Intensive poultry farming faces challenges like gut inflammation in the absence of antibiotics, resulting in reduced productivity, heightened susceptibility to enteric diseases, and other complications. Alternative strategies are needed to manage inflammation and maintain sustainable poultry production. Yaks living in high-altitude hypoxic environments have specialized gut microbes. However, yak probiotics remain largely uncharacterized. We previously isolated a strain of Bacillus pumilus (named TS2) from yaks and demonstrated its potential as a probiotic in vitro. Therefore, in this study, we evaluated the in vivo growth-promoting, antioxidant, immune, and anti-inflammatory effects of Bacillus pumilus isolated from yaks in broilers. We demonstrated the safety of TS2 isolated from yaks in broilers. Furthermore, we found that TS2 increased the average daily weight gain (ADWG) and reduced the feed conversion ratio (FCR). Supplementation with TS2 also improved the mucosal morphology, the ratio of villi to crypt cells, and enzyme activity. High-throughput sequencing showed that the abundance of Lactobacillus was higher in the TS2 treated broilers. Importantly, the serum level of malondialdehyde (MDA) was reduced and the levels of total antioxidant capacity (T-AOC) and superoxide dismutase (SOD) activity were increased in the low-dose TS2 group, while the inflammatory factors interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) were downregulated compared with the control group. We demonstrated that TS2 supplementation can increase the overall growth performance and ameliorate the blood parameters related to inflammation and immunity in broilers.

The black soldier fly (BSF) rearing technology has been a promising bioconversion method for food waste (FW) disposal. However, when used independently, it currently only achieves low efficiency and biomass transformation rates (BTR). This study screened and identified two strains of gut beneficial bacteria, Bacillus cereus and Bacterium YC-LK-LKJ45. The efficiency of a complex culture formulated by these strains was investigated, focusing on enhancing FW reduction and high-value biomass production during the rearing of BSF larvae. The coculture agent group (G1-10%, with two strains in 1:1 volume ratio at a 10 % dosage) exhibited higher larval yield (627.67 g·kg-1), BTR (47.90 %), FW reduction efficiency (80.67 %), and total protein and fat yield (261.99 g·kg-1and 46.24 g·kg-1) compared to the control and the monoculture agent group (which added a single gut beneficial bacteria agent, either Bacillus cereus or Bacterium YC-LK-LKJ45). The bacterial agent altered the richness and diversity of the gut microbial community of BSF, increasing the relative abundance of beneficial bacteria such as Bacillus, Oceano bacillus, and Akkermansia, while decreasing pathogenic bacteria, such as Acinetobacter and Escherichia-Shigella. Structural equation model quantification revealed that α-diversity (λ = 0.897, p < 0.001) and BTR (λ = 0.747, p < 0.001) are crucial drivers for enhancing high-value biomass during bioaugmentation rearing. This investigation provides a theoretical framework for the effective management of food waste using BSF, enhancing its decomposition and transformation into higher-value biomass.

Immune response and inflammation highly contribute to many metabolic syndromes such as inflammatory bowel disease (IBD), ageing and cancer with disruption of host metabolic homeostasis and the gut microbiome. Icariin-1 (GH01), a small-molecule flavonoid derived from Epimedium, has been shown to protect against systemic inflammation. However, the molecular mechanisms by which GH01 ameliorates ulcerative colitis via regulation of microbiota-mediated macrophages polarization remain elusive. In this study, we found that GH01 effectively ameliorated dextran sulfate sodium (DSS)-induced colitis symptoms in mice. Disruption of intestinal barrier function, commensal microbiota and its metabolites were also significantly restored by GH01 in a dose-dependent manner. Of note, we also found that GH01 enhanced phagocytic ability of macrophages and switched macrophage phenotype from M1 to M2 both in vitro and in vivo. Such macrophage polarization was highly associated with intestinal barrier integrity and the gut microbial community. Consequently, GH01 exhibited strong anti-inflammatory capacity by inhibiting TLR4 and NF-κB pathways and proinflammatory factors (IL-6). These findings suggested that GH01 might be a potential nutritional intervention strategy for IBD treatment with the gut microbial community-meditated macrophage as the therapeutic targets.

This study aimed to understand the changes in the milk and gut microbiota of dairy cows with mastitis, and to further explore the relationship between mastitis and the microbiota. In this study, we extracted microbial DNA from healthy and mastitis cows and performed high-throughput sequencing using the Illumina NovaSeq sequencing platform. OTU clustering was performed to analyze complexity, multi-sample comparisons, differences in community structure between groups, and differential analysis of species composition and abundance. The results showed that there were differences in microbial diversity and community composition in the milk and feces of normal and mastitis cows, where the diversity of microbiota decreased and species abundance increased in the mastitis group. There was a significant difference in the flora composition of the two groups of samples (P < 0.05), especially at the genus level, the difference in the milk samples was Sphingomonas (P < 0.05) and Stenotrophomonas (P < 0.05), the differences in stool samples were Alistipes (P < 0.05), Flavonifractor (P < 0.05), Agathobacter (P < 0.05) and Pygmaiobacter (P < 0.05). In conclusion, the microbiota of the udder and intestinal tissues of dairy cows suffering from mastitis will change significantly. This suggests that the development of mastitis is related to the endogenous pathway of microbial intestinal mammary glands, but the mechanisms involved need further study.

Polycyclic aromatic hydrocarbons found in crude oil can impair fish health following sublethal exposure. However, the dysbiosis of microbial communities within the fish host and influence it has on the toxic response of fish following exposure has been less characterized, particularly in marine species. To better understand the effect of dispersed crude oil (DCO) on juvenile Atlantic cod (Gadus morhua) microbiota composition and potential targets of exposure within the gut, fish were exposed to 0.05 ppm DCO for 1, 3, 7, or 28 days and 16 S metagenomic and metatranscriptomic sequencing on the gut and RNA sequencing on intestinal content were conducted. In addition to assessing species composition, richness, and diversity from microbial gut community analysis and transcriptomic profiling, the functional capacity of the microbiome was determined. Mycoplasma and Aliivibrio were the two most abundant genera after DCO exposure and Photobacterium the most abundant genus in controls, after 28 days. Metagenomic profiles were only significantly different between treatments after a 28-day exposure. The top identified pathways were involved in energy and the biosynthesis of carbohydrates, fatty acids, amino acids, and cellular structure. Biological processes following fish transcriptomic profiling shared common pathways with microbial functional annotations such as energy, translation, amide biosynthetic process, and proteolysis. There were 58 differently expressed genes determined from metatranscriptomic profiling after 7 days of exposure. Predicted pathways that were altered included those involved in translation, signal transduction, and Wnt signaling. EIF2 signaling was consistently dysregulated following exposure to DCO, regardless of exposure duration, with impairments in IL-22 signaling and spermine and spermidine biosynthesis in fish after 28 days. Data were consistent with predictions of a potentially reduced immune response related to gastrointestinal disease. Herein, transcriptomic-level responses helped explain the relevance of differences in gut microbial communities in fish following DCO exposure.

BACKGROUND: Accumulating evidence has shown that gut microbiota plays a key role in the progression of atopic dermatitis (AD). Fecal microbiota transplantation (FMT), as an effective method to restore gut microbiota homeostasis, has been successfully applied for treating many inflammatory diseases. However, the therapeutic effect of FMT on AD remains unclear. The following study examined the effect and mechanism of FMT on AD-skin lesions in an AD mouse model.
METHODS: In this study, we exposed the shaved back skin of BALB/c mice to calcipotriol (MC903) to induce AD model. Mice were then treated with FMT, which was performed with gut microbiota from healthy mice. The gut microbiota of treated mice was tracked by 16S rRNA gene sequencing. Mice skin tissues were examined by histopathology and inflammatory cytokines change in serum by ELISA.
RESULTS: FMT had a faster trend on the reversion of the increases in skin epidermal layer thicknesses and suppressed some of the representative inflammatory cytokines. The gut microbial community in the natural recovery process varied significantly in the FMT group at day 7 (ANOSIM P = 0.0229, r = 0.2593). Notably, FMT had a long-lasting and beneficial impact on the gut microbial compositions of AD mice by increasing the ratio of Firmicutes to Bacteroidetes and the amount of butyric-producing bacteria (BPB), including Erysipelotrichaceae, Lactobacillaceae, and Eubacteriacea. Furthermore, the relative abundances of gut microbiota-mediated functional pathways involved in the cell growth and death, amino acid, energy, lipid, and carbohydrate metabolisms, and immune system increased after FMT treatment.
CONCLUSIONS: FMT modulated the gut microbiota homeostasis and affected the recovery from AD-related inflammations, suggesting that it could be used as a treatment strategy for AD patients in the clinic.

The theory of the brain-gut axis has confirmed that gut microbiota and metabolites are involved in the progression of neurodegenerative diseases through multiple pathways. However, few studies have highlighted the role of gut microbiota in cognitive impairment induced by aluminum (Al) exposure and its correlations with the homeostasis of essential metal content in the brain. To explore the relationship between alterations in the content of essential metals in the brain and relative abundance changes in gut microbiota induced by Al exposure, the Al, zinc (Zn), copper (Cu), iron (Fe), chromium (Cr), manganese (Mn), and cobalt (Co) content level in the hippocampus, olfactory bulb, and midbrain tissue were measured by inductively coupled plasma mass spectrometry (ICP-MS) methods after Al maltolate was intraperitoneally injected every other day for exposed groups. Then the unsupervised principal coordinates analysis (PCoA) and linear discriminant analysis effect size (LEfSe) were used to analyze the relative abundance of the gut microbiota community and the structure of the gut microbiome. Finally, the correlations between gut microbiota composition and essential metal content in the different exposure groups were explored by using the Pearson correlation coefficient method. Based on the results, we indicated that the content of Al in the hippocampus, olfactory bulb, and midbrain tissue was increased and then decreased with the increasing exposure duration, with peaks occurring between 14 and 30 days. Concomitantly, Al-exposure decreased the Zn, Fe, and Mn levels in these tissues. 16 S rRNA gene sequencing results indicated that significant differences in the intestinal microbial community structure at the phylum, family, and genus levels were found in the Day 90 exposed group compared with the Day 7 exposed group. Ten enriched species in the exposed group were identified as markers at the three levels. Furthermore, ten bacteria at the genus level were identified to have a significantly strong correlation (r = 0.70-0.90) with Fe, Zn, Mn, and Co.

Deoxynivalenol (DON) is a major mycotoxin present in staple foods (particularly in cereal products) that induces intestinal inflammation and disrupts intestinal integrity. Lactoferrin (LF) is a multifunctional protein that contributes to maintaining intestinal homeostasis and improving host health. However, the protective effects of LF on DON-induced intestinal dysfunction remain unclear.
This study aimed to investigate the effects of LF on DON-induced intestinal dysfunction in mice, and its underlying protective mechanism.
Male BALB/c mice (5 wk old) with similar body weights were divided into 4 groups (n = 6/group) and treated as follows for 5 wk: Veh [peroral vehicle daily, commercial (C) diet]; LF (peroral 10 mg LF/d, C diet); DON (Veh, C diet containing 12 mg DON/kg); and LF + DON (peroral 10 mg LF/d, DON diet). Intestinal morphology, tight junction proteins, cytokines, and microbial community were determined. Data were analyzed by 2-factor ANOVA or Kruskal-Wallis test.
The DON group exhibited lower final body weight (-12%), jejunal villus height (VH; -41%), and jejunal occludin expression (-36%), and higher plasma IL-1β concentration (+85%) and jejunal Il1b mRNA expression (+98%) compared with the Veh group (P < 0.05). In contrast, final body weight (+19%), jejunal VH (+49%), jejunal occludin (+53%), and intelectin 1 protein expression (+159%) were greater in LF + DON compared with DON (P < 0.05). Additionally, jejunal Il1b mRNA expression (-31%) and phosphorylation of p38 and extracellular signal regulated kinase 1/2 (-40% and - 38%) were lower in LF + DON compared with DON (P < 0.05). Furthermore, the relative abundance of Clostridium XIVa (+181%) and colonic butyrate concentration (+53%) were greater in LF + DON compared with DON (P < 0.05).
Our study highlights a promising antimycotoxin approach using LF to alleviate DON-induced intestinal dysfunction by modulating the mitogen-activated protein kinase pathway and gut microbial community in mice.

The enteric morphology, enteric microbiota structure and serum metabolomics of M. salmoides before and after infected by A. hydrophila were analysed to explore the pathogenic mechanism of A. hydrophila infection in M. salmoides. The results revealed that, after the infection of A. hydrophila, the villus boundary of largemouth bass became less obvious; the relative abundance of Proteobacteria and decreasing relative abundance of Tenericutes were increasing; genera relative abundance of putatively beneficial bacteria (Mycoplasma) were decreasing, whereas the genus Aeromonas increased after infection; serum metabolomic analysis showed that infection with A. hydrophila caused disorder to the metabolic processes of largemouth bass, particularly amino acid metabolism, and caused inflammation; several potential pathogen infection-related and significantly differential intestinal microbiota-related metabolite markers were identified, such as 6-hydroxy-5-methoxyindole glucuronide, zalcitabine, bilirubin, aciclovir. This study may provide new insights into the potential association between enteric microbiota and serum metabolism and the pathogenic mechanism of M. salmoides infected by A. hydrophila, providing a scientific basis for disease control in largemouth bass breeding.

The aquaculture industry is in need of sustainable fish feed to reduce the use of expensive and environmentally invasive wild-caught fish currently fed to many carnivorous species. The black soldier fly (BSF) has become a popular sustainable alternative protein source; however, the nutritional waste byproduct of BSF, frass, has not been extensively studied as a feed replacement in carnivorous species. This study evaluates the potential of BSF frass on the growth, body composition, and intestinal microbiome of the Florida pompano, Trachinotus carolinus. Four experimental diets were formulated containing different levels of frass, replacing plant-based carbohydrate sources. As a result of this study, the frass did not improve the growth performance, resulting in a lower specific growth rate and higher feed conversion rate. While the frass diets did not alter the body composition, the visceral somatic index (VSI) significantly increased compared to the control diet and the hepatosomatic index (HIS) was lowered. The microbiome analysis showed high variation among the diets, with the control diet having the most distinct consortia, which may have been driven by the increased levels of starch compared to frass diets. This study indicates that BSF frass may not be a suitable feed replacement for carnivorous pompano; however, frass could still potentially be a replacement feed for herbivore or detritivore fish and should be further studied.