The effects of feed supplementing Akkemansia muciniphila on incidence, severity, and gut microbiota of necrotic enteritis in chickens

Akkermansia muciniphila (AM) is a mucin-degrading anaerobe, exerting beneficial effects on gut integrity improvement, inflammatory alleviation, and metabolic regulations in humans. Excess amounts of mucin and mucogenesis in the gut facilitate the development of necrotic enteritis (NE) in chickens. The study aimed to evaluate the effects of oral inoculation of AM on NE prevention and gut modulation in a NE-reproduced model coinfecting with Clostridium perfringens (CP) and Eimeria parasites. A total of 105 commercial 1-day-old broilers were randomly allocated into 5 groups, respectively challenged with Eimeria (Eimeria group), Eimeria and CP (Eimeria+CP group), Eimeria and CP with AM (Eimeria+CP+AM group), Eimeria and AM (Eimeria+AM group), and a placebo (Noninfected group). The treatment of AM exhibited a low degree of amelioration on NE severity. The application neither protected broilers from NE by decreasing NE-positive numbers nor reached a significant reduction in lesion scores in the small intestines. The development of NE reduced species diversity in jejunal microbiota; the pretreatments of AM exacerbated the consequence by losing species richness and promoted the similarity of the jejunal microbial community presented in the Eimeria+CP group. The participation of AM enhanced the increments of genera Clostridium sensu stricto 1 and Escherichia_Shigella and decreased the number of Lactobacillus. The significant variations of genera Clostridium sensu stricto 1 and Lactobacillus in jejunal microbiota were associated with NE development and promotion. In conclusion, oral inoculation of AM promoted the development of NE and modulated the jejunal microbiota favorable for CP overgrowth in broilers. The application of AM as a probiotic in broilers should be cautious on account of the effects to predispose NE.