What causes SIBO, how is it diagnosed and how is it treated?
One of the main causes of SIBO are thought to be altered intestinal motility. This is where the normal cleansing wave of the small intestine is disrupted, or stopped. This cleansing wave is called the Migrating Motor Complex (MMC), and occurs approximately every 90 minutes, typically between meals. The function of the MMC is to wash out accumulated bacteria and propel them toward the colon. Disrupted MMC function leads to bacterial stasis, which means that bacteria are allowed to grow throughout the small intestine. Dysfunctions in the MMC can be due to increased alcohol consumption (which causes inflammation in the gut), high blood glucose levels/diabetes (which cause neuropathy to the MMC), stress and over-use of pharmaceuticals that impair GIT motility (i.e. beta-blockers, narcotics, calcium channel blockers and opiate drugs).
However, dysfunctions in the MMC are most commonly a result of gut infections from parasites or bacteria that may been picked up while travelling or from food poisoning (i.e. post infectious gastroenteritis), There are 4 main infectious organisms responsible for post infection SIBO: Campylorbacter jejumi, E.coli, salmonella and shignella. The inflammation resulting from these infections causes damage to the neurons of the MMC, which is why some people can develop SIBO after a bad bout of food poisoning or gastroenteritis.
Once SIBO occurs, the overgrown bacteria and resulting inflammation further damages the MMC. Another main driver of SIBO is decreased stomach acid production as a result of stress, ageing and overuse of ant-acid drugs (e.g. nexium) for reflux. This is because stomach acid kills “bad” bacteria before it can move into the small intestine.
Another main driver of SIBO is decreased stomach acid production as a result of stress, ageing and overuse of ant-acid drugs (e.g. nexium) for reflux. This is because stomach acid kills “bad” bacteria before it can move into the small intestine.
Lastly, overuse of antibiotics (as it imbalances the gut flora), poor diet habits (e.g. lack of fibre from fruit and veggies and high processed carb intake), ageing, alcohol consumption, long term use of drugs such as immunosuppressant and the contraceptive pill, lack of sleep, lack of exercise, stress, altered intestinal anatomy and initial colonization of bad bacteria via caesarean birth/lack of breastfeeding, can all be driving factors behind SIBO. This is because all of these factors, through various mechanisms, can cause imbalances to the gut mirco-biome, as well as affect the MMC and decrease the gut’s immune defences to prevent overgrowth. This is through various mechanisms, which revolve around damaging the MMC, increasing inflammation in the gut and altering the composition of bacteria in the gut.