Effects of tannic acid on the immunity and intestinal health of broiler chickens with necrotic enteritis infection

Abstract

Background In broiler chickens, necrotic enteritis (NE) infection can reduce production performance. Tannic acid has shown great potential as a treatment of NE in broilers. However, the appropriate dosage of tannic acid in NE of broilers and the improvement effect on intestinal health are not very clear. In this study, we aimed to investigate the effects of different doses of tannic acid on the production performance, immunity, and intestinal health of broilers by constructing an NE model with C. perfringens infection and determining the appropriate dosage of tannic acid with regard to NE. Results Challenged birds showed significant reduction in body weight, villus height, and the ratio of villus height to crypt depth (P < 0.05) and increase in the feed consumption gain ratio, intestinal lesion score, and crypt depth (P < 0.05). The infection significantly reduced the relative Bacteroidota and Ligilactobacillus abundance (P < 0.05) and increased the ratio of Firmicutes/Bacteroidota and cecal content of C. perfringens (P < 0.05). Challenged birds fed diets supplemented with tannic acid showed significantly increased mRNA expression of nutrient transport carriers and intestinal barrier genes and growth performance and reduced serum zonulin and endotoxin levels (P < 0.05). Addition of tannic acid to the diet inhibited the inflammatory response by reducing the number of coccidia oocysts in feces and the content of C. perfringens in the cecum. Specifically, tannic acid reduced the serum levels of C reactive protein, myeloperoxidase, and specific IgY and ileal mucosal secretory immunoglobulin A levels in the ileal mucosa compared with those in the NE-infected birds. NE-infected birds fed diets supplemented with tannic acid also showed significantly increased relative Anaerocolumna, Thermoanaerobacterium, and Thermosinus abundance (P < 0.05); their microbial composition and functional predictions were similar to those of the NC group. Conclusions Tannic acid in the diet alleviated NE by enhancing the intestinal barrier and absorption function. The recommended dietary tannic acid additive level is 500–750 mg/kg. Our study findings would be useful in reducing related economic losses in the broiler industry.

Tannic acid extracted from gallnut improves intestinal health with regulation of redox homeostasis and gut microbiota of weaned piglets

“…Our results showed that the addition of 3.0 kg/t TA to the diet significantly reduced certain pathogenic bacteria, such as Candidatus Brocadia, [Eubacterium] oxidoreducens group, and Escherichia-Shigella in cecal digesta. These results also support that TA can effectively inhibit the growth of harmful bacteria and maintain intestinal microbial homeostasis in weaned piglets [16], which could also explain why TA has better intestinal morphology and lower pro-inflammatory cytokines than CON. Notably, olive extracts enriched various polyphenolic compounds (especially Hydroxytyrosol) could improve antioxidant capacity and attenuate oxidative stress by altering colonic microbiota in mice [52,53], suggesting that gut microbiota play an important role in modulating redox homeostasis under dietary polyphenolic compounds treatment.…”

“…However, studies increasingly found that appropriate doses of TA can reduce diarrhea incidence and improve gut health without any adverse effect on the growth performance of piglets [12][13][14][15]. The observed positive effects of TA on weaned piglets can be attributed to its polyphenolic hydroxyl structure, which exhibits strong physiological properties such as anti-diarrhea, bacteriostasis, and antioxidant activities [16,17]. Besides, TA have found to have similar functions as a prebiotic, capable of regulating gut microbiota [18].…”

Gallnut tannic acid alleviates gut damage induced by Salmonella pullorum in broilers by enhancing barrier function and modulating microbiota

“…The invasion of S. pullorum disrupts the mucus layer and facilitates the spread of harmful substances ( 37 – 39 ). The protective effect of TA on the intestinal barrier function of broiler chickens infected with S. pullorum was evaluated in this study based on the antimicrobial properties of TA and the regulation of tight junction proteins ( 13 , 20 ). The gene expression of intestinal claudin-1, occludin, ZO-1, and MUC2, as well as the number of goblet cells, were found to be significantly reduced as a result of S. pullorum infection.…”

“…The results presented above demonstrate TA's effective antimicrobial activity and biosafety. Furthermore, TA has been shown to effectively reduce damage to the intestinal mucosa caused by oxidative stress and inflammatory responses ( 16 , 17 ), improve gut microbial composition, and enhance intestinal barrier function ( 18 – 20 ). Therefore, TA may have a preventive effect against PD and could alleviate the intestinal damage caused by S. pullorum .…”

Effect of Tannic Acid on Antioxidant Function, Immunity, and Intestinal Barrier of Broilers Co-Infected with Coccidia and Clostridium perfringens

“…Dietary TA can also alleviate tissue inflammation and protect intestinal health by lowering the mRNA levels of tissue inflammation elements and increasing the mRNA levels of intestinal intact proteins in broilers [ 11 , 12 , 13 ]. It has been shown that TA can alleviate the inflammation of broilers with NE conditions and enhance the antioxidative ability by activating the Nrf2-Keap1 signaling pathway in rats [ 14 , 15 , 16 , 17 ]. However, whether TA could improve antioxidant capacity and alleviate oxidative stress through the Nrf2-Keap1 signaling pathway in broilers with NE condition has yet to be reported.…”