Small Intestinal Bacterial Overgrowth (SIBO) occurs when excessive gut bacteria colonize the small intestines. This situation can create symptoms like painful gas, constipation (methane-dominant SIBO), diarrhea (hydrogen-dominant SIBO), abdominal cramping, and bloating.
These symptoms are more than annoyances, and if left untreated SIBO can lead to nutrient deficiencies and conditions like leaky gut, IBS (irritable bowel syndrome), IBD (inflammatory bowel disease), autoimmune disorders, diabetes, Alzheimer’s, heart disease, and even cancer over time.
Correcting SIBO typically requires following steps like eliminating foods (temporarily) from the diet that feed the bacteria in the small intestine, reducing the excess bacteria with substances (like berberine or black walnut), and then restoring balance to the gut microbiome.
The intestinal microflora is complex and contains hundreds of known bacterial species, from Lactobacillus and Bifidobacterium to Escherichia coli and Enterococcus faecalis. Some are beneficial, some are commensal, while others can be pathogenic.
Soil-based probiotics are counted among the beneficial and tend not to exacerbate symptoms of SIBO the way other probiotics, like lactobacillus, may.
Bacterial strains found in soil-based probiotics include Bacillus clausii, Bacillus coagulans, and Bacillus subtilis which tend not to colonize the small intestines or feed the bacteria that are growing there, but help modulate the immune response, assist the good bacteria in colonizing the gut, and support gut repair, among other things.
Certain foods can contain these bacterial strains, such as sauerkraut and yogurt (Bacillus coagulans), and fermented soybeans, or natto (Bacillus subtilis). Adding these foods to your daily diet can be helpful for some with SIBO. Commercial supplements of soil-based probiotics such as these can be used to assist with SIBO. However, not all products contain what they claim, and locating a reputable provider is advised.
You can find a study that evaluates label claims from commercial probiotic products on the spore count and species marketed with Bacillus clausii here.