Comparative analysis of microbiota in the ceca of broiler chickens with necrotic enteritis fed a commercial corn diet or with corn high in flavonoids (Penn HFD1)

Authors: Miska, Kate; Proszkowiec-Weglarz, Monika; BUIATTE, VINICIUS - Pennsylvania State University; MAHMOUD, MAHMOUD - Pennsylvania State University; CHOPRA, SURINGDER - Pennsylvania State University; LESKO, TYLER - Pennsylvania State University; LORENZONI, ALBERTO - Pennsylvania State University

Submitted to: Frontiers in Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/28/2023
Publication Date: 10/25/2023
Citation: Miska, K.B., Proszkowiec-Wegla, M.K., Buiatte, V., Mahmoud, M., Chopra, S., Lesko, T., Lorenzoni, A.A. 2023. Comparative analysis of microbiota in the ceca of broiler chickens with necrotic enteritis fed a commercial corn diet or with corn high in flavonoids (Penn HFD1). Frontiers in Microbiology. 2:1212130.

Interpretive Summary: Broiler type chickens are raised for meat production however their husbandry can be challenging due to several diseases which can affect the flocks causing decrease in weight gain and mortality, which results in economic losses to poultry producers. One of the diseases which can cause gastrointestinal symptoms in broilers, resulting in diarrhea, intestinal lesions, decreased interest in feed, and mortality is necrotic enteritis. This is an opportunistic infection caused by a bacterium (Clostridium perfringens), which occurs when intestinal health of the chickens in compromised by feed type, stress, parasitic infection, immune deficiency. Because many of the antibiotics which have been previously used to treat this disease are no longer available due to regulations, alternatives to antibiotics are being sought. In the current study, a strain of corn which is high in flavonoid compounds was fed to chicks with necrotic enteritis. Flavonoids are naturally occurring in plants, are anti-inflammatory, and have anti-microbial properties. In a previous study it was found that addition of high flavonoid corn decreased mortality by 50% and decreased intestinal lesions. In the current study we investigated the changes in the microbiome of the ceca (large intestine) in chickens eating high flavonoid corn. We found that most of the microbiota changes were due to infection rather than diet. Infection affected the diversity of the bacteria present in the gut, and found that Escherichia coli, and Enterococcus cecorum, which are both opportunistic pathogens, were higher in birds with necrotic enteritis. Interestingly, the level of lactic acid bacteria which are thought to beneficial were also increased in infected chickens. Even though high flavonoid corn had a positive impact on mortality and intestinal health, it did not have many significant effects on the bacteria residing in the ceca, therefore the mechanism of action of flavonoid compounds in broiler chickens with necrotic enteritis must be further investigated.

Technical Abstract: The purpose of this study was to determine the microbiota changes in the cecal luminal (CE-L) and mucosal (CE-M) populations of broiler chickens undergoing clinical necrotic enteritis (NE) (co-infected with Eimeria maxima and Clostridium perfringens) while fed a diet containing a flavonoid rich corn (PennHFD1) or control diet using commercial corns. It was previously shown that chickens fed a diet high in flavonoids had improved performance parameters, lower mortality rate, and lower incidence of intestinal lesions. Flavonoids have been shown to have anti-bacterial, immuno-modulatory, and anti-inflammatory activity. We found that most of the microbiota changes were due to infection rather than diet. The alpha diversity in the infected (IF) chickens was lower in both populations, CE-L and CE-M of the ceca. The beta diversity of microbial communities was different between infected and uninfected (CTRL) chickens, as well as between uninfected chickens fed a commercial corn diet (CTRL-A) and uninfected chickens fed a high flavonoid corn diet (CTRL-B). The beta diversity of CTRL birds was more homogenous compared to IF samples. Taxonomic analysis showed a decrease in short chain fatty acid (SCFA) producing bacteria in IF birds. An increase in lactic acid producing bacteria, Escherichia coli, and Enterococcus cecorum was also observed in IF birds. It is possible that the effect of the high flavonoid corn on the microbiota was overcome by the effect of NE, or that the positive effects of increased flavonoids in NE challenged birds are a result of mechanisms which do not involve the microbiota. The effects of high flavonoid corn on NE infections should be further investigated as a possible alternative to anti-microbials.