Gastrointestinal Passage Research Articles

Właściwości probiotyczne drożdży Saccharomyces cerevisiae ŁOCK 0119

Probiotics including their combinations with prebiotics known as synbiotics have been extensively studied as an alternatives to antibiotic growth promoters commonly used in livestock breeding. Among many microorganisms that may be useful for their host, the Saccharomyces cerevisiae yeast exhibits probiotic potential. The objective of the research study was to select a S. cerevisiae strain suitable for use as a probiotic in newly developed synbiotic preparations for monogastric animals (poultry, swine). The survivability of yeast strains in the presence of bile salts and under low-pH conditions varied and after 4 h of incubation it ranged from 66 to 94 % and from 68 to 97 %, respectively. The S. cerevisiae ŁOCK 0119 strain was characterised by the highest survival rate; the number of live cells of this strain was reduced not more than 9 % after 4 h of incubation under the fixed conditions. Also, this strain exhibited hydrophilic properties and a strong auto- and co-aggregation potential. The selected yeast strain aggregated with pathogenic bacteria (Salmonella spp., Listeria monocytogenes) to a varying degree ranging between 40 and 75 %. The S. cerevisiae ŁOCK 0119 strain inhibited the adhesion of pathogens to the Caco-2 cells, whereby the adhesion of morbific bacteria attachment was reduced to a varying degree (15 ÷ 37 %). Based on the results obtained, it was concluded that the selected S. cerevisiae yeast strain had beneficial properties since it was able to survive during gastrointestinal passage, to colonize the intestines and to reduce the growth of pathogenic microbiota.

Low-moisture food matrices as probiotic carriers.

To exert a beneficial effect on the host, adequate doses of probiotics must be administered and maintaining their viability until consumption is thus essential. Dehydrated probiotics exhibit enhanced long-term viability and can be incorporated into low-moisture food matrices, which also possess high stability at refrigeration and ambient temperature. However, several factors associated with the desiccation process, the physicochemical properties of the matrix and the storage conditions can affect probiotic survival. In the near future, an increased demand for probiotics based on functionally dominant members of the gut microbiome ('next-generation probiotics', NGP) is expected. NGPs are very sensitive to oxygen and efficient encapsulation protocols are needed. Strategies to improve the viability of traditional probiotics and particularly of NGPs involve the selection of a suitable carrier as well as proper desiccation and protection techniques. Dehydrated probiotic microcapsules may constitute an alternative to improve the microbial viability during not only storage but also upper gastrointestinal tract passage. Here we review the main dehydration techniques that are applied in the industry as well as the potential stresses associated with the desiccation process and storage. Finally, low- or intermediate-moisture food matrices suitable as carriers of traditional as well as NGPs will be discussed.

Staged endoscopic balloon dilatation for cicatricial pyloric stenosis in children

Secondary pyloric stenosis quickly leads to homeostatic and nutritional disorders that determines the importance of early diagnosis and surgical treatment. In two clinical cases, we have shown that staged endoscopic balloon dilatation of the pylorus is devoid of the most of the known problems and shortcomings of conventional surgery and makes it possible to restore effectively gastrointestinal passage and to improve child's quality of life. This procedure has a high diagnostic and curative value and is followed by positive dynamics of condition of the child with pyloric stenosis.

A longitudinal study to investigate previous Chlamydia trachomatis infection as a risk factor for subsequent anorectal infection in men who have sex with men (MSM) and women visiting STI clinics in the Netherlands.

Although anorectal Chlamydia trachomatis (CT) infections are frequently diagnosed in men who have sex with men (MSM) and women, the reason for this infection often remains unexplained, as anal sex is not always reported. Oropharyngeal infections inoculating the gastrointestinal (GI) tract may contribute to anorectal-CT infections, as evidence in animals suggests that chlamydia bacteria undergo GI passage; however, no evidence exists in humans. Longitudinal patient clinic-registry data from MSM (n = 17 125) and women (n = 4120) from two Dutch sexually transmitted infection clinics were analysed. When adjusting for confounding socio-demographics, co-infections and risk behaviour, previous (from 3 weeks up to 24 months) oropharyngeal CT was not a risk factor for subsequent anorectal CT in women (odds ratio (OR) 0.46; 95% confidence interval (CI) 0.18-1.18; P = 0.11) and MSM (OR 1.33; 95% CI 0.86-2.07; P = 0.204). Despite the large dataset, the numbers did not allow for the estimation of risk in specific subgroups of interest. The role of the GI tract cannot be excluded with this epidemiological study, but the impact of preceding oropharyngeal CT on anorectal-CT infection is likely limited.

Dark chocolate as a stable carrier of microencapsulated Akkermansia muciniphila and Lactobacillus casei

ABSTRACT The viability of probiotics is affected by several factors during manufacturing, storage and gastrointestinal tract passage. Protecting the probiotics from harmful conditions is particularly critical for oxygen sensitive species like Akkermansia muciniphila, a bacterium which recently has been proposed as a next-generation probiotic candidate. Previously, we have developed a protocol for microencapsulating A. muciniphila in a xanthan/gellan gum matrix. Here, we report the enhanced survival during storage and in vitro gastric passage of microencapsulated A. muciniphila embedded in dark chocolate. Lactobacillus casei, as a representative species of traditional probiotics, was included in order to compare its behavior with that of A. muciniphila. For A. muciniphila we observed a 0.63 and 0.87 log CFU g−1 reduction during 60 days storage at 4°C or 15°C, respectively. The viability of L. casei remained stable during the same period. During simulated gastric transit (pH 3), microencapsulated A. muciniphila embedded in chocolate showed 1.80 log CFU mL−1 better survival than naked cells, while for L. casei survival was improved with 0.8 log CFU mL−1. In a hedonic sensory test, dark chocolate containing microcapsules were not significantly different from two commercially available chocolates. The developed protocol constitutes a promising approach for A. muciniphila dosage.

Evaluating the effect of chitosan layer on bioaccessibility and cellular uptake of curcumin nanoemulsions

Curcumin nanoemulsions stabilized by whey protein isolate were successfully developed using high-pressure homogenization. The effect of a chitosan layer deposition using the layer-by-layer technique on nanoemulsions' stability was evaluated during storage conditions, as well as during gastrointestinal tract passage. Lipids’ hydrolysis and curcumin bioaccessibility was assessed using a dynamic gastrointestinal model (simulating the stomach, duodenum, jejunum and ileum) and the cytotoxicity, cellular antioxidant activity and permeability analyses were carried out using Caco-2 cells. Results showed that both nanosystems were stable during one month of storage and at stomach pH conditions, whereas creaming and phase separation occurred at intestine pH conditions. The addition of a chitosan layer increased curcumin bioaccessibility, whereas cellular antioxidant activity studies revealed that nanoemulsions and multilayer nanoemulsions exhibited 9 and 10 times higher antioxidant capacity at the cellular level, respectively, when compared to free curcumin. Permeability assays showed that the use of a chitosan layer significantly increased the apparent permeability coefficient of curcumin through Caco-2 cells by 1.55-folds.

Personalized Gut Mucosal Colonization Resistance to Empiric Probiotics Is Associated with Unique Host and Microbiome Features

Empiric probiotics are commonly consumed by healthy individuals as means of life quality improvement and disease prevention. However, evidence of probiotic gut mucosal colonization efficacy remains sparse and controversial. We metagenomically characterized the murine and human mucosal-associated gastrointestinal microbiome and found it to only partially correlate with stool microbiome. A sequential invasive multi-omics measurement at baseline and during consumption ofan 11-strain probiotic combination or placebo demonstrated that probiotics remain viable upon gastrointestinal passage. In colonized, but not germ-free mice, probiotics encountered a marked mucosal colonization resistance. In contrast, humans featured person-, region- and strain-specific mucosal colonization patterns, hallmarked by predictive baseline host and microbiome features, but indistinguishable by probiotics presence in stool. Consequently, probiotics induced a transient, individualized impact on mucosal community structure and gut transcriptome. Collectively, empiric probiotics supplementation may be limited in universally and persistently impacting the gut mucosa, meriting development of new personalized probiotic approaches.

Biopolymer-Based Minimal Formulations Boost Viability and Metabolic Functionality of Probiotics Lactobacillus rhamnosus GG through Gastrointestinal Passage.

The delivery of probiotic microorganisms as food additives via oral administration is a straightforward strategy to improve the intestinal microbiota. To protect probiotics from the harsh environments in the stomach and small intestine, it is necessary to formulate them in biocompatible carriers, which finally release them in the ileum and colon without losing their viability and functions. Despite major progresses in various polymer-based formulations, many of them are highly heterogeneous and too large in size and hence often "felt" by the tongue. In this study, we established a new formulation for probiotics Lactobacillus rhamnosus GG (LGG) and systematically correlated the physicochemical properties of formulations with the functions of probiotics after the delivery to different gastrointestinal compartments. By reducing the stirring speed by 1 order of magnitude during the emulsification of polyalginate in the presence of xanthan gum, we fabricated microparticles with a size well below the limit of human oral sensory systems. To improve the chemical stability, we deposited chitosan and polyalginate layers on particle surfaces and found that the deposition of a 20 nm-thick layer is already sufficient to perfectly sustain the viability of all LGG. Compared to free LGG, the colony-forming units of LGG in these formulations were by factors of 107 larger in stomach fluid and 104 larger in small intestine fluid. The metabolic functionality of LGG in polymer formulations was assessed by measuring the amount of lactate produced by LGG in a human gastrointestinal simulator, showing 5 orders of magnitude larger values compared to free LGG. The obtained results have demonstrated that the minimal formulation of LGG established here boosts not only the viability but also the metabolic functionality of probiotics throughout oral uptake, passage through the gastrointestinal tract, and delivery to the ileum and colon.

Quantitative Recovery of Viable Lactobacillus paracasei CNCM I-1572 (L. casei DG®) After Gastrointestinal Passage in Healthy Adults.

Probiotics are live microorganisms, and viability after transit through the gastrointestinal tract (GIT) is considered an inherent property of the health benefits of probiotics. The aim of the present study was to quantify the viable and total loads of Lactobacillus paracasei DG cells after passage through the GIT following the consumption of the probiotic product Enterolactis (L. casei DG®; L. paracasei CNCM I-1572; L. paracasei DG) from drinkable vials by healthy adults. We developed a novel method for discriminating and enumerating culturable L. paracasei DG cells based on the unique sticky, filamentous phenotype of this strain on MRS agar containing vancomycin and kanamycin. The identity of DG was also confirmed with strain-specific primers by colony PCR. This method was used for a recovery study of the DG strain to quantify viable cells in the fecal samples of 20 volunteers during a 1-week probiotic consumption period and a 1-week follow-up. We isolated L. paracasei DG from at least one fecal sample from all the volunteers. The highest concentration of viable DG cells [ranging from 3.6 to 6.7 log10 colony-forming unit (CFU) per gram of feces] in the feces was observed between 4 and 8 days from the beginning of Enterolactis intake and for up to 5 days after cessation of intake. As expected, the total DG count determined by real-time quantitative PCR (qPCR) was mostly higher than the viable DG cells recovered. Viable count experiments, carried out by combining ad hoc culture-based discriminative conditions and strain-specific molecular biological protocols, unambiguously demonstrated that L. paracasei DG can survive gastrointestinal transit in healthy adults when ingested as Enterolactis in drinkable vials containing no less than one billion CFU at the end of shelf life.

Robustness of barrier membrane coated metoprolol tartrate matrix tablets: Drug release evaluation under physiologically relevant in vitro conditions

Robust in vitro drug release behavior is an important feature of extended release (ER) hydrophilic matrix formulations for accurate prediction of in vivo drug release. In this study, ER hydrophilic matrix tablets of metoprolol tartrate were formulated using a high viscosity grade of hypromellose as a rate-limiting polymer. Expectedly, this formulation showed an undesirable initial burst release followed by controlled drug release. Application of a barrier membrane (BM) coating of ethylcellulose with a pore former (hypromellose) resulted in the elimination of the burst effect. The aim of this study was to investigate the robustness of in vitro metoprolol release from BM-coated hydrophilic matrix tablets by simulating the physicochemical properties of gastrointestinal fluids and mechanical stress in the fasted- and fed state human gastrointestinal (GI) tract. Uncoated and BM-coated matrices were subjected to various dissolution studies simulating the varying pH conditions and additional physicochemical parameters, and the mechanical stress that can be caused by GI motility during both fasted and fed state GI passage. The BM-coated formulation showed robust drug release without an initial burst in all test scenarios. BM-coated matrix formulations thus represent a very promising approach for obtaining a highly controlled and robust drug release from oral ER formulations.

Glucosylation of T-2 and HT-2 toxins using biotransformation and chemical synthesis: Preparation, stereochemistry, and stability

Plant-derived phase II metabolites of T-2 toxin (T2) and HT-2 toxin (HT2) were first described in 2011 and further characterized in the following years. Since then, some efforts have been made to understand their biosynthesis, occurrence, toxicity, toxicokinetics, and finally relevance for consumers. Thus, the probably most important question is whether and how these metabolites contribute to toxicity upon hydrolysis either during food processing or the gastrointestinal passage. To answer this question, firstly, knowledge on the correct stereochemistry of T2 and HT2 glucosides is important as this affects hydrolysis and chemical behavior. So far, contradictory results have been published concerning the number and anomericity of occurring glucosides. For this reason, we set up different strategies for the synthesis of mg-amounts of T2, HT2, and T2 triol glucosides in both α and ß configuration. All synthesized glucosides were fully characterized by NMR spectroscopy as well as mass spectrometry and used as references for the analysis of naturally contaminated food samples to validate or invalidate their natural occurrence. Generally, 3-O-glucosylation was observed with two anomers of HT2 glucoside being present in contaminated oats. In contrast, only one anomer of T2 glucoside was found. The second aspect of this study addresses the stability of the glucosides during thermal food processing. Oat flour was artificially contaminated with T2 and HT2 glucosides individually and extruded at varying initial moisture content and temperature. All four glucosides appear to be more stable during food extrusion than the parent compounds with the glucosidic bond not being hydrolyzed.

Freeze-dried alginate-silica microparticles as carriers of probiotic bacteria in apple juice and beer

Herein the survivability of free and encapsulated Lactobacillus. rhamnosus GG (LGG) in alginate or in alginate-silica microcarriers was investigated upon storage in apple juice and 5vt% beer at 4 °C. This study showed that the encapsulation approach utilized herein limits the release of the bacteria over time into the beverages, with core-shell alginate-silica beads being more efficient than alginate beads alone. Additionally, the statistical analyses showed a p < 0.001 for apple juice and p < 0.005 for beer when comparing the viability of alginate vs silica-coated beads at the 1 week time point in both, the filtrate and inside the carriers. This is of particular importance for the further delivery of bacteria to the intestines, to which encapsulation generally appears to be beneficial during the gastrointestinal passage.

In vivo repressed genes of Vibrio cholerae reveal inverse requirements of an H+/Cl− transporter along the gastrointestinal passage

The facultative human pathogen Vibrio cholerae changes its transcriptional profile upon oral ingestion by the host to facilitate survival and colonization fitness. Here, we used a modified version of recombination-based in vivo expression technology to investigate gene silencing during the in vivo passage, which has been understudied. Using a murine model of cholera, we screened a V. cholerae transposon library composed of 10,000 randomly generated reporter fusions and identified 101 in vivo repressed (ivr) genes. Our data indicate that constitutive expression of ivr genes reduces colonization fitness, highlighting the necessity to down-regulate these genes in vivo. For example, the ivr gene clcA, encoding an H+/Cl- transporter, could be linked to the acid tolerance response against hydrochloric acid. In a chloride-dependent manner, ClcA facilitates survival under low pH (e.g., the stomach), but its presence becomes detrimental under alkaline conditions (e.g., lower gastrointestinal tract). This pH-dependent clcA expression is controlled by the LysR-type activator AphB, which acts in concert with AphA to initiate the virulence cascade in V. cholerae after oral ingestion. Thus, transcriptional networks dictating induction of virulence factors and the repression of ivr genes overlap to regulate in vivo colonization dynamics. Overall, the results presented herein highlight the impact of spatiotemporal gene silencing in vivo. The molecular characterization of the underlying mechanisms can provide important insights into in vivo physiology and virulence network regulation.

Viability of microencapsulated Akkermansia muciniphila and Lactobacillus plantarum during freeze-drying, storage and in vitro simulated upper gastrointestinal tract passage.

Akkermansia muciniphila, an abundant member of the human gut microbiota, has been suggested as a potential next-generation probiotic. However, its high sensitivity to oxygen limits the development of dosage protocols. Here, we describe microencapsulation, in a xanthan and gellan gum matrix, and a subsequent freeze-drying protocol for A. muciniphila DSM22959. For comparison Lactobacillus plantarum subsp. plantarum ATCC14917 was microencapsulated and freeze-dried using similar protocols. Four different mixtures were tested for cryoprotective properties: sucrose 5% plus trehalose 5%; agave syrup 10%; skim milk 10%, glucose 1%, yeast extract 0.5%, and mannitol 2.5%; as well as peptone 0.1% plus sorbitol 1.2%. Milli-Q-water served as control. Only cryoprotectant solutions with high sugar or protein content significantly improved the survival of both strains during freeze-drying. Microencapsulated cells were stored aerobically or anaerobically for 1 month at 4 °C or 25 °C. Survival of A. muciniphila was significantly better when stored anaerobically at 4 °C. The survival of microencapsulated L. plantarum, was relatively stable at both temperatures under anaerobic conditions. Survival of microencapsulated cells was compared with that of free cells during in vitro simulated upper gastrointestinal tract (GIT) transit at fasted and fed state. During in vitro simulated stomach passage, encapsulation significantly improved survival and viable cells remained at relevant levels after the entire simulated upper GIT transit. In conclusion, we here report a protocol for encapsulating A. muciniphila giving acceptable storage stability and enhancing survival during in vitro simulated upper GIT transit and thus constitutes an important step towards enabling future use of this important member of the human colonic microbiota as a probiotic.

Antimicrobial and bactericidal impacts of Bacillus amyloliquefaciens CECT 5940 on fecal shedding of pathogenic bacteria in dairy calves and adult dogs

Two experiments were carried out to evaluate the bactericidal impacts of Bacillus amyloliquefaciens CECT 5940 on the shedding of faecal pathogenic bacteria in dairy calves (Experiment 1) and in adults dogs (experiment 2). In the calves experiment, a completely randomized design was used to investigate the faecal bacteria profile of Holstein dairy calves fed with either pasteurized waste milk (PWM; n = 9) or a formulated non-medicated milk replacer (NMR; n = 9) for 60 d. The NMR containing sodium-butyrate and the active probiotic B. amyloliquefaciens CECT 5940. In the dogs experiment, addition of same probiotic (i.e., B. amyloliquefaciens CECT 5940) was carried out in two stages. The first stage started from day 7–37, and the second from day 44–71. The assessment of faecal score measured on day 22, 37, 42, 57, 71 and 77 to determine the texture of the stools. Calves received PWM consumed (P < 0.05) more starter feed between day 16 and day 45. The calves fed NMR had more moisture faeces and less cough reflux than the PWM-calves. Feeding NMR to calves increased faecal Klebsiella oxytoca and Proteus vulgaris counts in comparison to PWM-calves. The administration of B. amyloliquefaciens CECT 5940 to the dog diet has no significant effect on the hardness of the stool. Meanwhile, the bacillus count increases while the coliforms count decreases upon B. amyloliquefaciens CECT 5940 administration. This reveals that B. amyloliquefaciens CECT 5940 survived the gastrointestinal passage and rapidly colonized the dog intestine, which could positively affect the metabolism and composition of the intestinal microflora. These results show that B. amyloliquefaciens are a promising probiotic with an antimicrobial and bactericidal activities against the intestinal pathogenic bacteria for dairy calves and adult dogs.

Aqueous extract of yellow maca (Lepidium meyenii ) improves sperm count in experimental animals but response depends on hypocotyl size, pH and routes of administration

Lepidium meyenii, a Peruvian plant growing over 4000m.a.s.l., has effects on nutrition and fertility. The purpose of this study was to evaluate the sperm count in 105 male mice receiving boiled aqueous extract of yellow maca hypocotyls from different sizes, under different pH conditions and using two different routes of administration.Five mice per group were treated daily for 3days with vehicle (oral and intraperitoneal) or maca aqueous extracts (5mg/0.5ml/day) belonging to the first, second, third and fourth categories, according to their hypocotyl size. On day four, sperm count was evaluated at testis, epididymis and vas deferens.Sperm count was higher in mice receiving maca from the larger sizes (first and secondcategories). Reduction in maca extract pH increased sperm count, whereas an increase in the pH resulted in a reduction in sperm count. The effect of pH reduction is observed only in maca from the first and secondcategories. Aqueous extract of maca was effective only after oral administration. In conclusion, the larger size ofhypocotylspresented the best biological effect, and the low pH in the extract and the transformation after gastrointestinal passage are both important for its biological action.

Measurement of gastrointestinal passage rate in Atlantic salmon (Salmo salar) fed dry or soaked feed

A method for measurement of gastrointestinal passage rate was tried in Atlantic salmon, Salmo salar (body weight 1131g, temperature 13.5°C, salinity 32‰). Salmon were force fed one single ration (10g) extruded feed ‘as is’ (92% dry matter) or soaked 2h in sea water (70% dry matter), in triplicate with three individuals per replicate. Content from stomach, small intestine and distal intestine was collected at 2, 6, 12, 18, 24 and 48h after feeding.Two hours after feeding, significantly more feed was transferred from the stomach to the small intestine in salmon fed soaked feed than in those fed dry feed. After that, no significant differences in gastrointestinal passage rate were found. Numerically however, soaked feed seemed to pass through the gut faster than dry feed.The content in stomach declined gradually, and all stomachs were empty after 48h. Salmon in both treatment groups used 6–12h on average to empty the stomach 50%. The content in small intestine peaked at the sampling 12h post feeding for salmon fed both feed types. After 48h, the small intestines were empty in all three replicates of salmon fed soaked feed, and in one replicate fed dry feed. The largest amounts of dry matter in the distal intestine were found between 12 and 24h for both feed groups. Some dry matter was still present in the hindgut after 48h.Individual variation in the gastrointestinal passage rate was large and few significant differences were revealed. However, soaked feed gave a significantly higher gastric evacuation rate than dry feed shortly (2h) after feeding. As the fish regurgitated some pellets, the method may be most suitable when feeding small rations. Besides, due to variation a larger number of replicates would increase the power of the test.

Simulated gastrointestinal conditions increase adhesion ability of Lactobacillus paracasei strains isolated from kefir to Caco-2 cells and mucin

Gastrointestinal conditions along the digestive tract are the main stress to which probiotics administrated orally are exposed because they must survive these adverse conditions and arrive alive to the intestine. Adhesion to epithelium has been considered one of the key criteria for the characterization of probiotics because it extends their residence time in the intestine and as a consequence, can influence the health of the host by modifying the local microbiota or modulating the immune response. Nevertheless, there are very few reports on the adhesion properties to epithelium and mucus of microorganisms after passing through the gastrointestinal tract. In the present work, we evaluate the adhesion ability in vitro of L. paracasei strains isolated from kefir grains after acid and bile stress and we observed that they survive simulated gastrointestinal passage in different levels depending on the strain. L. paracasei CIDCA 8339, 83120 and 83123 were more resistant than L. paracasei CIDCA 83121 and 83124, with a higher susceptibility to simulated gastric conditions. Proteomic analysis of L. paracasei subjected to acid and bile stress revealed that most of the proteins that were positively regulated correspond to the glycolytic pathway enzymes, with an overall effect of stress on the activation of the energy source. Moreover, it is worth to remark that after gastrointestinal passage, L. paracasei strains have increased their ability to adhere to mucin and epithelial cells in vitro being this factor of relevance for maintenance of the strain in the gut environment to exert its probiotic action.

비피도박테리아의 생존성 증진을 위한 캡슐화 기술

The intestinal microbiota has been shown to have a vital role in various aspects of human health, and accumulating evidence has shown the beneficial effects of supplementation with bifidobacteria for the improvement of human health, ranging from protection against infection to various positive effects. However, maintaining bacterial cell viability during storage and gastrointestinal transit remains a challenge. Microencapsulation of probiotic bacterial cells provides protection against adverse conditions during processing, storage, and gastrointestinal passage. In this paper, we review the current knowledge, future prospects, and challenges of microencapsulation of probiotic Bifidobacterium spp.

Management of neglected Lisfranc Injury of foot -a tertiary referral centre experience

In vitro predatory activity of 157 native isolates of Arthrobotrys oligospora from China on larvae of trichostrongylides (Trichostrongylus colubriformis and Haemonchus contortus) in feces of sheep were assessed. The results showed that 135 of tested isolates of A. oligospora reduced the development of trichostrongylide larvae in feces by 90–99.99%, 11 isolates by 80–89.46% and 11 isolates by 14.58–78.82%. To understand their capacity of passing through gastrointestinal tract of sheep, 50 native isolates of A. oligospora were selected and assessed in sheep. Among these isolates, 16 isolates significantly reduced the number of larvae developing in the feces (P < 0.05); their percentage reduction of L3 ranged from 42.87% to 99.51% and the isolates tested were harvested in 5 g sub-samples of from sheep in each treatment group, indicating that these isolates had the capacity of preying larvae of trichostrongylides after the passage through gastrointestinal tract of sheep. The remaining isolates of A. oligospora were not able to survive after passage through gastrointestinal tract of sheep. In the following, the 16 isolates that presented more or less viability after sheep gastrointestinal passage were selected and assessed in goats. The results showed that the 11 isolates out of them could be able to pass through the digestive tract of goats without loss of ability of preying larvae of trichostrongylides in feces and their efficacies ranged from 53.88% to 94.28%, and that the isolates tested were harvested in 5 g sub-samples of feces from goats in each treatment group. In the current study, these isolates which demonstrated outstanding properties in vitro and could survive in the passage through the alimentary tract of sheep and goat should be potential candidates as a possible feed additive.