Diet-induced Changes in the Gut Micro-biome

Diet-Induced Dysbiosis of the Intestinal Microbiota and the Effects on Immunity and Disease

Read full article HERE

Kirsty Brown  †, Daniella DeCoffe  †, Erin Molcan and Deanna L. Gibson  *

Department of Biology, University of British Columbia Okanagan, Kelowna, BC V1V 1V7, Canada;

Abstract

The gastrointestinal (GI) microbiota is the collection of microbes which reside in the GI tract and represents the largest source of non-self antigens in the human body. The GI tract functions as a major immunological organ as it must maintain tolerance to commensal and dietary antigens while remaining responsive to pathogenic stimuli. If this balance is disrupted, inappropriate inflammatory processes can result, leading to host cell damage and/or autoimmunity. Evidence suggests that the composition of the intestinal microbiota can influence susceptibility to chronic disease of the intestinal tract including ulcerative colitis, Crohn’s disease, celiac disease and irritable bowel syndrome, as well as more systemic diseases such as obesity, type 1 diabetes and type 2 diabetes. Interestingly, a considerable shift in diet has coincided with increased incidence of many of these inflammatory diseases. It was originally believed that the composition of the intestinal microbiota was relatively stable from early childhood; however, recent evidence suggests that diet can cause dysbiosis, an alteration in the composition of the microbiota, which could lead to aberrant immune responses. The role of the microbiota and the potential for diet-induced dysbiosis in inflammatory conditions of the GI tract and systemic diseases will be discussed.

Microbial changes in the GI tract have profound effects on host inflammatory and metabolic responses. For example, protein-rich diets increase the activity of bacterial enzymes such as β-glucuronidase, azoreductase and nitroreductase, which produce toxic metabolites that trigger inflammatory responses. Because of the intricate balance that exists within the microbiota, alterations in one group or species may not only affect the host directly, but can also disrupt the entire microbial community. For example, members from the phyla Firmicutes, Actinobacteria, Verrucomicrobium and Bacteroidetes can degrade complex carbohydrates not absorbed by the host and can also inhibit the growth of opportunistic pathogens such as Clostridium spp. and members of Enterobacteriaceae like E. coli . Dysbiosis can also alter the metabolic activity of other members of the microbiota in the gut. Thus, it is conceivable that some diets promote the growth of microbes that could have detrimental effects on their host while other dietary factors could promote beneficial microbes. It is unknown whether diet-induced dysbiosis is a transient or long-term event. If dysbiosis is a long-term event, then postnatal nutrition could be used to promote changes in the microbiota early in life during the development of a more stable microbiota. In support of this, consumption of formula supplemented with fish oil has the capacity to alter the microbial composition in the infant; however, it is unknown if these microbial changes would be long lasting or transient. Although this study did not identify the specific microbes that changed, nor did it examine the effect on intestinal immunity, it does suggest that the microbiota could be modified through dietary factors to enrich beneficial microbes and prevent diseases associated with dysbiosis.

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Are Your Gut Microbes Making You Fat!?

Are Your Gut Microbes Making You Fat!?

There are trillions if bacteria living in your gut, that we know.  But did you know that the population of your microbes may determine if you are likely to be fat or thin?! As we study this amazing microbe machine inside of us, we are discovering the many and far reaching implications of having a healthy population of bugs in your gut.

Researchers recently found pairs of human twins in which one was obese and the other lean. They transferred gut bacteria from these twins into mice and watched what happened. The mice with bacteria from fat twins grew fat; those that got bacteria from lean twins stayed lean. The study published in Science on September 6, 2013, describes the details.

It is becoming more clear that our microbial colonies play critical roles in health, with doctors now curing people by transferring microbe-rich tissues from healthy people into sick ones. Where the term "fecal transplant" used to sound like science fiction, there is now strong enough evidence of potential benefits that there are major medical centers performing this procedure to treat resistant clostridium difficile colitis infections.  Could they be transplanting gut bugs in the future to cure obesity? Sounds crazy but perhaps not too far fetched...

I don't know about you... but I'd rather change my diet than exchange fecal matter! Keep reading on for how diet can change your microbes, too...

There is a caveat: Microbes associated with leanness can’t take up residence in mice with “obese” gut microbes unless the animals eat a healthy diet.

As part of the study, the twins’ gut microbes were transferred into mice that had been raised in a previously microbe-free environment. The researchers had a chance to observe what happens when a mouse carrying a collection of gut microbes from an obese twin is housed with another mouse carrying gut microbes from the lean twin.

“Eating a healthy diet encourages microbes associated with leanness to quickly become incorporated into the gut,” said senior author Jeffrey I. Gordon, MD, director of the Center for Genome Sciences & Systems Biology at Washington University. “But a diet high in saturated fat and low in fruits and vegetables thwarts the invasion of microbes associated with leanness. This is important as we look to develop next-generation probiotics as a treatment for obesity.”

In 2009, Gordon found that the microbes in obese individuals also lack diversity and contain more pathogenic species. Individuals with healthy microbes contain a larger variety and include species such as provatella and bifidobacter. Earlier research showed that obese individuals had a shift from more Bacteroidetes to greater proportion of Firmicutes. Those that remained lean continued to have high levels of bacteroidetes. There is also evidence showing that these gut bug populations also change as we age.  Perhaps the most important idea from that past decade of research is that the diet we consume has the ability to change our internal mileau!  More industrialized nations tend to have gut populations that favor Firmicutes while less industrialized societies that still rely heavily on unprocessed food sources have guts that remain high in Bacteroidetes.

These observations were confirmed by a recent Danish clinical study that linked the risk for metabolic disorders – obesity, cardiovascular disease, and diabetes – to a shortage of friendly intestinal.  The microbiome of bacteria-poor people were dominated by species that cause chronic inflammation in the body.

The "good" guys vs. the "bad" guys ... 

The Firmicutes ("bad" guys) and the Bacteroidetes ("good" guys)  are divisions of gut bacteria. The microbiota of the human gut is dominated by these two species, most of which are benign although a few are pathogenic.

The Firmicutes is the largest bacterial class, containing more than 250 types, including Lactobacillus, Mycoplasma, Bacillus and Clostridium.  They are a very diverse class and Clostridium species are obligate anaerobes whereas members of Bacillus form spores and many of them are obligate aerobes. Streptococcus pyogenes, the well-known cause of 'Strep throat', is also a member of the Firmicutes.

The Bacteroidetes include about 20 types. In the human gut, Bacteroidetes is probably the most abundant single genus. Species of Bacteroidetes are obligate anaerobes that are benign inhabitants of the gut. However, they are opportunistic pathogens that can cause disease if they gain access to the peritoneal cavity outside the gut, for example in bowel perforation or surgery. In addition research raises the question of how consumption of increasingly hygienic and processed food deprives our microbiota from useful environmental genes and possibly affects our health.

Could Probiotics Help?

Probiotics are bacteria that help maintain a healthful balance of microbes in the intestines, and generally benefit their host.  The average person’s digestive tract hosts about 400 kinds of probiotic bacteria, which help prevent the growth of harmful bacteria and promote healthy digestion.  Now we know they may also affect our disposition towards being thin or obese!

Lactobacillus are often given to patients following a course of antibiotics, and are also found in yogurt and most other cultured/fermented foods.  Probiotics may be used in infants to populate the gut after c-section and may benefit babies with colic.  For more on probiotics and how they can benefit your health, read this!  I believe we are just on the edge of understanding how these healthy bugs and supplementation of different strains may affect health and disease and weight.  Stay tuned for the coming research and blog articles...

So What Should I Eat?

The Paleo Diet may be beneficial in reducing your risk of chronic diseases such as diabetes, obesity, heart disease and many autoimmune and inflammatory conditions. I frequently use the basic principles of the paleo diet to help patients re-learn how to eat healthy, maintain ideal weight, and feel fabulous! Perhaps the most important thing about it is that it encourages you to get back to whole delicious real food.  It will allow you to feel better, lose weight easily and maintain muscle at any age. I challenge you to give it a try for yourself for 30 days and see if it doesn't change your life!

The Gut Immune System Connection - An Animated Video

The gut mucosa connects with the largest population of immune cells in the body!  Is it any wonder that in functional medicine we assess your gut function as one of the initial steps in cases of allergies, asthma, autoimmune disease, eczema, crohn's disease, ulcerative colitis, IBS, celiac disease, arthritis and more?  

It’s often the first point of exposure to pathogens.   Many microbes use it as a entry point into the rest of the body. The gut immune system therefore needs to be ready to respond to pathogens but at the same time it is constantly exposed to harmless environmental antigens, food particles and commensal microflora which need to be tolerated. Misdirected immune responses to harmless antigens are the underlying cause of food allergies and debilitating conditions such as inflammatory bowel disease. This animation introduces the key cells and molecular players involved in gut immune connection and disease.



By checking your gut's microbial environment and taking a functional medicine approach to health and wellness, we can actually modulate some of the underlying immune dysregulation and eliminate your symptoms!

Nature Immunology homepage: http://www.nature.com/ni/index.html

A Quick Start Guide To Paleo Diet...

You may have heard the recent buzz about Paleo Diet... so what's all the fuss about?

There are far reaching health benefits to eating more like our grandparents would have eaten...   That means real food, not the packaged processed stuff that has become norm in the Standard American Diet, or SAD for short.

The Paleo Diet may be beneficial in reducing your risk of chronic diseases such as diabetes, obesity, heart disease and many autoimmune and inflammatory conditions.   I frequently use the principles of the paleo diet to help patients re-learn how to eat healthy, maintain ideal weight, and feel fabulous!

You shouldn't be surprised to find a lack of packaged foods on the Paleo Diet menu. There were no convenience stores or super-sized grocery chains in the Stone Age.   And if you're one of the 31% of Americans who eats more packaged foods than fresh foods in your daily diet, it could be an adjustment.  What is amazing, however, are the profound benefits to your health that come from these changes.  If you suffer obesity, heart disease, high cholesterol, central weight gain, or autoimmune disease, like Hashimoto's thyroiditis, Crohn's disease, rheumatoid arthritis, or multiple sclerosis, you greatly benefit from eliminated all processed grains & sugar from your diet.  Plus you will not be eating two of the most common food allergens: gluten and dairy.  If you suffer from a leaky gut or gastrointestinal dysbiosis, the Paleo Diet will naturally restore the healthy microbial balance since there are no refined sugars or grains to feed the abnormal bacteria or yeast.

The Paleo Diet is basically this:  No sugar, No flours, No processed foods, No grains, no legumes (lectins), no dairy.  What you CAN eat is lean, clean (organic) unprocessed meats (chicken, fish, turkey, beef, bison, elk, lamb, etc), all fruits and veggies in moderation.  And coconut, nuts & seeds are to be eaten freely in unprocessed state.  If you need to make something special, almond or coconut "flour" can be used.

CORE PALEO DIET:

• Meat - GRASS-FED, not grain-fed. Grain causes the same problem in animals as they do in humans.  (bison, elk, buffalo are WONDERFUL red meats to incorporate)
• Fowl - Chicken, duck, hen, turkey…things with wings that (try to) fly.
• Fish - Wild caught fish (mercury and other toxins, like PCBs may be an issue in farmed fish)
• Eggs - Look for Omega-3 enriched eggs raised without hormones or antibiotics from free-range chickens
• Vegetables - As long as they’re not deep-fried, eat as many as you want.
• Oils - Olive oil, coconut oil, avocado oil – think natural.  No soybeans oil or processed oils.
• Fruits - Have natural sugar, and can be higher in calories, so limit if you’re trying to lose weight.
• Nuts - High in calories, so they’re good for a snack, but don’t eat bags and bags of them.
• Tubers - Sweet potatoes and yams.  Higher in calories and carbs, so these are good for right after a workout to replenish your glycogen levels

What's not allowed when following the Paloe diet?

• Grains (including popular cereal grains such as barley, corn, oats, rice, rye and wheat)
• Beans or legumes
• Dairy products
• Refined salt
• Refined sugars or artificial sweetners
• Refined fats
• Canned or processed meats
• Soda and fruit juices
• All chemicals, additives, artificial flavorings, MSG, yeast.

Perhaps the most important thing about Paleo is it encourages you to get back to whole delicious real food!  It will allow you to feel better, lose weight easily and maintain muscle at any age.  I challenge you to give it a try for yourself for 30 days and see if it doesn't change your life!


More Resources for Paleo Diet:

http://paleophysiciansnetwork.com
http://www.marksdailyapple.com
http://www.westonaprice.org/

Healthy Gut = Healthy You!

There is a microbial zoo living inside you, literally trillions of microscopic organisms―more than 10,000 different kinds of them―all co-existing with each other and you.

In fact they outnumber you ten to one and ninety percent of the genetic material, (DNA and RNA) in your body is not yours, it belongs to the bacteria that is located mostly in your gut, but some also live on your skin and even in your nose.

Exactly what those different life forms do has been the subject of some exciting research in recent years, and while a few of these organisms can sometimes wreak havoc with your system, the majority of these little "bugs" are good, helping you digest your food, stay protected from infections, and even keeping your immune system properly regulated to fend off autoimmune diseases like asthma, allergies, and diabetes.

The community of microbes living on and in your body is unique to you – like your fingerprints – and is now being regarded as a key contributor to your overall health.

More and more, science is finding that teeny tiny creatures living in your gut are there for a definite purpose. Known as your microbiome, about 100 trillion of these cells populate your body, particularly your intestines and other parts of your digestive system.

Although some of these bacteria can make you sick, the majority are good, and they work together as to aid your digestive system and keep you well. Beneficial bacteria, better known as probiotics, along with a host of other microorganisms, are so crucial to your health that researchers have compared them to "a newly recognized organ." We now know that your microflora influence your:

• Immune system function
• Brain development, mental health, and memory
• Obesity
• Genetic expression 
• Risk of diseases, including autoimmune disease, cancer, diabetes, and autism

According to the featured article in Time Magazine:

"Our surprisingly complex internal ecology has been a hot topic in medicine lately. Initiatives such as the Human Microbiome Project, an extension of the Human Genome Project, have been working tirelessly to probe potential links between the human microbiota and human health, and to construct strategies for manipulating the bacteria so that they work with us rather than against us.

...They've been linked to a range of nasty conditions, including obesity, arthritis, and high cholesterol. Now, two newer areas of research are pushing the field even further, looking at the possible gut bug link to a pair of very different conditions: autism and irritable bowel disease."

Most people, including many physicians, do not realize that 80 percent of your immune system is located in your digestive tract, making a healthy gut a major focal point in your efforts to achieve optimal health. In fact, the root of many health problems is related to an imbalance of intestinal bacteria.  

The beneficial bacteria in your gut has actually been found to help prevent allergies by training your immune system to distinguish between pathogens and non-harmful antigens and respond appropriately – and this may be one reason why they also appear so beneficial in conditions like allergies, asthma, and eczema

 Like it or not, the bugs in your gut have a lot to say about your health!  This is why I frequently test patients gut function for common complaints such as fatigue, migraines, mood disorders, depression, anxiety or insomnia, ecezma, allergies, asthma, autism, and even trouble with concentration & memory.  Getting the gut bugs back into proper balance is critical to your overall health and especially the health of your immune system.  The simplest way to jump start your overall health is pay attention to the gut...  Eliminate sugar and refined flours from your diet and add a high dose probiotic to you regimen.  You'll be well on your way to a happy and helpful intestinal "zoo"!

http://www.health.harvard.edu/healthbeat/the-gut-brain-connection
http://www.mercola.com/
http://www.metametrix.com/test-menu/profiles/gastrointestinal-function/dna-stool-analysis-gi-effects
https://wsunews.wsu.edu/pages/publications.asp?Action=Detail&PublicationID=32253&TypeID=1