Yellow Colon: A Case of Cryptosporidium Colitis

Vitamin D Modulates Intestinal Microbiota in Inflammatory Bowel Diseases

Inflammatory bowel disease (IBD) is a chronic inflammation of the gastrointestinal tract (GIT), including Crohn's disease (CD) and ulcerative colitis (UC), which differ in the location and lesion extensions. Both diseases are associated with microbiota dysbiosis, with a reduced population of butyrate-producing species, abnormal inflammatory response, and micronutrient deficiency (e.g., vitamin D hypovitaminosis). Vitamin D (VitD) is involved in immune cell differentiation, gut microbiota modulation, gene transcription, and barrier integrity. Vitamin D receptor (VDR) regulates the biological actions of the active VitD (1α,25-dihydroxyvitamin D3), and is involved in the genetic, environmental, immune, and microbial aspects of IBD. VitD deficiency is correlated with disease activity and its administration targeting a concentration of 30 ng/mL may have the potential to reduce disease activity. Moreover, VDR regulates functions of T cells and Paneth cells and modulates release of antimicrobial peptides in gut microbiota-host interactions. Meanwhile, beneficial microbial metabolites, e.g., butyrate, upregulate the VDR signaling. In this review, we summarize the clinical progress and mechanism studies on VitD/VDR related to gut microbiota modulation in IBD. We also discuss epigenetics in IBD and the probiotic regulation of VDR. Furthermore, we discuss the existing challenges and future directions. There is a lack of well-designed clinical trials exploring the appropriate dose and the influence of gender, age, ethnicity, genetics, microbiome, and metabolic disorders in IBD subtypes. To move forward, we need well-designed therapeutic studies to examine whether enhanced vitamin D will restore functions of VDR and microbiome in inhibiting chronic inflammation.

An Unconventional Diagnostic Method for Cryptosporidial Enteritis in a Healthy Host: Never Call It Quits!

Cryptosporidial enteritis has a rising incidence in the USA, mostly affecting immunocompromised individuals and children. It has a self-limiting course in healthy hosts. Herein, we present a unique case of a healthy middle-aged female who presented with a 1-month history of voluminous watery diarrhea and acute blood loss anemia. Cryptosporidial enteritis was diagnosed based on endoscopy with biopsy-proven evidence of 2 jejunal peptic ulcers infected with Cryptosporidiumspp. that was originally missed on routine stool culture, ova and parasite tests. The patient was successfully treated with nitazoxanide, and eradication of the protozoan was also confirmed on repeat endoscopic biopsies of the ulcer that were carried out 6 months later. To our knowledge, this is the first case to be reported in the literature with infective colonization of peptic ulcers with Cryptosporidiumspp. with consequent systemic symptoms.