Pediococcus acidilactici is a species of lactic acid bacteria commonly used as a probiotic, with growing scientific evidence supporting its beneficial effects on the small intestine and overall gut health. This microorganism is known for its ability to survive the harsh acidic environment of the stomach and reach the small intestine alive, where it can exert its effects. Several studies have demonstrated that P. acidilactici can help maintain or restore a healthy balance of gut microbiota, improve barrier function, and inhibit pathogenic bacteria.

Research in animal models and some human trials suggests that supplementation with P. acidilactici may reduce gastrointestinal disturbances such as diarrhea, modulate immune responses in the gut, and support digestive enzyme activity. For example, strains such as P. acidilactici MA18/5M have been shown to colonize the small intestine and positively influence intestinal health by increasing levels of beneficial bacteria and reducing inflammation.

While the evidence is promising, most clinical data are still preliminary or derived from small studies. The use of P. acidilactici for supporting small intestine health is therefore rated as 3 out of 5 for evidence strength: there is a moderate scientific basis, but more robust, large-scale human studies are needed to fully confirm its benefits for this body system.