A Lesson on SIBO
If so you know someone with SIBO, you may know that managing it can be very complicated! SIBO is no fun either. Symptoms can be often very uncomfortable, and these include bloating, distention, flatulence, malabsorption, and carbohydrate fermentation to name a few. The bloating with SIBO can be so severe at times, it can add several inches to your girth!
What is SIBO? SIBO is defined as small intestinal bacterial overgrowth, which occurs bacteria in the small intestine overgrows. This can be a problem, because the small intestine is not designed to host a large population of bacteria. Antimicrobial peptides, stomach acid and motility all help keep the bacterial content of a healthy small intestine low. When this delicate balance is disturbed, SIBO can occur. Recently, SIBO has also been associated with IBS, as the prevalence of SIBO is higher in patients with IBS. In addition, SIBO has also been associated with hypothyroidism. If you have IBS and are hypothyroid, you should suspect SIBO and be evaluated for it.
SIBO can negatively affect the structure and function of the small intestine, interfering with digestion of food and absorption of nutrients. In addition, the damage that occurs in the small intestine can also cause leaky gut, which can lead to downstream effects to your immune system, such as food allergies and intolerances, systemic inflammation and autoimmune disease.
There are multiple contributors to the development of SIBO. These include functional gut disorders, hormones, enteric nervous system, food intolerances, immune system, microbiome and genes. The cause is usually complex, with major risk factors including low stomach acid, IBS, Celiac disease, IBD, diabetes, multiple courses of antibiotics, and prior bowel surgery. However, there is one area in SIBO that is often overlooked; THE BRAIN.
Say Hello to the Enteric Nervous System
The enteric nervous system is a network of over 500 million neurons that line the cells of your intestine to direct intestinal mixing and smooth muscle peristaltic contractions. The migrating motor complex (MMC) plays a big role in this system. It is a group of motor neurons and nerves that controls the smooth muscular contractions in the intestine called peristalsis. This also involves a valve that acts like a door that separates the small and large intestine called the ileocecal valve. When the MMC function is impaired, bacteria can migrate up from the large intestine into the small intestine, and start the cascade for SIBO to occur. Your brain is heavily involved in this process! In fact, the brain communicates with your gut via a very important nerve called the vagus nerve. This system of communication between your gut and brain is called the gut-brain axis. The brain controls many important functions, such as gut motility, enzyme secretion, blood flow and valve control. When this axis is not working properly, this can affect the MMC, and you lose motility and small intestinal function. Bacteria can then translocate into your small intestine. When you eat carbs, they ferment and can cause distention, which opens the bowel even further for more bacteria to enter. As a result of the discomfort, you eat less fiber containing foods to avoid the discomfort. However, cutting back on fiber, you create a deficiency in the short chain fatty acids that the good bacteria in your large intestine need, and you end up with a disproportionate of good bacteria we call “dysbiosis”. This can set up the perfect storm for leaky gut and compromised gut integrity, which can cause gut inflammation. This leads to gut inflammation can activate glial cells in the brain and brain inflammation. In fact, people with IBS sometimes have white matter lesions in the brain. The classic symptoms of brain fog and fatigue? That is your brain on fire!
Gut disorders such as SIBO are often carry a significant neurological component that is bi-directional. But which came first? Gut inflammation or brain inflammation? The chicken or the egg?
In some cases, the gut dysfunction may have been the driver of the brain inflammation. But for other people, years of excess stress and adrenaline production, depleted cortisol output, increase in inflammatory cytokines, loss of peristalsis and subsequent gut dysfunction. In addition, the excess stress can lead to thyroid dysfunction, which can also influence motility and trigger SIBO. Other triggers include blood sugar dysregulation and chronic insulin surges, glycosylated end products (AGE’s) which can also trigger brain inflammation. Chronic inflammation caused by the bacterial overgrowth of SIBO can also impair production of key neurotransmitters that are important for neurological function such as serotonin and catecholamines. Some people with SIBO may also show high levels of glutamate- which can bind the NMDA receptors in the brain, which can cause oxidative stress, neurological damage, and decreased BDNF- which just can decrease our ability to repair the damage being done to the nervous system. SIBO is a huge driver of depression, anxiety and insomnia. If you have neurological conditions and gut symptoms, it is very likely you have SIBO!
What can be done? Patients often present with a myriad of symptoms that and associated conditions that require a methodical approach to healing. The treatment approach is often times not linear, and requires investigating multiple areas that may be impairing the gut-brain axis. What is impairing the brain? What is impairing the gut? And what is impairing their communication? A full work up is required, including checking for signs of impairment in circulation, glucose, and nutrient deficiencies that can be leading to neuroinflammation. Testing and replenishing the circulating levels of neurotransmitters can go a long way as part of the therapeutic interventions. Nourishing the brain with a clean, anti-inflammatory diet, fish oil, getting control of glucose and stress management. Addressing the sources of the inflammation, including taking botanicals to assist in eradicating the bacteria in the small intestine. Work with someone who is familiar with the testing, diet and supplements that can help you get on track to healing.