Effects of oral florfenicol and azithromycin on gut microbiota and adipogenesis in mice

COVID-19-associated encephalopathy: connection between neuroinflammation and microbiota-gut-brain axis

While neurological complications of COVID-19, such as encephalopathy, are relatively rare, their potential significant impact on long-term morbidity is substantial, especially given the large number of infected patients. Two proposed hypotheses for the pathogenesis of this condition are hypoxia and the uncontrolled release of proinflammatory cytokines. The gut microbiota plays an important role in regulating immune homeostasis and overall gut health, including its effects on brain health through various pathways collectively termed the gut-brain axis. Recent studies have shown that COVID-19 patients exhibit gut dysbiosis, but how this dysbiosis can affect inflammation in the central nervous system (CNS) remains unclear. In this context, we discuss how dysbiosis could contribute to neuroinflammation and provide recent data on the features of neuroinflammation in COVID-19 patients.

Faecal Microbiota Transplantation Alleviates Ferroptosis after Ischaemic Stroke

Ischaemic stroke can induce changes in the abundance of gut microbiota constituents, and the outcome of stroke may also be influenced by the gut microbiota. This study aimed to determine whether gut microbiota transplantation could rescue changes in the gut microbiota and reduce ferroptosis after stroke in rats. Male Sprague-Dawley rats (6 weeks of age) were subjected to ischaemic stroke by middle cerebral artery occlusion (MCAO). Fecal samples were collected for 16S ribosomal RNA (rRNA) sequencing to analyze the effects of FMT on the gut microbiota. Neurological deficits were evaluated using the Longa score. triphenyl tetrazolium chloride (TTC) staining was performed in the brain, and kits were used to measure malondialdehyde (MDA), iron, and glutathione (GSH) levels in the ipsilateral brain of rats. Western blotting was used to detect the protein expression levels of glutathione peroxidase 4 (GPX4), solute carrier family 7 member 11 (SLC7A11), and the transferrin receptor 2 (TFR2) in the ipsilateral brain of rats. Stroke induced significant changes in the gut microbiota, and FMT ameliorated these changes. TTC staining results showed that FMT reduced cerebral infarct volume. In addition, FMT diminished MDA and iron levels and elevated GSH levels in the ipsilateral brain. Western blot analysis showed that FMT increased GPX4 and SLC7A11 protein expression and decreased TFR2 protein expression in the ipsilateral brain after stroke. FMT can reverse gut microbiota dysbiosis, reduce cerebellar infarct volume, and decrease ferroptosis after stroke.

A review on the antibiotic florfenicol: Occurrence, environmental fate, effects, and health risks

Florfenicol, as a replacement for chloramphenicol, can tightly bind to the A site of the 23S rRNA in the 50S subunit of the 70S ribosome, thereby inhibiting protein synthesis and bacterial proliferation. Due to the widespread use in aquaculture and veterinary medicine, florfenicol has been detected in the aquatic environment worldwide. Concerns over the effects and health risks of florfenicol on target and non-target organisms have been raised in recent years. Although the ecotoxicity of florfenicol has been widely reported in different species, no attempt has been made to review the current research progress of florfenicol toxicity, hormesis, and its health risks posed to biota. In this study, a comprehensive literature review was conducted to summarize the effects of florfenicol on various organisms including bacteria, algae, invertebrates, fishes, birds, and mammals. The generation of antibiotic resistant bacteria and spread antibiotic resistant genes, closely associated with hormesis, are pressing environmental health issues stemming from overuse or misuse of antibiotics including florfenicol. Exposure to florfenicol at μg/L-mg/L induced hormetic effects in several algal species, and chromoplasts might serve as a target for florfenicol-induced effects; however, the underlying molecular mechanisms are completely lacking. Exposure to high levels (mg/L) of florfenicol modified the xenobiotic metabolism, antioxidant systems, and energy metabolism, resulting in hepatotoxicity, renal toxicity, immunotoxicity, developmental toxicity, reproductive toxicity, obesogenic effects, and hormesis in different animal species. Mitochondria and the associated energy metabolism are suggested to be the primary targets for florfenicol toxicity in animals, albeit further in-depth investigations are warranted for revealing the long-term effects (e.g., whole-life-cycle impacts, multigenerational effects) of florfenicol, especially at environmental levels, and the underlying mechanisms. This will facilitate the evaluation of potential hormetic effects and construction of adverse outcome pathways for environmental risk assessment and regulation of florfenicol.

Antibiotic exposure associated with nighttime sleep duration and daytime sleepiness in newlyweds

Few studies have explored the relationship between antibiotic exposure and sleep in newlyweds. We applied the actor-partner interdependence moderation model to estimate the relationships of antibiotic exposure with nighttime sleep duration (weekday, weekend, and average sleep durations) and daytime sleepiness in newlyweds. We found that 99.0% of the 2698 enrolled individuals were exposed to at least one antibiotic. Among the newlyweds, exposure to florfenicol (β, - 0.077; 95% confidence interval [CI], - 0.143, - 0.011), exposure to chloramphenicols (- 0.086 [- 0.160, - 0.011]), and exposure to veterinary antibiotics (VAs) (- 0.106 [- 0.201, - 0.010]) were negatively associated with weekday sleep duration. Florfenicol, chloramphenicols, and VAs were also inversely related to average sleep duration in the newlyweds. Ciprofloxacin and cyadox exposure was significantly associated with an increase of 0.264 (0.030, 0.497) and (0.375 [0.088, 0.663]) Epworth Sleepiness Scale (ESS) scores in the newlyweds, respectively. Gender moderated the actor-partner effects of erythromycin and tetracyclines on the newlyweds' weekday sleep duration and ESS scores. Overall, exposure to florfenicol, chloramphenicols, and VAs shortened weekday and average sleep durations of newlyweds. Exposure to ciprofloxacin and cyadox promoted daytime sleepiness. Gender moderated the actor-partner effects of specific antibiotics on the weekday sleep duration and ESS scores of the newlyweds.

Disruption of the early-life microbiota alters Peyer's patch development and germinal center formation in gastrointestinal-associated lymphoid tissue

During postnatal development, both the maturing microbiome and the host immune system are susceptible to environmental perturbations such as antibiotic use. The impact of timing in which antibiotic exposure occurs was investigated by treating mice from days 5-9 with amoxicillin or azithromycin, two of the most commonly prescribed medications in children. Both early-life antibiotic regimens disrupted Peyer's patch development and immune cell abundance, with a sustained decrease in germinal center formation and diminished intestinal immunoglobulin A (IgA) production. These effects were less pronounced in adult mice. Through comparative analysis of microbial taxa, Bifidobacterium longum abundance was found to be associated with germinal center frequency. When re-introduced to antibiotic-exposed mice, B. longum partially rescued the immunological deficits. These findings suggest that early-life antibiotic use affects the development of intestinal IgA-producing B cell functions and that probiotic strains could be used to restore normal development after antibiotic exposure.

Urinary antibiotic exposure and low grip strength risk in community-dwelling elderly Chinese by gender and age

Emerging studies have shown that environmental contaminants were related to decreased handgrip strength. Nevertheless, no prior research has investigated the relationship of exposure to environmental antibiotics with grip strength. Thus, we explored the relationship between urinary antibiotic burden and grip strength among the elderly in China. This study consisted of 451 men and 539 women from the baseline survey of a cohort study. Commonly used antibiotics for humans and animals were detected in 990 urine samples through a biomonitoring method. Grip strength was measured by an electronic dynamometer. We examined the associations of antibiotic exposure with low grip strength (LGS), grip strength, and grip strength index, respectively. Results suggested that 34.9% of participants developed LGS, and 93.0% of individuals were exposed to 1-10 antibiotics. Among women, oxytetracycline (Quartile 2: odds ratio: 2.97, 95% confidence interval: 1.36-6.50), florfenicol (Quartile 3: 2.60 [1.28-5.27]), fluoroquinolones (Quartile 4: 1.88 [1.07-3.30]), and chloramphenicols (Quartile 3: 2.73 [1.35-5.51]) could enhance LGS risk. Among men, ofloxacin (Quartile 2: 3.32 [1.45-7.59]) increased LGS risk, whereas tetracycline (Quartile 2: 0.31 [0.11-0.88]) was implicated in reduced LGS risk. In participants < 70 years, ofloxacin (Quartile 2: 3.00 [1.40-6.42]) could increase LGS risk. For participants who were 70 years of age or older, veterinary antibiotics (Quartile 3: 1.73 [1.02-2.94]) were linked to a 73% increased risk of LGS. Our findings suggested that antibiotics mainly pertained to LGS, and there were gender and age disparities in associations between antibiotic exposure and muscle strength indicators in the elderly Chinese population.

Antibiotics disrupt lipid metabolism in zebrafish (Danio rerio) larvae and 3T3-L1 preadipocytes

Antibiotics are emerging environmental contaminants with wide attention due to their high consumption and pseudo-persistence in the environment. They have been shown to induce obesity or obesity-related metabolic diseases in experimental animals, but the underlying toxicological mechanisms remain unclear. Here, the disruptive effects of four commonly used antibiotics, namely doxycycline (DC), enrofloxacin (ENR), florfenicol (FF) and sulfamethazine (SMT) on lipid metabolism were investigated in zebrafish (Danio rerio) larvae and murine preadipocyte cell line. Triglyceride (TG) content was reduced after 1 ng/L DC or ENR exposure but was increased at higher concentrations up to 100 mg/L. FF increased and SMT reduced TG content but did not show any concentration dependence. None of the antibiotics had any significant effect on total cholesterol (TC) content in zebrafish except 100 μg/L SMT. Expression levels of 8 lipid metabolism-related genes were also quantified. SMT was most disruptive by up-regulating six genes, followed by FF which up-regulated four genes and down-regulated one gene, whereas DC and ENR both up-regulated one gene. In 3T3-L1 preadipocytes, ENR, FF, and SMT in general increased TG content, while 100 mg/L FF reduced TG substantially. DC did not show any effect up to 10 mg/L, at which TG increased significantly. FF and SMT increased TC slightly at low concentrations but reduced it at high concentrations, whereas TC, DC and ENR had no effect at any tested concentrations. Gene expression measurement also indicated that SMT was most disruptive, followed by FF, DC, and ENR. Reporter gene assays showed that only SMT inhibited the transcriptional activity of peroxisome proliferator-activated receptor γ (PPARγ). The above experimental results and clustering analysis demonstrate that the four antibiotics exerted disruption on lipid metabolism through different mechanisms, and one of the mechanisms for SMT may be inhibition of PPARγ transcriptional activity.

Systematic review: microbial manipulation as therapy for primary sclerosing cholangitis

BACKGROUND

Primary sclerosing cholangitis (PSC) is a progressive liver disease with poor prognosis and no effective therapies to prevent progression. An aetiopathological link between PSC and gastrointestinal microbial dysbiosis has been suggested.

AIM

To evaluate all potential medical therapies which may exert their effect in PSC by modulation of the gut-liver axis.

METHODS

We conducted a comprehensive scoping review of PubMed and Cochrane Library, including all articles evaluating an intervention aimed at manipulating the gastrointestinal microbiome in PSC.

RESULTS

A wide range of therapies proposed altering the gastrointestinal microbiome for the treatment of PSC. In particular, these considered antibiotics including vancomycin, metronidazole, rifaximin, minocycline and azithromycin. However, few therapies have been investigated in randomised, placebo-controlled trials. Vancomycin has been the most widely studied antibiotic, with improvement in alkaline phosphatase reported in two randomised controlled trials, but with no data on disease progression. Unlike antibiotics, strategies such as faecal microbiota transplantation and dietary therapy can improve microbial diversity. However, since these have only been tested in small numbers of patients, robust efficacy data are currently lacking.

CONCLUSIONS

The gut-liver axis is increasingly considered a potential target for the treatment of PSC. However, no therapies have been demonstrated to improve transplant-free survival. Innovative and well-designed clinical trials of microbiome-targeted therapies with long-term follow-up are required for this orphan disease.

The contribution of gut-brain axis to development of neurological symptoms in COVID-19 recovered patients: A hypothesis and review of literature

The gut microbiota undergoes significant alterations in response to viral infections, particularly the novel SARS-CoV-2. As impaired gut microbiota can trigger numerous neurological disorders, we suggest that the long-term neurological symptoms of COVID-19 may be related to intestinal microbiota disorders in these patients. Thus, we have gathered available information on how the virus can affect the microbiota of gastrointestinal systems, both in the acute and the recovery phase of the disease, and described several mechanisms through which this gut dysbiosis can lead to long-term neurological disorders, such as Guillain-Barre syndrome, chronic fatigue, psychiatric disorders such as depression and anxiety, and even neurodegenerative diseases such as Alzheimer's and Parkinson's disease. These mechanisms may be mediated by inflammatory cytokines, as well as certain chemicals such as gastrointestinal hormones (e.g., CCK), neurotransmitters (e.g., 5-HT), etc. (e.g., short-chain fatty acids), and the autonomic nervous system. In addition to the direct influences of the virus, repurposed medications used for COVID-19 patients can also play a role in gut dysbiosis. In conclusion, although there are many dark spots in our current knowledge of the mechanism of COVID-19-related gut-brain axis disturbance, based on available evidence, we can hypothesize that these two phenomena are more than just a coincidence and highly recommend large-scale epidemiologic studies in the future.

Caffeine-Induced Sleep Restriction Alters the Gut Microbiome and Fecal Metabolic Profiles in Mice

Insufficient sleep is becoming increasingly common and contributes to many health issues. To combat sleepiness, caffeine is consumed daily worldwide. Thus, caffeine consumption and sleep restriction often occur in succession. The gut microbiome can be rapidly affected by either one's sleep status or caffeine intake, whereas the synergistic effects of a persistent caffeine-induced sleep restriction remain unclear. In this study, we investigated the impact of a chronic caffeine-induced sleep restriction on the gut microbiome and its metabolic profiles in mice. Our results revealed that the proportion of Firmicutes and Bacteroidetes was not altered, while the abundance of Proteobacteria and Actinobacteria was significantly decreased. In addition, the content of the lipids was abundant and significantly increased. A pathway analysis of the differential metabolites suggested that numerous metabolic pathways were affected, and the glycerophospholipid metabolism was most significantly altered. Combined analysis revealed that the metabolism was significantly affected by variations in the abundance and function of the intestinal microorganisms and was closely relevant to Proteobacteria and Actinobacteria. In conclusion, a long-term caffeine-induced sleep restriction affected the diversity and composition of the intestinal microbiota in mice, and substantially altered the metabolic profiles of the gut microbiome. This may represent a novel mechanism by which an unhealthy lifestyle such as mistimed coffee breaks lead to or exacerbates disease.

Diet-derived metabolites and mucus link the gut microbiome to fever after cytotoxic cancer treatment

Not all patients with cancer and severe neutropenia develop fever, and the fecal microbiome may play a role. In a single-center study of patients undergoing hematopoietic cell transplant (n = 119), the fecal microbiome was characterized at onset of severe neutropenia. A total of 63 patients (53%) developed a subsequent fever, and their fecal microbiome displayed increased relative abundances of Akkermansia muciniphila, a species of mucin-degrading bacteria (P = 0.006, corrected for multiple comparisons). Two therapies that induce neutropenia, irradiation and melphalan, similarly expanded A. muciniphila and additionally thinned the colonic mucus layer in mice. Caloric restriction of unirradiated mice also expanded A. muciniphila and thinned the colonic mucus layer. Antibiotic treatment to eradicate A. muciniphila before caloric restriction preserved colonic mucus, whereas A. muciniphila reintroduction restored mucus thinning. Caloric restriction of unirradiated mice raised colonic luminal pH and reduced acetate, propionate, and butyrate. Culturing A. muciniphila in vitro with propionate reduced utilization of mucin as well as of fucose. Treating irradiated mice with an antibiotic targeting A. muciniphila or propionate preserved the mucus layer, suppressed translocation of flagellin, reduced inflammatory cytokines in the colon, and improved thermoregulation. These results suggest that diet, metabolites, and colonic mucus link the microbiome to neutropenic fever and may guide future microbiome-based preventive strategies.

Fenofibrate enhances lipid deposition via modulating PPARγ, SREBP-1c, and gut microbiota in ob/ob mice fed a high-fat diet

Obesity is characterized by lipid accumulation in distinct organs. Presently, fenofibrate is a commonly used triglyceride-lowering drug. This study is designed to investigate whether long-term fenofibrate intervention can attenuate lipid accumulation in ob/ob mouse, a typical model of obesity. Our data demonstrated that fenofibrate intervention significantly decreased plasma triglyceride level by 21.0%, increased liver index and hepatic triglyceride content by 31.7 and 52.1%, respectively, and elevated adipose index by 44.6% compared to the vehicle group. As a PPARα agonist, fenofibrate intervention significantly increased the expression of PPARα protein in the liver by 46.3% and enhanced the expression of LDLR protein by 3.7-fold. However, fenofibrate dramatically increased the expression of PPARγ and SREBP-1c proteins by ~2.1- and 0.9-fold in the liver, respectively. Fenofibrate showed no effects on the expression of genes-related to fatty acid β-oxidation. Of note, it significantly increased the gene expression of FAS and SCD-1. Furthermore, fenofibrate modulated the gut microbiota. Collectively, long-term fenofibrate induces lipid accumulation in liver and adipose tissues in ob/ob mice by enhancing the expression of adipogenesis-related proteins and gut microbiota. These data suggest that fenofibrate may have limited effects on attenuating lipid deposition in obese patients.

Supplementing the early diet of broilers with soy protein concentrate can improve intestinal development and enhance short-chain fatty acid-producing microbes and short-chain fatty acids, especially butyric acid

Background

Research on nutrition in early-life commonly focuses on the maturation of the intestine because the intestinal system is crucial for ensuring continued growth. To explore the importance of early nutrition regulation in animals, soy protein concentrate (SPC) was added to the early diet of broilers to investigate its effects on amino acid digestibility, intestinal development, especially intestinal microorganisms, and broiler metabolites. A total of 192 one-day-old Arbor Acres (AA) male broilers were randomly assigned to two experimental treatments with 8 replicates of 12 birds. The control group was fed a basal diet (control), and the treatment group was fed a basal diet supplemented with 12% SPC (SPC12) during the first 10 d (starter phase). From d 11 to 21 (grower phase) and d 22 to 42 (finisher phase), a basal diet was fed to both treatment groups.

Results

SPC reduced the pH value and acid-binding capacity of the starter diet (P < 0.05, d 10); SPC in the early diet enhanced the gizzard weight (P < 0.05, d 10 and d 42) and the ileum weight (P < 0.05, d 10) and decreased the weight and length of the jejunum (P < 0.05, d 10) and the relative length of the duodenum and jejunum (P < 0.05, d 10). At the same time, SPC enhanced villus height (P < 0.05, d 10) and muscle thickness in the jejunum and ileum (P < 0.05, d 10) and increased the number of goblet cells in the duodenum (P < 0.05, d 10). Meanwhile, SPC increased the Chao1 index and the ACE index (P < 0.05, d 10) and altered the composition of caecal microflora at d 10. SPC also increased the relative abundance of Alistipes, Anaerotruncus, Erysipelatoclostridium, Intestinimonas and Flavonifractor bacteria (P < 0.05, d 10). At the same time, the concentrations of caecal butyric acid and total short-chain fatty acids (SCFAs) were also increased in the SPC12 group (P < 0.05, d 10).

Conclusions

In summary, the results showed that supplementing the starter diet of broilers with SPC has a significant effect on the early development of the intestine and the microflora.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s40104-022-00749-5.

Associations of typical antibiotic residues with elderly blood lipids and dyslipidemia in West Anhui, China

Growing evidence has indicated the association of clinical antibiotic use with abnormal blood lipid levels; however, no epidemiological study has examined the relationship of antibiotic exposure, probably derived from food chains, with blood lipid levels. This study investigated the relationships of urinary antibiotic levels with blood lipid levels and dyslipidemias in the older population. Baseline data of 960 participants from the Cohort of Elderly Health and Environment Controllable Factors were used in the present study. High-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was performed to detect antibiotic residues in the urine samples of the participants. Our findings revealed that each 1 μg/g increase in enrofloxacin and ciprofloxacin levels was associated with an increase of 0.084 (95 % confidence interval (CI): 0.030, 0.139) and 0.049 (95 % CI: 0.012, 0.086) in triglyceride levels, respectively. Enrofloxacin was associated with an increased risk of hypertriglyceridemia. Each 1 μg/g increase in the enrofloxacin level corresponded to an increase of 0.052 (95 % CI: 0.006, 0.098) in the low-density lipoprotein cholesterol level. Furthermore, florfenicol exposure increased the risks of both hyperbetalipoproteinemia and hypoalphalipoproteinemia. By contrast, each 1 μg/g increase in sulfaclozine and doxycycline levels was associated with a - 0.062 (95 % CI: -0.111, -0.020), and - 0.083 (95 % CI: -0.160, -0.007) decrease in total cholesterol levels, respectively. Sulfaclozine was closely related to a decreased risk of hypercholesterolemia. Stratification analysis revealed specific differences in the correlation between antibiotic exposure and lipid levels based on the waist circumference (WC) values of the participants. Except for sulfaclozine and doxycycline, other antibiotics exerted adverse effects on lipid levels and increased dyslipidemia prevalence. The older participants with higher WC values were vulnerable to antibiotic exposure. Therefore, an appropriate understanding of the epidemiological attributes of antibiotic residues is indispensable to prevent abdominal obesity in the older population.

Antibiotic exposure and risk of overweight/obesity in school children: A multicenter, case-control study from China

BACKGROUND

Although the use of antibiotics during early life has been associated with increased risk of adipogenesis, effect of antibiotic exposure from various sources, including food or drinking water, on adiposity in children is largely unknown.

OBJECTIVE

To investigate associations between urinary biomarkers of multiple antibiotics and risk of adipogenesis in school children.

METHODS

This case-control study recruited 410 overweight/obese school children aged 6-9 years and 410 controls from Shandong and Guangdong Province, China, matched on sex, age and school. Diagnosis of overweight and obesity was based on body mass index-based criteria derived from national data. Urinary concentrations of 45 antibiotics from 8 categories (macrolides, β-lactams, tetracyclines, fluoroquinolones, sulfonamides, phenicols, lincosamides, and quinoxalines), including 6 human antibiotics (HAs), 6 antibiotics preferred as HAs (PHAs), 16 veterinary antibiotics (VAs), and 17 antibiotics preferred as VA (PVAs), were measured by ultra-performance liquid chromatography coupled to triple-quadrupole tandem mass spectrometry. Conditional logistic regression analyses were used to assess odds ratios (ORs) of childhood overweight/obesity in relation to urinary antibiotic concentrations.

RESULTS

A total of 32 antibiotics were found in urine samples with an overall detection frequency of 92.93 %. Children with overweight/obesity have higher veterinary antibiotic levels than those with normal weight. Compared with undetected levels of antibiotics, the multivariable-adjusted ORs (95 % confidence interval) of overweight/obesity for high levels of antibiotics divided according to median values were 1.63 (1.02, 2.62) for florfenicol, 1.62 (1.04, 2.54) for phenicols, and 1.41 (0.97, 2.04) for sum of VAs and PVAs. These associations predominantly existed in boys and remained significant in florfenicol after FDR multiple testing correction (FDR adjusted p < 0.05).

CONCLUSION

Exposure to certain antibiotic for veterinary use mainly from food or drinking water was associated with an increased risk of adipogenesis in children. Further studies are needed to confirm our findings and clarify the underlying mechanisms.

Acute and persistent effects of commonly used antibiotics on the gut microbiome and resistome in healthy adults

Antibiotics are deployed against bacterial pathogens, but their targeting of conserved microbial processes means they also collaterally perturb the commensal microbiome. To understand acute and persistent effects of antibiotics on the gut microbiota of healthy adult volunteers, we quantify microbiome dynamics before, during, and 6 months after exposure to 4 commonly used antibiotic regimens. We observe an acute decrease in species richness and culturable bacteria after antibiotics, with most healthy adult microbiomes returning to pre-treatment species richness after 2 months, but with an altered taxonomy, resistome, and metabolic output, as well as an increased antibiotic resistance burden. Azithromycin delays the recovery of species richness, resulting in greater compositional distance. A subset of volunteers experience a persistent reduction in microbiome diversity after antibiotics and share compositional similarities with patients hospitalized in intensive care units. These results improve our quantitative understanding of the impact of antibiotics on commensal microbiome dynamics, resilience, and recovery.

Importance of gut microbiome regulation for the prevention and recovery process after SARS-CoV-2 respiratory viral infection (Review)

Infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been reported to affect organs other than the lungs, including the liver, brain, kidneys and intestine, and gastrointestinal symptoms, such as nausea, vomiting, diarrhea and abdominal discomfort, have also been reported. Thus, SARS-CoV-2 could potentially directly or indirectly regulate the gut microbiome profile and its homeostasis. The abundance of Coprobacillus, Clostridium ramosum and Clostridium are associated with the severity of COVID-19, and Firmicutes, Bacteriodetes, Proteobacteria and Actinobacteria are also related to COVID-19 infection. The four phyla are correlated with the severity of COVID-19 infection in patients. The modulation of factors that control the physiological growth of the gut microbiome will determine the proportionate ratio of microbiome types (profile). Taken together, gut microbiome profile alterations in COVID-19 patients may have a cross effect with the modulation of cytokine levels in COVID-19 infection. With these findings, several factors that regulate gut microbiome homeostasis may support the degree of the clinical symptoms and hasten the recovery process after COVID-19 infection.

Observation of the Gut Microbiota Profile in BALB/c Mice Induced by Plasmodium yoelii 17XL Infection

Rodent malaria caused by Plasmodium yoelii 17XL (Py 17XL) is an ideal animal model for human malaria studies. Although the gut microbiota plays an important role in the occurrence and development of infectious diseases, the gut microbiota associated with Py 17XL infection remains unclear. In the current study, the gut microbiota composition of infected BALB/c mice was surveyed. Mouse fecal samples were collected at 0, 2, 5 days post-infection (dpi), and the gut microbiota was characterized by 16S rRNA sequencing. Operational taxonomic units (OTUs) were 634 ± 26 on average. Firmicutes and Bacteroidetes were typically predominant in the gut microbiota composition at the phylum level. Compared with the Ctrl, Firmicutes was significantly decreased after infection, while Bacteroidetes was notably increased. The most dominant family was Lactobacillaceae in all samples. The alpha diversity index showed that compared with that of the Ctrl, the observed OTU number was decreased at 2 dpi and then slightly increased at 5 dpi. LEfSe analysis revealed several bacterial taxa were notably related to Py-infected mice at the phylogenetic level. Several bacterial genera, such as Lactobacillus, were overrepresented in the Py-infected fecal microbiota at 2 dpi, while Muribaculaceae was overrepresented at 5 dpi. Moreover, Alistipes and Helicobacter were overrepresented at 5 dpi compared with 2 dpi. The results indicated Py infection could alter the gut microbiota composition of mice. Besides, biomarkers could serve as direct targets to elucidate their roles in the progression and pathogenesis of malaria and provide insights into studies of antimalarial drugs and malaria vaccines.

The exposure levels and health risk assessment of antibiotics in urine and its association with platelet mitochondrial DNA methylation in adults from Tianjin, China: A preliminary study

There has been extensive research on antibiotics exposure in adults by biomonitoring, but the biological mechanisms and potential risks to human health remain limited. In this study, 102 adults aged 26-44 years in Tianjin were studied and 23 common antibiotics in urine were analyzed by Liquid chromatography-mass spectrometry (LC-MS). All antibiotics were detected in urine, with an overall detection frequency of 40.4% (the detection frequencies of phenothiazines, quinolones, sulfonamides, tetracyclines, and chloramphenicol were 77%, 54%, 24%, 28%, and 49%, respectively.). Ofloxacin and enrofloxacin had the highest detection frequencies (85% and 81%), with median concentrations of 0.26 (IQR: 0.05-1.36) and 0.09 (IQR: 0.03-0.14) ng/mL, respectively. Based on health risk assessment, the predicted estimated daily exposures (EDEs) ranged from 0 μg/kg/day to 13.98 μg/kg/day. The hazard quotient (HQ) values of all the antibiotics except ofloxacin and ciprofloxacin were bellow one, which are considered safe. For all blood samples, the mitochondrial DNA (mtDNA) methylation levels in the MT-ATP6 (ranging between 3.86% and 34.18%) were slightly higher than MT-ATP8 and MT-ND5 (ranging between 0.57% and 9.32%, 1.08% and 19.62%, respectively). Furthermore, mtDNA methylation from MT-ATP6, MT-ATP8 and MT-ND5 were measured by bisulfite-PCR pyrosequencing. The association (P < 0.05) was found between mtDNA methylation level (MT-ATP8 and MT-ND5) and individual antibiotics including chlorpromazine, ciprofloxacin, enrofloxacin, norfloxacin, pefloxacin, sulfaquinoxaline, sulfachloropyridazine, chloramphenicol, and thiamphenicol, indicating that persistent exposure to low-dose multiple antibiotics may affect the mtDNA methylation level and in turn pose health risks.

Do Antibiotics Cause Obesity Through Long-term Alterations in the Gut Microbiome? A Review of Current Evidence

PURPOSE OF REVIEW

In this review, we summarize current evidence on the association between antibiotics and the subsequent development of obesity through modulation of the gut microbiome. Particular emphasis is given on (i) animal and human studies and their limitations; (ii) the reservoir of antibiotics in animal feed, emerging antibiotic resistance, gut dysbiosis, and obesity; (iii) the role of infections, specifically viral infections, as a cause of obesity; and (iv) the potential therapeutic approaches other than antibiotics to modulate gut microbiome.

RECENT FINDINGS

Overall, the majority of animal studies and meta-analyses of human studies on the association between antibiotics and subsequent development of obesity are suggestive of a link between exposure to antibiotics, particularly early exposure in life, and the development of subsequent obesity as a result of alterations in the diversity of gut microbiota. The evidence is strong in animal models whereas evidence in humans is inconclusive requiring well-designed, long-term longitudinal studies to examine this association. Based on recent meta-analyses and epidemiologic studies in healthy children, factors, such as the administration of antibiotics during the first 6 months of life, repeated exposure to antibiotics for ≥ 3 courses, treatment with broad-spectrum antibiotics, and male gender have been associated with increased odds of overweight/obesity. Early antibiotic exposure in animal models has shown that reductions in the population size of specific microbiota, such as Lactobacillus, Allobaculum, Rikenellaceae, and Candidatus Arthromitus, are related to subsequent adiposity. These data suggest that the loss of diversity of the gut microbiome, especially early in life, may have potential long-term detrimental effects on the adult host gut microbiome and metabolic health. Genetic, environmental, and age-related factors influence the gut microbiome throughout the lifetime. More large-scale, longer-term, longitudinal studies are needed to determine whether changes that occur in the microbiome after exposure to antibiotics, particularly early exposure, are causal of subsequent weight gain or consequent of weight gain in humans. Further well-designed, large-scale RCTs in humans are required to evaluate the effects of administration of antibiotics, particularly early administration, and the subsequent development of overweight/obesity. Therapeutic interventions, such as bacteriophage treatment or the use of probiotics, especially genetically engineered ones, need to be evaluated in terms of prevention and management of obesity.

Early Life Exposure to Environmental Contaminants (BDE-47, TBBPA, and BPS) Produced Persistent Alterations in Fecal Microbiome in Adult Male Mice

The gut microbiome is a pivotal player in toxicological responses. We investigated the effects of maternal exposure to 3 human health-relevant toxicants (BDE-47, tetrabromobisphenol [TBBPA], and bisphenol S [BPS]) on the composition and metabolite levels (bile acids [BAs] and short-chain fatty acids [SCFAs]) of the gut microbiome in adult pups. CD-1 mouse dams were orally exposed to vehicle (corn oil, 10 ml/kg), BDE-47 (0.2 mg/kg), TBBPA (0.2 mg/kg), or BPS (0.2 mg/kg) once daily from gestational day 8 to the end of lactation (postnatal day 21). 16S rRNA sequencing and targeted metabolomics were performed in feces of 20-week-old adult male pups (n = 14 - 23/group). Host gene expression and BA levels were quantified in liver. BPS had the most prominent effect on the beta-diversity of the fecal microbiome compared with TBPPA and BDE-47 (QIIME). Seventy-three taxa were persistently altered by at least 1 chemical, and 12 taxa were commonly regulated by all chemicals (most of which were from the Clostridia class and were decreased). The most distinct microbial biomarkers were S24-7 for BDE-47, Rikenellaceae for TBBPA, and Lactobacillus for BPS (LefSe). The community-wide contributions to the shift in microbial pathways were predicted using FishTaco. Consistent with FishTaco predictions, BDE-47 persistently increased fecal and hepatic BAs within the 12α hydroxylation pathway, corresponding to an up-regulation with the hepatic BA-synthetic enzyme Cyp7a1. Fecal BAs were also persistently up-regulated by TBBPA and BPS (liquid chromatography-mass spectrometry). TBBPA increased propionic acid and succinate, whereas BPS decreased acetic acid (gas chromatography-mass spectrometry). There was a general trend in the hepatic down-regulation of proinflammatory cytokines and the oxidative stress sensor target gene (Nqo1), and a decrease in G6Pdx (the deficiency of which leads to dyslipidemia). In conclusion, maternal exposure to these toxicants persistently modified the gut-liver axis, which may produce an immune-suppressive and dyslipidemia-prone signature later in life.

Human milk oligosaccharide 2'-fucosyllactose supplementation improves gut barrier function and signaling in the vagal afferent pathway in mice

2′-Fucosyllactose (2′-FL) is one of the predominant oligosaccharides found in human milk and has several well-established beneficial effects in the host. It has previously been shown that 2′-FL can improve the metabolic phenotype in high-fat (HF)-fed mice. Here we investigated whether dietary supplementation with 2′-FL was associated with improved intestinal barrier integrity, signaling in the vagal afferent pathway and cognitive function. Mice were fed either a low-fat (LF, 10% fat per kcal) or HF (45% fat per kcal) diet with or without supplementation of 2′-FL (10% w/w) in the diet for 8 weeks. Body weight, energy intake, fat and lean mass, intestinal permeability (ex vivo in Ussing chambers), lipid profiles, gut microbiome and microbial metabolites, and cognitive functions were measured. Vagal afferent activity was measured via immunohistochemical detection of c-Fos protein in the brainstem in response to peripheral administration of cholecystokinin (CCK). 2′-FL significantly attenuated the HF-induced increase in fat mass and energy intake. 2′-FL significantly reduced intestinal permeability and significantly increased expression of interleukin (IL)-22, a cytokine known for its protective role in the intestine. Additionally, 2′-FL led to changes in the gut microbiota composition and in the associated microbial metabolites. Signaling in the vagal afferent pathway was improved but there was no effect on cognitive function. In conclusion, 2′-FL supplementation improved the metabolic profiles, gut barrier integrity, lipid metabolism and signaling in the vagal afferent pathway. These findings support the utility of 2′-FL in the control of gut barrier function and metabolic homeostasis under a metabolic challenge.

2’-Fucosyllactose (2’-FL), a predominant human milk oligosaccharide, attenuates HF diet-induced metabolic and intestinal barrier impairment, improves gut hormone resistance, and alters the intestinal microbiota and microbiota-derived metabolites.

Fuzhuan brick tea supplemented with areca nuts: Effects on serum and gut microbiota in mice

Areca nut and Fuzhuan brick tea, a type of natural plant products, have obvious effects of fat reduction and weight loss; however, there is no report on their synergistic effect. This study investigated the effects of Fuzhuan brick tea supplemented with different concentrations of areca nut (5% (LAF), 10% (MAF), and 20% (HAF)) on serum and gut microbiota in Kunming (KM) mice. The results showed that Fuzhuan brick tea supplemented with areca nuts (AFTs) could reduce weight, prevent the accumulation of fat, inhibit the increase in the levels of serum triglyceride, total cholesterol, low-density lipoprotein cholesterol, blood glucose, free fatty acid, insulin, and total bile acid, alleviate the decrease in high-density lipoprotein cholesterol level, and regulate the composition of gut microbiota by high-fat diet intervention. The HAF group with 20% areca nut content showed the best effect. These results could provide a novel approach to prevent obesity and hyperlipidemia. PRACTICAL APPLICATIONS: Consumption of areca nut and tea is widespread in Asia and other regions. As a controversial raw material, the damage due to areca nut to oral mucosa health has often aroused public concern and heated discussion; however, its medicinal value has been confirmed in terms of its pharmacological effects in various aspects. Fuzhuan brick tea, a type of traditional postfermented dark tea, has been confirmed to exert effects of antiobesity. Therefore, the areca nut and Fuzhuan brick tea, as a type of natural plant products, have obvious effects of fat reduction and weight loss; however, their synergistic effect has not been reported. To our knowledge, this study is the first to explore the effects of the Fuzhuan brick tea supplemented with areca nuts (AFTs) on serum and gut microbiota in mice. On the premise of exerting their beneficial effects (especially in terms of easing food stagnation and eliminating indigestion) and reducing their toxic and side effects, the effects of AFTs on health were further clarified, which could provide a novel direction for the development and utilization of areca nut. Moreover, our research would increase public understanding of areca nut and provide guidance to the Fuzhuan brick tea processing industry.

Antibiotics biomonitored in urine and obesogenic risk in a community-dwelling elderly population

BACKGROUND

Experimental and epidemiological studies have linked antibiotics use to gut dysbiosis-mediated risk of chronic metabolic diseases. However, whether adiposity is linked to antibiotic exposure in elderly remains inadequately understood.

OBJECTIVE

To investigate the association between internal exposure of antibiotics and adiposity in elderly by using a biomonitoring method.

METHODS

We included 990 participants (≥60 years) from the baseline survey of the Cohort of Elderly Health and Environment Controllable Factors in Lu'an city, China, from June to September 2016. Forty-five antibiotics and two metabolites in urine were monitored through liquid chromatography-electrospray tandem mass spectrometry (HPLC-MS/MS). Creatinine-corrected urinary concentrations were used to assess antibiotic exposure levels. Body mass index (BMI), waist circumference (WC) and body fat percentage (BFP) were used as indicators of adiposity. Multiple linear regression and binary logistic regression analyses were used to analyze the association of antibiotic concentrations with obesity-related indices. Subsequently, a gender-stratified analysis was performed.

RESULTS

Of the included elderly, 50.7% were defined as having overweight/ obesity, 59.8% as having central preobesity/obesity, and 37.5% as having slightly high/high BFP. Linear regression analysis revealed that a 1-unit increase in the logarithmic transformation of norfloxacin concentrations was related with an increase of 0.29 kg/m² (95% CI: 0.02-0.04), 0.99 cm (95% CI：0.24-1.75), and 0.69% (95% CI：0.21-1.17) in BMI, WC, and BFP, respectively. Compared with the control group, exposure to doxycycline (tertile 2: odds ratio, 2.06 [95% CI: 1.12-3.76]) and norfloxacin (tertile 2: 2.13 [1.05-4.29]; tertile 3: 2.07 [1.03-4.17]) had BMI-based overweight/obesity risk. Additionally, ciprofloxacin (tertile 2: 2.06 [1.12-3.76]), norfloxacin (tertile 3: 2.95 [1.34-6.49]), and florfenicol (tertile 3: 1.84 [1.07-3.14]) were related to WC-based central preobesity/obesity risk. Norfloxacin (tertile 3: 2.54 [1.23-5.24]) was positively associated with a slightly high/high BFP risk. Gender-stratified analysis demonstrated an increased adiposity risk in women compared with men.

CONCLUSIONS

Our research provided an evidence that exposure to specific types of antibiotics (tetracyclines and fluoroquinolones) probably from the food chain contributed to obesity in elderly. Prospective cohort studies with larger sample size are warrented to explore the causation.

Qiweibaizhu Decoction Treats Diarrheal Juvenile Rats by Modulating the Gut Microbiota, Short-Chain Fatty Acids, and the Mucus Barrier

Background

Qiweibaizhu decoction (QBD), a classic Chinese herbal formula, has been widely used for treating diarrhea in infants and children with spleen deficiency syndrome for centuries, but its mechanism of action remains unclear. The gut microbiota, short-chain fatty acids (SCFAs), and intestinal mucus are closely associated with diarrhea.

Methods

In this study, the composition of the gut microbiota in diarrheal rats was analyzed by 16S rDNA amplicon sequencing. The concentrations of colon SCFAs were determined using gas chromatography-mass spectrometry (GC-MS). The expression of mucin 2 (MUC2) in the colon was detected by immunofluorescence.

Results

Diarrhea significantly changed the diversity and structure of the gut microbiota and disrupted the mucus barrier in juvenile rats. QBD did not significantly change the diversity and structure of the intestinal flora, but it enhanced the increasing tendencies of Verrucomicrobia and Akkermansia and decreased the abundance of Turicibacter (P=0.037) and Flavonifractor (P=0.043). QBD tends to repair the mucus layer and promote MUC2 expression in juvenile rats with diarrhea. Moreover, S. boulardii significantly increased the abundance of Parasutterella (P=0.043). In addition, QBD treatment tends to increase the propionic acid concentration during diarrhea, but its levels of acetic acid, propionic acid, butyric acid, and total SCFAs were lower than those in the S. boulardii group.

Conclusion

S. boulardii significantly increased the abundance of Parasutterella, leading to increased production of acetic acid, propionic acid, and butyric acid, consequently leading to alleviation of diarrhea. In comparison, QBD affected diarrhea via regulation of the intestinal flora, especially by increasing the abundance of Verrucomicrobia and Akkermansia, resulting in mucus barrier repair, protection of the intestines, and treatment of diarrhea.

Long-Term Impact of Suppressive Antibiotic Therapy on Intestinal Microbiota

The aim was to describe the safety of indefinite administration of antibiotics, the so-called suppressive antibiotic therapy (SAT) and to provide insight into their impact on gut microbiota. 17 patients with SAT were recruited, providing a fecal sample. Bacterial composition was determined by 16S rDNA massive sequencing, and their viability was explored by PCR-DGGE with and without propidium monoazide. Presence of antibiotic multirresistant bacteria was explored through the culture of feces in selective media. High intra-individual variability in the genera distribution regardless of the antibiotic or antibiotic administration ingestion period, with few statistically significant differences detected by Bray-Curtis distance-based principle component analysis, permutational multivariate analysis of variance and linear discriminant analysis effect size analysis. However, the microbiota composition of patients treated with both beta-lactams and sulfonamides clustered by a heat map. Curiously, the detection of antibiotic resistant bacteria was almost anecdotic and CTX-M-15-producing E. coli were detected in two subjects. Our work demonstrates the overall clinical safety of SAT and the low rate of the selection of multidrug-resistant bacteria triggered by this therapy. We also describe the composition of intestinal microbiota under the indefinite use of antibiotics for the first time.

State of the Art in the Culture of the Human Microbiota: New Interests and Strategies

The last 5 years have seen a turning point in the study of the gut microbiota with a rebirth of culture-dependent approaches to study the gut microbiota. High-throughput methods have been developed to study bacterial diversity with culture conditions aimed at mimicking the gut environment by using rich media such as YCFA (yeast extract, casein hydrolysate, fatty acids) and Gifu anaerobic medium in an anaerobic workstation, as well as media enriched with rumen and blood and coculture, to mimic the symbiosis of the gut microbiota. Other culture conditions target phenotypic and metabolic features of bacterial species to facilitate their isolation. Preexisting technologies such as next-generation sequencing and flow cytometry have also been utilized to develop innovative methods to isolate previously uncultured bacteria or explore viability in samples of interest. These techniques have been applied to isolate CPR (Candidate Phyla Radiation) among other, more classic approaches. Methanogenic archaeal and fungal cultures present different challenges than bacterial cultures. Efforts to improve the available systems to grow archaea have been successful through coculture systems. For fungi that are more easily isolated from the human microbiota, the challenge resides in the identification of the isolates, which has been approached by applying matrix-assisted laser desorption ionization-time of flight mass spectrometry technology to fungi. Bacteriotherapy represents a nonnegligible avenue in the future of medicine to correct dysbiosis and improve health or response to therapy. Although great strides have been achieved in the last 5 years, efforts in bacterial culture need to be sustained to continue deciphering the dark matter of metagenomics, particularly CPR, and extend these methods to archaea and fungi.

Profiling the mid-adult cecal microbiota associated with host healthy by using herbal formula Kang ShuaiLao Pian treated mid-adult mice

With the occurrence of aging process, decreased neuron dopamine, disrupted brown adipose tissue (BAT) remodeling and decreased butyrate level all reflect a weak host healthy in certain degree. Nevertheless, the signs of mid-adult gut microbiota, and its association with host healthy are not well understood. In current study, we deemed to illustrate the associations of age, neuron dopamine, BAT remodeling, butyrate and gut microbiota with the aid of traditional herbal formula Kang Shuai Lao Pian (KSLP), which is known for its anti-aging effect. Here, ELISA was performed to detect the production of brain dopamine, the mass of inguinal white adipose tissue versus interscapular brown adipose tissue (iWAT/iBAT) was calculated and considered as a sign of BAT remodeling, 16S rRNA gene sequencing was used to the detection of gut microbiota profiling and gas chromatography was used to measure the butyrate level in mice feces. Our results indicated mid-adult mice already present distinctive gut microbiota profiling compared with young mice, concomitant with which are the lower brain dopamine level and disrupted brown adipose remodeling. KSLP treatment improved the host healthy and regulated gut microbiota with enriched Firmicutes at the expense of Bacteroidetes, particularly increased the relative abundance of bacteria functionally related to dopamine and butyrate productions, which suggest KSLP treatment constructs a healthier gut environment. In conclusion, modulation of gut microbiota and butyrate may connectively regulate dopamine production and BAT remodeling through gut-brain axis and gut-metabolism axis.

Enrofloxacin Shifts Intestinal Microbiota and Metabolic Profiling and Hinders Recovery from Salmonella enterica subsp. enterica Serovar Typhimurium Infection in Neonatal Chickens

Enrofloxacin is an important antibiotic used for prevention and treatment of Salmonella infection in poultry in many countries. However, oral administration of enrofloxacin may lead to the alterations in the microbiota and metabolome in the chicken intestine, thereby reducing colonization resistance to the Salmonella infection. To study the effect of enrofloxacin on Salmonella in the chicken cecum, we used different concentrations of enrofloxacin to feed 1-day-old chickens, followed by oral challenge with Salmonella enterica subsp. enterica serovar Typhimurium (S. Typhimurium). We then explored the distribution pattern of S. Typhimurium in cecum contents in vivo and analyzed the microbial community structure of cecum contents using microbial 16S amplicon sequencing. Untargeted metabolomics was used to explore the gut metabolome on day 14. Faecalibacterium and Anaerostipes, which are closely related to the chicken intestinal metabolome, were screened using a multi-omics technique. The abundance of S. Typhimurium was significantly higher in the enrofloxacin-treated group than in the untreated group, and S. Typhimurium persisted longer. Moreover, the cecal colony structures of the three groups exhibited different characteristics, with Lactobacillus reaching its highest abundance on day 21. Notably, S. Typhimurium infection is known to affect the fecal metabolome of chickens differently. Thus, our results suggested that enrofloxacin and Salmonella infections completely altered the intestinal microbiota and metabolism of chickens.IMPORTANCE In this study, we examined the effects of S. Typhimurium infection and enrofloxacin treatment on the microbiota and metabolite synthesis in chicken cecum, in order to identify target metabolites that may promote S. Typhimurium colonization and aggravate inflammation and to evaluate the important microbiota that may be associated with these metabolites. Our findings may facilitate the use of antibiotics to prevent S. Typhimurium infection.

Dendrobium officinale Kimura et Migo and American ginseng mixture: A Chinese herbal formulation for gut microbiota modulation

Dendrobium officinale Kimura et Migo (D. officinale) is a famous traditional Chinese medicine (TCM). A mixture of D. officinale and American ginseng has been shown to enhance cell-mediated immunity, humoral immunity, and monocyte/macrophage functions in mice. Here, the effects of a D. officinale and American ginseng mixture on the structure of gut microbial community in dogs were examined using high-throughput 16S rRNA gene amplicon sequencing. The data revealed that while the mixture did not change the diversity of gut microbial community significantly, differences among individuals were significantly reduced. Furthermore, the mixture-responsive operational taxonomic units (OTUs) exhibited a phase-dependent expression pattern. Fifty-five OTUs were found to exhibit a mixture-induced expression pattern, among which one third were short-chain fatty acid (SCFA)-producing genera and the others were probiotic genera included Lactobacillus spp., Sutterella, Alistipes, Anaerovorax, Bilophila, Coprococcus, Gordonibacter, Oscillibacter, among others. By contrast, 36% of the OTUs exhibiting a mixture-repressed expression pattern were disease-associated microorganisms, and six genera, namely Actinomyces, Escherichia/Shigella, Fusobacterium, Slackia, Streptococcus and Solobacterium, were associated with cancer. In addition, five genera were closely associated with diabetes, namely Collinsella, Rothia, Howardella, Slackia and Intestinibacter. Our results indicate that this D. officinale and American ginseng mixture may be used as a prebiotic agent to enhance SCFA-producing genera and prevent gut dysbiosis.

Maternal antibiotic concentrations in pregnant women in Shanghai and their determinants: A biomonitoring-based prospective study

Consumption of antibiotics is continuing to increase, with China accounting for approximately one quarter of the global intake. As a class of emerging environmental contaminants, antibiotics may pose a potential threat to human health, especially in children. However, the internal antibiotic exposure levels in pregnant women and their determinants remain unclear. Here we investigated the urinary creatinine-corrected concentration of 15 antibiotics in 762 pregnant women from the Shanghai Prenatal Cohort, by liquid chromatography-tandem mass spectrometry. Logistic regression analysis identified associations between high-antibiotic-level and maternal dietary factors. Results show that cumulatively antibiotics were detected at a frequency of 0.13 - 82.7%, with veterinary antibiotics (VAs) and preferred veterinary antibiotics (PVAs) detected in 76.9% and 98.2% of samples, respectively; PVAs were the most significant contributors to hazard index values > 1. Further, ciprofloxacin was the predominant antibiotic (median: 73.5 μg/mg creatinine), followed by norfloxacin (54.2 μg/mg creatinine); while sulfamethoxazole, enrofloxacin, and ciprofloxacin levels, used as a PVA or VA, were significantly higher in normal-weight and underweight women compared to overweight and obese women. Also, sulfamethoxazole, sulfadiazine, and ciprofloxacin were more frequently detected in mothers with a relatively low education degree. Interestingly, pregnant women with higher milk intake had a 1.96-times (95% CI: 1.10-3.49) greater risk of high-VA-exposure-level than the lower-intake group. The odds of exposure to high PVA, VA, PVA + VA, and all antibiotics levels for mothers with high egg consumption frequency were more than twice that of low-consumption individuals. Collectively, pregnant women in Shanghai are exposed to multiple environmental antibiotics, primarily as PVAs and VAs. Herein, we provide evidence for the association between dietary factors and maternal environmental antibiotic exposure in China. Special attention to antibiotic exposure and confirmation of potential determinants should be taken in the future.

Lactobacillus acidophilus JCM 1132 Strain and Its Mutant with Different Bacteriocin-Producing Behaviour Have Various in Situ Effects on the Gut Microbiota of Healthy Mice

The production of bacteriocin is considered to be a probiotic trait of lactic acid bacteria (LAB). However, not all strains of LAB harbour bacteriocin genes, even within the same species. Moreover, the effects of bacteriocins on the host gut microbiota and on host physiological indicators are rarely studied. This study evaluated the effects of the bacteriocin-producing Lactobacillus acidophilus strain JCM1132 and its non-producing spontaneous mutant, L. acidophilus CCFM720, on the physiological statuses and gut microbiota of healthy mice. Mice that received the bacteriocin-producing strain JCM1132 exhibited reduced water and food intake. Furthermore, the administration of these strains induced significant changes in the compositional abundance of faecal microbiota at the phylum and genus levels, and some of these changes were more pronounced after one week of withdrawal. The effects of CCFM720 treatment on the gut microbiota seemed to favour the prevention of metabolic diseases to some extent. However, individuals that received JCM1132 treatment exhibited weaker inflammatory responses than those that received CCFM720 treatment. Our results indicate that treatment with bacteriocin-producing or non-producing strains can have different effects on the host. Accordingly, this trait should be considered in the applications of LAB.

Antibiotic-Induced Perturbations Are Manifested in the Dominant Intestinal Bacterial Phyla of Atlantic Salmon

The intestinal microbiota of certain farmed fish are often exposed to antimicrobial substances, such as antibiotics, that are used to prevent and treat bacterial diseases. Antibiotics that kill or inhibit the growth of harmful microbes can rapidly alter intestinal microbial diversity and composition, with potential effects on the host health. In this study, we have elucidated the impact of two antibiotics, florfenicol and oxolinic acid, by employing a high-throughput 16S rRNA gene amplicon sequencing technique on the distal and mid intestinal microbial communities of Atlantic salmon (Salmo salar). For this, Atlantic salmon were offered diets with or without antibiotics. We then investigated the bacterial communities in the intestinal mucus of the fish. Our results showed that antibiotic exposure shifts the intestinal microbial profile differentially. In addition, the bacterial compositions of the control and antibiotic-fed groups were significantly different. Antibiotic feeding altered the composition and abundance of the dominant bacterial phyla, namely Proteobacteria, Actinobacteria, Firmicutes, Spirochaetes, Bacteroidetes, Tenericutes, and Thermotogae. The bacterial association network analysis also indicated the differential pattern of co-occurrence of bacteria in the three study groups. The results regarding the differences in the structure and association of the intestinal microbiota of Atlantic salmon after florfenicol and oxolinic acid feeding can be employed to attenuate the adverse effects of antibiotic feeding on fish.

Maternal Genistein Intake Mitigates the Deleterious Effects of High-Fat Diet on Glucose and Lipid Metabolism and Modulates Gut Microbiota in Adult Life of Male Mice

Adverse early-life exposures program increased risk of chronic metabolic diseases in adulthood. However, the effects of genistein supplementation in early life on metabolic health in later life are largely unclear. Our objective was to investigate whether maternal genistein intake could mitigate the deleterious influence of a maternal high-fat diet on glucose and lipid metabolism in offspring and to explore the role of gut microbiota in mediating the transgenerational effects. C57BL/6 female mice were fed either a high-fat diet (HF), high-fat diet with genistein (0.6 g/kg diet) (HFG) or normal control diet (C) for 3 weeks before pregnancy and throughout pregnancy and lactation. The male offspring had ad libitum access to normal chow diet from weaning to 24 weeks of age. Then the content of inguinal subcutaneous adipose tissue (SAT) and epididymal visceral adipose tissue (VAT) were weighed. Glucose tolerance test (GTT), the level of serum insulin and lipid profiles were analyzed. The caecal contents were collected for 16S rDNA sequencing. The results showed that maternal genistein intake could significantly reduce blood glucose levels during GTT, fasting insulin levels, VAT mass and serum triglyceride levels as well as increase high-density lipoprotein cholesterol in adult male offspring. Significant decrease of germs from the Tenericutes phylum and enrichment of Rikenella as well as SCFA (short-chain fatty acid)-producing bacteria, including Alloprevotella, Odoribacter, and Clostridium XlVa, in offspring of genistein fed dams might play crucial roles in the improvement of glucose and lipid metabolism. Overall, early-life genistein intake attenuated the harmful effects of maternal HF on metabolism in adult offspring and the protective effects were associated with the alterations in gut microbiota, which provides new evidence and targets for mitigate the poor effects of adverse early-life exposures on metabolic health in later life.

Metabolic and Gut Microbial Characterization of Obesity-Prone Mice under a High-Fat Diet

Obesity is characterized with high heterogeneity due to genetic abnormality, energy imbalance, gut dysbiosis, or a combination of all three. Obesity-prone (OP) and -resistant (OR) phenotypes are frequently observed in rodents, even in those given a high-fat diet (HFD). However, the underlying mechanisms are largely unknown. Male C57BL/6J mice were fed with chow or a HFD for 8 weeks. OP and OR mice were defined based on body weight gain, and integrated serum metabolic and gut microbial profiling was performed by the gas chromatography-mass spectroscopy-based metabolomic sequencing and pyrosequencing of 16S rDNA of cecum contents. A total of 60 differential metabolites were identified in comparisons among Con, OP, and OR groups, in which 27 were OP-related. These differential metabolites are mainly involved in glycolysis, lipids, and amino acids metabolism and the TCA cycle. Meanwhile, OP mice had a distinct profile in gut microbiota compared to those of OR or Con mice, which showed a reduced ratio of Firmicutes to Bacteroidetes and increased Proteobacteria. Moreover, the gut microbial alteration of OP mice was correlated with the changes of the key serum metabolites. OP-enriched Parasutterella from the Proteobacteria phylum correlated to most of metabolites, suggesting that it was essential in obesity. OP mice are distinct in metabolic and gut microbial profiles, and OP-related metabolites and bacteria are of significance for understanding obesity development.

Obesity, diabetes, and the gut microbiome: an updated review

Obesity and diabetes are two of the most prevalent health problems and leading causes of death globally. As research on the intestinal microbiome increases, so does our understanding of its intricate relationship to these diseases, although this has yet to be fully elucidated. Areas covered: This review evaluates the role of the gut microbiome in obesity and diabetes, including the influences of internal and environmental factors. Literature searches were performed using the keywords 'diabetes,' 'insulin resistance,' 'gut microbiome,' 'gut microbes,' 'obesity,' and 'weight gain.' Expert commentary: Highlights of recent research include new findings regarding the effects of caloric restriction, which expound the importance of diet in shaping the gut microbiome, and studies reinforcing the lasting implications of antibiotic use for diabetes and obesity, particularly repeated doses in early childhood. Mechanistically, interactions between the microbiome and the host innate immune system, mediated by TLR4-LPS signaling, have been shown to meditate the metabolic benefits of caloric restriction. Further, gut microbes haven now been shown to regulate oxygen availability via butyrate production, thus protecting against the proliferation of pathogens such as E. coli and Salmonella. However, many microbial metabolites remain unidentified and their roles in obesity and diabetes remain to be determined.

Improved Glucose and Lipid Metabolism in the Early Life of Female Offspring by Maternal Dietary Genistein Is Associated With Alterations in the Gut Microbiota

Maternal over-nutrition can lead to metabolic disorders in offspring, whereas maternal dietary genistein may have beneficial effects on the metabolic health of offspring. Our objective was to determine whether maternal dietary genistein could attenuate the detrimental effects of a maternal high-fat diet on their offspring's metabolism and to explore the role of the gut microbiota on their offspring's glucose and lipid metabolism. C57BL/6 female mice were fed either a high-fat diet without genistein (HF), high-fat diet with low-dose genistein (0.25 g/kg diet) (HF.LG), high-fat diet with high-dose genistein (0.6 g/kg diet) (HF.HG) or normal control diet (Control) for 3 weeks prior to breeding and throughout gestation and lactation. The female offspring in the HF group had lower birth weights and glucose intolerance and higher serum insulin, triacylglycerol (TG) and total cholesterol (TC) levels at weaning compared with the Control group. Offspring from HF.LG dams had increased birth weight, improved glucose tolerance, and decreased fasting insulin, whereas the serum TG and TC levels were decreased in HF.HG offspring in comparison with HF offspring. The significant enrichment of Bacteroides and Akkermansia in offspring from genistein-fed dams might play vital roles in improving glucose homeostasis and insulin sensitivity, and the significantly increased abundance of Rikenella and Rikenellaceae_RC9_ gut_group in the HF.HG group may be associated with the decreased serum levels of TG and TC. In conclusion, maternal dietary genistein negates the harmful effects of a maternal high-fat diet on glucose and lipid metabolism in female offspring, in which the altered gut microbiota plays crucial roles. The ability of maternal genistein intake to improve offspring metabolism is important since this intervention could fight the transmission of diabetes to subsequent generations.

Microbial Shifts in the Intestinal Microbiota of Salmonella Infected Chickens in Response to Enrofloxacin

Fluoroquinolones (FQs) are important antibiotics used for treatment of Salmonella infection in poultry in many countries. However, oral administration of fluoroquinolones may affect the composition and abundance of a number of bacterial taxa in the chicken intestine. Using 16S rRNA gene sequencing, the microbial shifts in the gut of Salmonella infected chickens in response to enrofloxacin treatments at different dosages (0, 0.1, 4, and 100 mg/kg b.w.) were quantitatively evaluated. The results showed that the shedding levels of Salmonella were significantly reduced in the high dosage group as demonstrated by both the culturing method and 16S rRNA sequencing method. The average values of diversity indices were higher in the control group than in the three medicated groups. Non-metric multidimensional scaling (NMDS) analysis results showed that the microbial community of high dosage group was clearly separated from the other three groups. In total, 25 genera were significantly enriched (including 6 abundant genera: Lactococcus, Bacillus, Burkholderia, Pseudomonas, Rhizobium, and Acinetobacter) and 23 genera were significantly reduced in the medicated groups than in the control group for the treatment period, but these bacterial taxa recovered to normal levels after therapy withdrawal. Additionally, 5 genera were significantly reduced in both treatment and withdrawal periods (e.g., Blautia and Anaerotruncus) and 23 genera (e.g., Enterobacter and Clostridium) were significantly decreased only in the withdrawal period, indicating that these genera might be the potential targets for the fluoroquinolones antimicrobial effects. Specially, Enterococcus was significantly reduced under high dosage of enrofloxacin treatment, while significantly enriched in the withdrawal period, which was presumably due to the resistance selection. Predicted microbial functions associated with genetic information processing were significantly decreased in the high dosage group. Overall, enrofloxacin at a dosage of 100 mg/kg b.w. significantly altered the microbial community membership and structure, and microbial functions in the chicken intestine during the medication. This study fully investigates the chicken intestinal microbiota in response to enrofloxacin treatment and identifies potential targets against which the fluoroquinolones may have potent antimicrobial effects. These results provide insights into the effects of the usage of enrofloxacin on chicken and will aid in the prudent and rational use of antibiotics in poultry industry.