The Claims:
We are hearing and reading about all kinds of stuff that can disrupt the gut: medicine by-products and antibiotics, stuff in our water supply, chemicals and pesticides in the ground that leech into our fruits and vegetables (or sprayed directly on them), chemical additives and preservatives in processed foods, hormones and antibiotics in cows, pigs, and chickens, and whatever else we are exposed to and absorb in our day to day lives. That’s quite a list, and some of it seems unavoidable.
Considering the seriously important functions of the gut, it is really important to maintain a ‘healthy gut’. So, what does that mean and how do we do it? And, how many of you, like me, have experienced symptoms of dysbiosis (an unbalanced gut)? These are the things that many people don’t really like to talk about (we dietitians get used to it); diarrhea, constipation, loss of appetite, fatigue, and pain from gas and bloating. These gut symptoms can also lead to greater and more serious imbalances within the body.
The Science:
The gut is actually a pipeline throughout the body and is not actually inside the body. It is a system of organs and ‘tubes’ which food passes through from mouth to anus. This basically includes the mouth, esophagus, stomach, small intestine, large intestine, and anus. Everything we need from food and fluids must be absorbed through our intestinal walls in order to enter the body and be used. Therefore, it is very important to have a healthy gut in order to absorb and process nutrients effectively as well as eliminate non-nutrients (toxins, chemicals, etc.). The terms ‘gut permeability’ and ‘intestinal integrity’ are both used to describe this process.
Now, about those organisms…
Intestinal flora, gut microbes, healthy bacteria- there are different names for the myriad bacteria that live inside our gut. Healthy, normal gut function REQUIRES these bacteria populations, as well as the gastric mucosa (the inside lining of the intestinal walls where these little guys adhere and function, the barrier between inside the gut and inside the body). There are an estimated 100 trillion bacteria inside the human gut, which includes hundreds of different species in both the small and large intestines (1). The primary functions of these bacteria and the lining of the intestines are:
-maintain proper pH for good bacteria to thrive and bad bacteria (pathogens) cannot thrive.
-breakdown food (digestion) for proper absorption through mucosal wall into bloodstream.
-to prevent harmful stuff from being absorbed, such as drug and chemical by-products, foreign or ‘non-food’ food ingredients, and bacteria waste (1).
-production of certain vitamins including vitamin B12 and vitamin K.
-maintain a strong immune system.
In fact, the gut is the largest part of our body’s immune system. Termed GALT, or gut-associated lymphoid tissue, 50-60% of the body’s lymph tissue surrounds the gut. Galt contains more lymphocytes (white blood cells, immune system cells) than anywhere else in the body (1). This means that if something harmful does get through the intestinal lining, GALT will get it before it enters our bloodstream. FYI, the other areas where lymphatic tissue is found include the neck, underarm and inner thigh areas.
In 2008, the National Institutes of Health launched the Human Microbiome Project, to identify the microorganisms inside the body. Consider this: “Within the body of a healthy adult, microbial cells are estimated to outnumber human cells ten to one”(2). Of course there are bacterium all over the body (in our noses, ears, eyes, mouth, and genitals also), but such an astounding amount in the gut. It is now known that this microbiome plays an integral role in health and disease, and research is identifying more and more unique bacteria and their role in human health. Exciting stuff!
Some of the more well-known and studied beneficial organisms include lactobacillis and bifidobacterium. One such study showed that certain strains of bifidobacterium are proportionately linked to immune cells (i.e. more healthy bacteria present = more immune cells)(3). Another study at the University of Maryland links 26 species of bacteria to metabolic syndrome, a term for health risks associated with obesity, diabetes, and heart disease (4). And another study showed that with a healthy gut pH, good bacteria actually produce organic acids that destroy harmful bacteria inside the gut (5)!
There is a plethora of research going on, and it is safe to say that in the near future we will be seeing more and more ways to improve health by altering or restoring balance to this immense culture of bacterial organisms inside our bodies.
My two cents:
Considering how connected these organisms are to keeping us healthy, it is essential to ensure that our gut environment is properly balanced. Some signs of a balanced gut are normal food and fluid intake (with a diet rich in fiber and healthy fats and fluids), and being ‘regular’. Being ‘regular’ means different things for different people. If you are eating food everyday, then you should be eliminating waste everyday too. For many people this means going number 2 once daily. For others, it can mean several times a day. There is no ideal that fits every person, as these things depend on diet, fluid intake, physical activity, etc.
Dysbiosis, or gut imbalance, can produce many different symptoms. Without getting too gory here, one can have irregularity, bloating, pain, or intestinal inflammation. Think of these symptoms as a message from your gut. Also, keep in mind that one distressing symptom in the gut often leads to other symptoms, including fatigue, poor appetite, perhaps even weight loss due to not absorbing nutrients properly. I would also argue that symptoms of gut distress could be due to emotional stress. This is an eastern philosophy, and I can attest that I’ve seen enough proof of this in my life to believe that it is all connected. Sure, we cannot physically poop out a stressful feeling or emotion, but the gut is the largest system of elimination in the body (the others being the lungs, skin, and urinary tract), and sometimes it will try!
So, if you are experiencing gastro-intestinal distress, what should you do? Before running out to spend money on a bunch of stuff the person at the health food store tells you to buy, take a look at a few things going on in your life. Perhaps you can identify a recent event or change in your life that altered your ‘gut health’. This could be a major physical or emotional stressor, antibiotic or other pharmaceutical therapy, a change in your food/fluid intake, or a change in your daily schedule that has affected your food intake. Whatever the cause, fortunately for us, our diet has some serious power over the gut, and this means we can often fix things with diet and perhaps a supplement.
To restore or rebalance the gut, first make sure your diet has the necessary ingredients to support a healthy gut environment. This means lots of fiber from fruits, vegetables, and whole grains. Get enough healthy fats. Make sure you are drinking enough water to keep things moving. Try to eat small, frequent meals and snacks for consistency. Include chlorophyll-rich foods that can inhibit bad flora in the digestive tract, making it more habitable for the good flora (6). Chlorophyll-rich foods include greens, wheat grass, algae and seaweed.
Second, eat prebiotics and probiotcs, to ensure that your gut is happily populated with the good bacteria. Prebiotics are basically fibers and sugars that feed the good bacteria, and they are found in dietary fibers and fructo-oligosaccharides, or FOS. Foods such as honey, beer, onions, asparagus, rye, bananas, oats, and burdock root are good sources of prebiotics (1). Probiotics are the actual good bacteria we need to be living inside the intestines. Probiotics are in fermented or cultured foods such as yogurt and kefir, tempeh and miso, soy sauce, sauerkraut, and pickles and vinegars Note that the pasteurization process kills off the bacteria, so look for unpasteurized products to ensure the bacteria are alive and functional.
Third, consider probiotic supplements. They are increasingly popular, and can provide millions more bacteria than cultured foods alone. As usual, be aware of what you are buying. A study showed that not all lactobacillis supplements are effective, i.e. some strains adhere in the gut and work and some do not adhere and are flushed right out (not beneficial) (5). In this study, the strain called ‘North Carolina Food Microbiology strain, or NCFM, was the most effective. You should be able to find out this information from a supplement company, and it may be written on the supplement bottle. I checked the website of a few companies and they did say where their probiotics came from; this is an important step to ensure you are getting what you want and not wasting your time and money. I hope this article has shed some light on these organisms and their importance to our health.
References
1. Mahan L.K., Escott-Stump S. Krause’s Food, Nutrition, and Diet Therapy, 10th ed. 2000 W. B. Sounders Company.
2. National Institutes of Health Human Microbiome project
3. H. Yasui, N. Nagaoka, A. Mike, K. Hayakawa, M. Ohwaki. Detection of Bifidobacterium Strains that Induce Large Quantities of IgA. Microbial Ecology in Health and Disease. 1992, vol. 5:155-162.
4. University of Maryland
5. Schauss AG. Lactobacillus acidophilus: method of action, clinical application, and toxicity data. 1990, J Adv Med 3:163-178.
6. Pitchford, Paul. Healing with Whole Foods, Oriental Traditions and Modern Nutrition. 1993 North Atlantic Books.
