Natural Pig Plasma Immunoglobulins Have Anti-Bacterial Effects: Potential for Use as Feed Supplement for Treatment of Intestinal Infections in Pigs

Hedegaard, Chris J.; Strube, Mikael L.; Hansen, Marie B.; Lindved, Bodil K.; Lihme, Allan; Boye, Mette; Heegaard, Peter M. H.

The purified plasma IgG was tested in weaning piglets orally inoculated with an ETEC F4 + isolate. It was found that the faecal clearance of F4+ E. coli was significantly faster in ppIgGfed piglets than in the infected control group not being fed ppIgG. Furthermore, deep sequencing of part of the 16S rRNA genes obtained from the total ileal microbiota revealed that the proportion of family Enterobacteriaceae was significantly lower in the group of weaners receiving the ppIgG product than in the infected control group not receiving ppIgG and the non-infected control group. Importantly, the Enterobacteriaceae family comprises E. coli. Conversely, the ileal colonization with both Enterococcoceae and Streptococcaceae was significantly higher in the pigs receiving ppIgG compared to the two control groups. The biological significance of this is uncertain. Enteroccoccus has been shown to be associated with piglet neo-natal diarrhoea, however this appears to require co-colonization with E. coli [35] , which is not the case in the present study. The Shannon-index, a measure of diversity, of the ppIgG-treated animals was higher, suggesting a more diverse microbial community which is generally linked to a healthier and more disease resilient microbiota [36] . Overall, the decreased proportion of Enterobactericeae as well as the increased diversity, suggest a direct positive effect on the ileal microbiome by ppIgG and in the context of antibiotic alternatives for ETEC treatment, the ppIgG product characterised in this study shows potential for reducing colonization by ETEC.