Gastrus Pure Action contains two highly specific strains of Lactobacillus reuteri that work through complementary mechanisms to address both constipation and diarrheal episodes. This dual-action approach targets the underlying gut-brain-motility axis disruption that characterizes irregular bowel function.

Lactobacillus reuteri DSM 17938 supports normal intestinal motility by producing short-chain fatty acids (SCFAs) that stimulate colonic peristalsis and reduce intraluminal pH, enhancing natural bowel movements. The strain also interacts with enteric nervous system pathways, increasing excitability of myenteric neurons via serotonin (5-HT) and BDNF modulation. Additionally, L. reuteri alters the composition of methane-producing microbiota by reducing Methanobrevibacter smithii, a key factor that normally slows transit; decreasing methane reduces inhibition of peristaltic waves, thereby normalizing motility irregularity [10].

For diarrheal conditions, Lactobacillus reuteri DSM 17938 helps reduce and shorten episodes through several coordinated mechanisms. It restores microbiota balance disrupted by infection or antibiotics, adheres to intestinal epithelial cells, and produces antimicrobial compounds such as reuterin, which inhibits pathogenic bacteria including E. coli, Salmonella, C. difficile, and rotavirus. The strain also enhances mucin production, stabilizing the mucosal barrier and preventing pathogen binding to enterocytes [10].

Clinical research demonstrates the effectiveness of both therapeutic approaches. For constipation management, L. reuteri taken twice daily for four weeks produced a significant increase in weekly bowel movements, along with reductions in abdominal discomfort, pain, and bloating. Another adult trial showed that L. reuteri reduced methane production, which correlated with improved stool frequency [10]. For diarrheal episodes, numerous clinical trials demonstrate that L. reuteri DSM 17938 significantly shortens the duration and severity of acute watery diarrhea. Administration of 1000 CFU decreased diarrhea in children by day 2, with diarrhea persisting in only 48% of high-dose L. reuteri versus 80% of placebo [10].

The inclusion of Lactobacillus reuteri (ATCC PTA 6475) provides additional support for digestive health through similar mechanisms, working synergistically with DSM 17938 to strengthen epithelial tight junctions, reduce fluid loss into the lumen, promote regulatory T-cell activity, decrease intestinal inflammation, and reduce microbial translocation. This multi-layered set of actions restores barrier integrity, reduces pathogen burden, and normalizes fluid secretion and absorption [10].