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Dietary iron modulates fecal microbiota and severity of enterotoxigenic E. coli infection in a weanling pig model
Author(s) -
Ji Peng,
Li Chong,
Kim Byeonghyeon,
Jinno Cynthia Nanako
Publication year - 2020
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.2020.34.s1.08708
Subject(s) - weanling , feces , enterotoxigenic escherichia coli , diarrhea , inoculation , biology , weaning , anemia , iron deficiency , hematocrit , zoology , physiology , medicine , microbiology and biotechnology , immunology , endocrinology , enterotoxin , escherichia coli , biochemistry , gene
Background Enterotoxigenic E. coli (ETEC) infection is among the leading causes of diarrhea in young children who live in resource‐limited countries, wherein iron deficiency anemia is usually more prevalent. It is debated whether iron supplementation increases the risk of enteric infection. Objective the study used a weanling piglet model to investigate the effect of dietary iron on severity of ETEC infection and host microbiota. Methods Thirty‐two weaned piglets were blocked by body weight and randomized to the treatments. Pigs were fed 1) an iron‐replete diet (150 mg iron/kg) and received sham inoculation (CON), 2) a low‐iron diet (54 mg iron/kg) and orally inoculated with ETEC (LOI), 3) the iron‐replete diet and orally inoculated with ETEC (COI), or 4) a high‐iron diet (700 mg elemental iron /kg) and orally inoculated with ETEC (HII). Pigs were individually housed with free access to water and diets. After 10 days adaptation to diet, pigs were orally inoculated with a 3‐mL dose of F18 + ETEC (10 10 cfu) or sterile saline solution for 3 days. Alertness and fecal consistency were scored daily since day 0 post‐inoculation (d0PI). Fecal samples were collected for 16S RNA sequencing and examining the presence of pathogen. Data was analyzed using PROC MIXED of SAS (v.9.4) with repeated measures for variables measured over time. Results Pathogen was positive in fecal samples from inoculated pigs on d3PI, but was absent in most pigs on d6PI. Pigs in LOI had lower hemoglobin and hematocrit compared to those in HII before ETEC infection (P < 0.05), but dietary iron content did not affect growth before infection. Enterotoxigenic E. coli infection reduced hemoglobin and hematocrits compared to CON, but only pigs in LOI had significantly retarded growth after infection (P < 0.05). There were more days of diarrhea (fecal score > 2) in LOI than in CON and COI (P < 0.05). Treatment did not affect alpha‐diversity on d0 or d7PI. Relative abundance of Actinobacteria and Firmicutes were affected by treatment on d7PI. Within the phylum of Actinobacteria , Bifidobacteriaceae was more abundant in LOI (37.3%) than that in CON (2.0%) and HII (5.0%), while the opposite pattern was observed for Coriobacteriaceae . Within the phylum of Firmicutes , Lactobacillaceae had the greatest abundance in LOI (28.8% and 31.7%) in comparison with all the other groups (7.8% – 17.7%) on d0 and d7PI (P < 0.05). Same pattern was observed for Veillonellaceae , while Clostridiaceae had the highest abundance in HII (22.8%) and the lowest in LOI (5.7%) on d7PI (P = 0.07). Conclusion Iron deficiency predisposed host to increased vulnerability to ETEC infection in weanling pigs. Both iron‐deficient and iron‐excess diet alters fecal microbiota with more prominent effect post‐ETEC infection. Support or Funding Information NIFA hatch project