Diarrheal diseases remain a leading cause of deaths in children (~1.2 million/year) worldwide. In addition to its significant mortality and morbidity i developing countries, even in western countries, diarrhea associated with IBD and infection by food-borne pathogens or hospital acquired infections remains a major healthcare challenge. Therefore, better and novel treatment modalities are needed. In this regard, studies during our previous funding cycle provided pioneering in vitro and in vivo evidence for a potential probiotic Lactobacillus acidophilus (LA) based approach for the amelioration of diarrhea. We demonstrated that the mechanism of LA-mediated antidiarrheal effects involved stimulation of intestinal NaCl absorption, involving upregulation of the activities of NHE3 and DRA (the key intestinal apical membrane Na+/H+ and Cl-/HCO3- exchangers, respectively). Most importantly, the bacteria-free culture supernatant (CS) of LA was equally effective in stimulating NaCl absorption, defining a novel therapeutic modality to utilize bacteria-derived bioactive molecules, rather than live bacteria, for treating diarrheal disorders. Our studies further indicated that LA r LA- CS-induced enhancement of Cl-/HCO3- exchange activity involved increased levels of DRA on the apical membrane as well as its increased expression via transcriptional mechanisms. However, detailed cellular and molecular events governing LA- or LA-CS-induced alterations in DRA trafficking and regulation of DRA expression at the transcriptional level under normal physiology and under disease states are not known. Therefore, based on our published reports and strong preliminary data presented here we hypothesized that bacteria-free culture supernatant of L. acidophilus stimulates intestinal epithelial Cl-/HCO3- exchange activity via multiple mechanisms involving alterations of both intracellular trafficking of DRA as well as DRA expression. We also hypothesize that LA or LA-CS can combat the repression of DRA in models of IBD. We will test these hypotheses by systematic set of approaches utilizing both in vitro and in vivo models and state-of-the-art imaging and advanced molecular biology techniques. Studies proposed in Specific Aim 1 will investigate the mechanisms of LA-CS induced modulation of DRA trafficking in Caco2 cell monolayers and elucidate the role of lipid rafts, cytoskeletal and PDZ proteins;
Specific Aim 2 will focus on elucidating mechanisms of LA-CS-induced stimulation of DRA transcription in Caco2 cells;and studies in Specific Aim 3 will examine the effects of short-term as well as long-term LA treatment on DRA function and membrane targeting mechanisms in in-vivo mouse models including IBD models. These studies will not only enhance our understanding of the mechanisms underlying proabsorptive/antidiarrheal role of probiotic LA but will also highlight the potential of the secreed bioactive molecules in LA-CS in combating the IBD associated diarrhea.

Public Health Relevance

Diarrheal diseases still result in ~1.2 million deaths/year worldwide in children under the age of five. In this regard, probiotics are beneficial bacteria which have been shown to be useful in clinical trials in treating diarrheal diseases. The studies proposed in this application will determine molecular and cellular mechanisms responsible for antidiarrheal effects of a probiotic bacteria Lactobacillus acidophilus. Understanding of the mechanisms of its beneficial effects and the bacteria derived molecules responsible for them may assist in designing novel and superior treatment strategies in for diarrheal diseases.

National Institute of Health (NIH)
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Research Project (R01)
Project #
Application #
Study Section
Special Emphasis Panel (ZRG1)
Program Officer
Grey, Michael J
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
University of Illinois at Chicago
Internal Medicine/Medicine
Schools of Medicine
United States
Zip Code
Kumar, Anoop; Chatterjee, Ishita; Anbazhagan, Arivarasu N et al. (2018) Cryptosporidium parvum disrupts intestinal epithelial barrier function via altering expression of key tight junction and adherens junction proteins. Cell Microbiol 20:e12830
Engevik, Amy C; Kaji, Izumi; Engevik, Melinda A et al. (2018) Loss of MYO5B Leads to Reductions in Na+ Absorption With Maintenance of CFTR-Dependent Cl- Secretion in Enterocytes. Gastroenterology 155:1883-1897.e10
Priyadarshini, Medha; Kotlo, Kumar U; Dudeja, Pradeep K et al. (2018) Role of Short Chain Fatty Acid Receptors in Intestinal Physiology and Pathophysiology. Compr Physiol 8:1091-1115
Zhang, Yong-Guo; Singhal, Megha; Lin, Zhijie et al. (2018) Infection with enteric pathogens Salmonella typhimurium and Citrobacter rodentium modulate TGF-beta/Smad signaling pathways in the intestine. Gut Microbes 9:326-337
Jayawardena, Dulari; Guzman, Grace; Gill, Ravinder K et al. (2017) Expression and localization of VPAC1, the major receptor of vasoactive intestinal peptide along the length of the intestine. Am J Physiol Gastrointest Liver Physiol 313:G16-G25
Kumar, Anoop; Chatterjee, Ishita; Gujral, Tarunmeet et al. (2017) Activation of Nuclear Factor-?B by Tumor Necrosis Factor in Intestinal Epithelial Cells and Mouse Intestinal Epithelia Reduces Expression of the Chloride Transporter SLC26A3. Gastroenterology 153:1338-1350.e3
Singhal, Megha; Manzella, Christopher; Soni, Vinay et al. (2017) Role of SHP2 protein tyrosine phosphatase in SERT inhibition by enteropathogenic E. coli (EPEC). Am J Physiol Gastrointest Liver Physiol 312:G443-G449
Anbazhagan, Arivarasu N; Thaqi, Mentor; Priyamvada, Shubha et al. (2017) GLP-1 nanomedicine alleviates gut inflammation. Nanomedicine 13:659-665
Jayawardena, Dulari; Anbazhagan, Arivarasu N; Guzman, Grace et al. (2017) Vasoactive Intestinal Peptide Nanomedicine for the Management of Inflammatory Bowel Disease. Mol Pharm 14:3698-3708
Anbazhagan, Arivarasu N; Priyamvada, Shubha; Gujral, Tarunmeet et al. (2016) A novel anti-inflammatory role of GPR120 in intestinal epithelial cells. Am J Physiol Cell Physiol 310:C612-21

Showing the most recent 10 out of 56 publications