Host Health Research Articles

Opportunities and challenges of a community-based bull breeding programme: a case of the regional pastoral livelihood resilience project in Uganda

The Regional Pastoral Livelihood Resilience Project Community-Based Breeding Programme (CBBP) was designed with the objective of increasing production and productivity of local Zebu cattle by introducing Sahiwal bulls among sedentary and agro-pastoral livestock farmers. This study mapped out actors, their roles and level of influence in the CBBP as well as the opportunities and challenges encountered during its implementation using the Process Net-Map tool. The results revealed that there were differences in number and type of influential actors between sedentary and agro-pastoral livestock farmers. The bull host and subcounty veterinary officer were the most influential actors among the sedentary livestock farmers whereas it was the herdsman, bull host, and Community Animal Health Workers (CAHWs) among the agro-pastoral farmers. The CBBP was associated with benefits such as increased market value for cattle, reduced chances for cattle rustling, increased cattle productivity in terms of milk and beef production volumes and ease of access to veterinary services. In contrast, the challenges encountered were related to both governance (limited availability of veterinarians, cattle rustling, exclusion of farmers in the planning phase of the CBBP, political interference and failure of collective action) and bull management (high costs of keeping and maintaining the bulls in terms of feeding, housing, watering and veterinary care, heavy bulls injuring or breaking the small cows, sexually transmitted reproductive diseases among others). Lastly, this paper recommends adoption of a combination of well-organized and facilitated Artificial Insemination (AI) programmes alongside the improved bull service scheme as each has capacity to address the challenges of another.

Exploring the Probiotic Potential of Bacteroides spp. Within One Health Paradigm.

Probiotics are pivotal in maintaining or restoring the balance of human intestinal microbiota, a crucial factor in mitigating diseases and preserving the host's health. Exploration into Bacteroides spp. reveals substantial promise in their development as next-generation probiotics due to their profound interaction with host immune cells and capability to regulate the microbiome's metabolism by significantly impacting metabolite production. These beneficial bacteria exhibit potential in ameliorating various health issues such as intestinal disorders, cardiovascular diseases, behavioral disorders, and even cancer. Though it's important to note that a high percentage of them are as well opportunistic pathogens, posing risks under certain conditions. Studies highlight their role in modifying immune responses and improving health conditions by regulating lymphocytes, controlling metabolism, and preventing inflammation and cancer. The safety and efficacy of Bacteroides strains are currently under scrutiny by the European Commission for authorization in food processing, marking a significant step towards their commercialization. The recent advancements in bacterial isolation and sequencing methodologies, coupled with the integration of Metagenome-Assembled Genomes (MAGs) binning from metagenomics data, continue to unveil the potential of Bacteroides spp., aiding in the broader understanding and application of these novel probiotics in health and disease management.

The potential influence and intervention measures of gut microbiota on sperm: it is time to focus on testis-gut microbiota axis.

As the global male infertility rate continues to rise, there is an urgent imperative to investigate the underlying causes of sustained deterioration in sperm quality. The gut microbiota emerges as a pivotal factor in host health regulation, with mounting evidence highlighting its dual influence on semen. This review underscores the interplay between the Testis-Gut microbiota axis and its consequential effects on sperm. Potential mechanisms driving the dual impact of gut microbiota on sperm encompass immune modulation, inflammatory responses mediated by endotoxins, oxidative stress, antioxidant defenses, gut microbiota-derived metabolites, epigenetic modifications, regulatory sex hormone signaling. Interventions such as probiotics, prebiotics, synbiotics, fecal microbiota transplantation, and Traditional natural herbal extracts are hypothesized to rectify dysbiosis, offering avenues to modulate gut microbiota and enhance Spermatogenesis and motility. Future investigations should delve into elucidating the mechanisms and foundational principles governing the interaction between gut microbiota and sperm within the Testis-Gut microbiota Axis. Understanding and modulating the Testis-Gut microbiota Axis may yield novel therapeutic strategies to enhance male fertility and combat the global decline in sperm quality.

Comparative analysis based on shared amplicon sequence variants reveals that cohabitation influences gut microbiota sharing between humans and dogs.

The One Health concept is a comprehensive understanding of the interaction between humans, animals, and the environment. The cohabitation of humans and pets positively affects their physical, mental, and social well-being. It is recognized as an essential factor from the One Health perspective. Furthermore, a healthy balance in the gut microbiome is essential for good health, and the changes in the gut microbiome associated with cohabitation between humans and pets could potentially affect various aspects of the health of both hosts. Therefore, elucidating the sharing of gut bacteria between humans and pets associated with cohabitation is important for understanding One Health. However, most studies have examined sharing at the taxonomic level, and it remains unclear whether the same bacteria are transferred between humans and pets, and whether they mutually influence each other. Here, microbiome analysis and shared 16S rRNA gene amplicon sequence variant (ASV) analysis were conducted before the start of cohabitation between humans and dogs, as well as at 2 weeks, 1 month, and 3 months after cohabitation. 16S rRNA gene ASVs analysis indicated that gut microbes have been transferred between humans and dogs. The overall structure of the gut microbiota within human-dog pairs remained unchanged after 3 months of adaptation. However, 11ASVs were shared within human-dog pairs. Many shared ASVs were highly abundant within each host, and this high abundance may be considered a factor that influences bacterial transfer between hosts. Our results provide important insights into the potential for the transfer of gut bacteria between humans and dogs. These findings are considered crucial for understanding the impact of human-dog cohabitation on various aspects of health.

Novel Encapsulation Approaches in the Functional Food Industry: With a Focus on Probiotic Cells and Bioactive Compounds.

Bioactive substances can enhance host health by modulating biological reactions, but their absorption and utilization by the body are crucial for positive effects. Encapsulation of probiotics is rapidly advancing in food science, with new approaches such as 3D printing, spray-drying, microfluidics, and cryomilling. Co-encapsulation with bioactives presents a cost-effective and successful approach to delivering probiotic components to specific colon areas, improving viability and bioactivity. However, the exact method by which bioactive chemicals enhance probiotic survivability remains uncertain. Co-crystallization as an emerging encapsulation method improves the physical characteristics of active components. It transforms the structure of sucrose into uneven agglomerated crystals, creating a porous network to protect active ingredients. Likewise, electrohydrodynamic techniques are used to generate fibers with diverse properties, protecting bioactive compounds from harsh circumstances at ambient temperature. Electrohydrodynamic procedures are highly adaptable, uncomplicated, and easily expandable, resulting in enhanced product quality and functionality across various food domains. Furthermore, food byproducts offer nutritional benefits and technical potential, aligning with circular economy principles to minimize environmental impact and promote economic growth. Hence, industrialized nations can capitalize on the growing demand for functional foods by incorporating these developments into their traditional cuisine and partnering with businesses to enhance manufacturing and production processes.

Glycaemic sugar metabolism and the gut microbiota: past, present and future.

Non-communicable diseases (NCDs), such as type 2 diabetes (T2D) and metabolic dysfunction-associated fatty liver disease, have reached epidemic proportions worldwide. The global increase in dietary sugar consumption, which is largely attributed to the production and widespread use of cheap alternatives such as high-fructose corn syrup, is a major driving factor of NCDs. Therefore, a comprehensive understanding of sugar metabolism and its impact on host health is imperative to rise to the challenge of reducing NCDs. Notably, fructose appears to exert more pronounced deleterious effects than glucose, as hepatic fructose metabolism induces de novo lipogenesis and insulin resistance through distinct mechanisms. Furthermore, recent studies have demonstrated an intricate relationship between sugar metabolism and the small intestinal microbiota (SIM). In contrast to the beneficial role of colonic microbiota in complex carbohydrate metabolism, sugar metabolism by the SIM appears to be less beneficial to the host as it can generate toxic metabolites. These fermentation products can serve as a substrate for fatty acid synthesis, imposing negative health effects on the host. Nevertheless, due to the challenging accessibility of the small intestine, our knowledge of the SIM and its involvement in sugar metabolism remains limited. This review presents an overview of the current knowledge in this field along with implications for future research, ultimately offering potential therapeutic avenues for addressing NCDs.

Select Probiotics Exhibit Antioxidative and Anti-Inflammatory Properties for Gut Modulation: In Vitro Analysis

Abstract The gut microbiota harbors a complex ecosystem of bacteria that govern host health homeostasis. Alterations to the intestinal environment, known as gut dysbiosis, is associated with several diseases. Targeting the gut with microbiome-engineered therapeutics, such as probiotics, is a promising approach to restore microbial homeostasis and host health. Probiotics can effectively improve the gut environment, although strain-specific mechanisms remain largely unknown. Thus, this study aims to identify beneficial action of select probiotics to modulate the gut environment through antioxidative and anti-inflammatory properties. To this end, we tested the interaction among three probiotic strains – Lactobacillus gasseri A237 (LgA237), Lactobacillus plan-tarum WCFS1 (LpWCFS1) and Lactobacillus fermentum NCIMB 5221 (Lf5221) – and a human intestinal epithelial cell line, HT-29, for adhesion properties, radical scavenging abilities and anti-inflammatory activities. All three probiotics adhere well to HT-29 cells, indicating proper gut colonization. LpWCFS1 demonstrated the greatest adhesion capacity (68.3%), followed by LgA237 (35.5%) and Lf5221 (25.9%). The probiotics also exhibit excellent antioxidant properties via DPPH radical scavenging activity, comparable to quercetin, a known and potent antioxidant. Moreover, LgA237, LpWCFS1 and Lf5221 decrease interleukin-8 expression in lipopolysaccharide (LPS)-damaged HT-29 cells (41.19, 34.53 and 14.80% reduction, respectively), compared to non-treated cells. Further investigation of LpWCFS1 and LgA237 revealed a significant (p<0.0001) reduction in monocyte chemotactic and activating factor (MCAF) protein expression by 63.81 and 60.33%, respectively, in colitis-induced IECs. Overall, our results indicate adhesion, antioxidative and anti-inflammatory therapeutic potential of the tested probiotics through antioxidative and anti-inflammatory activities. These findings may be used to further understand the role of the tested probiotics in treating inflammation that underlies gut-related diseases. Such knowledge is essential for the development and translation of novel, targeted probiotic therapies to beneficially modulate the gut environment and reduce inflammation, improving host health.

Hooked on fish blood: the reliance of a gill parasite on haematophagy.

Parasitism involves diverse evolutionary strategies, including adaptations for blood feeding, which provides essential nutrients for growth and reproduction. Sparicotyle chrysophrii (Polyopisthocotyla: Microcotylidae), an ectoparasitic flatworm, infects the gills of gilthead seabream (Sparus aurata), significantly affecting fish health, welfare and Mediterranean cage farm profitability. Despite its impact, limited information exists on its feeding behaviour. This study demonstrates the presence of blood and exogenous haem groups in S. chrysophrii and explores its digestive tract using light and electron microscopy, elucidating its internal morphology and spatial arrangement. Elemental analysis of the digestive haematin cells shows residual oxidized haem depots as haematin crystals. Additionally, we studied the impact of the blood feeding on the host by estimating the average volume of blood intake for an adult parasite (2.84 ± 2.12µl·24h-1) and we described the significant drop of the plasmatic free iron levels in infected hosts. Overall, we demonstrate the parasite's reliance on its host blood, the parasite's buccal and digestive morphological adaptations for blood feeding and the provoked effect on the fish host's health.

Trophic transfer induced gut inflammation, dysbiosis, and inflammatory pathways in zebrafish via Artemia franciscana: A differential analysis of nanoplastic toxicity

Rising glbal population and plastic consumption have caused a dramatic increase in plastic waste, leading to micro- and nanoplastic ingestion by aquatic organisms and subsequent bioaccumulation in their tissues. This transfer to higher trophic levels raises nanoplastic concentrations and bioavailability, potentially harming organisms' health and development. This poses a risk to human health via seafood. To address these issues, this study assesses the toxicological impacts of nanoplastics (NPs) on brine shrimp (Artemia franciscana) and their trophic transfer to zebrafish. The research unveiled concentration-dependent bioaccumulation of NPs in zebrafish and Artemia franciscana (A. franciscana). Polystyrene nanoplastics (PS-NPs) exhibited higher accumulation in A. franciscana whereas PP-NPs showed greater accumulation in zebrafish gut. Histopathological analysis under PS-NPs exposure revealed significant tissue alterations, indicative of inflammatory responses and impaired mucosal barrier integrity. Gene expression analyses confirmed these findings, showing activation of the P38-MAPK pathway by PS-NPs, which correlated with increased inflammatory cytokines. Additionally, PE-NPs activated the JNK-MAPK pathway, while PP-NPs exposure triggered the NOD-like receptor signaling pathway. Moreover, the composition of gut microbiota shifted to a dysbiotic state, characterized by an increase in pathogenic bacteria in the PS-NPs and PP-NPs groups, elevating the risk of developing Inflammatory Bowel Disease (IBD). PS-NPs were regarded as the most toxic due to their lower stability and higher aggregation tendencies, followed by PP-NPs and PE-NPs. Taken together, the overall study highlighted the complex interactions between NPs, gut microbiota, and host health, emphasizing the importance of thoroughly assessing the ecological and physiological impacts of nanoplastic pollution.

Differences in body condition and hepatic cellular metabolism among distinct populations of cestode-infected pumpkinseed sunfish (Lepomis gibbosus)

Host populations can vary in the prevalence and intensity of their parasites, which may influence the impacts of infection on host physiology and health. Parasite-induced effects on hosts may be due to underlying changes in cellular energy metabolism, predominantly driven by the mitochondria. However, limited research has been conducted on understanding variation in host–parasite interactions across populations. We sampled three wild populations of pumpkinseed sunfish ( Lepomis gibbosus (Linnaeus, 1758)), two of which are infected by cestodes, to study correlations among infection intensity, host body condition, and key metabolic enzyme activities in liver tissue. In both infected populations, cestode infection was associated with reduced hepatic lipid metabolism and increased hepatic lactic fermentation. Interestingly, Lake Cromwell fish showed a decrease in body condition, electron transport system activity, and antioxidant activity with cestode intensity, whereas the contrary was observed for Lake Long fish. This suggests that Lake Long fish could be boosting their immune system and food intake to better tolerate infection, unlike Cromwell fish. This study not only highlights how different populations can vary in their response to parasite infections but also the importance of accounting for infection when studying animal physiology.

Colonization profiles of gut microbiota in goat kids from neonatal to weaning period.

Understanding the colonization and change patterns of gut microbiota is pivotal for comprehending host health. As a newly cultured breed, the studies on the gut microbiota of Tianfu goats remain limited. This study aimed to address this gap by analyzing the microbial composition and colonization patterns of fecal samples collected from goat kids from birth to weaning. Fecal samples were collected on days 0, 7, 14, 21, 28, 35, 42, 49, 53, 55, 57, and 64, and the changes and colonization patterns of microorganisms were analyzed through high-throughput 16S rRNA sequencing. The results showed that the abundance of fecal microbiota in goat kids gradually increased over time, followed by a decrease after weaning and stabilization, with reduced individual differences. The colonization of fecal microorganisms mainly presented three different stages: days 0-14, days 21-49, and days 53-64. During the suckling period, the relative abundance of Proteobacteria (72.34%) was the highest, followed by Firmicutes (21.66%). From 21 days old, the microbiota in goat kids gradually to be diverse, with Lachnospiraceae and Ruminococcaceae being dominant. During post-weaning, Ruminococcaceae (30.98-33.34%) was becoming prominence which helpful for cellulose decomposition. LEfSe analyzed three important time points (d0 vs. d7, d7 vs. d14, d49 vs. d53, LDA score > 4 and p < 0.05), 53 microbial communities with stage differences were identified. Functional prediction using PICRUSt revealed that differential microbial communities are mainly related to carbohydrate and amino acid metabolism pathways. Overall, this study addresses the intricate relationship between ages, diets, and microbiota compositions in Tianfu goat kids, and also offering insights into microorganisms-host interactions.

Pangenomes of human gut microbiota uncover links between genetic diversity and stress response

The genetic diversity of the gut microbiota has a central role in host health. Here, we created pangenomes for 728 human gut prokaryotic species, quadrupling the genes of strain-specific genomes. Each of these species has a core set of a thousand genes, differing even between closely related species, and an accessory set of genes unique to the different strains. Functional analysis shows high strain variability associates with sporulation, whereas low variability is linked with antibiotic resistance. We further map the antibiotic resistome across the human gut population and find 237 cases of extreme resistance even to last-resort antibiotics, with a predominance among Enterobacteriaceae. Lastly, the presence of specific genes in the microbiota relates to host age and sex. Our study underscores the genetic complexity of the human gut microbiota, emphasizing its significant implications for host health. The pangenomes and antibiotic resistance map constitute a valuable resource for further research.

Stratification of human gut microbiomes by succinotype is associated with inflammatory bowel disease status

BackgroundThe human gut microbiome produces and consumes a variety of compounds that interact with the host and impact health. Succinate is of particular interest as it intersects with both host and microbiome metabolism. However, which gut bacteria are most responsible for the consumption of intestinal succinate is poorly understood.ResultsWe build upon an enrichment-based whole fecal sample culturing approach and identify two main bacterial taxa that are responsible for succinate consumption in the human intestinal microbiome, Phascolarctobacterium and Dialister. These two taxa have the hallmark of a functional guild and are strongly mutual exclusive across 21,459 fecal samples in 94 cohorts and can thus be used to assign a robust “succinotype” to an individual. We show that they differ with respect to their rate of succinate consumption in vitro and that this is associated with higher concentrations of fecal succinate. Finally, individuals suffering from inflammatory bowel disease (IBD) are more likely to have the Dialister succinotype compared to healthy subjects.ConclusionsWe identified that only two bacterial genera are the key succinate consumers in human gut microbiome, despite the fact that many more intestinal bacteria encode for the succinate pathway. This highlights the importance of phenotypic assays in functionally profiling intestinal microbiota. A stratification based on “succinotype” is to our knowledge the first function-based classification of human intestinal microbiota. The association of succinotype with IBD thus builds a bridge between microbiome function and IBD pathophysiology related to succinate homeostasis.1f3imNYWH_SuaBpDzz9CS6Video

Balancing the Oral-Gut-Brain Axis with Diet.

Background: The oral microbiota is the second largest microbial community in humans. It contributes considerably to microbial diversity and health effects, much like the gut microbiota. Despite physical and chemical barriers separating the oral cavity from the gastrointestinal tract, bidirectional microbial transmission occurs between the two regions, influencing overall host health. Method: This review explores the intricate interplay of the oral-gut-brain axis, highlighting the pivotal role of the oral microbiota in systemic health and ageing, and how it can be influenced by diet. Results: Recent research suggests a relationship between oral diseases, such as periodontitis, and gastrointestinal problems, highlighting the broader significance of the oral-gut axis in systemic diseases, as well as the oral-gut-brain axis in neurological disorders and mental health. Diet influences microbial diversity in the oral cavity and the gut. While certain diets/dietary components improve both gut and oral health, others, such as fermentable carbohydrates, can promote oral pathogens while boosting gut health. Conclusions: Understanding these dynamics is key for promoting a healthy oral-gut-brain axis through dietary interventions that support microbial diversity and mitigate age-related health risks.

Temporal changes in the mouse gut bacteriota influenced by host sex, diet, and exercise.

The gut microbiota plays an important role in host physiology. However, the effects of host sex, lifestyle, and temporal influences on the bacterial community within the gut remain ill-defined. To address this gap, we evaluated 56 male and female mice over a 10-wk study to assess the effects of sex, diet, and exercise on gut community dynamics. Mice were randomly assigned to high-fat or control diet feeding and had free access to running wheels or remained sedentary throughout the study period. The fecal bacterial community was characterized by rRNA operon profiling via nanopore sequencing. Differential abundance testing indicated that ∼200 bacterial taxa were significantly influenced by sex, diet, or exercise (4.2% of total community), which also changed over time (82 taxa, 1.7% of total community). Phylogenetic analysis of taxa closely related to Dysosmobacter welbionis, and several members of the family Muribaculaceae were examined more closely and demonstrated distinct species/strain level subclustering by host sex, diet, and exercise. Collectively, these data suggest that sex and lifestyle can alter the gut bacteriota at the species/strain level that may play a role in host health. These results also highlight the need for improved characterization methods to survey microbial communities at finer taxonomic resolution.NEW & NOTEWORTHY This study demonstrates that host sex, diet, and exercise can each modulate gut bacterial community structure, which may have consequences to host physiology. Our analysis shows selection of novel strains and genera for some members of the Oscillospiraceae and Muribaculaceae by host sex, diet, and activity status. Overall, these findings provide a framework for detecting the next generation of beneficial bacteria targeting obesity and associated metabolic diseases in a sex-specific manner.

Genomic analysis and functional properties of Lactobacillus johnsonii GJ231 isolated from healthy beagles.

Probiotics are one of the management tools to improve the host's healthy microbiota. The positive effects of probiotics on host health are species-specific, so probiotics isolated from host's own gut may be most beneficial. Many of the metabolites (e.g., short-chain fatty acids, bacteriocins, and hydrogen peroxide) produced by Lactobacillus johnsonii have specific inhibitory profiles against invading pathogens. In this study, we isolated L. johnsonii GJ231 from the intestinal tract of healthy female beagles. The genome size of 1.763 M encoded a total of 1,691 predicted genes. Many carbohydrate-active enzymes responsible for carbohydrate degradation and the production of short-chain fatty acids were also predicted. The metabolic profile of short-chain fatty acids in L. johnsonii GJ231 was determined using LC-MS/MS. The bacteriocin-producing gene bacteriocin (lactacin F) in L. johnsonii GJ231 was also predicted. In vitro, experiments demonstrated that GJ231 can thrive in weak acids, 0.3% bile salts, and artificial gastrointestinal fluid models. It was tolerant of to high temperatures up to 70°C, was non- hemolytic, inhibited pathogenic bacteria, and had a high antioxidant capacity. In vivo safety experiments conducted in mice revealed that oral administration of GJ231 not only had no toxic side effect but also increased their antioxidant capacity. In conclusion, combining the above test results, which collectively demonstrate that canine-derived L. johnsonii GJ231 was a non-pathogenic, acid-tolerant and bile-salt-tolerant probiotic strain that inhibits pathogenic bacteria and improves host antioxidant function. This may make it a promising candidate for the development of innovative functional foods for pets.

Unveiling the dynamic processes of dietary advanced glycation end-products (dAGEs) in absorption, accumulation, and gut microbiota metabolism.

This study delves into the dynamics of dietary advanced glycation end-products (dAGEs) on host health and gut microbiota. Using 13C-labeled carboxymethyllysine (CML) bound casein, we identify bound AGEs as the primary entry route, in contrast to free AGEs dominating urinary excretion. Specifically, our results show that the kidneys accumulate 1.5 times more dAGEs than the liver. A high AGE (HA) diet prompts rapid gut microbiota changes, with an initial stress-induced mutation phase, evidenced by a 20% increase in Bacteroides and Parabacteroides within the first week, followed by stabilization. These bacteria emerge as potential dAGE-utilizing bacteria, influencing the microbiota composition. Concurrent metabolic shifts affect lipid and carbohydrate pathways, with lipid metabolism alterations persisting over time, impacting host metabolic homeostasis. This study illuminates the intricate interplay between dietary AGEs, gut microbiota, and host health, offering insights into the health consequences of short- and long-term HA dietary patterns.

Interaction between intestinal mycobiota and microbiota shapes lung inflammation.

Gut microbiota is an intricate microbial community containing bacteria, fungi, viruses, archaea, and protozoa, and each of them contributes to diverse aspects of host health. Nevertheless, the influence of interaction among gut microbiota on host health remains uncovered. Here, we showed that the interaction between intestinal fungi and bacteria shaped lung inflammation during infection. Specifically, antifungal drug-induced dysbiosis of gut mycobiota enhanced lung inflammation during infection. Dysbiosis of gut mycobiota led to gut Escherichia coli (E. coli) overgrowth and translocation to the lung during infection, which induced lung accumulation of the CD45+F4/80+Ly6G-Ly6C-CD11b+CD11c+ macrophages. Clearance of macrophages or deletion of TLR4 (Toll-like receptor 4, recognition of LPS) rather than Dectin-1 (recognition of beta-1,3/1,6 glucans on fungi) blocked the antifungal drug-induced aggravation of lung inflammation during infection. These findings suggest that the interaction between intestinal mycobiota and commensal bacteria affects host health through the gut-lung axis, offering a potential therapeutic target for ameliorating lung inflammation during infection.

PSVI-6 Genomic determinants of the rumen microbiome and metabolome in Angus steers

Abstract The rumen microbiome provides approximately 70% of energy required for the ruminant host through fermentation byproducts. Due to microbial impacts on host health and productivity, several studies have associated microbiome and metabolome variation with important sustainability phenotypes, such as feed efficiency and methane emissions. Recent studies have indicated the microbial communities present in rumen fluid are under low-to-moderate host genetic control. However, microorganisms present on the rumen wall have been underrepresented in research, negating their unique role in host-microbiome interactions. Current studies investigating heritability of the rumen planktonic microorganisms are plagued by small sample sizes, high management and breed heterogeneity, and low resolution for classifying microbial communities. To determine the heritability of the rumen fluid and epithelium-associated microbiome and metabolome, Angus steers (n = 350) were enrolled in a 70-d feed efficiency trial, where real-time dry matter intake was measured. Body weights were collected throughout the trial to calculate average daily gain and residual feed intake. Mid-trial, a novel surgery method was used to swab the rumen wall to capture epithelium-associated microorganisms. On d 70, 50 mL of rumen fluid was obtained from steers using orogastric tubing for collection of planktonic microbial communities. Metagenomic DNA extracted from both rumen fluid and epimural samples was used for reduced representation sequencing to predict microbial features such as diversity, composition, and putative function. Genomic DNA isolated from whole blood was used to perform low-pass whole genome sequencing for use in downstream heritability estimates and variant association analyses. Many core microbial abundances are under low-to-moderate host genetic control (h2 &amp;gt; 0.15; P &amp;lt; 0.05); however, many microorganisms had low heritability estimates (h2 &amp;lt; 0.10). Preliminary genome-wide associations studies are vastly underpowered to detect host genetic variants associated with microbial features, but data generated using the total number of animals will better refine these polymorphisms. Several key heritable metabolites were identified in amino acid metabolism pathways in rumen fluid (P &amp;lt; 0.05). The rumen microbiome appears to act as a complex polygenic trait and incorporating microbial features into prediction models may improve feed efficiency estimations. Understanding host genetic control of the rumen microbiome and metabolome may empower downstream applications to enhance genomic and phenotypic predictions for feed efficiency and other sustainability traits in beef cattle.

32 Biotics: Are there differences?

Abstract In companion animals, the search for dietary ingredients and supplements that may promote health and longevity continues. Because stool quality issues and gastrointestinal diseases are common, substances addressing gastrointestinal health are of interest and some of the most heavily studied. Given the importance that microbiota have on host health and disease, many strategies function by directly or indirectly influencing the microbial species that inhabit the gut. Dietary fibers may impact gut health by maintaining stool quality, providing laxation, reducing fecal odor, and modulating fermentative end-products. A variety of biotic substances may also be used to promote gastrointestinal health. Four primary biotic substances exist, namely probiotics, prebiotics, synbiotics, and postbiotics. Over the past decade, the International Scientific Association for Probiotics and Prebiotics (ISAPP) has sponsored expert consensus panels to update the biotic definitions, offer criteria for qualification, outline guiding principles for research and development, and provide implications for a variety of stakeholders (scientists; media; regulators; industry). In 2014, Hill et al. defined probiotics as “live microorganisms that when administered in adequate amounts confer a health benefit”. Gibson et al. (2017) defined prebiotics as “substrates that are selectively utilized by host microorganisms conferring a health benefit.” Probiotics and prebiotics have been widely used in pet products over the past few decades. Swanson et al. (2020) updated the synbiotic definition to be a “mixture comprising live microorganisms and substrate(s) selectively utilized by host microorganisms that confer a health benefit”. Synbiotics may contain components that operate independently (complementary synbiotic) or in together (synergistic synbiotic) to promote host health. In 2021, Salminen et al. defined postbiotics as “preparations of inanimate microorganisms and/or their components that confer a health benefit.” Yeast and bacteria-based mixtures falling under this definition have become more popular in pet nutrition as of late, but the postbiotic definition is often misused. This presentation will discuss each biotic substance category in regard to their use in dogs and cats. Mechanisms of action, potential benefits of consumption, evidence of successful use in companion animals, and ideas for the future of biotics will be presented.