New research offers promising insights on the role of poly-γ-glutamic acid (γ-PGA) as a potential treatment for slow transit constipation (STC), a common gastrointestinal disorder. STC, characterized by infrequent bowel movements, hard stools, and discomfort, affects millions worldwide and can severely impact quality of life. Current treatment options, particularly osmotic laxatives like polyethylene glycol (PEG), often come with side effects, prompting the need for safer alternatives.
Research conducted at Shandong University investigated the effects of γ-PGA on loperamide-induced STC in mice. The study found significant improvements among the mice treated with γ-PGA over the course of one week, with those receiving the highest dose (10 g/kg/d) exhibiting remarkable outcomes. Defecation frequency increased substantially alongside fecal water content restoration—34.23% for the high-dose group, which was markedly higher than both the lower doses and the control treatments.
“γ-PGA effectively promoted fecal output properties and enhanced gastrointestinal peristalsis function,” the authors noted, highlighting the compound’s ability to generate positive physiological changes without introducing the negative effects associated with traditional laxatives. This polymer, derived from the fermentation of glutamic acid by bacteria, demonstrates moisture retention properties beneficial for improving stool consistency.
Further analyses showed γ-PGA significantly reduced the expression of inflammatory markers such as interleukins and improved the expression of tight junction proteins responsible for maintaining intestinal barrier integrity. Histological assessments confirmed the effective repair of intestinal tissue, which is often compromised in STC. The treatment not only supported enhanced middle intestinal motility but also modulated the expression of aquaporins—proteins integral to maintaining water balance within the intestinal epithelium.
Importantly, γ-PGA also appeared to positively influence gut microbiota composition. Research suggests constipation is frequently linked to dysbiosis, where beneficial bacteria are outnumbered by harmful counterparts. Notably, γ-PGA treatment correlated with increased richness of beneficial bacterial families, including Rikenellaceae and Lachnospiraceae, positions these microorganisms as key players for gut health restoration during constipation treatment.
Conducting such animal model research allows for significant insights, yet future studies will be necessary to confirm these findings' applicability to human subjects and to explore broader therapeutic potential. “The integrity of small intestine villi is a Critical factor in assessing the severity of constipation,” emphasized the authors, pointing to the need for research focusing on gut barrier function and microbiome health.
This study contributes to the growing body of literature surrounding γ-PGA's efficacy and safety across food and biomedical applications, reiterates the urgency for new constipation treatments, and positions γ-PGA as a considerable candidate toward achieving long-term digestive health. Given its approach, the findings spark hope for patients seeking effective management of chronic constipation without exacerbation of symptoms.