What happens if your microbiome becomes too excessive and colonizes parts of the body where it really shouldn’t set up camp? SIBO, or Small Intestinal Bacterial Overgrowth, is an example of just that! Since this comes up very frequently in discussions with patients, it’s time to share some information about it. This problem is much more common than most would realize, and like many such things can be looked at as a “spectrum” from mild to severe/debilitating. If you feel worse after eating, and feel like taking probiotics makes things worse instead of better, these are some of the symptoms of low stomach acidity.
In the normally functioning digestive tract, the stomach is (relatively) sterile, having a very low pH due to the production of HCl, hydrochloric acid along with enzymes. This means that the stomach is a filter of sorts, killing most bacteria and viruses that might be present on food or beverage you consume. This understanding is validated by the observation that an animal’s stomach acidity is directly related to its place in the food chain. Animals that are pure carrion eaters or predators have the most acidic stomach secretions, while those that eat plants have the least. This serves two purposes: the first is to disinfect food that may even be actively decomposing, while the second is to break the peptide bonds that hold amino acids together to build proteins in meat. Since the stomach is so acidic in meat-eaters, they can eat roadkill and not become ill. A healthy human’s stomach acid inhibits bacterial growth in the stomach and the first part of the small intestine, before it is neutralized by bile secretions. This limits the amount of bacteria that can exist in those areas. This is part of our evolutionary heritage that allowed early Humans to survive on anything from seafood to insects, hunted or trapped meat animals, or stealing the prey of other predators.
Modern lifestyles conspire to reduce this needed acidity. Lack of sleep, too much stimulation, poor breathing dynamics all cause an autonomic imbalance that promotes everything from high blood pressure to poor digestion from low stomach acid. If stomach acid stays abnormally low for too long though, some organisms such as Helicobacter pylori can colonize and take over. This organism will then inhibit stomach acid production, wrecking your health in the process. So, without high stomach acid levels the predator (or human) would get infections and become ill; he also wouldn’t be able to digest the meat he consumes. Humans do not produce quite the stomach acid levels of a cat or dog, but are much closer to that level than a goat or cow.
The first question that brings up is the old debate about whether we are evolved to be vegetarians or meat-eaters. The facts here point squarely toward our physiology being optimized for some of each; definitely a meat-eater but capable of digesting plants too.
It is important to note that in this way, our individual “optimum diet” may be tied to our gastric acid status. If you have low stomach acidity, you’re not likely to digest meat very well, and may find yourself gravitating toward a vegetarian diet. If this choice is made due to low stomach acidity, it’s really running from the problem and still leaving the door open to a dysfunctional disease state. On the other hand, if you’d really like to do well on a Paleo type diet, you should also make sure your autonomics are balanced enough that you can produce adequate stomach acid to break down meat.
The second question is about what would happen if our stomach were not acidic? The obvious answer is bacterial colonization of the stomach and small intestine, with overgrowth compared to the normal condition. This results in a variety of symptoms, from heartburn (think summer roadkill in your stomach…ick) to bloating, allergic sensitization, indigestion, etc. It most definitely results in disruption of the entire microbiome downstream from the stomach also, with many consequences!
Now it gets interesting: What do most people do when presented with those symptoms? Take antacids! I have seen many patients who have been prescribed PPI (protein pump inhibitor; acid-blocking) medications, despite having never undergone any tests to confirm their symptoms indicated excess stomach acid. Stomach acidity declines with age, which is probably because of autonomic imbalance. Our fight-or-flight system (sympathetic system) becomes the dominant system when we’re under stress, fatigued, or if our brain is slowing down. Sound familiar? The parasympathetic system is stimulated by relaxation, deep breathing, less stress, slow relaxed eating, better sleep. Are you getting these things in your life?
To really build a balanced and high-functioning microbiome, it is necessary to start with balanced stomach function, then work downstream from there. Better liver function, small intestine function, large intestine function. One of the reasons many people cannot balance their large intestinal microbiome is that they haven’t managed their stress, breathing, sleep, and eating habits and therefore still have low stomach acid and SIBO to one degree or another.
Lifestyle habits that can help re-balance your autonomic function include deep breathing, yoga, meditation, taking time for yourself to do those things you love, scheduling and planning sleep more effectively, and taking the time to relax and breathe when you eat. There are also very specific functional neurology rehab activities that can aid in this goal. It is also possible to take a supplement that includes HCl and enzymes, to help kill off excess bacteria/H. pylori and begin to heal from SIBO.
So, be nice to your stomach, and your symbionts will thank you!