” I can’t eat beans!”

Or peas, or fruit, or asparagus, or onions, or mushrooms, or shallots, or tomatoes, or eggplant . . .

Too often, I hear that people identify some food intolerance, eliminate or minimize that food, experience relief from abdominal discomfort, bloating, diarrhea, skin rash, asthma attack or other reaction, then think that the problem is thereby solved.

Not even close.

Most, if not all, such reactions are not allergies nor do they reflect some unwanted component in the food. The majority of these reactions are due to small intestinal bacterial overgrowth, SIBO. Intolerance to prebiotic fibers, such as those from inulin, legumes, peas, jicama, or asparagus, is such a reliable sign of SIBO that we say that it is “pathognomic,” i.e., virtually diagnostic, especially if the reaction occurs within the first 60 minutes of consumption. Recall that in SIBO unhealthy bacterial species have ascended up from the colon and inhabit the ileum, jejunum, duodenum, and stomach, i.e., the upper gastrointestinal tract. Because the bacteria are high up the gastrointestinal tract, intolerance to, say, black beans occurs quickly because the prebiotic fiber-containing food does not need to go far down the gastrointestinal tract to encounter bacteria. Distinguish this from the gas you experience later, say, 4-12 hours after consuming a food with prebiotic fibers—this is not due to SIBO, but to fermentation of prebiotic fibers by bacteria in the colon, a normal response.

The association of intolerance to prebiotic fibers and SIBO is so solid that I call it “The Prebiotic Fiber Test“—if you experience it, you have SIBO almost without question. But the same holds true with these other food intolerances. If you are intolerant to nightshades, or FODMAPs, or fructose, or even develop new lactose intolerance, there’s a high likelihood that you have SIBO.

Because the relationship is so strong, I believe it is reasonable to proceed on a SIBO management program (such as our Undoctored Protocol for SIBO in my Undoctored Inner Circle, coupled with the feedback and guidance provided on our live Virtual Meetups) based on this reaction alone, an empiric approach, i.e., one based on your best educated guess. Or you could confirm with the AIRE device that detects breath hydrogen gas after consuming a prebiotic fiber.

The wrong thing to do is to not pursue this question and just live with SIBO. Just allowing SIBO to percolate will lead you down some unhealthy paths that include fibromyalgia, irritable bowel syndrome, autoimmune conditions, coronary disease, neurodegenerative diseases like multiple sclerosis, diverticular disease, and colon cancer. So recognize food intolerances for what they are and don’t stop at just food elimination.