Antibiotic-induced gut dysbiosis and barrier disruption and the potential protective strategies

Gut Microbiota Dysbiosis: Pathogenesis, Diseases, Prevention, and Therapy

Dysbiosis refers to the disruption of the gut microbiota balance and is the pathological basis of various diseases. The main pathogenic mechanisms include impaired intestinal mucosal barrier function, inflammation activation, immune dysregulation, and metabolic abnormalities. These mechanisms involve dysfunctions in the gut-brain axis, gut-liver axis, and others to cause broader effects. Although the association between diseases caused by dysbiosis has been extensively studied, many questions remain regarding the specific pathogenic mechanisms and treatment strategies. This review begins by examining the causes of gut microbiota dysbiosis and summarizes the potential mechanisms of representative diseases caused by microbiota imbalance. It integrates clinical evidence to explore preventive and therapeutic strategies targeting gut microbiota dysregulation, emphasizing the importance of understanding gut microbiota dysbiosis. Finally, we summarized the development of artificial intelligence (AI) in the gut microbiota research and suggested that it will play a critical role in future studies on gut dysbiosis. The research combining multiomics technologies and AI will further uncover the complex mechanisms of gut microbiota dysbiosis. It will drive the development of personalized treatment strategies.

Human Milk Oligosaccharide Lacto-N-Neotetraose Promotes Gut Microbiota Recovery in the Context of Antibiotic-Induced Dysbiosis

Human milk oligosaccharides (HMOs) may shape intestinal homeostasis, although the optimal form of HMOs to restore the gut microbiota in antibiotic-induced dysbiosis remains unclear. Here, we found that HMOs with various structures modulate microbial communities differently after antibiotic exposure. Lacto-N-neotetraose (LNnT) better promotes the recovery of intestinal microbiota (chiefly Lactobacillus) and increases the level of Bifidobacterium compared to 3'-sialyllactose, 2'-fucosyllactose, and the mixture. Additionally, LNnT decreases the potential pathogenic bacteria Klebsiella level and the microbial dysbiosis index. Although supplementation with LNnT does not decrease the Clostridioides difficile burden or alleviate the decline in the fecal numbers of Lactobacillus and Bifidobacterium after C. difficile infection (CDI), LNnT attenuates intestinal epithelial damage, decreases inflammatory status, and alters metabolome profiles after CDI. Collectively, LNnT may function as a promising prebiotic to promote gut microbiota recovery in the context of antibiotic-induced dysbiosis.

Probiotic effects of Clostridium cellabutyricum against Pseudomonas aeruginosa infection in antibiotic-induced gut microbial dysbiosis mice model

Gut microbiota dysbiosis induced by antibiotic use weakens its colonization resistance against opportunistic pathogens, increasing the risk of invasion and infection. While probiotics have the potential to restore the impaired gut microbial structure and prevent respiratory tract infections, the effectiveness of specific strains and the underlying mechanisms remain largely unexplored. In this study, the preventive effects of a novel butyrate-producing bacterium, Clostridium cellabutyricum YQ-FP-027T against Pseudomonas aeruginosa infection after antibiotic exposure were investigated in antibiotic-pretreated mice model. Phenotypic characterizations including the bacterial load in the lung, the assessment of gene expression of immune factors in lung tissue using qPCR, and detection of gut microbial composition using 16S rRNA sequencing were conducted. Pulmonary bacterial load and expression levels of immune factors of lung tissue, and gut microbial composition were evaluated. Our results demonstrated that YQ-FP-027T ameliorated lung tissue integrity, significantly reduced pulmonary bacterial burden, and decreased the expression of IL-1β and TNF-α, while enhancing the expression of IL-10 and CRAMP. Furthermore, YQ-FP-027T increased the abundance of Lachnospiraceae in the gut and reduced the abundance of opportunistic pathogens such as Enterococcaceae and Helicobacteraceae. These results suggest YQ-FP-027T exerts probiotic effects by restoring gut microbiota balance, enhancing intestinal barrier function, and positively influencing pulmonary immune responses through the gut-lung axis. This study reveals the preventive potential of YQ-FP-027T against P. aeruginosa infection in the context of gut microbiota dysbiosis, offering a novel preventive strategy.

Widespread heteroresistance to antibiotics in Lactobacillus species

Lactobacilli are prevalent members of the intestinal and reproductive tract microbiota of humans and other species. They are commonly used in probiotics and various food products due to their beneficial effects on human health. For example, these beneficial microbes are used to treat diarrhea caused by antibiotic therapy and are commonly given during antibiotic treatment. Despite the many studies conducted to understand the beneficial effects of Lactobacilli, less is known about their resistance and heteroresistance to antibiotics. In this study, we evaluated the resistance heterogeneity in eight Lactobacillus species. Our results demonstrate that several Lactobacilli species, including Lactobacillus rhamnosus, are heteroresistant to antibiotics, a recently discovered phenotype commonly seen in multidrug-resistant organisms that cause clinical failures but understudied in commensals and probiotics.

Antibiotic-induced gut dysbiosis: unraveling the gut-heart axis and its impact on cardiovascular health

Cardiovascular diseases (CVDs) remain the major cause of morbidity and mortality amongst people of all ages across the world. Research suggests that the initiation and progression of CVDs are associated with antibiotic-induced gut dysbiosis. Antibiotics are primarily intended to be used to treat bacterial infections, which can alter gut microbiota (GM) composition, by lowering the abundance of beneficial bacteria, like Firmicutes, Bacteroidetes, and increasing the profusion of Enterobacteriaceae, leading to harm on gut health. Additionally, it reduces short-chain fatty acids (SCFAs) and bile acid metabolism, increases trimethylamine N-oxide (TMAO) production, intestinal permeability allowing lipopolysaccharide (LPS) and TMAO into systemic circulation. SCFAs play a key role in lipid metabolism, inflammation, and strengthening of the intestinal barrier, and participate in CVDs through FFAR2 and FFAR3 receptors, whereas dysbiosis reduces SCFAs levels and worsens these effects. TMAO enhances oxidative stress, inflammation, endothelial dysfunction, and cholesterol dysregulation, thus worsening CVDs. Furthermore, LPS develops systemic inflammation, insulin resistance, and endothelial dysfunction by activating the NF-κB pathway. Dysbiosis also affects bile acid synthesis, disrupting lipid and glucose metabolism, further participating in the progression of CVDs. This article aims to explore the role of gut dysbiosis in various CVDs, including congenital heart disease, hypertension, valvular heart disease, coronary heart disease, and heart failure. Furthermore, this article aims to bridge the knowledge gap regarding the gut-heart axis by exploring how antibiotics alter the gut microbiota homeostasis, further contributing to the development of CVDs and therapeutic interventions that reduce cardiovascular risks and restore the gut microbiota homeostasis.

Rising of natural therapies: Potential and challenges of traditional Chinese medicine in the management of gastrointestinal diseases

In the contemporary medical landscape, the burgeoning interest in natural therapies, particularly for managing gastrointestinal disorders, has brought traditional Chinese medicine (TCM) to the forefront. This article explains the core principles and clinical applications of TCM in treating these conditions, furthering the discourse through an examination of integrated TCM strategies, as demonstrated in the study by Zhou et al. While TCM has shown promising clinical outcomes, it encounters significant hurdles in standardization, mechanistic research, and clinical validation. Future investigations should aim to solidify the scientific underpinnings of TCM and expand its use in gastrointestinal disease management, striving for a seamless fusion of traditional and contemporary medical practices.

Antibiotics-induced dysbiosis impacts dendritic morphology of adult mouse cortical interneurons

Introduction

A growing body of evidence suggests that the gut microbiome may contribute to changes in brain morphology. The microbiota-gut-brain axis (MGBA) has been shown to influence neurogenesis, axon myelination, and synapse structure. However, it remains unclear whether the MGBA can influence the morphology and density of inhibitory GABAergic interneurons. The aim of this study was to determine whether antibiotic-induced dysbiosis (AID) is associated with alterations in dendritic morphology of GABAergic inhibitory interneurons in the medial entorhinal cortex (mEC), somatosensory cortex (SSC), motor cortex (MC), and hippocampus (Hp).

Methods

A cohort of six-month-old GAD-67-EGFP transgenic mice was treated with an antibiotic cocktail for two weeks, resulting in gut dysbiosis as validated by collecting stool samples at baseline and after treatment, then using next-generation sequencing of 16S ribosomal RNA.

Results

The results demonstrate that the proposed model effectively exhibited the defining features of gut dysbiosis, including a significant reduction in microbiome diversity, expansion of pathobionts, and loss of beneficial microbes. The AID group showed alterations in density and morphology of GABAergic interneurons in different brain areas. The mean dendritic length and mean dendritic segments of the SSC and Hp were found to be significantly decreased, while no such decrease was observed in the mEC or MC. Furthermore, the density of interneurons was decreased in the mEC, Hp, and SSC areas, while no change was observed in the MC area.

Discussion

The interneuron dysfunction plays a role in the pathogenesis of neurological disease. The findings of this study suggest that AID potentially influences the density and morphology of the interneurons, which may contribute to the development of neurological disorders.

Development of a Pre-Modification Strategy to Overcome Restriction-Modification Barriers and Enhance Genetic Engineering in Lactococcus lactis for Nisin Biosynthesis

Due to the barriers imposed by the restriction-modification (RM) system, Nisin-producing industrial strains of Lactococcus lactis often encounter low transformation efficiency, which seriously hinders the widespread application of genetic engineering in non-model L. lactis. Herein, we present a novel pre-modification strategy (PMS) coupled with optimized plasmid delivery systems designed to systematically evade RM barriers and substantially improve Nisin biosynthesis in L. lactis. Through the use of engineered Escherichia coli strains with methylation profiles specifically optimized for L. lactis C20, we have effectively evaded RM barriers, thereby facilitating the efficient introduction of large Nisin biosynthetic gene clusters into L. lactis. The PMS tools, which significantly improve the transformation efficiency (~103 transformants per microgram of DNA), have been further improved in combination with a Rolling Circle Amplification, resulting in a higher enhancement in transformation efficiency (~104 transformants per microgram of DNA). Using this strategy, large Nisin biosynthetic gene clusters and the expression regulation of all genes within the cluster were introduced and analyzed in L. lactis, leading to a highest Nisin titer of 11,052.9 IU/mL through a fed-batch fermentation in a 5 L bioreactor. This is the first systematic report on the expression regulation and application of a complete Nisin biosynthesis gene cluster in L. lactis. Taken together, our studies provide a versatile and efficient strategy for systematic evasion and enhancement of RM barriers and Nisin biosynthesis, thereby paving the way for genetic modification and metabolic engineering in L. lactis.

Association between antibiotics and treatment efficacy in metastatic urothelial carcinoma patients

BACKGROUND

Antibiotic therapy (ABT)-induced dysbiosis may affect the efficacy of immune checkpoint inhibitors (ICI) therapy. We investigated the association between ABT and real-world overall survival (rwOS) and progression-free survival (rwPFS) in patients with metastatic urothelial carcinoma (mUC) receiving ICI or cisplatin-based chemotherapy (CIS).

METHODS

Three thousand, one hundred seventy-nine patients were included from a nationwide electronic health record-derived de-identified database. Three-month landmark Kaplan-Meier methods and log-rank tests were used to estimate rwOS/PFS between treatment modalities based on ABT groups (stratified by exposure, timing, excretion mode, and administration route). Cox proportional models with time-varying coefficients were used to investigate the associations between ABT, treatment modality, and rwOS/PFS.

RESULTS

A total of 402 (27.1%) ICI and 655 (38.6%) CIS patients received ABT (p < 0.001). ICI receipt (OR 0.65, p < 0.001) and advanced age (OR 0.98, p < 0.001) were associated with lower ABT use. ICI exclusive findings included a negative correlation with rwOS in patients who received post-treatment initiated (ICI median: pre-13.2 vs post-7.9 vs none-13.3 months; p = 0.009), oral (median oral-9.6 vs none-13.3 months, p = 0.03), and renally cleared (median renal-9.9 vs none-13.3 months, p = 0.04) ABT. ABT's effect was negatively associated with rwOS in ICI patients within first 6 months (HR 1.36, 95% CI 1.107-1.74, p = 0.01) but not thereafter (p = 0.7).

CONCLUSIONS

This study identified a potential ICI-specific negative correlation between ABT and rwOS in patients with mUC, specifically those exposed to ABT pills and receipt before treatment initiation. These results emphasize the importance of antibiotic stewardship and continued investigation of the role of gut microbiome in mUC treatment efficacy.

Immunostimulatory effects of isomalto/malto-polysaccharides via TLR2 and TLR4 in preventing doxycycline-induced cytokine loss

Isomalto/malto-polysaccharides (IMMPs) are α-glucans with prebiotic potential used as food ingredients. However, their ability to exert direct cellular effects remains unknown. IMMPs may enhance immunity by activating toll-like receptors (TLRs), key for defense against pathogens. Doxycycline is an antibiotic that requires an effective immune function but paradoxically has immune-attenuating effects by reducing TLR2 activity, potentially increasing antibiotic needs. We hypothesize that IMMPs are recognized by various cell surface TLRs, leading to the activation of the NF-κB signaling pathway. Furthermore, IMMPs' immune-stimulating effect could prevent the doxycycline-induced reduction of TLR2 activity in immune cells. IMMPs activated TLR2, increasing NF-κB signaling by 3.42- and 6.37-fold at 1 and 2 mg/mL, respectively. TLR4 activation increased 5.47-, 7.39-, and 8.34-fold at 0.5, 1, and 2 mg/mL. IMMPs enhanced IL-8, TNFα, and IL1-RA production in THP-1 monocytes. Additionally, preincubation of macrophages with IMMPs enhanced cytokine production and partially prevented doxycycline-induced cytokine reduction in response to TLR2 activation. Molecular docking analyses support IMMPs and doxycycline binding to these TLRs. These findings suggest that IMMPs stimulate immunity via TLR2 and TLR4, partially mitigating doxycycline's adverse effects. This provides a dietary strategy to enhance pathogen clearance, reduce antibiotic needs, and support immune health.

A randomized controlled study protocol of the TOBBI trial: the effect of a 6 weeks intervention with synbiotics on the recovery speed of the gut microbiota after antibiotic treatment in Dutch toddlers

BACKGROUND

Antibiotic-induced disruption of the gut microbiome in the first 1000 days of life is linked to an increased risk of the development of immunological, metabolic, and neurobehavioral childhood-onset conditions. Supporting the recovery of the gut microbial community after it has been perturbed by antibiotics might be a promising strategy to reduce these risks. In this clinical study, the effect of a 6 weeks supplementation with synbiotics (Bifidobacterium breve M-16 V, short chain galacto-oligosaccharides and long chain fructo-oligosaccharides) after antibiotic treatment on the recovery speed of the gut microbiota of toddlers will be studied.

METHODS/DESIGN

A cohort of 126 Dutch toddlers aged 12 to 36 months old, who receive an amoxicillin or amoxicillin/clavulanic acid treatment, will be followed for 12 weeks. Participants will be randomized into an intervention group, who will consume the study product over a 6 weeks period starting at the last day of the antibiotic treatment or into a control group that will continue their usual eating pattern. Stool samples and their characteristics will be collected weekly by both groups. Stool samples will be analyzed for total microbiota and Bifidobacterium spp.. The differences in the proportion of Bifidobacterium out of total gut microbiota, composition of species belonging to Bifidobacterium, and beta diversity overtime will be compared between the two groups to study the effect of the intervention on the gut microbiota after perturbation. Furthermore, the effect of the treatment will also be studied in terms of the gut microbiota metabolic activity and stool characteristics. Additionally, food intake will be recorded to investigate whether diet, especially dietary fibers, may influence the gut microbiota as well. The findings may highlight a potential intervention strategy to support the recovery of the gut community after it has been perturbed by antibiotics in early life.

TRIAL REGISTRATION

The TOBBI trial was approved by the board of Medical Ethics Review Committee NedMec in June 2022 and registered at  https://www.onderzoekmetmensen.nl/en/trial/20358 under the code NL75975.081.20, and at the World Health Organization at https://trialsearch.who.int/Trial2.aspx?TrialID=NL-OMON20358 under NTR-new: NL8996.

Dysbiosis and extraintestinal cancers

The gut microbiota plays a crucial role in safeguarding host health and driving the progression of intestinal diseases. Despite recent advances in the remarkable correlation between dysbiosis and extraintestinal cancers, the underlying mechanisms are yet to be fully elucidated. Pathogenic microbiota, along with their metabolites, can undermine the integrity of the gut barrier through inflammatory or metabolic pathways, leading to increased permeability and the translocation of pathogens. The dissemination of pathogens through the circulation may contribute to the establishment of an immune-suppressive environment that promotes carcinogenesis in extraintestinal organs either directly or indirectly. The oncogenic cascade always engages in the disruption of hormonal regulation and inflammatory responses, the induction of genomic instability and mutations, and the dysregulation of adult stem cell proliferation. This review aims to comprehensively summarize the existing evidence that points to the potential role of dysbiosis in the malignant transformation of extraintestinal organs such as the liver, breast, lung, and pancreas. Additionally, we delve into the limitations inherent in current methodologies, particularly the challenges associated with differentiating low loads gut-derived microbiome within tumors from potential sample contamination or symbiotic microorganisms. Although still controversial, an understanding of the contribution of translocated intestinal microbiota and their metabolites to the pathological continuum from chronic inflammation to tumors could offer a novel foundation for the development of targeted therapeutics.

Fecal microbiota transplant from long-living Ames dwarf mice alters the microbial composition and biomarkers of liver health in normal mice

Aging is associated with intestinal dysbiosis, a condition characterized by diminished microbial biodiversity and inflammation. This leads to increased vulnerability to extraintestinal manifestations such as autoimmune, metabolic, and neurodegenerative conditions thereby accelerating mortality. As such, modulation of the gut microbiome is a promising way to extend healthspan. In this study, we explore the effects of fecal microbiota transplant (FMT) from long-living Ames dwarf donors to their normal littermates, and vice versa, on the recipient gut microbiota and liver transcriptome. Importantly, our previous studies highlight differences between the microbiome of Ames dwarf mice relative to their normal siblings, potentially contributing to their extended lifespan and remarkable healthspan. Our findings demonstrate that FMT from Ames dwarf mice to normal mice significantly alters the recipient's gut microbiota, potentially reprogramming bacterial functions related to healthy aging, and changes the liver transcriptome, indicating improved metabolic health. Particularly, the microbiome of Ames dwarf mice, characterized by a higher abundance of beneficial bacterial families such as Peptococcaceae, Oscillospiraceae, and Lachnospiraceae, appears to play a crucial role in modulating these effects. Alongside, our mRNA sequencing and RT-PCR validation reveals that FMT may contribute to the significant downregulation of p21, Elovl3, and Insig2, genes involved with cellular senescence and liver metabolic pathways. Our data suggest a regulatory axis exists between the gut and liver, highlighting the potential of microbiome-targeted therapies in promoting healthy aging. Future research should focus on functional validation of altered microbial communities and explore the underlying biomolecular pathways that confer geroprotection.

Si-Ni-San ameliorates cholestatic liver injury by favoring P. goldsteinii colonization

ETHNOPHARMACOLOGICAL RELEVANCE

Current treatment options for cholestatic liver diseases are limited, and addressing impaired intestinal barrier has emerged as a promising therapeutic approach. Si-Ni-San (SNS) is a Traditional Chinese Medicine (TCM) formula commonly utilized in the management of chronic liver diseases. Our previous studies have indicated that SNS effectively enhanced intestinal barrier function through the modulation of gut microbiota.

AIM OF THE STUDY

This study aims to verify the therapeutic effects of SNS on cholestatic liver injury, focusing on elucidating the underlying mechanism involving the gut-liver axis.

MATERIALS AND METHODS

The 16s RNA gene sequencing, non-targeted metabolomics were used to investigate the effects of SNS on the gut microbiota dysbiosis. Fecal microbiota transplantation (FMT) was conducted to identify potential beneficial probiotics underlying the therapeutic effects of SNS.

RESULTS

Our results demonstrated that SNS significantly ameliorated cholestatic liver injury induced by partial bile duct ligation (pBDL). Additionally, SNS effectively suppressed cholestasis-induced inflammation and barrier dysfunction in both the small intestine and colon. While SNS did not impact the intestinal FXR-FGF15-hepatic CYP7A1 axis, it notably improved gut microbiota dysbiosis and modulated the profile of microbial metabolites, including beneficial secondary bile acids and tryptophan derivatives. Furthermore, gut microbiota depletion experiments and FMT confirmed that the therapeutic benefits of SNS in cholestatic liver disease are dependent on gut microbiota modulation, particularly through the promotion of the growth of potential probiotic P. goldsteinii. Moreover, a synergistic improvement in cholestatic liver injury was observed with the co-administration of P. goldsteinii and SNS.

CONCLUSION

Our study underscores that SNS effectively alleviates cholestatic liver injury by addressing gut microbiota dysbiosis and enhancing intestinal barrier function, supporting its rational clinical utilization. Furthermore, we highlight P. goldsteinii as a promising probiotic candidate for the management of cholestatic liver diseases.

Oral amoxicillin treatment disrupts the gut microbiome and metabolome without interfering with luminal redox potential in the intestine of Wistar Han rats

Oral antibiotic treatment is well known to be one of the main factors affecting gut microbiota composition by altering bacterial diversity. It decreases the abundance of butyrate-producing bacteria such as Lachnospiraceae and Ruminococcaceae, while increasing abundance of Enterobacteriaceae. The recovery time of commensal bacteria post-antibiotic treatment varies among individuals, and often, complete recovery is not achieved. Recently, gut microbiota disruption has been associated with increased gut oxygen levels and higher redox potential in faecal samples. Given that redox balance is crucial for microbial metabolism and gut health, influencing fermentation processes and maintaining anaerobic conditions, we investigated the impact of oral amoxicillin treatment on the redox potential in the caecum. We used 24 Wistar Han male rats and measured caecal redox potential in situ with a probe, before and after 7 days of amoxicillin treatment, as well as after 7 days of recovery. Additionally, we analysed caecal weight, pH, antioxidant capacity, caecal microbiota, metabolome, and colonic tissue expression of relevant genes involved in the redox potential state. Our findings show that oral amoxicillin treatment significantly reduced archaeal load, and decreased the bacterial alpha diversity and affected bacterial composition of the caecal microbiome. The caecal metabolome was also significantly affected, exemplified by reduced amounts of short chain fatty acids during amoxicillin treatment. While the caecal metabolome fully recovered 7 days post amoxicillin treatment, the microbiome did not fully recover within this time frame. However, amoxicillin did not lead to an increase in luminal redox potential in the cecum during or post amoxicillin treatment. Limited differences were observed for colonic expression of genes involved in intestinal barrier function and generation of reactive oxygen species, except for the catalase gene, which was significantly upregulated post-amoxicillin treatment. Our results suggest that while oral amoxicillin disrupts the gut microbiome and metabolome, it does not directly interfere with gut luminal redox state.

Recovery of intestinal microbial community in Penaeus vannamei after florfenicol perturbation

The concept and application of probiotic intervention for restoring intestinal microbial dysbiosis induced by antibiotics in aquaculture are still in early stages. This study aimed to investigate potential responses of various recovery strategies, including natural recovery and probiotic intervention, in restoring the growth and intestinal microbial community of Penaeus vannamei following florfenicol perturbation. The basal diet (control, CN) was supplemented with florfenicol (FC) or Lactobacillus plantarum W2 (LM) throughout the entire feeding trial. Meanwhile, the basal diet was supplemented with florfenicol for 7 days, followed by a period without florfenicol (natural recovery, FB), or with live strain W2 (probiotic recovery, FM), for a duration of 35 days. Results indicated that dietary supplementation of strain W2, whether continuous or following florfenicol perturbation, along with continuous florfenicol supplementation, significantly enhanced the growth performance of shrimp. Early natural recovery and probiotic intervention did not induce significant alterations in microbial diversity and community structure. Florfenicol perturbation resulted in a decrease in the abundance of potentially beneficial bacteria in intestinal microbial community of shrimp. However, both probiotic intervention and natural recovery strategies gradually reduced the abundance of potentially pathogenic bacteria while increasing the abundance of potentially beneficial ones. The robustness of microbial network decreased during florfenicol perturbation, showed gradual improvement during probiotic recovery, and remained relatively low during natural recovery and continuous florfenicol supplementation. Moreover, the microbial community composition in intestinal habitat significantly differed under various recovery strategies compared to the control. Notably, the microbial community composition of intestinal habitat following probiotic recovery exhibited greater similarity to that of continuous strain W2 supplementation without florfenicol perturbation. In summary, dietary supplementation of florfenicol perturbed intestinal microbial community stability of shrimp, whereas probiotic intervention and natural recovery facilitated the attainment of new stable states by altering keystone taxa. Considering intestinal microbial community stability of shrimp, the recovery of microbial community through probiotic intervention appears to be more effective than natural recovery.

Effect of preconception antibiotics exposure on female reproductive health and pregnancy outcomes: a systematic review and meta-analysis

Background

The preconception period is a window of opportunity to influence maternal and pregnancy outcomes. Inappropriate use of antibiotics results in gut dysbiosis and may affect host reproductive health through multiple dimensions. Animal studies demonstrate that antibiotic treatment profoundly affects ovarian functions and the estrous cycle, and it has a direct implication for infertility. Infertility was defined as the inability to conceive after 12 months of unprotected intercourse. However, whether antibiotic exposure in the preconception period influences female fertility, miscarriage, and congenital malformation remains obscure and controversial.

Methods

A systematic review and meta-analysis until April 20, 2024, was conducted by searching PubMed, Web of Science, Scopus, and Science Direct without restrictions to designs and language. The risk of bias was assessed by two independent reviewers using the Newcastle Ottawa Scale (NOS) and the Risk of Bias 2 (RoB-2) tools. The report followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Relative risks (RR), odds ratios (OR), and fecundability ratios (FR) with a 95% confidence interval (CI) were effect size measures determined with a random effect model. Heterogeneity across included studies was assessed using I 2 , T2, and H2. The review protocol is registered in PROSPERO, CRD42024515680.

Findings

Fifteen studies with a total of 1,206,583 participants were included. Preconception exposure to macrolides reduced the FR by 35% (FR: 0.65, 95% CI: 0.48, 0.88, P < 0.001). Sulfonamide users were also at 2.35 times (OR:2.35, 95% CI: 1.86, 2.97; P < 0.001) more risk of developing infertility. Using beta-lactams other than penicillin G reduced the odds of infertility by 64% (OR: 0.36, 95% CI: 0.26,0.50; P < 0.001). The possibility of infertility among quinolone users was 13% lower (OR: 0.87, 95% CI: 0.77, 0.99; P = 0.03) than non-users. Preconception antibiotics exposure increased the risk of spontaneous miscarriage by 34% (RR: 1.34, 95% CI: 1.16, 1.53; P < 0.001). Moreover, trimethoprim intake also increased the odds of congenital malformations by 85% (OR:1.85, 95% CI: 1.54, 2.23; P < 0.001).

Interpretation

Preconception antibiotics exposure in females increases the risk of infertility, miscarriage, and congenital anomalies. Macrolides, sulfonamides, and trimethoprim increase the risk of infertility, spontaneous miscarriage, and congenital malformation while beta-lactams and quinolones reduce the risk. Clinicians, pregnancy planners, and health care policymakers should be warranted for pregnancy needs and success. Further clinical and mechanistic studies are required to illustrate their specific functions and cause effects.

Funding

Funded by Leading Discipline Development Fund (No. 403947), The Second Affiliated Hospital of Shaanxi University of Traditional Chinese Medicine; and The Hong Kong Obstetrical and Gynaecological Trust Fund.

Unveiling the role of gut microbiota in curcumin metabolism using antibiotic-treated mice

Curcumin might exert its therapeutic effects by interacting with gut microbiota. However, the role of gut microbiota in curcumin metabolism in vivo remains poorly understood. To address this, we used antibiotics to deplete gut microbiota and compared curcumin metabolism in control and antibiotic-treated mice. Using Q-TOF and triple quadrupole mass spectrometry, we identified and quantified curcumin metabolites, revealing distinct metabolic pathways in these two mice groups. The novel metabolites, hexahydro-dimethyl-curcumin and hexahydro-didemethyl-curcumin were exclusively derived from gut microbiota. Additionally, gut bacteria deconjugated curcumin metabolites back into their bioactive forms. Moreover, control mice exhibited significantly lower curcumin degradation, suggesting a protective role of gut microbiota against degradation. In conclusion, our results indicated that gut microbiota might enhance the effectiveness of curcumin by deconjugation, production of active metabolites, and protection against degradation in the large intestine. This study enhances our understanding of the interactions between curcumin and gut microbiota.

Preventive effect of probiotics on infections following colorectal cancer surgery: An umbrella meta-analysis

BACKGROUND

Postoperative infections remain a significant source of morbidity among patients undergoing colorectal cancer (CRC) surgery. While probiotics have been proposed as a potential strategy to mitigate the risk of these infections, contemporary meta-analyses have produced conflicting findings.

AIM

To synthesize the available evidence regarding the prophylactic efficacy of probiotics in preventing infections following CRC surgery.

METHODS

A comprehensive search of PubMed and Scopus was conducted to identify relevant meta-analyses published up to February 2024. To assess the efficacy of probiotics on outcomes, relative risks (RR) and their corresponding 95%CI were pooled using a random effects model.

RESULTS

This comprehensive umbrella meta-analysis integrated eleven meta-analyses encompassing 11518 participants who fulfilled the inclusion criteria. Probiotics administration resulted in a statistically significant reduction in the incidence of total infections (RR: 0.40, 95%CI: 0.31-0.51; moderate certainty), surgical site infections (RR: 0.56, 95%CI: 0.49-0.63; high certainty), pneumonia (RR: 0.38, 95%CI: 0.30-0.48; high certainty), urinary tract infections (RR: 0.44, 95%CI: 0.31-0.61; moderate certainty), bacteremia (RR: 0.41, 95%CI: 0.30-0.56; high certainty), and sepsis (RR: 0.35, 95%CI: 0.25-0.44; high certainty). However, probiotics did not significantly affect intra-abdominal, central line, or peritoneal infections.

CONCLUSION

Probiotics have demonstrated potential in mitigating postoperative infectious complications among patients undergoing CRC surgery.

Effects of antibiotic and disinfectant exposure on the mouse gut microbiome and immune function

This study explores the effects of disinfectant and antibiotic exposure on gut health, focusing on gut microbiota balance and gut immune function. Our analysis indicates that disinfectants increase the proportion of Gram-positive bacteria, particularly increasing Staphylococcus levels, while antibiotics increase the proportion of Gram-negative bacteria, especially Bacteroides levels. These changes disrupt microbial harmony and affect the gut microbiome's functional capacity. Additionally, our research reveals that both disinfectants and antibiotics reduce colon length and cause mucosal damage. A significant finding is the downregulation of NLRC4, a key immune system regulator in the gut, accompanied by changes in immune factor expression. This interaction between chemical exposure and immune system dysfunction increases susceptibility to inflammatory bowel disease and other gut conditions. Given the importance of disinfectants in disease prevention, this study advocates for a balanced approach to their use, aiming to protect public health while minimizing adverse effects on the gut microbiome and immune function.

IMPORTANCE

Disinfectants are extensively employed across various sectors, such as the food sector. Disinfectants are widely used in various sectors, including the food processing industry, animal husbandry, households, and pharmaceuticals. Their extensive application risks environmental contamination, impacting water and soil quality. However, the effect of disinfectant exposure on the gut microbiome and the immune function of animals remains a significant, unresolved issue with profound public health implications. This highlights the need for increased scrutiny and more regulated use of disinfectants to mitigate unintended consequences on gut health and maintain immune system integrity.

Gut microbiota-derived butyrate improved acute leptospirosis in hamster via promoting macrophage ROS mediated by HDAC3 inhibition

Leptospirosis is a re-emerging worldwide zoonotic disease. Infected patients and animals often exhibit intestinal symptoms. Mounting evidence suggests that host immune responses to bacterial infection are closely associated with intestinal homeostasis. Our previous research has shown that the gut microbiota can protect the host from acute leptospirosis, while the specific bacterial metabolic mediators participating in the pathogenesis remain to be identified. Short-chain fatty acids (SCFAs) are metabolites produced mainly by the gut microbiota that play a role in immune regulation. However, whether SCFAs are the key to protecting the host against leptospirosis and the underlying regulatory mechanisms are unknown. In this study, our results showed that the SCFA butyrate is involved in ameliorating leptospirosis. The depletion of SCFAs by antibiotic cocktail treatment reduced survival time after Leptospira infection while supplementation with butyrate but not acetate or propionate significantly amelioration of leptospirosis. In vitro experiments showed that butyrate treatment enhanced the intracellular bactericidal activity mediated by reactive oxygen species (ROS) production. Mechanistically, butyrate functions as a histone deacetylase 3 inhibitor (HDAC3i) to promote ROS production via monocarboxylate transporter (MCT). The protection of butyrate against acute leptospirosis mediated by ROS was also proven in vivo. Collectively, our data provide evidence that the butyrate-MCT-HDAC3i-ROS signaling axis is a potential therapeutic target for acute leptospirosis. Our work not only interprets the microbial metabolite signaling involved in transkingdom interactions between the host and gut microbiota but also provides a possible target for developing a prevention strategy for acute leptospirosis.

IMPORTANCE

Leptospirosis is a worldwide zoonotic disease caused by Leptospira. An estimated 1 million people are infected with leptospirosis each year. Studies have shown that healthy gut microbiota can protect the host against leptospirosis but the mechanism is not clear. This work elucidated the mechanism of gut microbiota protecting the host against acute leptospirosis. Here, we find that butyrate, a metabolite of gut microbiota, can improve the survival rate of hamsters with leptospirosis by promoting the bactericidal activity of macrophages. Mechanistically, butyrate upregulates reactive oxygen species (ROS) levels after macrophage infection with Leptospira by inhibiting HDAC3. This work confirms the therapeutic potential of butyrate in preventing acute leptospirosis and provides evidence for the benefits of the macrophage-HDAC3i-ROS axis.

Agmatine modulation of gut-brain axis alleviates dysbiosis-induced depression-like behavior in rats

Depression is a global health concern affecting nearly 280 million individuals. It not only imposes a significant burden on economies and healthcare systems but also manifests complex physiological connections and consequences. Agmatine, a putative neuromodulator derived primarily from beneficial gut microbes specially Lactobacillus, has emerged as a potential therapeutic agent for mental health. The microbiota-gut-brain axis is involved in the development of depression through the peripheral nervous system, endocrine system, and immune system and may be a key factor in the effect of agmatine. Therefore, this study aimed to investigate the potential mechanism of agmatine in antibiotic-induced dysbiosis and depression-like behavior in rats, focusing on its modulation of the gut-brain axis. Depression-like behavior associated with dysbiosis was induced through a seven-day regimen of the broad-spectrum antibiotic, comprising ampicillin and metronidazole and validated through microbial, biochemical, and behavioral alterations. On day 8, antibiotic-treated rats exhibited loose fecal consistency, altered fecal microbiota, and depression-like behavior in forced swim test. Pro-inflammatory cytokines were elevated, while agmatine and monoamine levels decreased in the hippocampus and prefrontal cortex. Antibiotic administration disrupted tight junction proteins in the ileum, affecting gut architecture. Oral administration of agmatine alone or combined with probiotics significantly reversed antibiotic-induced dysbiosis, restoring gut microbiota and mitigating depression-like behaviors. This intervention also restored neuro-inflammatory markers, increased agmatine and monoamine levels, and preserved gut integrity. The study highlights the regulatory role of endogenous agmatine in the gut-brain axis in broad-spectrum antibiotic induced dysbiosis and associated depression-like behavior.

Effects of Tanreqing injection on the gut microbiota in healthy volunteers

Objectives

Many studies have confirmed that antibacterial agents can disrupt the human gut microbiota. In China, Tanreqing injection (TRQ) is a drug with antibacterial activity that is widely used in the treatment of respiratory infections. However, its specific influence on gut microbiota remains unclear. This study aimed to investigate the effect of TRQ on the gut microbiota of healthy volunteers.

Methods

Twelve healthy adults received 20 ml of TRQ intravenously daily for 7 consecutive days. At six timepoints (Pre, on D1, D3, D5, D7 and follow-up visit) fecal samples were collected and analyzed using 16S rRNA gene sequencing.

Results

Eleven people were included in the analysis finally. TRQ did not significantly alter gut microbiota diversity or richness (Shannon and Simpson and Chao1 index) in healthy people during the intervention. Gut microbial structure was stable (weighted and unweighted Unifrac). Using a machine learning method based on PLS-DA analysis, the separation trend on D7 at the genus level was found, returning to baseline two days after discontinuation. The abundance of major genus fluctuated on D7 compared with that prior to treatment, including an increase of unclassified_f_Enterobacteriaceae (13.0611%), a decrease of Bifidobacterium and Escherichia-Shigella (6.887%, 10.487%). Functional prediction analysis did not reveal any significant difference.

Conclusions

Our study showed short-term use of TRQ at conventional doses may not cause perturbations to the gut microbiota in healthy adults. This finding provides some useful information for the safe use of TRQ in the treatment of respiratory infections.

Clinical trial registration

https://www.medicalresearch.org.cn/, identifier MR-31-24-014367.

The Combination of Exercise and Konjac Glucomannan More Effectively Prevents Antibiotics-Induced Dysbiosis in Mice Compared with Singular Intervention

Our previous studies have demonstrated that konjac glucomannan (KGM) can prevent dysbiosis induced by antibiotics. While exercise may also impact the gut microbiome, there are limited studies reporting its protective effect on antibiotic-induced dysbiosis. Therefore, this study investigated the preventive and regulatory effects of a combination of 6-week exercise and KGM intervention on antibiotic-induced dysbiosis in C57BL/6J mice compared with a single intervention. The results showed that combined exercise and KGM intervention could restore the changes in the relative abundance of Bacteroides (3.73% with CTL versus 14.23% with ATBX versus 4.46% with EK) and Prevotellaceae_Prevotella (0.33% with CTL versus 0.00% with ATBX versus 0.30% with EK) induced by antibiotics (p < 0.05), and minimized the Bray-Curtis distance induced by antibiotics (0.55 with CTL versus 0.81 with ATBX versus 0.80 with EXC versus 0.83 with KGM versus 0.75 with EK). Compared with the combined intervention, exercise intervention also produced a certain level of recovery effects; the relative abundance of Rikenellaceae (1.96% with CTL versus 0.09% with ATBX versus 0.49% with EXC) was restored, while KGM supplementation showed the best preventive effect. In addition, the combination of exercise and KGM significantly enriched microbial purine metabolic pathways (p < 0.05). These findings indicate that combining exercise with KGM could be a promising approach to reducing the side effects of antibiotics on the gut microbiome.

What prognostic factors have impacted the efficacy of immune checkpoint inhibitors in patients with recurrent or metastatic oral cancer?

BACKGROUND

Immune checkpoint inhibitors (ICIs) are widely adapted for recurrent or metastatic head and neck cancer (RM-HNC), and various studies on its prognostic factors have been reported. We aimed to elucidate the prognostic factors of ICI treatment for RM oral cancer (RM-OC) in a retrospective study.

METHODS

We retrospectively reviewed patients with RM-OC treated with ICIs (nivolumab and pembrolizumab) at our department from May 2017 to February 2023. The objective response rate (ORR) for ICI treatment and the relationship between several potential prognostic factors, progression-free survival (PFS), and overall survival (OS) were analyzed statistically.

RESULTS

The investigation enrolled 31 patients, 16 with nivolumab and 15 with pembrolizumab. There were no significant differences in the ORR or disease control rate between the nivolumab and pembrolizumab groups (p = 0.4578 and 0.2524). In multivariate analysis, the prognostic nutritional index (PNI) and C-reactive protein to albumin ratio (CAR) exhibited statistical correlations with PFS, whereas the use of antibiotics and proton pump inhibitors (PPIs), neutrophil to lymphocyte ratio (NLR), and PNI demonstrated statistical associations with OS.

CONCLUSION

Our findings imply that the use of antibiotics and PPIs, which can modify the gut microbiota, may also serve as a prognostic determinant for ICI treatment in RM-OC, consistent with previous studies. Additionally, PNI may be essential in affecting the survival rates of both PFS and OS and could be an exceedingly valuable inflammatory biomarker for RM-OC.

Cy3-Based Nanoviscosity Determination of Mucus: Effect of Mucus Collection Methods and Antibiotics Treatment

The integrity of the protective mucus layer as a primary defense against pathogen invasion and microbial leakage into the intestinal epithelium can be compromised by the effects of antibiotics on the commensal microbiome. Changes in mucus integrity directly affect the solvent viscosity in the immediate vicinity of the mucin network, that is, the nanoviscosity, which in turn affects both biochemical reactions and selective transport. To assess mucus nanoviscosity, a reliable readout via the viscosity-dependent fluorescence lifetime of the molecular rotor dye cyanine 3 is established and nanoviscosities from porcine and murine ex vivo mucus are determined. To account for different mucin concentrations due to the removal of digestive residues during mucus collection, the power law dependence of mucin concentration on viscosity is used. The impact of antibiotics combinations (meropenem/vancomycin, gentamycin/ampicillin) on ex vivo intestinal mucus nanoviscosity is presented. The significant increase in viscosity of murine intestinal mucus after treatment suggests an effect of antibiotics on the microbiota that affects mucus integrity. This method will be a useful tool to assess how drugs, directly or indirectly, affect mucus integrity. Additionally, the method can be utilized to analyze the role of mucus nanoviscosity in health and disease, as well as in drug development.

Antibiotic-induced gut microbiota disruption promotes vascular calcification by reducing short-chain fatty acid acetate

BACKGROUND

Vascular calcification is a common vascular lesion associated with high morbidity and mortality from cardiovascular events. Antibiotics can disrupt the gut microbiota (GM) and have been shown to exacerbate or attenuate several human diseases. However, whether antibiotic-induced GM disruption affects vascular calcification remains unclear.

METHODS

Antibiotic cocktail (ABX) treatment was utilized to test the potential effects of antibiotics on vascular calcification. The effects of antibiotics on GM and serum short-chain fatty acids (SCFAs) in vascular calcification mice were analyzed using 16 S rRNA gene sequencing and targeted metabolomics, respectively. Further, the effects of acetate, propionate and butyrate on vascular calcification were evaluated. Finally, the potential mechanism by which acetate inhibits osteogenic transformation of VSMCs was explored by proteomics.

RESULTS

ABX and vancomycin exacerbated vascular calcification. 16 S rRNA gene sequencing and targeted metabolomics analyses showed that ABX and vancomycin treatments resulted in decreased abundance of Bacteroidetes in the fecal microbiota of the mice and decreased serum levels of SCFAs. In addition, supplementation with acetate was found to reduce calcium salt deposition in the aorta of mice and inhibit osteogenic transformation in VSMCs. Finally, using proteomics, we found that the inhibition of osteogenic transformation of VSMCs by acetate may be related to glutathione metabolism and ubiquitin-mediated proteolysis. After adding the glutathione inhibitor Buthionine sulfoximine (BSO) and the ubiquitination inhibitor MG132, we found that the inhibitory effect of acetate on VSMC osteogenic differentiation was weakened by the intervention of BSO, but MG132 had no effect.

CONCLUSION

ABX exacerbates vascular calcification, possibly by depleting the abundance of Bacteroidetes and SCFAs in the intestine. Supplementation with acetate has the potential to alleviate vascular calcification, which may be an important target for future treatment of vascular calcification.

Fecal microbiota transplantation accelerates restoration of florfenicol-disturbed intestinal microbiota in a fish model

Antibiotic-induced dysbiosis in the fish gut causes significant adverse effects. We use fecal microbiota transplantation (FMT) to accelerate the restoration of florfenicol-perturbed intestinal microbiota in koi carp, identifying key bacterial populations and metabolites involved in the recovery process through microbiome and metabolome analyses. We demonstrate that florfenicol disrupts intestinal microbiota, reducing beneficial genera such as Lactobacillus, Bifidobacterium, Bacteroides, Romboutsia, and Faecalibacterium, and causing mucosal injuries. Key metabolites, including aromatic amino acids and glutathione-related compounds, are diminished. We show that FMT effectively restores microbial populations, repairs intestinal damage, and normalizes critical metabolites, while natural recovery is less effective. Spearman correlation analyses reveal strong associations between the identified bacterial genera and the levels of aromatic amino acids and glutathione-related metabolites. This study underscores the potential of FMT to counteract antibiotic-induced dysbiosis and maintain fish intestinal health. The restored microbiota and normalized metabolites provide a basis for developing personalized probiotic therapies for fish.

Postoperative delayed gastric emptying: may gut microbiota play a role?

Postoperative delayed gastric emptying is a prevalent complication following surgical procedures, imposing heavy physical and financial burdens on patients. However, current treatment options remain suboptimal. In recent years, an increasing number of studies have highlighted that the gut microbiota and its metabolites are closely associated with postoperative complications. Various factors can disrupt the gut microbiome after surgery. This review discusses the potential mechanisms by which the gut microbiota and their metabolites may contribute to the pathogenesis of postoperative delayed gastric emptying. However, the current knowledge base is limited in terms of fully understanding the exact mechanisms involved. It is therefore evident that further research is required to fully elucidate the role of the gut microbiome in postoperative delayed gastric emptying, with the aim of uncovering new possibilities for preventive measures and therapeutic treatments.

Kidney transplantation and gut microbiota

Kidney transplantation is an effective way to improve the condition of patients with end-stage renal disease. However, maintaining long-term graft function and improving patient survival remain a key challenge after kidney transplantation. Dysbiosis of intestinal flora has been reported to be associated with complications in renal transplant recipients. The commensal microbiota plays an important role in the immunomodulation of the transplant recipient responses. However, several processes, such as the use of perioperative antibiotics and high-dose immunosuppressants in renal transplant recipients, can lead to gut dysbiosis and disrupt the interaction between the microbiota and the host immune responses, which in turn can lead to complications such as infection and rejection in organ recipients. In this review, we summarize and discuss the changes in intestinal flora and their influencing factors in patients after renal transplantation as well as the evidence related to the impact of intestinal dysbiosis on the prognosis of renal transplantation from in vivo and clinical studies, and conclude with a discussion of the use of microbial therapy in the transplant population. Hopefully, a deeper understanding of the function and composition of the microbiota in patients after renal transplantation may assist in the development of clinical strategies to restore a normal microbiota and facilitate the clinical management of grafts in the future.

In vitro analysis of postbiotic antimicrobial activity against Candida Species in a minimal synthetic model simulating the gut mycobiota in obesity

Gut fungal imbalances, particularly increased Candida spp., are linked to obesity. This study explored the potential of Lactiplantibacillus plantarum cell-free extracts (postbiotics) to modulate the growth of Candida albicans and Candida kefyr, key members of the gut mycobiota. A minimal synthetic gut model was employed to evaluate the effects of Lactiplantibacillus plantarum postbiotics on fungal growth in mono- and mixed cultures. Microreactors were employed for culturing, fungal growth was quantified using CFU counting, and regression analysis was used to evaluate the effects of postbiotics on fungal growth. Postbiotics at a concentration of 12.5% significantly reduced the growth of both Candida species. At 24 h, both C. albicans and C. kefyr in monocultures exhibited a decrease in growth of 0.11 log CFU/mL. In contrast, mixed cultures showed a more pronounced antifungal effect, with C. albicans and C. kefyr reductions of 0.62 log CFU/mL and 0.64 log CFU/mL, respectively. Regression analysis using the Gompertz model supported the antifungal activity of postbiotics and revealed species-specific differences in growth parameters. These findings suggest that L. plantarum postbiotics have the potential to modulate the gut mycobiota by reducing Candida growth, potentially offering a therapeutic approach for combating fungal overgrowth associated with obesity.

Potential Probiotic Weizmannia coagulans WC10 Improved Antibiotic-Associated Diarrhea in Mice by Regulating the Gut Microbiota and Metabolic Homeostasis

Antibiotic-associated diarrhea (AAD) is a common side effect of long-term and heavy antibiotic therapy. Weizmannia coagulans (W. coagulans) is an ideal probiotic because of its high viability, stability, and numerous health benefits to the host. In this study, the strains were first screened for W. coagulans WC10 (WC10) with a high combined ability based on their biological properties of gastrointestinal tolerance, adhesion, and short-chain fatty acid production ability. The effect of WC10 on mice with AAD was further evaluated. The results showed that WC10 was effective in improving the symptoms of AAD, effectively restoring antibiotic-induced weight loss, and reducing diarrhea status score and fecal water content. In addition, WC10 decreased the expression of pro-inflammatory cytokines and increased the expression of anti-inflammatory cytokines, alleviated intestinal tissue damage and inflammation, and improved intestinal epithelial barrier function by decreasing serum levels of enterotoxin, DAO, and D-lactic acid, and by increasing the expression of the intestinal mucosal immune factors sIgA and occludin. Importantly, the composition and function of the gut microbiota gradually recovered after WC10 treatment, increasing the number of SCFAs-producing Bifidobacterium and Roseburia. Subsequently, the short-chain fatty acid (SCFA) content was examined and WC10 significantly increased acetate, propionate, and butyrate production. Additionally, metabolomic analysis also showed that WC10 reversed the antibiotic interference with major metabolic pathways. These findings provide a solid scientific basis for the future application of W. coagulans WC10 in the treatment of AAD.

Prevention and treatment of antibiotics-associated adverse effects through the use of probiotics: A review

BACKGROUND

The human gut hosts a diverse microbial community, essential for maintaining overall health. However, antibiotics, commonly prescribed for infections, can disrupt this delicate balance, leading to antibiotic-associated diarrhea, inflammatory bowel disease, obesity, and even neurological disorders. Recognizing this, probiotics have emerged as a promising strategy to counteract these adverse effects.

AIM OF REVIEW

This review aims to offer a comprehensive overview of the latest evidence concerning the utilization of probiotics in managing antibiotic-associated side effects.

KEY SCIENTIFIC CONCEPTS OF REVIEW

Probiotics play a crucial role in preserving gut homeostasis, regulating intestinal function and metabolism, and modulating the host immune system. These mechanisms serve to effectively alleviate antibiotic-associated adverse effects and enhance overall well-being.

Polyvalent Bacterial Lysate with Potential Use to Treatment and Control of Recurrent Urinary Tract Infections

Overuse of antimicrobials has greatly contributed to the increase in the emergence of multidrug-resistant bacteria, a situation that hinders the control and treatment of infectious diseases. This is the case with urinary tract infections (UTIs), which represent a substantial percentage of worldwide public health problems, thus the need to look for alternatives for their control and treatment. Previous studies have shown the usefulness of autologous bacterial lysates as an alternative for the treatment and control of UTIs. However, a limitation is the high cost of producing individual immunogens. At the same time, an important aspect of vaccines is their immunogenic amplitude, which is the reason why they must be constituted of diverse antigenic components. In the case of UTIs, the etiology of the disease is associated with different bacteria, and even Escherichia coli, the main causal agent of the disease, is made up of several antigenic variants. In this work, we present results on the study of a bacterial lysate composed of 10 serotypes of Escherichia coli and by Klebsiella pneumoniae, Klebsiella aerogenes, Enterococcus faecalis, Proteus mirabilis, Citrobacter freundii, and Staphylococcus haemolyticus. The safety of the compound was tested on cells in culture and in an animal model, and its immunogenic capacity by analysing in vitro human and murine macrophages (cell line J774 A1). The results show that the polyvalent lysate did not cause damage to the cells in culture or alterations in the animal model used. The immunostimulatory activity assay showed that it activates the secretion of TNF-α and IL-6 in human macrophages and TNF-α in murine cells. The obtained results suggest that the polyvalent lysate evaluated can be an alternative for the treatment and control of chronic urinary tract infections, which will reduce the use of antimicrobials.

Baicalin restore intestinal damage after early-life antibiotic therapy: the role of the MAPK signaling pathway

Antibiotic related intestinal injury in early life affects subsequent health and susceptibility. Here, we employed weaned piglets as a model to investigate the protective effects of baicalin against early-life antibiotic exposure-induced microbial dysbiosis. Piglets exposed to lincomycin showed a marked reduction in body weight (p < 0.05) and deterioration of jejunum intestinal morphology, alongside an increase in antibiotic-resistant bacteria such as Staphylococcus, Dolosicoccus, Escherichia-Shigella, and Raoultella. In contrast, baicalin treatment resulted in body weights, intestinal morphology, and microbial profiles that closely resembled those of the control group (p > 0.05), with a significant increase in norank_f_Muribaculaceae and Prevotellaceae_NK3B31_group colonization compared with lincomycin group (p < 0.05). Further analysis through fecal microbial transplantation into mice revealed that lincomycin exposure led to significant alterations in intestinal morphology and microbial composition, notably increasing harmful microbes and decreasing beneficial ones such as norank_Muribaculaceae and Akkermansia (p < 0.05). This shift was associated with an increase in harmful metabolites and disruption of the calcium signaling pathway gene expression. Conversely, baicalin supplementation not only counteracted these effects but also enhanced beneficial metabolites and regulated genes within the MAPK signaling pathway (MAP3K11, MAP4K2, MAPK7, MAPK13) and calcium channel proteins (ORA13, CACNA1S, CACNA1F and CACNG8), suggesting a mechanism through which baicalin mitigates antibiotic-induced intestinal and microbial disturbances. These findings highlight baicalin's potential as a plant extract-based intervention for preventing antibiotic-related intestinal injury and offer new targets for therapeutic strategies.

Enrofloxacin exposure undermines gut health and disrupts neurotransmitters along the microbiota-gut-brain axis in zebrafish

The environmental prevalence of antibiotic residues poses a potential threat to gut health and may thereby disrupt brain function through the microbiota-gut-brain axis. However, little is currently known about the impacts of antibiotics on gut health and neurotransmitters along the microbiota-gut-brain axis in fish species. Taking enrofloxacin (ENR) as a representative, the impacts of antibiotic exposure on the gut structural integrity, intestinal microenvironment, and neurotransmitters along the microbiota-gut-brain axis were evaluated in zebrafish in this study. Data obtained demonstrated that exposure of zebrafish to 28-day environmentally realistic levels of ENR (6 and 60 μg/L) generally resulted in marked elevation of two intestinal integrity biomarkers (diamine oxidase (DAO) and malondialdehyde (MDA), upregulation of genes that encode inter-epithelial tight junction proteins, and histological alterations in gut as well as increase of lipopolysaccharide (LPS) in plasma, indicating an evident impairment of the structural integrity of gut. Moreover, in addition to significantly altered neurotransmitters, markedly higher levels of LPS while less amount of two short-chain fatty acids (SCFAs), namely acetic acid and valeric acid, were detected in the gut of ENR-exposed zebrafish, suggesting a disruption of gut microenvironment upon ENR exposure. Along with corresponding changes detected in gut, significant disruption of neurotransmitters in brain indicated by marked alterations in the contents of neurotransmitters, the activity of acetylcholin esterase (AChE), and the expression of neurotransmitter-related genes were also observed. These findings suggest exposure to environmental antibiotic residues may impair gut health and disrupt neurotransmitters along the microbiota-gut-brain axis in zebrafish. Considering the prevalence of antibiotic residues in environments and the high homology of zebrafish to other vertebrates including human, the risk of antibiotic exposure to the health of wild animals as well as human deserves more attention.

Current treatment options for leptospirosis: a mini-review

Leptospirosis, one of the most common global zoonotic infections, significantly impacts global human health, infecting more than a million people and causing approximately 60,000 deaths annually. This mini-review explores effective treatment strategies for leptospirosis, considering its epidemiology, clinical manifestations, and current therapeutic approaches. Emphasis is placed on antibiotic therapy, including recommendations for mild and severe cases, as well as the role of probiotics in modulating the gut microbiota. Furthermore, novel treatment options, such as bacteriophages and newly synthesized/natural compounds, are discussed, and the findings are expected to provide insights into promising approaches for combating leptospirosis.

Photothermal hydrogels for infection control and tissue regeneration

In this review, we report investigating photothermal hydrogels, innovative biomedical materials designed for infection control and tissue regeneration. These hydrogels exhibit responsiveness to near-infrared (NIR) stimulation, altering their structure and properties, which is pivotal for medical applications. Photothermal hydrogels have emerged as a significant advancement in medical materials, harnessing photothermal agents (PTAs) to respond to NIR light. This responsiveness is crucial for controlling infections and promoting tissue healing. We discuss three construction methods for preparing photothermal hydrogels, emphasizing their design and synthesis, which incorporate PTAs to achieve the desired photothermal effects. The application of these hydrogels demonstrates enhanced infection control and tissue regeneration, supported by their unique photothermal properties. Although research progress in photothermal hydrogels is promising, challenges remain. We address these issues and explore future directions to enhance their therapeutic potential.

Effects of dietary intervention on human diseases: molecular mechanisms and therapeutic potential

Diet, serving as a vital source of nutrients, exerts a profound influence on human health and disease progression. Recently, dietary interventions have emerged as promising adjunctive treatment strategies not only for cancer but also for neurodegenerative diseases, autoimmune diseases, cardiovascular diseases, and metabolic disorders. These interventions have demonstrated substantial potential in modulating metabolism, disease trajectory, and therapeutic responses. Metabolic reprogramming is a hallmark of malignant progression, and a deeper understanding of this phenomenon in tumors and its effects on immune regulation is a significant challenge that impedes cancer eradication. Dietary intake, as a key environmental factor, can influence tumor metabolism. Emerging evidence indicates that dietary interventions might affect the nutrient availability in tumors, thereby increasing the efficacy of cancer treatments. However, the intricate interplay between dietary interventions and the pathogenesis of cancer and other diseases is complex. Despite encouraging results, the mechanisms underlying diet-based therapeutic strategies remain largely unexplored, often resulting in underutilization in disease management. In this review, we aim to illuminate the potential effects of various dietary interventions, including calorie restriction, fasting-mimicking diet, ketogenic diet, protein restriction diet, high-salt diet, high-fat diet, and high-fiber diet, on cancer and the aforementioned diseases. We explore the multifaceted impacts of these dietary interventions, encompassing their immunomodulatory effects, other biological impacts, and underlying molecular mechanisms. This review offers valuable insights into the potential application of these dietary interventions as adjunctive therapies in disease management.

Gut microbiota-based discriminative model for patients with ulcerative colitis: A meta-analysis and real-world study

Gut microbiota directly interacts with intestinal epithelium and is a significant factor in the pathogenesis of ulcerative colitis (UC). A meta-analysis was performed to investigate gut microbiota composition of patients with UC in the United States. We also collected fecal samples from Chinese patients with UC and healthy individuals. Gut microbiota was tested using 16S ribosomal RNA gene sequencing. Meta-analysis and 16S ribosomal RNA sequencing revealed significant differences in gut bacterial composition between UC patients and healthy subjects. The Chinese UC group had the highest scores for Firmicutes, Clostridia, Clostridiales, Streptococcaceae, and Blautia, while healthy cohort had the highest scores for P-Bacteroidetes, Bacteroidia, Bacteroidales, Prevotellaceae, and Prevotella_9. A gut microbiota-based discriminative model trained on an American cohort achieved a discrimination efficiency of 0.928 when applied to identify the Chinese UC cohort, resulting in a discrimination efficiency of 0.759. Additionally, a differentiation model was created based on gut microbiota of a Chinese cohort, resulting in an area under the receiver operating characteristic curve of 0.998. Next, we applied the model established for the Chinese UC cohort to analyze the American cohort. Our findings suggest that the diagnostic efficiency ranged from 0.8794 to 0.9497. Furthermore, a combined analysis using data from both the Chinese and US cohorts resulted in a model with a diagnostic efficacy of 0.896. In summary, we found significant differences in gut bacteria between UC individuals and healthy subjects. Notably, the model from the Chinese cohort performed better at diagnosing UC patients compared to healthy subjects. These results highlight the promise of personalized and region-specific approaches using gut microbiota data for UC diagnosis.

The hidden threat: Environmental toxins and their effects on gut microbiota

The human gut microbiota (GM), which consists of a complex and diverse ecosystem of bacteria, plays a vital role in overall wellness. However, the delicate balance of this intricate system is being compromised by the widespread presence of environmental toxins. The intricate connection between contaminants in the environment and human well-being has garnered significant attention in recent times. Although many environmental pollutants and their toxicity have been identified and studied in laboratory settings and animal models, there is insufficient data concerning their relevance to human physiology. Consequently, research on the toxicity of environmental toxins in GM has gained prominence in recent years. Various factors, such as air pollution, chemicals, heavy metals, and pesticides, have a detrimental impact on the composition and functioning of the GM. This comprehensive review aims to comprehend the toxic effects of numerous environmental pollutants, including antibiotics, endocrine-disrupting chemicals, heavy metals, and pesticides, on GM by examining recent research findings. The current analysis concludes that different types of environmental toxins can lead to GM dysbiosis and have various potential adverse effects on the well-being of animals. We investigate the alterations to the GM composition induced by contaminants and their impact on overall well-being, providing a fresh perspective on research related to pollutant exposure.

Effects of Varied Sulfamethazine Dosage and Exposure Durations on Offspring Mice

The development of antibiotics was a turning point in the history of medicine; however, their misuse and overuse have contributed to the current global epidemic of antibiotic resistance. According to epidemiological studies, early antibiotic exposure increases the risk of immunological and metabolic disorders. This study investigated the effects of exposure to different doses of sulfamethazine (SMZ) on offspring mice and compared the effects of exposure to SMZ on offspring mice in prenatal and early postnatal periods and continuous periods. Furthermore, the effects of SMZ exposure on the gut microbiota of offspring mice were analyzed using metagenome. According to the results, continuous exposure to high-dose SMZ caused weight gain in mice. IL-6, IL-17A, and IL-10 levels in the female offspring significantly increased after high-dose SMZ exposure. In addition, there was a significant gender difference in the impact of SMZ exposure on the gut microbiota of offspring: Continuous high-dose SMZ exposure significantly decreased the relative abundance of Ligilactobacillus murinus, Limosilactobacillus reuteri, Lactobacillus johnsonii, and Bifidobacterium pseudolongum (p < 0.05) in female offspring mice; however, these significant changes were not observed in male offspring mice.

Dietary nobiletin regulated cefuroxime- and levofloxacin-associated "gut microbiota-metabolism" imbalance and intestinal barrier dysfunction in mice

Nobiletin (NOB) exhibits significant biological activities and may be a potential dietary treatment for antibiotic-associated gut dysbiosis. In this study, mice were gavaged with 0.2 mL day-1 of 12.5 g L-1 cefuroxime (LFX) and 10 g L-1 levofloxacin (LVX) for a duration of 10 days, accompanied by 0.05% NOB to investigate the regulatory effect and potential mechanisms of NOB on antibiotic-induced intestinal microbiota disorder and intestinal barrier dysfunction. Our results indicated that dietary NOB improved the pathology of intestinal epithelial cells and the intestinal permeability by upregulating the expression of intestinal tight junction proteins (TJs) and the number of goblet cells. Furthermore, dietary NOB reduced the levels of serum lipopolysaccharide (LPS) and pro-inflammatory factors (TNF-α and IL-1β), thereby facilitating the restoration of the intestinal mucosal barrier. Additionally, dietary NOB increased the abundance of beneficial bacteria f_Lachnospiraceae and regulated the metabolic disorders of short-chain fatty acids (SCFAs) and bile acids (BAs). Notably, NOB supplementation resulted in elevated levels of butyric acid and lithocholic acid (LCA), which contributed to the repair of the intestinal mucosal barrier function and the maintenance of intestinal homeostasis. Collectively, our results propose a healthy dietary strategy for the prevention or mitigation of antibiotic-associated gut dysbiosis by dietary NOB.

Arabinoxylans: A review on protocols for their recovery, functionalities and roles in food formulations

Arabinoxylans (AXs) are compounds with high nutritional value and applicability, including prebiotics or supplementary ingredients, in food manufacturing industries. Unfortunately, the recovery of AXs may require advanced separation and integrated strategies. Here, an analysis of the emerging techniques to extract AXs from cereals and their by-products is discussed. This review covers distinct methods implemented over the last 2-3 years, identifying that the type of method, extraction source, AX physicochemical properties and pre-treatment conditions are the main factors influencing the recovery yield. Alkaline extraction is among the most used methods nowadays, mostly due to its simplicity and high recovery yield. Concurrently, recovered AXs applied in food applications is timely reviewed, such as potential bread ingredient, prebiotic and as a wall material for probiotic encapsulation, in beer and non-alcoholic beverage manufacturing, complementary ingredient in bakery products and cookies, improvers in Chinese noodles, 3D food printing and designing of nanostructures for delivery platforms.

Pectin supplementation accelerates post-antibiotic gut microbiome reconstitution orchestrated with reduced gut redox potential

Antibiotic-induced gut dysbiosis (AID) presents a big challenge to host health, and the recovery from this dysbiosis is often slow and incomplete. AID is typically characterized by elevation in redox potential, Enterobacteriaceae load, and aerobic metabolism. In our previous study, a pectin-enriched diet was demonstrated to decrease fecal redox potential and modulate the gut microbiome. Therefore, we propose that pectin supplementation may modulate gut redox potential and favor post-antibiotic gut microbiome reconstitution from dysbiosis. In the present study, rats with AIDwere used to investigate the effects of pectin supplementation on post-antibiotic gut microbiome reconstitution from dysbiosis. The results showed that pectin supplementation accelerated post-antibiotic reconstitution of gut microbiome composition and function and led to enhancement of anabolic reductive metabolism and weakening of catabolic oxidative pathways. These results were corroborated by the measurement of redox potential, findings suggesting that pectin favors post-antibiotic recovery from dysbiosis. Pectin-modulated fecal microbiota transplantation accelerated the decrease in antibiotics-elevated redox potential and Enterobacteriaceae load similarly to pectin supplementation. Moreover, both pectin supplementation and Pectin-modulated fecal microbiota transplantation enriched anaerobic members, primarily from Lachnospiraceae orchestration with enhancement of microbial reductive metabolism in post-antibiotic rats. These findings suggested that pectin supplementation accelerated post-antibiotic gut microbiome reconstitution orchestrated with reduced gut redox potential and that the effect of pectin on redox potential was mediated by remodeling of the intestinal microbiota.

Role of probiotics in managing various human diseases, from oral pathology to cancer and gastrointestinal diseases

The imbalance of microbial composition and diversity in favor of pathogenic microorganisms combined with a loss of beneficial gut microbiota taxa results from factors such as age, diet, antimicrobial administration for different infections, other underlying medical conditions, etc. Probiotics are known for their capacity to improve health by stimulating the indigenous gut microbiota, enhancing host immunity resistance to infection, helping digestion, and carrying out various other functions. Concurrently, the metabolites produced by these microorganisms, termed postbiotics, which include compounds like bacteriocins, lactic acid, and hydrogen peroxide, contribute to inhibiting a wide range of pathogenic bacteria. This review presents an update on using probiotics in managing and treating various human diseases, including complications that may emerge during or after a COVID-19 infection.

Decoding the role of the gut microbiome in gut-brain axis, stress-resilience, or stress-susceptibility: A review

Increased exposure to stress is associated with stress-related disorders, including depression, anxiety, and neurodegenerative conditions. However, susceptibility to stress is not seen in every individual exposed to stress, and many of them exhibit resilience. Thus, developing resilience to stress could be a big breakthrough in stress-related disorders, with the potential to replace or act as an alternative to the available therapies. In this article, we have focused on the recent advancements in gut microbiome research and the potential role of the gut-brain axis (GBA) in developing resilience or susceptibility to stress. There might be a complex interaction between the autonomic nervous system (ANS), immune system, endocrine system, microbial metabolites, and bioactive lipids like short-chain fatty acids (SCFAs), neurotransmitters, and their metabolites that regulates the communication between the gut microbiota and the brain. High fiber intake, prebiotics, probiotics, plant supplements, and fecal microbiome transplant (FMT) could be beneficial against gut dysbiosis-associated brain disorders. These could promote the growth of SCFA-producing bacteria, thereby enhancing the gut barrier and reducing the gut inflammatory response, increase the expression of the claudin-2 protein associated with the gut barrier, and maintain the blood-brain barrier integrity by promoting the expression of tight junction proteins such as claudin-5. Their neuroprotective effects might also be related to enhancing the expression of brain-derived neurotrophic factor (BDNF) and glucagon-like peptide (GLP-1). Further investigations are needed in the field of the gut microbiome for the elucidation of the mechanisms by which gut dysbiosis contributes to the pathophysiology of neuropsychiatric disorders.

The current state of phage therapy in livestock and companion animals

In a global context, bacterial diseases caused by pathogenic bacteria have inflicted sustained damage on both humans and animals. Although antibiotics initially appeared to offer an easy treatment for most bacterial infections, the recent rise of multidrug-resistant bacteria, stemming from antibiotic misuse, has prompted regulatory measures to control antibiotic usage. Consequently, various alternatives to antibiotics are being explored, with a particular focus on bacteriophage (phage) therapy for treating bacterial diseases in animals. Animals are broadly categorized into livestock, closely associated with human dietary habits, and companion animals, which have attracted increasing attention. This study highlights phage therapy cases targeting prominent bacterial strains in various animals. In recent years, research on bacteriophages has gained considerable attention, suggesting a promising avenue for developing alternative substances to antibiotics, particularly crucial for addressing challenging bacterial diseases in the future.

Preoperative oral antibiotic administration in patients undergoing curative resection with stoma creation for colorectal cancer: effectiveness in preventing surgical site infection and the possibility of peristomal candidiasis induced by enterobacterial alteration

AIM

There are many reports that preoperative oral antibiotics (OAs) are effective in preventing surgical site infections (SSIs) in colorectal surgery. However, there is no consensus on the optimal dose of OAs. In this study, we investigated the efficacy of OAs in preventing SSIs and the possibility that OAs induce enterobacterial alteration in the intestinal tract.

METHOD

We performed a retrospective cross-sectional analysis of 389 patients who underwent R0 resection and stoma creation for colorectal cancer in our department between 2009 and 2020. We focused on the incidence of peristomal candidiasis (PSC) as an indicator of enterobacterial alteration and used kanamycin (KM) and metronidazole (MNZ) as the OAs. A low-dose group received 1000 mg/day of both KM and MNZ, and a high-dose group received 2000 mg/day of both KM and MNZ.

RESULTS

SSI occurred in 60 of the 389 cases (15.4%). Regardless of stoma type, SSI was significantly more common in the non-OA group, while PSC was significantly less common. When examined by OA dose, the incidence of SSI was not significantly different between the low-dose and high-dose groups. However, PSC was significantly more common in the high-dose group than in the non-OA and low-dose groups. Analysis of bacterial and fungal levels in stool samples showed that bacterial levels after OAs were significantly lower than before OAs, while fungal levels increased.

CONCLUSION

OAs significantly reduce SSI in colorectal cancer surgery. However, excess OAs were significantly associated with the occurrence of PSC without contributing to further reduction in SSI.

Reduced bacterial resistance antibiotics with improved microbiota tolerance in human intestinal: Molecular design and mechanism analysis

Antibiotic selectivity and bacterial resistance are critical global public health issues. We constructed a multi-class machine learning model to study antibiotic effects on human intestinal microbiota abundance and identified key features. Binding energies of β-lactam antibiotics with Escherichia coli PBP3 mutant protein were calculated, and a 2D-QSAR model for bacterial resistance was established. Sensitivity analysis identified key features affecting bacterial resistance. By coupling key features from the machine learning model and 2D-QSAR model, we designed ten flucloxacillin (FLU) substitutes that improved intestinal microbiota tolerance and reduced antibiotic bacterial resistance. Concurrently, the substitutes exhibited superior degradability in soil, aquatic environments, and under photolytic conditions, coupled with a reduced environmental toxicity compared to the FLU. Evaluations under combined medication revealed significant improvements in functionality and bacterial resistance for 80% of FLU substitutes, with 50% showing more than a twofold increase. Mechanistic analysis demonstrated enhanced binding to target proteins and increased biodegradability for FLU substitutes due to more concentrated surface charges. Reduced solvent hindrance and increased cell membrane permeability of FLU substitutes, mainly due to enhanced interactions with phospholipid bilayers, contributed to their functional selectivity. This study aims to address poor antibiotic selectivity and strong bacterial resistance, providing guidance for designing antibiotic substitutes.