, it most commonly affects the last part of the small intestine and the first part of the large intestine. When the intestine narrows, it is said to have a ‘stricture’.
Symptoms of Crohn’s disease include abdominal pain along with diarrhea (sometimes with blood), weight loss, mouth sores, blocked bowel and anal tears/fissures – all again related to your gut health. These symptoms may lead to osteoporosis, arthritis, skin problems and anemia.
The cause of Crohn’s disease remains unknown. Although frequently thought to be an autoimmune disease, according to research chronic inflammation happens not because of the immune system assaulting the body itself, but because it is the result of the immune system attacking harmless bacteria, virus or even food in the gut.
An extreme complication of Crohn’s disease is creation of a fistula. Fistulas are ulcers that develop so interiorly that they can produce opening and tunnels to other organs; like connecting the intestines to the bladder, small bowel or skin, all of which can result in serious infections.
- Ulcerative colitis:
Ulcerative colitis is a form of inflammatory bowel disease (IBD), and causes inflammation, irritation and long-lasting sores in the lining of the digestive tract. It affects the innermost lining of the large intestine (colon) and rectum.
Symptoms include abdominal pain, blood stools, diarrhea (with pus or blood), increased abdominal sounds, fever, weight loss, malnutrition, urgency to defecate yet inability to do so, and rectal pain and bleeding. A healthy gut flora can prevent most of these problems.
Like Crohn’s disease, the exact cause of ulcerative colitis is unknown; however, a problematic immune system is thought to be the likely cause where the immune system mistakenly attacks healthy tissue.
Possible complications of ulcerative colitis include severe dehydration, severe bleeding, a hole in the colon (perforated colon), bone loss (osteoporosis), increased risk of colon cancer, rapidly swelling colon (toxic megacolon), increased risk of blood clots in arteries and veins, and inflammation of eyes, skin and joints.
- Irritable bowel syndrome (IBS):
This is a common disorder of the large intestine (colon). The main job of the colon is to absorb nutrients and water from partially digested food. If the colonic muscles do not work at the right speed for proper digestion and move the food along, or if the synchronization with the pelvic or rectal muscles is interrupted, this leads to slowing down the speed of food moving in the colon. This results in bloating, excess gas, mucus in the stool, stomach cramps, diarrhea and constipation, which may be signs for IBS. Antibiotics or probiotics alter the bacteria in the gut, which in turn may improve symptoms.
Symptoms include weight loss, rectal bleeding, nausea and/or recurrent vomiting, fever, abdominal pain not relieved by bowel movement, diarrhea, anemia, and onset of signs and symptoms after age 50.
The precise causative factor for irritable bowel syndrome is unknown although food allergies, stress and hormones do play an important part in triggering this disease.
Irritable bowel syndrome does not have life-threatening complications, although it is not completely harmless. IBS can cause an impacted bowel, food intolerance, malnourishment, hemorrhoids, pregnancy complications (digestive issues, heartburn), compromised quality of life resulting in depression and anxiety, etc.
If a person is more than 20% over his/her ideal body weight, or if the body mass index (BMI) is greater than 25, he/she is considered obese. A new connection has been discovered between obesity and gut bacteria. According to researchers, particular amino acids in our blood can be linked to both obesity and the gut microbiome composition. Our gut bacteria determine how our food is digested, how the fat is stored, and whether we feel full or hungry. Therefore, healthy gut bacteria are key to maintaining a healthy weight.
Obesity symptoms include increased sweating, breathlessness, snoring, feeling very tired every day, inability to perform sudden physical activity smoothly, back and joint pains, feeling isolated, low confidence and self-esteem.
Most common causes of obesity include physical inactivity, overeating, genetics, medications, diseases, social issues, etc.
Obesity, as a condition, increases the risk of developing a variety of chronic diseases like insulin resistance (leading to type 2 diabetes), high blood pressure, high cholesterol, stroke, cancer, gallstones, gout/gouty arthritis, osteoarthritis and heart attack/congestive heart failure.
- Type 2 Diabetes Mellitus:
Also known as the ‘silent killer,’ diabetes is technically a condition where the levels of glucose (a type of sugar) in the blood becomes too high. Glucose enters the body through the food one consumes. This glucose needs to be converted into energy for the body to carry on with its activities, and this job is done by a hormone called insulin which is produced in the pancreas. When insulin is not produced in adequate quantity (or not produced at all) by the body, the glucose in the body cannot be converted into energy to the extent that it should. This condition results in a surplus of glucose in the blood – and the individual is diagnosed as being a diabetic.
There are many types of diabetes; some of them are type 1, type 2 and type 3 diabetes, gestational diabetes, steroid-induced diabetes, secondary diabetes, diabetes insipidus, juvenile diabetes, etc.
The most common type, however, is type 2, or “acquired” diabetes, and hence is correctly called a lifestyle disorder. This occurs when the body is not able to utilize or manage it insulin in the correct way, a condition sometimes referred to as ‘insulin resistance’. This ‘handicap’ causes the levels of sugar (glucose) in the body to build up. When the body becomes insulin resistant or when the pancreas is unable to produce the required amount of insulin in the body, we develop type 2 diabetes.
There are a number of causes for diabetes mellitus type 2, and most of them are related to the digestive tract (or, your gut) and lifestyle. Some of the reasons that cause diabetes mellitus type 2 are being overweight, an unhealthy diet (consuming foods or drinks with sugar and simple carbohydrates, artificial sweeteners), lack of activity/exercise, stress and anxiety, family history, race, age, gestational diabetes, etc.
Lately, it has been determined that human resident microbiota associated with chronic inflammation promotes the development of type 2 diabetes mellitus. The gut microbiota is altered in diabetes type 2 patients. A healthy gut diet can lower the risk of getting this disease exponentially.
The role of gut microbiome in development of type 2 diabetes has been established. When we consume fibers in our diet, they are acted upon by our gut bacteria to produce short-chain fatty acids (SCFAs). SCFAs are known to exert an anti-inflammatory effect by enhancing the production of IgA (Immunoglobulin A, a type of antibody produced by our immune cells) and certain kinds of potent immunochemicals. SCFAs also improve insulin sensitivity (the loss of which may give rise to a diabetic condition).
A diet that has less fiber than is required leads to lowered production of SCFAs, and may subsequently lead to type 2 diabetes.
Some symptoms for type 2 diabetes include fatigue, unintended weight loss, constant hunger, lack of energy, blurry vision, dry mouth, itchy skin, high levels of thirst, urinating more frequently, areas of darkened skin usually in the neck and armpits, tingling or numb sensations in the hands or feet and wounds or infections that take more time to heal, etc.
Over time, high blood glucose levels can damage the body’s organs. That’s not all, though. This can potentially lead to critical – sometimes fatal – complications like heart attack, stroke and ailments of the kidneys, eyes, gums, feet and nerves. Indeed, more serious maladies like Alzheimer’s disease, Polycystic Ovary Syndrome (PCOS), Cushing’s Syndrome and Pancreatic Cancer have also been linked to diabetes.
- Heart disease:
As the name suggests, it covers any kind of condition that affects the functioning of the heart. Although, unlike cardiovascular disease which describes problems with the blood vessels and circulatory system as well as the heart, heart disease refers to issues and deformities in the heart itself.
Our gut microbiome produces proteins which travels all around our body and affect our health, including the condition of our heart. Our gut bacteria can affect the levels of LDL (bad) cholesterol in our blood as well as our blood pressure. People who suffer from diabetes, obesity, high blood pressure or high levels of LDL cholesterol are at an increased risk for developing heart disease.
And that is not all – bacteria in our gut can adversely affect the plaques of atherosclerosis in the arteries of our heart, which is the most common cause of heart disease. When a plaque of atherosclerosis is ruptured, it causes a clot to form in the artery. As a result, the artery narrows, thereby blocking the blood flow and causing a part of the heart muscle to die, which we know as a heart attack.
The gut microbiome can increase the likelihood of a plaque to rupture, lessen the ability of the artery to widen and increase the chance of blood to clot – all leading to a heart condition. Hence, healthy gut flora helps in keeping the heart healthy.
There are different types of heart disease, with some of them being arrhythmia, atherosclerosis, cardiomyopathy, congenital heart defects, coronary artery disease (CAD), heart infections, etc. Therefore, symptoms also vary depending on what condition a patient is suffering from; e.g., chest pain, chest tightness, chest pressure, chest discomfort, shortness of breath, numbness in your arms or legs, either racing or slow heartbeat, lightheadedness, dizziness, fatigue, etc.
Some types of heart disease are genetic, and hence may occur before a person is born. Lifestyle choices can increase the risk of heart disease – like overweight and obesity, smoking, diabetes, junk food diet, high blood pressure and cholesterol, family history, age, preeclampsia during pregnancy, being sedentary or being in a stationary position for long periods of time such as sitting at work, etc.
Complications of heart disease includes heart failure, heart attack, stroke, aneurysm, peripheral artery disease, sudden cardiac arrest, etc. Having a healthy diet and a healthy gut goes a long, long way to have a fit heart.
- Chronic kidney disease (CKD):
Chronic kidney disease results in gradual loss of kidney function. We have 2 bean-shaped organs (kidneys) as part of our renal system. Healthy kidneys clean the blood, separate waste and remove the extra fluid from our body. Kidneys also help in filtering blood and sending it back to the heart. Kidneys make renin (an enzyme), which controls our blood pressure. Kidneys also manufacture a chemical called erythropoietin, which triggers the body to make red blood cells. Vitamin D, needed for bone health among other things, is also made by the kidneys.
Therefore, with a damaged kidney, waste products and fluids can accumulate in the body, damage our other organs and eventually stop working, which can lead to a life-threatening situation.
Chronic kidney disease can introduce changes in both the structure and metabolic activity of the gut microbiota, resulting in consequences for various physiological processes. Furthermore, when we have kidney disease, it also affects the production of red blood cells and vitamin D metabolism needed for bone health.
In CKD, the accumulation of uremic toxins accelerates the progression of the disease and hence, mortality. Uremic toxins are produced by an altered gut microbiota. Therefore, reducing the accumulation of uremic toxins is important for the protection against and amelioration of renal damage.
CKD and related changes in the gut microbiota harms the intestinal barrier fitness. It also promotes transfer of bacterial elements into the circulation (the ‘bad’ bacteria start flowing in our blood). This in turn harms the immunological health by causing stubborn systemic inflammation and failure of the immune system.
Chronic kidney disease and related changes in the gut microbiota also impair cardiovascular and metabolic fitness by secreting metabolites that favor obesity, insulin resistance, endothelial (the thin layer of cells covering the inner surface of blood vessels) dysfunction and cardiovascular ageing.
Signs and symptoms of chronic kidney disease develop over time when the kidney damage progresses slowly. Signs and symptoms of kidney disease may include nausea, vomiting, fatigue and weakness, loss of appetite, change in how much you urinate, sleep problems, muscle cramps and twitches, persistent itching, swollen ankles and feet, decreased mental sharpness, chest pain, shortness of breath, high blood pressure (hypertension), etc. Unfortunately, symptoms may not appear until your kidneys are badly damaged. In the late stages of kidney disease, as you are approaching kidney failure, you may notice symptoms triggered by waste and extra fluid building up in your body.
The foremost causes of chronic kidney disease are diabetes type 2 and high blood pressure. Compromised immune system diseases, long-lasting viral illnesses, polycystic kidney disease, glomerulonephritis, interstitial nephritis, vesicoureteral reflux, pyelonephritis, etc. are other causes of chronic kidney disease.
When we suffer from chronic kidney disease, we can have problems with the rest of our bodily functions, and it also directly affects the heart. Some common complications of chronic kidney disease include heart disease, anemia, bone disease, high calcium, high potassium, fluid buildup, gout, metabolic acidosis, neurological problems (caused by chemical imbalances), stroke, encephalopathy, cognitive dysfunction, etc.
- Lyme disease:
This is a disease spread by ticks (usually carried by deer). The bacteria of the animal which the tick had bitten before you are transferred to your blood stream. In this condition, the usual sign of infection is an area of skin redness that appears where you have been bit by a tick and the redness expands. Lyme as well as other infections causes imbalance in the gut function, thereby affecting gut health. With an unhealthy gut, you are more like to develop a ‘leaky’ gut, which in turn makes you prone to developing food intolerances and sensitivities (allergies).
Rashes, fatigue; achy, stiff or swollen joints; dizziness, fever, headache, night sweats and disturbed sleep, cognitive decline, skin outbreaks, heart problems, mood changes, etc. are some of the usual signs and symptoms of Lyme disease.
Lyme disease is caused by tick bites, but researchers are unsure about the causative factor(s) for chronic Lyme disease; although there is a theory that some bacteria which survive the treatment for Lyme disease continue to cause symptoms. Lyme disease is contracted only through tick bites.
Although it sounds less dangerous than the other chronic diseases, Lyme disease can have serious complications like arthritis (specifically of the knee), heart rhythm irregularities, neurologic symptoms like facial palsy and neuropathy, and even cognitive defects like impaired memory, etc. Lyme disease affects your gut health, which in turn affects your immune system and makes you prone to infections and diseases.
A healthy gut flora population can not only help prevent, but even reverse chronic diseases.
The most common signs of an unhealthy gut are an upset stomach, unintentional weight changes, constant fatigue or disturbed sleep, skin irritation, autoimmune conditions and food intolerances. Now that we know the effects of a healthy and unhealthy gut flora on our overall health, let us avoid some bad choices and make sure we eat a gut-friendly, healthy diet to keep the chronic diseases away and lead a long, healthy life.
The following dietary approach can help maintain healthy gut flora levels:
- Consume a diverse range of foods, which can lead to a diverse microbiota. A diverse microbiota is considered to be a healthy one because the more species of bacteria you have, more are the number of health benefits they may be able to come up with.
- Probiotics have ‘friendly bacteria’ and yogurt is an excellent source of such. Gut-friendly foods of the probiotic type are kefir (fermented milk), miso (fermented soya beans and barley or rice), sauerkraut (fermented chopped cabbage), kimchi (fermented vegetables), sourdough (fermented dough), almonds, olive oil, kombucha (fermented tea drink), etc.
- Gut bacteria needs fiber to thrive, so consumption of fruits and vegetables is immensely helpful. Whole grains, peas, Brussel sprouts, legumes, beans, berries, bananas, asparagus, leeks, plant-based foods, etc. are some of the high fiber foods.
- Garlic has antifungal and antibacterial properties, which can keep the ‘bad’ bacteria controlled, and also helps balance the yeast present in the gut. Garlic and onion may have some immune system enhancing and anti-cancer properties.
- Fresh ginger, meanwhile, helps to produce stomach acid and also stimulates the digestive system to keep moving the food through the gut.
- Collagen-rich foods like salmon and bone broth may be beneficial to your gut health and overall health as well.
- Polyphenols are plant compounds that have numerous health benefits like reducing inflammation and blood pressure, and lowering cholesterol levels. Good sources of polyphenols are cocoa and dark chocolate, red wine (yes, finally some good ones!), green tea, almonds, onions, grape skins, blueberries, broccoli, etc.
- Spice things up. Spices like turmeric, ginger and garlic have powerful antibacterial chemicals that are bad for the ‘bad’ bacteria.
Be careful of the following food items and groups to preserve your gut flora health:
- Animal protein. Although quite beneficial as they are rich in protein and other nutrients essential for the body, excessive consumption might result in inflammatory bowel disease or IBD (discussed above).
- FODMAP (fermentable oligosaccharide, disaccharides, monosaccharides, polyols) diet. These are foods that contain simple sugar which may irritate the stomach. Processed foods, fruit juices, condiments, etc. fall under this category.
- Foods having antibiotics. Animals are often treated with antibiotics to reduce the risk of serious infections. Antibiotic resistance in our body may occur when there is excessive exposure to antibiotics. Antibiotics kill both the ‘good’ as well as the ‘bad’ bacteria in the gut.
- Fried foods. They are harder for the body to digest. When cooked in rich oils, they may irritate the stomach and cause diarrhea, stomach pain and gas. Fried foods encourage the growth of harmful gut bacteria as well. And to top it all, reducing fried foods limits the risk of liver disease.
Apart from the dietary measures, we also have to introduce some lifestyle changes:
- Get moving. Research has shown that active people have healthier microbiomes than inactive ones. So, move!
- Avoid unnecessary medications and antibiotics. Medicines like antacids, steroids, hormone replacers, birth control, NSAIDs (non-steroidal anti-inflammatory drugs) harm your gut flora. Antibiotics also tend to kill the ‘good’ bacteria with the ‘bad’. So, be very cautious while taking them and try to find natural alternatives wherever possible.
- Eat a healthy, diverse diet. We are what we eat – healthy food, healthy gut. The kind of food we consume effects the composition of our microbiome. Avoid sugary and processed foods or anything containing artificial sweeteners, pesticides or emulsifiers because they kill the ‘good’ bacteria. What you DON’T eat can benefit your gut as well, so intermittent fasting is also a good way to let your gut microbes rest from their regular digestive duties and recharge.
- Control your portion sizes. Gluttony is considered a sin, and for good reason too! Don’t overwork your gut bacteria day in, day out! Even they need time to regenerate… As suggested above, fasting once a while is a way to rest your gut microbes.
- Eat enough probiotics and prebiotics. As discussed above, the friendly bacteria are an asset to your gut microbiota. Eat fibrous foods, although a prebiotic powder or a probiotic drink is one of the easiest ways to give your ‘good’ bacteria a perfect powerhouse meal!
- Get dirty! Yes, you can’t be ‘too clean!’ Studies show that antibacterial soaps might be silently damaging your microbiome, and also that we need to expose ourselves to germs and dirt to train our immune system to fight them diligently. So, don’t be afraid of a little dirt and use ordinary natural soaps and water to clean either yourself or your fruits and vegetables!
- Get out! Exposure to nature, organic soil and animals makes you intermingle with a wonderful abundant mix of bacteria, which will eventually strengthen your immunity system. So try gardening, have outdoor adventures with your family and pet(s), go camping, etc. to have a healthy dose of microbes (and relieve your stress, too)!
- Try to let go of your stress because yes, stress causes chaos on all the ‘good’ microbes. When you are stressed, your gut becomes more accessible to harmful bacteria, toxins and antigens. Therefore, try to practice yoga, meditation and other techniques to relax and keep stress as far as possible (from your gut as well!).
- Get enough sleep. According to recent research, not sleeping enough has a negative effect on microbiome health, which in turn can lead to additional health issues. So, don’t take your electronic devices when you go to bed and sleep for 7-8 hours every night. Rest with your microbiome!
Take care of your gut flora, and your gut flora will return the gesture.
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