ABSTRACT
OBJECTIVE: To determine the efficacy of oral supplementation of the gut enzyme intestinal alkaline phosphatase (IAP) in preventing antibiotic-associated infections from Salmonella enterica serovar Typhimurium (S. Typhimurium) and Clostridium difficile. BACKGROUND: The intestinal microbiota plays a pivotal role in human health and well-being. Antibiotics inherently cause dysbiosis, an imbalance in the number and composition of intestinal commensal bacteria, which leads to susceptibility to opportunistic bacterial infections. Previously, we have shown that IAP preserves the normal homeostasis of intestinal microbiota and that oral supplementation with calf IAP (cIAP) rapidly restores the normal gut flora. We hypothesized that oral IAP supplementation would protect against antibiotic-associated bacterial infections. METHODS: C57BL/6 mice were treated with antibiotic(s) ± cIAP in the drinking water, followed by oral gavage of S. Typhimurium or C. difficile. Mice were observed for clinical conditions and mortality. After a defined period of time, mice were killed and investigated for hematological, inflammatory, and histological changes. RESULTS: We observed that oral supplementation with cIAP during antibiotic treatment protects mice from infections with S. Typhimurium as well as with C. difficile. Animals given IAP maintained their weight, had reduced clinical severity and gut inflammation, and showed improved survival. CONCLUSIONS: Oral IAP supplementation protected mice from antibiotic-associated bacterial infections. We postulate that oral IAP supplementation could represent a novel therapy to protect against antibiotic-associated diarrhea (AAD), C. difficile-associated disease (CDAD), and other enteric infections in humans.
Subject(s)
Alkaline Phosphatase/therapeutic use , Anti-Bacterial Agents/adverse effects , Clostridioides difficile , Clostridium Infections/prevention & control , Gastrointestinal Agents/therapeutic use , Salmonella Infections/prevention & control , Salmonella typhimurium , Administration, Oral , Alkaline Phosphatase/metabolism , Alkaline Phosphatase/pharmacology , Animals , Anti-Bacterial Agents/administration & dosage , Biomarkers/metabolism , Clostridium Infections/etiology , Colon/drug effects , Colon/metabolism , Colon/microbiology , Diarrhea/etiology , Diarrhea/prevention & control , Female , Gastrointestinal Agents/pharmacology , Intestinal Mucosa/drug effects , Intestinal Mucosa/metabolism , Intestinal Mucosa/microbiology , Mice , Mice, Inbred C57BL , Salmonella Infections/etiology , Streptomycin/administration & dosage , Streptomycin/adverse effects , Treatment OutcomeABSTRACT
BACKGROUND: The brush-border enzyme intestinal alkaline phosphatase (IAP) functions as a gut mucosal defense factor and detoxifies different toll-like receptor ligands. This study aimed to determine the therapeutic effects of locally administered calf IAP (cIAP) in a cecal ligation and puncture (CLP) model of polymicrobial sepsis. METHODS: C57BL/6 mice underwent CLP followed by intraperitoneal injection of cIAP or normal saline. Blood leukocyte counts, levels of cytokines and liver enzymes, and lung myeloperoxidase activity were determined. Peritoneal lavage fluid (PLF) was assayed for neutrophil infiltration and both aerobic and anaerobic bacterial counts. RESULTS: After intraperitoneal injection, cIAP activity in PLF decreased 50% within 15 min with minimal activity evident at 4 h. Compared with irrigation with normal saline, cIAP irrigation increased the 7-day survival rate in mice undergoing CLP, with maximal effects seen at 25 units of cIAP (0% vs. 46% survival rate, respectively; p < 0.001). cIAP treatment reduced lung inflammation, liver damage and levels of tumor necrosis factor alpha and interleukin-6. CONCLUSIONS: Peritoneal irrigation with cIAP significantly enhances survival in a mouse model of peritonitis, likely through reduction of local inflammation and remote organ damage. We suggest that intraperitoneal cIAP irrigation could be a novel therapy for intra-abdominal sepsis.
Subject(s)
Alkaline Phosphatase/administration & dosage , Peritoneal Lavage/methods , Peritonitis/prevention & control , Animals , Disease Models, Animal , Male , Mice , Mice, Inbred C57BL , Treatment OutcomeABSTRACT
BACKGROUND: The brush border enzyme intestinal alkaline phosphatase (IAP) functions as a gut mucosal defense factor and is protective against dextran sulfate sodium (DSS)-induced acute injury in rats. The present study evaluated the potential therapeutic role for orally administered calf IAP (cIAP) in two independent mouse models of chronic colitis: 1) DSS-induced chronic colitis, and 2) chronic spontaneous colitis in Wiskott-Aldrich Syndrome protein (WASP)-deficient (knockout) mice that is accelerated by irradiation. METHODS: The wildtype (WT) and IAP knockout (IAP-KO) mice received four cycles of 2% DSS ad libitum for 7 days. Each cycle was followed by a 7-day DSS-free interval during which mice received either cIAP or vehicle in the drinking water. The WASP-KO mice received either vehicle or cIAP for 6 weeks beginning on the day of irradiation. RESULTS: Microscopic colitis scores of DSS-treated IAP-KO mice were higher than DSS-treated WT mice (52±3.8 versus 28.8±6.6, respectively, P<0.0001). cIAP treatment attenuated the disease in both groups (KO=30.7±6.01, WT=18.7±5.0, P<0.05). In irradiated WASP-KO mice cIAP also attenuated colitis compared to control groups (3.3±0.52 versus 6.2±0.34, respectively, P<0.001). Tissue myeloperoxidase activity and proinflammatory cytokines were significantly decreased by cIAP treatment. CONCLUSIONS: Endogenous IAP appears to play a role in protecting the host against chronic colitis. Orally administered cIAP exerts a protective effect in two independent mouse models of chronic colitis and may represent a novel therapy for human IBD.
