Dairy based-LAB Improved Constipation Via Increasing Fecal Bulk and Decreasing Concentration of Fecal Threonine While Preserving Colonic Goblet Cell Count
Constipation, which refers to difficulties in defecation and infrequent bowel movement in emptying the gastrointestinal system that ultimately produces hardened fecal matters, is a health concern in livestock and aging animals. The present study aimed to evaluate the potential effects of dairy-isolated LAB strains to alleviate constipation as an alternative therapeutic intervention for constipation treatment in the aging model. Rats were aged via daily subcutaneous injection of D-galactose (600 mg/body weight (kg)), prior to induction of constipation via oral administration of loperamide hydrochloride (5 mg/body weight (kg)). LAB strains (<italic>L. fermentum</italic> USM 4189 or <italic>L. plantarum</italic> USM 4187) were administered daily via oral gavage (10 log CFU/day) while the control group received sterile saline. Aged rats as shown with shorter telomere lengths exhibited increased fecal bulk and soften fecal upon administration of LAB strains amid constipation as observed using the Bristol Stool Chart, accompanied by a higher fecal moisture content as compared to the control (<italic>p</italic><0.05). Fecal water-soluble metabolite profiles showed a reduced concentration of threonine upon administration of LAB strains compared to the control (<italic>p</italic><0.05). Histopathological analysis also showed that the administration of LAB strains contributed to a higher colonic goblet cell count as compared to the control (<italic>p</italic><0.05). The present study illustrates the potential of dairy-sourced LAB strains as probiotics to ameliorate the adverse effect of constipation amid aging, and as a potential dietary intervention strategy for dairy foods including yogurt and cheese.