No abstract

1AbstractEnterotoxigenic Escherichia coli (ETEC) is a leading cause of bacterial diarrhea in travelers, military personnel and children in developing countries. Infection has the potential to cause long-term gastrointestinal dysfunction. Preventative treatments for ETEC-induced diarrhea exist, yet the effects of these treatments on gastrointestinal commensals in healthy individuals is unclear. Whether administration of a prophylactic preventative treatment for ETEC-induced diarrhea causes specific shifts in gut microbial populations in controlled environments is also unknown. Here we studied the effects of a hyperimmune bovine colostrum (IMM-124E) used in the manufacture of Travelan® (AUST L 106709) on gastrointestinal bacteria in healthy C57BL/6 mice. Using next generation sequencing, we aimed to test the onset and magnitude of potential changes to the mouse gut microbiome in response to the anti-diarrheagenic hyperimmune bovine colostrum product, rich in immunoglobulins against select ETEC strains (Travelan®, Immuron Ltd). We engineered changes in mouse fecal and cecal bacterial communities by delivering lipopolysaccharide (LPS) antibodies derived from bovine colostrum via dietary supplementation. Holstein Friesian and Jersey cows between 28- and 35-weeks’ gestation stimulated by subcutaneous delivery of three important pathogenic and antigenic determinants; LPS, flagella, and colonization factor antigen (CFA), produced a hyperimmune colostrum (IMM-124E) with demonstrated beneficial effects on health via modulation of metabolic pathways and immune function. We show that in mice administered colostrum containing LPS antibodies there was an increased abundance of potentially gut-beneficial bacteria, such as Akkermansia and Desulfovibrio, without disrupting the underlying ecology of the gastrointestinal tract. Compared to controls, there was no difference in overall weight gain, body or cecal weights or small intestine length following LPS antibody colostrum supplementation. Overall, dietary supplementation with colostrum containing LPS antibodies produced subtle alterations in gut bacterial composition of mice. Primarily, Travelan® LPS antibody treatment decreased the ratio of Firmicutes/Bacteroidetes in gut microbial populations in unchallenged healthy mice. Further studies are required to examine the effect of Travelan® LPS antibody treatment to engineer the microbiome in a diseased state and during recovery.