Lactobacillus crispatus-Mediated Gut-Reproductive Tract Axis-Alleviated Microbial Dysbiosis and Oviductal Inflammation in a Laying Hen Model.

Oviductal inflammation (OI) significantly reduces the egg production and economic returns in poultry farming. While Lactobacillus crispatus (LAC) is effective against inflammation, its role in treating or preventing oviductal inflammation is understudied. In this study, we investigated the therapeutic mechanisms of LAC on oviductal inflammation, with a focus on reproductive tract health, microbiome, gene expression, and cytokine levels. This study involved 24 Jingfen No. 6 laying hens aged 60 weeks, divided into four groups: the CON, OI, OI + LAC, and OI + heat-killed Lactobacillus crispatus (HLAC) groups. And it included a 10-day adaptation, a 7-day period for the development of OI using inflammation-inducing drugs (the control received saline), followed by an 8-day treatment in which the CON and OI groups received 1 mL of MRS broth daily, and the OI + LAC and OI + HLAC groups were treated with live and heat-killed Lactobacillus crispatus (109 CFUs/mL), respectively, with six hens in each group. This study showed that Lactobacillus crispatus supplementation significantly reduced the oviductal inflammation and atrophy in the hens, with the affected hens showing markedly lower egg production rates (p < 0.001) compared to the control and treated groups (OI + HLAC and OI + LAC). The daily intake of fresh (OI + LAC, p = 0.076) or heat-killed (OI + HLAC, p < 0.01) Lactobacillus crispatus notably enhanced the feed conversion efficiency. The OI group suffered significant ovarian damage and vascular rupture, more so than the CON group, while Lactobacillus crispatus supplementation mitigated this damage. The IL-1ß, IL-6, and IL-8 levels were significantly elevated in the OI group compared to those in the OI + LAC group (p < 0.05), with a significant reduction in the TNF-α levels in the latter (p < 0.001). The supplementation improved the microbial composition in the cecum, isthmus, and shell gland, enriching the cecum with beneficial bacteria, such as Ruminococcus_torques_group and Megamonas. This approach fostered ovarian health and follicle differentiation and preserved the epithelial cell barrier function in the shell gland, reducing inflammatory damage in the genital tract. This dual efficacy underscores the role of the probiotic in diminishing oviductal inflammation, regardless of its state.

Agaro-oligosaccharides mitigate deoxynivalenol-induced intestinal inflammation by regulating gut microbiota and enhancing intestinal barrier function in mice.

Agarose-derived agaro-oligosaccharides (AgaroS) have been extensively studied in terms of structures and bioactivities; they reportedly possess antioxidant and anti-inflammatory activities that maintain intestinal homeostasis and host health. However, the protective effects of AgaroS on deoxynivalenol (DON)-induced intestinal dysfunction remain unclear. We investigated the effects of AgaroS on DON-induced intestinal dysfunction in mice and explored the underlying protective mechanisms. In total, 32 mice were randomly allocated to four treatments (n = 8 each) for 28 days. From day 1 to day 21, the control (CON) and DON groups received oral phosphate-buffered saline (200 µL per day); the AgaroS and AgaroS + DON groups received 200 mg AgaroS per kg body weight once daily by orogastric gavage. Experimental intestinal injury was induced by adding DON (4.8 mg per kg body weight) via gavage from day 21 to day 28. Phosphate-buffered saline was administered once daily by gavage in the CON and AgaroS groups. Herein, AgaroS supplementation led to a higher final body weight and smaller body weight loss and a lower concentration of plasma inflammatory cytokines, compared with the DON group. The DON group showed a significantly reduced ileal villus height and villus height/crypt depth, compared with the CON and AgaroS + DON groups. However, AgaroS supplementation improved DON-induced intestinal injury in mice. Compared with the DON group, ileal and colonic protein expression levels of claudin, occludin, Ki67, and mucin2 were significantly higher in the AgaroS supplementation group. Colonic levels of the anti-inflammatory cytokine IL-1ß tended to be higher in the DON group than in the AgaroS + DON group. AgaroS altered the gut microbiota composition, accompanied by increased production of short-chain fatty acids in mice. In conclusion, our findings highlight a promising anti-mycotoxin approach whereby AgaroS alleviate DON-induced intestinal inflammation by modulating intestinal barrier functional integrity and gut microbiota in mice.

Using low-protein diet in egg production for win-win of productivity and environmental benefits should be prudent: Evidence from pilot test.

A shortage of feed protein resources restricts poultry productivity. Key strategies to alleviate this problem include improvements to the structure of the gut microbiota by the appropriate intake of high-quality protein, improvements to the comprehensive protein utilization rate, and reducing the consumption of protein raw materials. In addition, damage to the environment caused by nitrogen emissions needs to be reduced. The aim of the study was to evaluate the effects of dietary protein levels on laying performance, host metabolism, ovarian health, nitrogen emissions, and the gut microbial structure and function of laying hens. In total, 360 hens at the age of 38 weeks were randomly allotted four treatments. Each of the groups consisted of nine replicates, with 10 birds per replicate, used for 12 weeks of study. Dietary protein levels of the four groups were 13.85 %, 14.41 %, 15.63 %, and 16.30 %. Results revealed that, compared with the 13.85 % crude protein (CP) group, the 15.63 % CP group experienced significantly enhanced final body weight, average daily gain, egg production, and egg mass. Compared with the 16.30 % CP group, the other groups' serum concentrations of immunoglobulin G (IgG) and immunoglobulin M (IgM) were significantly reduced. Compared with the 16.30 % CP group, the 13.85 % and 15.63 % groups had increased CP utilization rates but reduced nitrogen emission rate, and daily per egg and per kilogram egg nitrogen emissions rose with increased dietary protein levels. Compared to the 13.85 % and 14.41 % CP groups, the 16.30 % CP group exhibited a significant increase in the expression of genes related to amino acids and carbohydrate metabolic pathways. According to the linear discriminant analysis effect size diagram, the predominant bacteria in the 15.63 % CP group (e.g., Subdoligranulum, and Ruminococcaceae_UCG-013) were significantly related to CP utilization. The results of this study emphasize that production performance is significantly reduced when protein levels are too low, whereas too high protein levels lead to gut microbiota imbalance and a reduction in the utilization efficiency of nutrients. Therefore, on the premise of ensuring the health of hens, the structure of the gut microbiota can be improved by appropriately reducing protein levels, which helps to balance the relationships among host health, productivity, resources, and the environment.