Probiotics added to that feeding frenzy the bacterium lactobacillus, which produces D-lactic acid as it breaks down sugars, The acid get absorbed in the blood and can reach the brain.
All those with brain fogginess, SIBO and/or D-lactic acidosis, were given antibiotics that targeted their bacterial population and asked to discontinue probiotics. Those without SIBO were asked to halt probiotics and stop eating yogurt, which is considered one of the best sources of probiotics. Those with SIBO and D-lactic acidosis but no brain fogginess also took antibiotics.
Following treatment, 70 percent of patients reported significant improvement in their symptoms and 85 percent said their brain fogginess was gone. Those without brain fogginess but with SIBO and high levels of D-lactic acid reported significant improvement in symptoms like bloating and cramping within three months.
Abdominal pain was the most common symptom in both groups and before treatment, six of those with brain fogginess reported a tremendous increase in their abdominal size within just a few minutes of eating.
All patients received extensive examination of their gastrointestinal tract, including a motility test, to rule out other potential causes of their symptoms. They filled out questionnaires about symptoms like abdominal pain, belching and gas and answered questions about related issues like antibiotic and probiotic use as well as food fads and yogurt consumption.
They were given carbohydrates followed by extensive metabolic testing looking at the impact on things like blood glucose and insulin levels. Levels of D-lactic acid and L-lactate acid, which results from our muscles’ use of glucose as energy and can cause muscle cramps, also were measured.
Probiotic use may be particularly problematic for patients who have known problems with motility, as well as those taking opioids and proton pump inhibitors, which reduce stomach acid secretion and so the natural destruction of excessive bacteria.
Probiotics are supposed to work in the colon and not the small intestines or stomach, Rao says, so motility issues can result in problems with probiotic bacteria reaching the proper place. A wide variety of problems, from conditions like diabetes to drugs like antidepressants and minerals like iron, can slow movement and increase the possibility that probiotics will remain too long in the upper gut where they can cause harm, he says.
Probiotics definitely can help, for example, people who have gastroenteritis, or stomach flu, or are left with diarrhea and other problems after antibiotics wipe out their natural gut bacteria, Rao says.
“In those situations, we want to build up their bacterial flora so probiotics are ideal,” he says.
Rao’s pursuit of a possible connection between probiotics, brain fogginess and bloating started with a memorable patient who developed significant amounts of both problems within a minute of eating.
“It happened right in front of our eyes,” Rao says of the dramatic abdominal distention. They knew the woman had diabetes, which can slow motility. When they looked in the blood and urine at a variety of metabolic compounds, they found the high levels of D-lactic acid and soon learned the patient used probiotics and regularly ate yogurt.
Next steps include additional studies in which the investigators better quantify and characterize the brain fogginess reported by patients and following patients for longer periods to ensure their problems remain resolved. Some patients in the current study required a couple of rounds of antibiotics, Rao notes.
Good food sources of probiotics include yogurt, sauerkraut, kimchi, kefir and dark chocolate, which are generally safe because of the small amounts of bacteria present, Rao says.
The 19-foot long small intestine has been a bit of an understudied organ, likely in part because it’s hard to visualize via the mouth or anus, Rao says. “I think the small bowel can be a source of huge mystery,” Rao says.
Your helpful gut bacteria, or microbiome, which are essential to things like a well-functioning immune system and general health, are largely in the large intestine and colon.