Environmental Origin Research Articles

Comprehensive insights into the impact of bacterial indole-3-acetic acid on sensory preferences in Drosophila melanogaster

Several bacteria of environmental and clinical origins, including some human-associated strains secrete a cross-kingdom signaling molecule indole-3-acetic acid (IAA). IAA is a tryptophan (trp) derivative mainly known for regulating plant growth and development as a hormone. However, the nutritional sources that boost IAA secretion in bacteria and the impact of secreted IAA on non-plant eukaryotic hosts remained less explored. Here, we demonstrate significant trp-dependent IAA production in Pseudomonas juntendi NEEL19 when provided with ethanol as a carbon source in liquid cultures. IAA was further characterized to modulate the odor discrimination, motility and survivability in Drosophila melanogaster. A detailed analysis of IAA-fed fly brain proteome using high-resolution mass spectrometry showed significant (fold change, ± 2; p ≤ 0.05) alteration in the proteins governing neuromuscular features, audio-visual perception and energy metabolism as compared to IAA-unfed controls. Sex-wise variations in differentially regulated proteins were witnessed despite having similar visible changes in chemo perception and psychomotor responses in IAA-fed flies. This study not only revealed ethanol-specific enhancement in trp-dependent IAA production in P. juntendi, but also showed marked behavioral alterations in flies for which variations in an array of proteins governing odor discrimination, psychomotor responses, and energy metabolism are held responsible. Our study provided novel insights into disruptive attributes of bacterial IAA that can potentially influence the eukaryotic gut-brain axis having broad environmental and clinical implications.

Comorbidities in women with polycystic ovary syndrome: a sibling study

BackgroundPolycystic ovary syndrome (PCOS) has previously been associated with several comorbidities that may have shared genetic, epigenetic, developmental or environmental origins. PCOS may be influenced by prenatal androgen excess, poor intrauterine or childhood environmental factors, childhood obesity and learned health risk behaviors. We analyzed the association between PCOS and several relevant comorbidities while adjusting for early-life biological and socioeconomic conditions, also investigating the extent to which the association is affected by familial risk factors.MethodsThis total-population register-based cohort study included 333,999 full sisters, born between 1962 and 1980. PCOS and comorbidity diagnoses were measured at age 17-45 years through national hospital register data from 1997 to 2011, and complemented with information on the study subjects´ early-life and social characteristics. In the main analysis, sister fixed effects (FE) models were used to control for all time-invariant factors that are shared among sisters, thereby testing whether the association between PCOS and examined comorbidities is influenced by unobserved familial environmental, social or genetic factors.ResultsThree thousand five hundred seventy women in the Sister sample were diagnosed with PCOS, of whom 14% had obesity, 8% had depression, 7% had anxiety and 4% experienced sleeping, sexual and eating disorders (SSE). Having PCOS increased the odds of obesity nearly 6-fold (adjusted OR (aOR): 5.9 [95% CI:5.4-6.5]). This association was attenuated in models accounting for unobserved characteristics shared between full sisters, but remained considerable in size (Sister FE: aOR: 4.5 [95% CI: 3.6-5.6]). For depression (Sister FE: aOR: 1.4 [95% CI: 1.2-1.8]) and anxiety (Sister FE: aOR: 1.5 [95% CI: 1.2-1.8), there was a small decrease in the aORs when controlling for factors shared between sisters. Being diagnosed with SSE disorders yielded a 2.4 aOR (95% CI:2.0-2.6) when controlling for a comprehensive set of individual-level confounders, which only decreased slightly when controlling for factors at the family level such as shared genes or parenting style. Accounting for differences between sisters in observed early-life circumstances influenced the estimated associations marginally.ConclusionHaving been diagnosed with PCOS is associated with a markedly increased risk of obesity and sleeping, sexual and eating disorders, also after accounting for factors shared between sisters and early-life conditions.

Vitamin D receptor gene polymorphism in Egyptian multiple sclerosis patients

One of the most common neurological illnesses in the world is multiple sclerosis (MS), a chronic autoimmune demyelinating disease of the central nervous system (CNS). MS has both a genetic and an environmental origin. In terms of environmental factors, vitamin D deficiency is one of the most important risk factors and closely connected with gene polymorphisms involved in vitamin D metabolism, transport, or activity. Since vitamin D activity requires a receptor-mediated response, any changes to the vitamin D receptor (VDR) may have an effect on the pathophysiology of the disease. In this study, we aimed to identify the relationship between VDR gene polymorphisms, FokI A>G (rs2228570), ApaI A>C (rs7975232) and BsmI C>T (rs1544410) and MS. FokI, ApaI and BsmI genotypes were determined in 50 patients with relapsing remitting MS (RRMS) and in 50 control subjects. DNA was isolated from blood samples, and then FokI, ApaI and BsmI gene polymorphisms were identified using allelic discrimination real time polymerase chain reaction (PCR) assay. The distribution of FokI, ApaI and BsmI polymorphisms did not show any significant differences between MS patients and controls. Thus, we concluded that there is no association between the studied VDR gene polymorphisms and MS.

Neighborhood features moderate genetic and environmental influences on children's social information processing.

Neighborhood is a key context where children learn to process social information; however, the field has largely overlooked the ways children's individual characteristics might be moderated by neighborhood effects. We examined 1,030 six- to 11-year-olds (48.7% female; 82% White) twin pairs oversampled for neighborhood disadvantage from the Twin Study of Behavioral and Emotional Development in Children. We evaluated neighbor reports (N = 1,880) of neighborhood structural and social characteristics as moderators of genetic and environmental influences on children's social processing. Although there was no evidence of moderation for children's hostile attributions, there was robust evidence that the social and structural characteristics of the neighborhood moderated the genetic and environmental origins of children's positive expectations of aggressive behavior. Specifically, we found that genetic influences on aggressive expectations increased in the presence of neighborhood deprivation and decreased in the presence of protective social processes and availability of resources. Such findings suggest that protective neighborhood social processes may buffer against the development of aggressive expectations during middle childhood by suppressing the expression of genetic influences on those outcomes. In doing so, they suggest that neighborhood social processes may be able to promote youth resilience to neighborhood deprivation "under the skin." (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Distinct genetic and environmental origins of hierarchical cognitive abilities in adult humans

Human cognitive abilities ranging from basic perceptions to complex social behaviors exhibit substantial variation in individual differences. These cognitive functions can be categorized into a two-order hierarchy based on the levels of cognitive processes. Second-order cognition including metacognition and mentalizing monitors and regulates first-order cognitive processes. These two-order hierarchical cognitive functions exhibit distinct abilities. However, it remains unclear whether individual differences in these cognitive abilities have distinct origins. We employ the classical twin paradigm to compare the genetic and environmental contributions to the two-order cognitive abilities in the same tasks from the same population. The results reveal that individual differences in first-order cognitive abilities were primarily influenced by genetic factors. Conversely, the second-order cognitive abilities have a stronger influence from shared environmental factors. These findings suggest that the abilities of metacognition and mentalizing in adults are profoundly shaped by their environmental experiences and less determined by their biological nature.

Simultaneous determination of 19 bromophenols by gas chromatography–mass spectrometry (GC-MS) after derivatization

Bromophenols (BPs) are a class of ubiquitous emerging halogenated pollutants. Their 19 congeners are problematically separated and detected. This work described the separation and detection of 19 BP congeners by gas chromatography-mass spectrometry (GC-MS). Investigations into the derivatization of bromophenols were carried out using two silylation reagents (N,O-bis(trimethylsilyl)trifluoroacetamide and N-methyl-N-(trimethylsily)trifluoroacetamide), two alkylation reagents (methyl iodide and trimethylsilyldiazomethane) and acetic anhydride prior to GC-MS analysis. Optimal chromatographic separation, sensitivity, and linearity were achieved after BP derivatization using acetic anhydride, featuring the equipment detection limits of 0.39–1.26 pg and correlation coefficients of 0.9948–0.9999 (linear range: 0.5–250 ng mL−1) for all 19 BP congeners. Furthermore, the simultaneous determination of 19 bromophenols and 19 bromoanisoles, common environmental transformation products of BPs, is also demonstrated. The improved analytical performance on GC-MS after derivatization would benefit investigations on the environmental origins, behaviors and fates of BPs and their environmental metabolites.

Effects of psychological stress on the emission of volatile organic compounds from the skin

Thirty-five women were included in a clinical study to characterize the volatile organic compounds (VOCs) emitted by the skin during exposure to psychological stress. An original silicon-based polymeric phase was used for VOC sampling on the forehead before and after stress induction. Cognitive stress was induced using specialized software that included a chronometer for semantic and arithmetic tasks. Assessment of stress was monitored using a State-trait anxiety inventory questionnaire, analysis of participants’ verbal expressions and clinical measurements. Identification and relative quantification of VOCs were performed by gas chromatography-mass spectrometry. Stress induction was validated by a significant increase in state-anxiety as indicated by the questionnaire, modifications in electrodermal activity measurements and the expression of stress verbatims. In parallel, a sebum production increase and a skin pH decrease were observed. A total of 198 VOCs with different potential sources were identified. They were categorized in 5 groups: probable cosmetic composition, VOCs produced by the body or its microbiota, environmental origin, and dietary intake. In our qualitative statistical approach, three VOCs were found to be correlated with stress induction and 14 compounds showed significance in the paired Wilcoxon test. Fatty-acyls derived from lipids were predominantly identified as well as ethylbenzenes.

Characterization of the diversity of type IV secretion system-encoding plasmids in Acinetobacter

ABSTRACT The multi-drug resistant pathogen Acinetobacter baumannii has gained global attention as an important clinical challenge. Owing to its ability to survive on surfaces, its capacity for horizontal gene transfer, and its resistance to front-line antibiotics, A. baumannii has established itself as a successful pathogen. Bacterial conjugation is a central mechanism for pathogen evolution. The epidemic multidrug-resistant A. baumannii ACICU harbours a plasmid encoding a Type IV Secretion System (T4SS) with homology to the E. coli F-plasmid, and plasmids with homologous gene clusters have been identified in several A. baumannii sequence types. However the genetic and host strain diversity, global distribution, and functional ability of this group of plasmids is not fully understood. Using systematic analysis, we show that pACICU2 belongs to a group of almost 120 T4SS-encoding plasmids within four different species of Acinetobacter and one strain of Klebsiella pneumoniae from human and environmental origin, and globally distributed across 20 countries spanning 4 continents. Genetic diversity was observed both outside and within the T4SS-encoding cluster, and 47% of plasmids harboured resistance determinants, with two plasmids harbouring eleven. Conjugation studies with an extensively drug-resistant (XDR) strain showed that the XDR plasmid could be successfully transferred to a more divergent A. baumanii, and transconjugants exhibited the resistance phenotype of the plasmid. Collectively, this demonstrates that these T4SS-encoding plasmids are globally distributed and more widespread among Acinetobacter than previously thought, and that they represent an important potential reservoir for future clinical concern.

The composition of the bacterial communities collected from the PM10 samples inside the Seoul subway and railway station

Health implications of indoor air quality (IAQ) have drawn more attention since the COVID epidemic. There are many different kinds of studies done on how IAQ affects people’s well-being. There hasn’t been much research that looks at the microbiological composition of the aerosol in subway transit systems. In this work, for the first time, we examined the aerosol bacterial abundance, diversity, and composition in the microbiome of the Seoul subway and train stations using DNA isolated from the PM10 samples from each station (three subway and two KTX stations). The average PM10 mass concentration collected on the respective platform was 41.862 µg/m3, with the highest average value of 45.95 µg/m3 and the lowest of 39.25 µg/m3. The bacterial microbiomes mainly constituted bacterial species of soil and environmental origin (e.g., Acinetobacter, Brevundimonas, Lysinibacillus, Clostridiodes) with fewer from human sources (Flaviflexus, Staphylococcus). This study highlights the relationship between microbiome diversity and PM10 mass concentration contributed by outdoor air and commuters in South Korea’s subway and train stations. This study gives insights into the microbiome diversity, the source, and the susceptibility of public transports in disease spreading.

Presence of Zonula Occludens Toxin-Coding Genes among Vibrio parahaemolyticus Isolates of Clinical and Environmental Origin.

In recent studies, emphasis has been placed on the zonula occludens toxin (Zot) from the non-toxigenic Vibrio parahaemolyticus strain PMC53.7 as an agent inducing alterations in the actin cytoskeleton of infected Caco-2 cells and which appears as a relevant virulence factor. Universal zot primers were designed by the alignment of different types of zot gene and identification of conserved sequences to investigate the presence in diverse environmental and clinical V. parahaemolyticus isolates, in co-occurrence with virulence factors, such a hemolysins and secretion systems. The study screened a total of 390 isolates from environmental sources from Chile and Italy and 95 Chilean clinical isolates. The results revealed that around 37.2% of Chilean environmental strains and 25.9% of Italian strains, and 24.2% of clinical isolates carried the zot gene. The Zot-C2 cluster was present in 71.4% of Chilean environmental strains but absent in clinical isolates, while the Zot-C4 cluster was identified in 28.6% of environmental and 100% of clinical isolates. Understanding the role of zot in V. parahaemolyticus virulence is crucial, especially considering the risk associated with consuming diverse isolates from bivalves and the co-occurrence with virulence factors such as TDH, TRH or T3SS2.

Cosmic Reionization on Computers: Statistics, Physical Properties, and Environments of Lyman Limit Systems at z ∼ 6

Lyman limit systems (LLSs) are dense hydrogen clouds with high enough H i column densities to absorb Lyman continuum photons emitted from distant quasars. Their high column densities imply an origin in dense environments; however, the statistics and distribution of LLSs at high redshifts still remain uncertain. In this paper, we use self-consistent radiative transfer cosmological simulations from the Cosmic Reionization on Computers (CROC) project to study the physical properties of LLSs at the tail end of cosmic reionization at z ∼ 6. We generate 3000 synthetic quasar sight lines to obtain a large number of LLS samples in the simulations. In addition, with the high physical fidelity and resolution of CROC, we are able to quantify the association between these LLS samples and nearby galaxies. Our results show that the fraction of LLSs spatially associated with nearby galaxies increases with H i column density. Moreover, we find that LLSs that are not near any galaxy typically reside in filamentary structures connecting neighboring galaxies in the intergalactic medium (IGM). This quantification of the distribution and association of LLSs to large-scale structure informs our understanding of the IGM–galaxy connection during the “Epoch of Reionization,” and provides a theoretical basis for interpreting future observations.

Prevalence and variability of siderophore production in the Achromobacter genus.

Achromobacter spp. are recognized as emerging opportunistic pathogens in humans with various underlying diseases, including cystic fibrosis (CF). Although their pathophysiological traits are increasingly studied, their virulence factors remain incompletely described. Particularly, siderophores that represent important factors of bacterial growth have not yet been studied in this genus. A population-based study was performed to explore the ability of members of the Achromobacter genus to produce siderophores, both overall and in relevant subgroups (Achromobacter species; strain origin, either clinical-from CF or non-CF patients-or environmental). This study provides original data showing that siderophore production is a common trait of Achromobacter strains, particularly observed among clinical strains. The major species, Achromobacter xylosoxidans, encompassed both one of the highest prevalence of siderophore-producing strains and strains producing the largest amounts of siderophores, particularly observed for CF strains. These observations may represent additional advantages accounting for the epidemiological success of this species.

Neural Toxicity And Deviating Behaviors: A Review Study

Background: neural toxicity can be mediated by several agents including the accumulation of heavy metal. Neural toxicity could cause deviating behaviors and violent actions. Study objectives: the main objectives of the present study were to review the literature regarding the impacts of neural toxicity on deviating behaviors and violent actions and to explore the impacts of heavy metals including lead (pb) on violent actions. Methodology: literature was reviewed for articles involved in the neural toxicity and their impacts on deviating behaviors such as violence. Articles were studied and summarized to extract the appropriate information, this helped in making up the current study. Results: reviewed literature showed that exposure to heavy metals is associated with violent behaviors and deviating actions. Previous studies indicated that prisoners had higher levels of lead (pb) compared with their counter controls. It was also shown that schoolchildren who had poor academic achievement and committed to violent actions has higher levels of lead (pb). Conclusions: violent actions and deviating behaviors have their environmental origin such as exposure to heavy metals.assessment of heavy metals may be a future indicator to evaluate persons with violent attitudes

A study of the value of the natural environment and its sources based on a material value theory perspective

In various academic disciplines and contexts, the value attributed to the natural environment encompasses two primary dimensions: the economic significance, which pertains to the economic value of the natural environment, and the philosophical dimension, which refers to the intrinsic (or subjective) value of the natural environment. This paper, after scrutinizing prevalent perspectives within the academic community regarding the value of the natural environment and its origins, asserts that the labor theory of value inadequately and inaccurately captures the essence of the natural environment’s value. Consequently, the paper suggests employing the “material theory of value” as a more apt framework to elucidate the origins of the natural environment’s value. The “material value theory” centers on the reciprocal relationship between humans and nature, with the objective of fostering an equitable exchange wherein human responsibilities and obligations toward the natural environment are traded for the “value” it provides. This approach aims to establish a harmonious and balanced exchange between humanity and the natural environment.

Tratamento de mastite não severa em vacas de leite no Brasil: um estudo comparativo entre o uso de amoxicilina associada ao ácido clavulânico e um protocolo tradicional

ABSTRACT: The association of amoxicillin and clavulanic acid has shown high efficacy to treat mastitis worldwide, also promoting a shorter milk disposal period compared to other antimicrobials. However, no previous investigations regarding its application to treat mastitis in Brazilian dairy cows were developed. This study evaluated the effectiveness of amoxicillin-clavulanic acid to treat Brazilian dairy cows with mastitis, comparing it with a reference protocol treatment combination of tetracycline, neomycin and bacitracin. Holstein cows (n = 468) from three different dairy herds in Brazil were assigned to two groups: combination of tetracycline, neomycin and bacitracin (n = 178; positive control group) and amoxicillin-clavulanic acid protocol (n = 290). Before the treatment, milk samples were collected and cultivated in chromogenic media. After finishing the antimicrobial treatment (intramammary), milk samples were also collected and cultivated in chromogenic media. Results from microbiological analysis obtained before and after treatment were compared to determine the healing rate. Nine different microbiological agents were identified: eight of environmental origin and one of contagious origin; being eight gram-positive and one gram-negative bacteria. TThe positive control group and the treatment group showed similar healing rate (86.5% and 90.3%, respectively; P > 0.05). No differences were found between the groups for the healing rate, when the causing agent was considered. Therefore, it is possible to indicate the amoxicillin-clavulanic acid-based protocol to treat intramammary mastitis in Brazilian dairy cows, achieving great healing rates and providing a substantial reduction in milk disposal.

Alterations in RNA editing in skeletal muscle following exercise training in individuals with Parkinson's disease.

Parkinson's Disease (PD) is the second most common neurodegenerative disease behind Alzheimer's Disease, currently affecting more than 10 million people worldwide and 1.5 times more males than females. The progression of PD results in the loss of function due to neurodegeneration and neuroinflammation. The etiology of PD is multifactorial, including both genetic and environmental origins. Here we explored changes in RNA editing, specifically editing through the actions of the Adenosine Deaminases Acting on RNA (ADARs), in the progression of PD. Analysis of ADAR editing of skeletal muscle transcriptomes from PD patients and controls, including those that engaged in a rehabilitative exercise training program revealed significant differences in ADAR editing patterns based on age, disease status, and following rehabilitative exercise. Further, deleterious editing events in protein coding regions were identified in multiple genes with known associations to PD pathogenesis. Our findings of differential ADAR editing complement findings of changes in transcriptional networks identified by a recent study and offer insights into dynamic ADAR editing changes associated with PD pathogenesis.

Phenotypic characteristics of environmental Pseudomonas aeruginosa: an in vitro study on epidemiological aspects

Pseudomonas aeruginosa is one of the most commonly isolated species among non-fermenting Gram-negative bacteria, both from clinical samples and from environmental sources. The survival of the species in harsh conditions is ensured by the production of a protective biofilm; assessment of biofilm-forming capacity aids future pathogen eradication strategies. The aim of our present study was to assess the relationship between antibiotic resistance, biofilm-forming capacity and other phenotypic virulence factors in environmental P. aeruginosa isolates. One hundred and fourteen (n = 114) isolates were included in the study, which were obtained from various geographical regions and environmental origins. Antimicrobial susceptibility testing was carried out using standard protocols. Biofilm-forming capacity and pyocyanin pigment production were tested using microtiter plate-based methods. Swarming, swimming and twitching motility, and siderophore-production were assessed using agar-plate based methodologies. Resistance in environmental isolates were highest for levofloxacin/ciprofloxacin 49.12% (n = 56), ceftazidime 42.98% (n = 49) and cefepime 35.96% (n = 41), while lowest for colistin 0% (n = 0); overexpression of RND-type efflux pumps was seen in 33.33% (n = 33) of isolates. 21.93% (n = 25) met the criteria to be classified as multidrug resistant (MDR). 17.54% (n = 20) of isolates were weak/non-biofilm producers, while (25.45%, n = 29) and (57.01%, n = 65) were moderate and strong biofilm producers, respectively. No significant differences were noted in biofilm-formation (OD570 values non-MDR [mean ± SD]: 0.396 ± 0.138 vs. MDR: 0.348 ± 0.181; p > 0.05) or pyocyanin pigment production (OD686 values non-MDR: 0.403 ± 0.169 vs. MDR: 0.484 ± 0.125; p > 0.05) between MDR and non-MDR environmental P. aeruginosa. Highest motility values were observed for swarming motility, followed by swimming and twitching motility; no relevant differences (p > 0.05) in motility were noted in the context of MDR status or biofilm-formation in the tested isolates. P. aeruginosa is an opportunistic pathogen with high medical importance, being a causative agent of recalcitrant infections, which are becoming difficult to treat with the onset of MDR. Further studies are warranted to assess biofilm-forming capacity, and to provide insights into the mechanisms underlying biofilm-formation both in isolates of clinical and environmental origins.

Ripening dynamics revisited: an automated method to track the development of asynchronous berries on time-lapse images

BackgroundGrapevine berries undergo asynchronous growth and ripening dynamics within the same bunch. Due to the lack of efficient methods to perform sequential non-destructive measurements on a representative number of individual berries, the genetic and environmental origins of this heterogeneity, remain nearly unknown. To address these limitations, we propose a method to track the growth and coloration kinetics of individual berries on time-lapse images of grapevine bunches.ResultsFirst, a deep-learning approach is used to detect berries with at least 50 ± 10% of visible contours, and infer the shape they would have in the absence of occlusions. Second, a tracking algorithm was developed to assign a common label to shapes representing the same berry along the time-series. Training and validation of the methods were performed on challenging image datasets acquired in a robotised high-throughput phenotyping platform. Berries were detected on various genotypes with a F1-score of 91.8%, and segmented with a mean absolute error of 4.1% on their area. Tracking allowed to label and retrieve the temporal identity of more than half of the segmented berries, with an accuracy of 98.1%. This method was used to extract individual growth and colour kinetics of various berries from the same bunch, allowing us to propose the first statistically relevant analysis of berry ripening kinetics, with a time resolution lower than one day.ConclusionsWe successfully developed a fully-automated open-source method to detect, segment and track overlapping berries in time-series of grapevine bunch images acquired in laboratory conditions. This makes it possible to quantify fine aspects of individual berry development, and to characterise the asynchrony within the bunch. The interest of such analysis was illustrated here for one cultivar, but the method has the potential to be applied in a high throughput phenotyping context. This opens the way for revisiting the genetic and environmental variations of the ripening dynamics. Such variations could be considered both from the point of view of fruit development and the phenological structure of the population, which would constitute a paradigm shift.

Nanopore adaptive sampling enriches for antimicrobial resistance genes in microbial communities.

Antimicrobial resistance (AMR) is a global public health threat. Environmental microbial communities act as reservoirs for AMR, containing genes associated with resistance, their precursors, and the selective pressures promoting their persistence. Genomic surveillance could provide insights into how these reservoirs change and impact public health. Enriching for AMR genomic signatures in complex microbial communities would strengthen surveillance efforts and reduce time-to-answer. Here, we tested the ability of nanopore sequencing and adaptive sampling to enrich for AMR genes in a mock community of environmental origin. Our setup implemented the MinION mk1B, an NVIDIA Jetson Xavier GPU, and Flongle flow cells. Using adaptive sampling, we observed consistent enrichment by composition. On average, adaptive sampling resulted in a target composition 4× higher than without adaptive sampling. Despite a decrease in total sequencing output, adaptive sampling increased target yield in most replicates. We also demonstrate enrichment in a diverse community using an environmental sample. This method enables rapid and flexible genomic surveillance.

Effects of spore-forming Bacillus probiotics on growth performance, intestinal morphology, and immune system of broilers housed on deep litter

Aim of the study: to evaluate the effects of feed supplementation of Bacillus subtilis KATMIRA1933, B. subtilis KB41, and Bacillus amyloliquefaciens KB54 probiotics on growth performance, biochemical blood parameters, intestinal morphology, and the immune system of Ross 308 broilers housed on deep litter. Methods and Results: a total of 160 newly hatched Ross 308 broilers were involved in the 42-day-long study with evaluation of growth performance at 7, 14, 21, 28, 35, and 42 days and biochemical blood analysis, histological investigation of jejunum tissues and analysis of IL-6 and IL-10 gene expression of broilers at 42 days. As a result, probiotic KB41 significantly improved growth performance on the 42nd day of the experiment (p<0.01), increased the number of Lactobacillus bacteria in the ceca (p=0.03), and promoted IL-6 and IL-10 genes expression in the spleen of the chickens (p<0.01). The results of this study generally correspond to our previous study, which included an evaluation of Bacillus-based KB41 and KB54 probiotics on production performance and the immune system of broilers housed in cages, although the effects are less prominent. Conclusions: less prominent effects are probably linked to the colonization of the broilers' gastrointestinal tract with unknown bacilli of apparent environmental origin, as the broilers were housed in standard conditions. Significance and Impact of Study: this study provides more evidence of B. subtilis KB41 and B. amyloliquefaciens KB54 effectiveness in poultry.