Dietary High Sodium Fluoride Impairs Digestion and Absorption Ability, Mucosal Immunity, and Alters Cecum Microbial Community of Laying Hens

Abstract

(1) Background: This study was conducted to investigate the effects of dietary fluoride (F) on tissue retention, digestive enzymes activities, mucosal immunity, and cecum microbial community of laying hens. (2) Methods: Total of 288 37-week-old Hy-Line Gray laying hens with similar laying rate (85.16% ± 3.87%) were adapted to the basal diets for ten days, and then allocated into three groups at random (n = 9, 6, 6 replicates/group). The concentrations of F in the diets were 31.19 (the control group, CON), 431.38 (F400, low-F group) and 1237.16 mg/kg (F1200, high-F group), respectively. The trial lasted for 59 days. (3) Results: Results suggested that F residuals in duodenum responded to dietary F concentrations positively. The activities of amylase, maltase and lactase were decreased in high-F group, compared with those in the control group. The mRNA expression levels of jejunum and ileum secretory immunoglobulin A (sIgA) and Mucin 2, and sIgA concentrations were decreased inhigh-F group, than those in the control group. The observed operational taxonomic units (OTUs) of laying hens in high-F group were higher than the CON and low-F groups, and the bacterial structure was different from the other two groups. The Lactobacillus was higher in the control group, while Gammaproteobacteria, Escherichia-Shigella, Streptococcaceae, and Enterobacteriaceae were higher in the high-F group. (4) Conclusions: The actual results confirmed that dietary high F intake increased the F residuals in duodenum, and reduced the digestion and absorption of nutrients and immunity via decreasing the activities of digestive enzymes, impairing intestine mucosal immunity, and disturbing the cecum microbial homeostasis of laying hens.

Effects of dietary supplement of ε‐polylysine hydrochloride on laying performance, egg quality, serum parameters, organ index, intestinal morphology, gut microbiota and volatile fatty acids in laying hens

“…Streptococcus comprise a common group of Gram-positive cocci that are considered to be in a state of respiratory or intestinal pathological infection when their abundance increases. 59 Desulfovibrio is a sulfate-reducing bacterium that is the main cause of hydrogen sulfide release from the intestine of livestock and poultry. 60,61 Hydrogen sulfide has been reported to increase the risk of respiratory diseases in poultry and is also considered as one of the main causes of air pollution in poultry industry.…”

“…Furthermore, we found that ε‐PLH 0.05% decreased the relative abundance of Desulfovibrio and Streptococcus at the genus level. Streptococcus comprise a common group of Gram‐positive cocci that are considered to be in a state of respiratory or intestinal pathological infection when their abundance increases 59 . Desulfovibrio is a sulfate‐reducing bacterium that is the main cause of hydrogen sulfide release from the intestine of livestock and poultry 60,61 .…”

The active core microbiota of two high-yielding laying hen breeds fed with different levels of calcium and phosphorus

“…Moreover, in a companion study that used the same hens, Paffected the immune system by increasing immune cell numbers and mitogen-induced response of innate and adaptive immune cells (Hofmann et al, 2021). In contrast, the relative abundance of potential pathogen Helicobacter increased with higher levels of P in the diet, which could have indicated some effect on the immune system (Fox, 1997;Miao et al, 2020); however, the numbers of T cells and CD4 + increased in the same hens (Hofmann et al, 2021).…”