Probiotics Modulate Intestinal Motility and Inflammation in Zebrafish Models

UHPLC-Q/Orbitrap HRMS combined with spectrum-effect relationship and network pharmacology to discovery the gastrointestinal motility-promoting material basis in Citri Sarcodactylis Fructus

ETHNOPHARMACOLOGICAL RELEVANCE

The prevalence of gastrointestinal motility disorders (GMD) is increasing and is characterized by long-term recurrence. Citri Sarcodactylis Fructus (CSF), as a traditional Chinese medicine (TCM) known in "regulating qi and harmonizing the stomach", has therapeutic effects on GMD. However, the material basis of its efficacy is not clear.

AIM OF THE STUDY

The aim of this study was to evaluate the gastrointestinal motility-promoting activity of CSF extracts and to screen their active ingredients and to perform a preliminary validation.

METHODS

The chemical composition spectrum of different extracts of CSF were established by ultra high-performance liquid chromatography coupled with quadrupole orbitrap high-resolution mass spectrometry (UHPLC-Q/Orbitrap HRMS). The gastrointestinal motility-promoting activities of CSF were investigated by determining the intestinal propulsion rate, gastric emptying rate, acetylcholinesterase activity, and motilin content in L-arginine-induced GMD mice. Spectrum-effect relationship and network pharmacology analysis were used for the screening of potential active ingredients. A zebrafish gastrointestinal motility model traced with Nile Red was established to validate the active ingredients. Molecular docking prediction was used to explore the mechanism of action of the active ingredient. Finally, western blotting and TUNEL staining were performed to validate the molecular docking predictions.

RESULTS

In total, 42 shared components were identified. The main active fraction of CSF to promote gastrointestinal motility was 70% ethanol elution fraction. Eleven potential active ingredients were screened by grey correlation analysis, orthogonal partial least squares analysis, and "active ingredient-target" network. Six compounds were confirmed as the pharmacodynamic substances of CSF by zebrafish gastrointestinal motility model, namely, quercetin, kaempferol, isorhamnetin, diosmetin, hesperetin, and 5,7,3'-trihydroxy-6,4',5'-trimethoxyflavone. Molecular docking predictions and western blotting assays indicated that CSF may act on AKT and MMP9 targets to exert gastrointestinal motility-promoting activity.

CONCLUSION

This study provided a foundation for elucidating the gastrointestinal motility-promoting activity of CSF and its material basis by integrating spectrum-effect relationship and network pharmacology. It also provided a theoretical basis for quality control of CSF and a new idea for the discovery and validation of pharmacodynamic substances in TCM.

Chemometric-based analysis and bioassay guided identification of potent compounds with intestinal motility promoting effects from Dalitong Granules

ETHNOPHARMACOLOGICAL RELEVANCE

Dalitong Granules (DLT), a potent Traditional Chinese Medicine known for its ability to promote gastrointestinal motility, is widely used in clinical practice for the treatment of Functional Dyspepsia (FD). Despite the remarkable clinical efficacy of DLT, the specific components responsible for its effectiveness remains unclear.

AIM OF THE STUDY

The study aimed to identify potential active ingredients of DLT for treating FD through spectrum-effect relationship analysis, multivariate statistical analysis and network pharmacology analysis. The efficacy of these identified compounds was subsequently validated using the zebrafish intestinal peristalsis model.

MATERIALS AND METHODS

The fingerprints of various solvent-extracted DLT were analyzed using high performance liquid chromatography coupled with tandem high-resolution mass spectrometry. The intestinal motility-promoting activities of DLT extracted by different solvents were evaluated through an intestinal propulsion test in mice. Potential therapeutic substances in DLT for treating FD were screened via chemometric analysis based on spectrum-effect relationship analysis. The correlation between the intensity of common peaks in the total ion chromatogram and the pharmacodynamic indices was assessed using multivariate statistical analysis. Additionally, given the complexity of Traditional Chinese Medicine, which comprises multiple components and targets, a network pharmacology analysis was performed to investigate the potential active ingredients in DLT. Finally, the pharmacological effects of these compounds in DLT were validated using a zebrafish intestinal motility model.

RESULTS

Through spectral-effect relationships analysis and network pharmacology analysis, it was determined that ten ingredients in DLT contribute to the promotion of intestinal motility. In a zebrafish intestinal motility model, it was observed that eight chemicals (excluding tetrahydropalmatine) demonstrate favorable activity of promoting gastrointestinal motility. These findings suggest that these ingredients may serve as potential therapeutic agents for improving gastric motility disorders.

CONCLUSIONS

This study employed spectral-effect relationship and network pharmacology analysis to identify the active ingredients in DLT. The findings were then validated using a zebrafish intestinal peristalsis model. These results provide a scientific foundation for the clinical application of DLT as a key traditional herbal formula for managing FD.

The protective effects of Kefir extract (KE) on intestinal damage in larval zebrafish induced by Oxytetracycline: Insights into intestinal function, morphology, and molecular mechanisms

The antibiotic oxytetracycline (OTC) can be detected in contemporary natural aquatic environments and has been implicated in causing intestinal damage in humans exposed to OTC-contaminated food or water. The irreversible damage caused by high concentrations of OTC to the intestine suggests that treatment through dietary means could still be necessary. This study proved the effectiveness of kefir extract (KE) in reversing intestinal damage caused by oxytetracycline (OTC) exposure. Following a 24-hour KE treatment subsequent to OTC exposure from 3 to 8 days post-fertilization of zebrafish larvae, molecular-level and microbiomic assessments revealed significant improvements. These included reduced expression of proinflammatory factors (IL-8 and IL-1β), increased antioxidant levels, and reversed unhealthy distribution of intestinal microbiota. Furthermore, KE supplementation showed potential in enhancing intestinal motility in the experiment of Nile red staining and fluorescent microbead transit. However, histological analysis showed that this short-term treatment with KE only partially reversed the intestinal morphological changes induced by OTC, suggesting that a longer treatment period might be necessary for complete restoration.

Assessment of Multifunctional Activity of a Postbiotic Preparation Derived from Lacticaseibacillus paracasei Postbiotic-P6

Postbiotics possess various functional activities, closely linked to their source bacterial strains and preparation methods. Therefore, the functional activities of postbiotics need to be evaluated through in vitro and in vivo methods. This study aims to prepare a postbiotic and explore its antihemolytic, anti-inflammatory, antioxidant, and antibacterial activities. Specifically, a postbiotic preparation named PostbioP-6 was prepared by intercepting 1-5 kDa of Lacticaseibacillus paracasei Postbiotic-P6 fermentation broth. The results demonstrate that PostbioP-6 exhibited notable biological activities across multiple assays. It showed significant antihemolytic activity, with a 4.9-48.1% inhibition rate at 10-50% concentrations. Anti-inflammatory effects were observed both in vitro, where 8-40% PostbioP-6 was comparable to 259.1-645.4 μg/mL diclofenac sodium, and in vivo, where 3.5 and 4.0 μL/mL PostbioP-6 significantly reduced neutrophil counts in inflamed zebrafish (p < 0.05). Antioxidant properties were evident through increased reducing power (OD700 increased from 0.279 to 2.322 at 1.25-12.5% concentrations), DPPH radical scavenging activity (38.9-92.4% scavenging rate at 2.5-50% concentrations), and hydroxyl radical scavenging activity (4.66-10.38% scavenging rate at 0.5-4% concentrations). Additionally, PostbioP-6 demonstrated antimicrobial activity against two Gram-positive bacteria, eight Gram-negative bacteria, and one fungus. Furthermore, PostbioP-6 significantly inhibited the increase in peroxide value and malondialdehyde content in cookies, highlighting its potential application in food preservation. In conclusion, we prepared a novel postbiotic, termed PostbioP-6, which proved to have prominent anti-hemolytic, anti-inflammatory, antioxidant, and broad-spectrum antimicrobial activities. The multifunctional properties of PostbioP-6 position it as a potentially effective functional food supplement or preservative. In the future, further research is necessary to elucidate the precise mechanisms of action, identify the active components, and validate its biological activities in animal models or clinical trials.

A review on current advancement in zebrafish models to study chronic inflammatory diseases and their therapeutic targets

Chronic inflammatory diseases are caused due to prolonged inflammation at a specific site of the body. Among other inflammatory diseases, bacterial meningitis, chronic obstructive pulmonary disease (COPD), atherosclerosis and inflammatory bowel diseases (IBD) are primarily focused on because of their adverse effects and fatality rates around the globe in recent times. In order to come up with novel strategies to eradicate these diseases, a clear understanding of the mechanisms of the diseases is needed. Similarly, detailed insight into the mechanisms of commercially available drugs and potent lead compounds from natural sources are also important to establish efficient therapeutic effects. Zebrafish is widely accepted as a model to study drug toxicity and the pharmacokinetic effects of the drug. Moreover, researchers use various inducers to trigger inflammatory cascades and stimulate physiological changes in zebrafish. The effect of these inducers contrasts with the type of zebrafish used in the investigation. Hence, a thorough analysis is required to study the current advancements in the zebrafish model for chronic inflammatory disease suppression. This review presents the most common inflammatory diseases, commercially available drugs, novel therapeutics, and their mechanisms of action for disease suppression. The review also provides a detailed description of various zebrafish models for these diseases. Finally, the future prospects and challenges for the same are described, which can help the researchers understand the potency of the zebrafish model and its further exploration for disease attenuation.

Magnolia Officinalis Alcohol Extract Alleviates the Intestinal Injury Induced by Polygala Tenuifolia Through Regulating the PI3K/AKT/NF-κB Signaling Pathway and Intestinal Flora

Purpose

Polygala tenuifolia Willd. (PT), a traditional Chinese medicinal plant extensively employed in managing Alzheimer's disease, exhibits notable gastrointestinal side effects as highlighted by prior investigations. In contrast, Magnolia officinalis Rehd. et Wils (MO), a traditional remedy for gastrointestinal ailments, shows promising potential for ameliorating this adverse effect of PT. The objective of this study is to examine the underlying mechanism of MO in alleviating the side effects of PT.

Methods

Hematoxylin-eosin (H&E) staining was used to observe the structural damage of zebrafish intestine, and enzyme-linked immunosorbent assay (ELISA) was used to detect the levels of inflammatory factors and oxidative stress. The integrity of the intestinal tight junctions was examined using transmission electron microscope (TEM). Moreover, the expression of intestinal barrier genes and PI3K/AKT/NF-κB signaling pathway-related genes was determined through quantitative real-time PCR. The changes in intestinal microbial composition were analyzed using 16S rRNA and metagenomic techniques.

Results

MO effectively ameliorated intestinal pathological damage and barrier gene expression, and significantly alleviated intestinal injury by reducing the expression of inflammatory cytokines IL-1β, IL-6, TNF-α, and inhibiting the activation of PI3K/AKT/NF-κB pathway. Furthermore, MO could significantly increase the relative abundance of beneficial microorganisms (Lactobacillus, Blautia and Saccharomyces cerevisiae), and reduce the relative abundance of pathogenic bacteria (Plesiomonas and Aeromonas).

Conclusion

MO alleviated PT-induced intestinal injury, and its mechanism may be related to the inhibition of PI3K/AKT/NF-κB pathway activation and regulation of intestinal flora.

Lactobacillus rhamnosus GG triggers intestinal epithelium injury in zebrafish revealing host dependent beneficial effects

Lactobacillus rhamnosus GG (LGG), the well-characterized human-derived probiotic strain, possesses excellent properties in the maintenance of intestinal homeostasis, immunoregulation and defense against gastrointestinal pathogens in mammals. Here, we demonstrate that the SpaC pilin of LGG causes intestinal epithelium injury by inducing cell pyroptosis and gut microbial dysbiosis in zebrafish. Dietary SpaC activates Caspase-3-GSDMEa pathways in the intestinal epithelium, promotes intestinal pyroptosis and increases lipopolysaccharide (LPS)-producing gut microbes in zebrafish. The increased LPS subsequently activates Gaspy2-GSDMEb pyroptosis pathway. Further analysis reveals the Caspase-3-GSDMEa pyroptosis is initiated by the species-specific recognition of SpaC by TLR4ba, which accounts for the species-specificity of the SpaC-inducing intestinal pyroptosis in zebrafish. The observed pyroptosis-driven gut injury and microbial dysbiosis by LGG in zebrafish suggest that host-specific beneficial/harmful mechanisms are critical safety issues when applying probiotics derived from other host species and need more attention.

Effect of Probiotics in Stress-Associated Constipation Model in Zebrafish (Danio rerio) Larvae

The pathophysiology of functional bowel disorders is complex, involving disruptions in gut motility, visceral hypersensitivity, gut-brain-microbiota interactions, and psychosocial factors. Light pollution, as an environmental stressor, has been associated with disruptions in circadian rhythms and the aggravation of stress-related conditions. In this study, we investigated the effects of environmental stress, particularly continuous light exposure, on intestinal motility and inflammation using zebrafish larvae as a model system. We also evaluated the efficacy of probiotics, specifically Bifidobacterium longum (B. longum), at alleviating stress-induced constipation. Our results showed that continuous light exposure in zebrafish larvae increased the cortisol levels and reduced the intestinal motility, establishing a stress-induced-constipation model. We observed increased inflammatory markers and decreased intestinal neural activity in response to stress. Furthermore, the expressions of aquaporins and vasoactive intestinal peptide, crucial for regulating water transport and intestinal motility, were altered in the light-induced constipation model. Administration of probiotics, specifically B. longum, ameliorated the stress-induced constipation by reducing the cortisol levels, modulating the intestinal inflammation, and restoring the intestinal motility and neural activity. These findings highlight the potential of probiotics to modulate the gut-brain axis and alleviate stress-induced constipation. Therefore, this study provides a valuable understanding of the complex interplay among environmental stressors, gut function, and potential therapeutic strategies.

Systematic analysis of proximal midgut- and anorectal-originating contractions in larval zebrafish using event feature detection and supervised machine learning algorithms

BACKGROUND

Zebrafish larvae are translucent, allowing in vivo analysis of gut development and physiology, including gut motility. While recent progress has been made in measuring gut motility in larvae, challenges remain which can influence results, such as how data are interpreted, opportunities for technical user error, and inconsistencies in methods.

METHODS

To overcome these challenges, we noninvasively introduced Nile Red fluorescent dye to fill the intraluminal gut space in zebrafish larvae and collected serial confocal microscopic images of gut fluorescence. We automated the detection of fluorescent-contrasted contraction events against the median-subtracted signal and compared it to manually annotated gut contraction events across anatomically defined gut regions. Supervised machine learning (multiple logistic regression) was then used to discriminate between true contraction events and noise. To demonstrate, we analyzed motility in larvae under control and reserpine-treated conditions. We also used automated event detection analysis to compare unfed and fed larvae.

KEY RESULTS

Automated analysis retained event features for proximal midgut-originating retrograde and anterograde contractions and anorectal-originating retrograde contractions. While manual annotation showed reserpine disrupted gut motility, machine learning only achieved equivalent contraction discrimination in controls and failed to accurately identify contractions after reserpine due to insufficient intraluminal fluorescence. Automated analysis also showed feeding had no effect on the frequency of anorectal-originating contractions.

CONCLUSIONS & INFERENCES

Automated event detection analysis rapidly and accurately annotated contraction events, including the previously neglected phenomenon of anorectal contractions. However, challenges remain to discriminate contraction events based on intraluminal fluorescence under treatment conditions that disrupt functional motility.

Alleviative effects of quercetin of Botrytis cinerea-induced toxicity in zebrafish (Danio rerio) larvae

Quercetin is a kind of flavonoid substance extensively existing in the plant, which has antioxidant, anti-inflammatory, and anti-apoptosis effects. It was reported that the higher concentration of spores present in the environment could cause abnormal development in zebrafish larvae. Therefore, this study set out to investigate whether quercetin could reduce the zebrafish larvae damage caused by Botrytis cinerea exposure as well as to examine the molecular basis for this action. The findings demonstrated that 50 μM quercetin improved the developmental dysplasia of zebrafish larvae induced by 102 CFU/mL Botrytis cinerea spore suspension, reduced abnormal apoptosis, enhanced antioxidant system, relieved inflammation, reshaped intestinal morphology and recovered intestinal motility. At the molecular level, quercetin decreased the transcriptional abundance of pro-apoptotic factors (bax, p53, caspase3, and caspase9) and up-regulated the anti-apoptotic gene (bcl-2) expression to reduce apoptosis. Moreover, quercetin enhanced the activities of downstream antioxidant enzymes (SOD and CAT) to clear excess ROS and MDA due to Botrytis cinerea exposure by up-regulating the expression of antioxidant genes (nrf2, ho-1, sod, and cat) in the Keap1-Nrf2 pathway. Additionally, quercetin inhibited the elevation of TNF-α by regulating the gene expression of key targets (jak3, pi3k, pdk1, akt, and ikk2) and the content of major proteins NF-κB (P65) and IκB in the NF-κB pathway. In conclusion, this work enriched the contents of the biological research of Botrytis cinerea and provided a new direction for the drug development and targeted therapy of quercetin.

Probiotics mitigate kidney damage after exposure to Sri Lanka's local groundwater from chronic kidney disease with uncertain etiology (CKDu) prevalent area in zebrafish

Groundwater in Sri Lanka, contaminated with environmental toxins, is suspected to potentially induce chronic kidney disease of uncertain etiology (CKDu) in humans. This study aims to elucidate the potential mitigating effects of probiotics on kidney damage induced by exposure to this local groundwater (LW) in zebrafish. We used zebrafish as a model organism and exposed them to local groundwater to evaluate the risk of CKDu. Probiotics were then added at a concentration of 108 colony-forming units per milliliter (CFU/mL). Our findings revealed that exposure to local groundwater resulted in abnormalities, such as tail deletion and spinal curvature in zebrafish larvae. However, the addition of probiotics mitigated these effects, improving the hatching rate, heart rate, length, weight, deformity rate, survival rate, and abnormal behavior of zebrafish. It also positively influenced the differential expression levels of kidney development and immunity-related genes (dync2h1, foxj1, pkd2, gata3, slc20a1, il1β, and lyso). Furthermore, exposure to LW decreased both the diversity and abundance of microbiota in zebrafish larvae. However, treatment with probiotics, such as L. plantarum and L. rhamnosus partially restored the disrupted gut microbiota and significantly impacted the cellular process pathways of the microbial community, as determined by KEGG (Kyoto Encyclopedia of Genes and Genomes) analysis. In conclusion, this study highlights the risks associated with Sri Lanka's local groundwater from a CKDu prevalent area and confirms the beneficial effects of different probiotics. These findings may provide new insights into bacterial function in host kidney health.

Developmental toxicity and inflammatory response induced by Botrytis cinerea in zebrafish (Danio rerio) larvae

Botrytis cinerea can reduce the yield of fruits and vegetables by infecting plants. The conidia produced by Botrytis cinerea can be transmitted to the aquatic environment via air and water, but the effects of Botrytis cinerea on aquatic animals is unknown. In this research, the influence of Botrytis cinerea on the development, inflammation, and apoptosis of zebrafish larvae and the underlying mechanism was evaluated. Results indicated that, compared with the control group, the larvae exposed to 10¹-10³ CFU/mL of Botrytis cinerea spore suspension had a delayed hatching rate, lower head and eye area, shorter body length, and larger yolk sac at 72 h post-fertilization. In addition, the quantitative fluorescence intensity of treated larvae displayed a dose-dependent increase in apoptosis sign, revealing that Botrytis cinerea could generate apoptosis. Subsequently, zebrafish larvae were inflamed after exposure to Botrytis cinerea spore suspension, which was characterized as inflammatory infiltration and macrophage aggregation in the intestine. The enrichment of the pro-inflammatory factor TNF-α activated the NF-κB signaling pathway, generating the increase of the transcription level of target genes (jak3, pi3k, pdk1, akt, and ikk2) and the high expression of major proteins NF-κB (P65) in this pathway. Likewise, elevated content of TNF-α could activate JNK, which turned on the P53 apoptotic pathway, leading to a significant increase in the bax, caspase3, and caspase9 transcript abundances. This study demonstrated that Botrytis cinerea could cause developmental toxicity, morphological malformation, inflammation, and cell apoptosis in zebrafish larvae, which provided data support and a theoretical basis for ecological health risk assessment and filled the gap in biological research of Botrytis cinerea.

Effects of three different probiotics of Tibetan sheep origin and their complex probiotics on intestinal damage, immunity, and immune signaling pathways of mice infected with Clostridium perfringens type C

Tibetan sheep have unique intestinal microorganisms in their intestines that are adapted to the highland alpine and anoxic environment. To further clarify the probiotic properties of Tibetan sheep-derived probiotics, we selected three Tibetan sheep-derived probiotic isolates (Enterococcus faecalis EF1-mh, Bacillus subtilis BS1-ql, and Lactobacillus sakei LS-ql) to investigate the protective mechanisms of monocultures and their complex strains against Clostridium perfringens type C infection in mice. We established a model of C. perfringens type C infection and used histology and molecular biology to analyze the effects and mechanisms of different probiotic treatments on mice after C. perfringens type C infection. After supplementation with either probiotics or complex probiotics, mice were improved in terms of weight reduction and reduced the levels of cytokines in serum and increased the levels of intestinal sIgA, and supplementation with complex probiotics was effective. In addition, both probiotic and complex probiotic supplementation effectively improved the damage of intestinal mucosa and spleen tissue. The relative expressions of Muc 2, Claudin-1, and Occludin genes were increased in the ileum. The three probiotics and the compound probiotics treatment significantly reduced the relative mRNA expression of toll-like/MyD88/NF-κB/MAPK. The effect of probiotic treatment was similar to the results of engramycin treatment, but the effect of engramycin treatment on intestinal sIgA was not significant. Our results clarify the immunomodulatory effects of the three probiotic isolates and the complex probiotics on C. perfringens infection, and the repair of the intestinal mucosal barrier.

The therapeutic and preventive effects of a canine-origin VB12 -producing Lactobacillus on DSS-induced colitis in mice

Vitamin B12 (VB12 ) plays vital roles as a cofactor in reactions related to biosynthesis and metabolic regulation. Animals with diarrhoea from intestinal inflammation are susceptible to VB12 deficiency due to dysfunctional absorption. No current medications for canine intestinal inflammation can simultaneously act as VB12 supplements. Here we have tested a strain of VB12 -producing Lactobacillus, to investigate its safety in healthy dogs and test for hypothesized therapeutic and preventive effects on murine colitis. Results from enzyme-linked immunosorbent assay, histopathological analysis, and quantitative polymerase chain reaction showed normal physical conditions of healthy dogs given Lactobacillus, and blood biochemical indices showed no significant differences in markers, indicating safety of Lactobacillus to healthy dogs. The microbiota in animals receiving VB12 -producing Lactobacillus probiotic exhibited decreased abundance of Escherichia coli and concomitant increase in Lactobacillus. The probiotic supplement also resulted in downregulation of proinflammatory cytokines in murine colon tissues, reduced myeloperoxidase activity and malondialdehyde level, and significantly increased serum VB12 level and decreased homocysteine in therapeutic and preventive experiments. Moreover, Lactobacillus supplement decreased colonic inflammation and injury, improved gut microbiota, and ameliorated VB12 deficiency as an adjunctive therapy. We conclude this product is potentially beneficial for efficient therapy and prevention of VB12 deficiency form intestinal inflammation in canine clinical practice.

Lactobacillus rhamnosus GG normalizes gut dysmotility induced by environmental pollutants via affecting serotonin level in zebrafish larvae

Intestinal peristalsis is essential for gastrointestinal function, which could maintain the appropriate progression and digestion of food and reduce bacterial aggregation through mixing function. Even though certain ingredients of foodstuff are known to increase or decrease intestinal peristalsis, the role of environmental pollutants on intestinal peristalsis is relatively unknown. Therefore, the effects of four typical environmental pollutants (oxytetracycline, arsenic, polychlorinated biphenyls and chlorpyrifos) on intestinal peristalsis in the zebrafish model and then tested the recovery effect of the constipation-resistant probiotic. The results showed that 4-day environmental pollutants exposures on the zebrafish embryos at 1 day post fertilization clearly decreased the intestinal peristalsis through decreasing the serotonin (5-HT) production and down-regulating the expression of key genes involved in 5-HT synthesis. Pollutants-evoked change of gut motility could be normalized in the presence of Lactobacillus rhamnosus GG (LGG) via increasing 5-HT secretion. Exogenous 5-hydroxytryptophan (100 µg/L) could also rescue the dysfunction of gut motility in pollutants-treated zebrfish. The data identified that LGG normalized disorder of intestinal peristalsis induced by environmental pollutants through increasing 5-HT level. The stimulant effect of LGG on peristalsis may be associated with 5-HT system, which could provide references for the application of probiotics in regulation of gut dysmotility.

Bifidobacterium lactis BL-99 modulates intestinal inflammation and functions in zebrafish models

This study was designed to explore the therapeutics and the mechanisms of a patented and marked gastric acid and intestine juice-resistant probiotics Bifidobacterium lactis BL-99 (B. lactis BL-99) on the intestinal inflammation and functions in the zebrafish models. After feeding for 6 hours, B. lactis BL-99 was fully retained in the larval zebrafish intestinal tract and stayed for over 24 hours. B. lactis BL-99 promoted the intestinal motility and effectively alleviated aluminum sulfate-induced larval zebrafish constipation (p < 0.01). Irregular high glucose diet induced adult zebrafish intestinal functional and metabolic disorders. After fed with B. lactis BL-99, IL-1β gene expression was significantly down-regulated, and IL-10 and IL-12 gene levels were markedly up-regulated in this model (p < 0.05). The intestinal lipase activity was elevated in the adult zebrafish intestinal functional disorder model after B. lactis BL-99 treatment (p < 0.05), but tryptase content had no statistical changes (p > 0.05). B. lactis BL-99 improved the histopathology of the adult zebrafish intestinal inflammation, increased the goblet cell numbers, and up-and-down metabolites were markedly recovered after treatment of B. lactis BL-99 (p < 0.05). These results suggest that B. lactis BL-99 could relieve intestinal inflammation and promote intestinal functions, at least in part, through modulating intestinal and microbial metabolism to maintain intestinal health.

Utilizing Probiotics for the Prevention and Treatment of Gastrointestinal Diseases

Probiotics are heavily advertised to promote a healthy gastrointestinal tract and boost the immune system. This review article summarizes the history and diversity of probiotics, outlines conventional in vitro assays and in vivo models, assesses the pharmacologic effects of probiotic and pharmaceutical co-administration, and the broad impact of clinical probiotic utilization for gastrointestinal disease indications.