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Alterations of gut microbiota are associated with blood pressure: a cross-sectional clinical trial in Northwestern China.
Lv, J, Wang, J, Yu, Y, Zhao, M, Yang, W, Liu, J, Zhao, Y, Yang, Y, Wang, G, Guo, L, et al
Journal of translational medicine. 2023;21(1):429
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Hypertension (HTN) is a complex and modifiable risk factor for cardiovascular diseases (CVDs) and stroke, while a diverse range of endogenous and environmental factors contribute to both HTN onset and progression. The adult gut microbiota (GM) consists of trillions of microorganisms and maintains the gut immunity and whole-body homeostasis. The aim of this study was to investigate the GM characteristics in HTN subjects in Northwestern China, and evaluate the associations of GM with blood pressure levels based on sex differences. This study was a cross-sectional study. Participants were randomly selected for the HTN and control groups. A total of 36 HTN subjects (24 females and 12 males) and 18 controls (9 females and 9 males) were randomly selected for metagenomic analysis. Results showed a positive association between GM characteristics and alterations and HTN in both females and males. Thus, GM dysbiosis underlies HTN pathogenesis. Authors conclude that further studies are needed to elucidate the underlying mechanisms and potential therapeutic interventions targeting GM for HTN prevention and management
Abstract
BACKGROUND The human gut microbiota (GM) is involved in the pathogenesis of hypertension (HTN), and could be affected by various factors, including sex and geography. However, available data directly linking GM to HTN based on sex differences are limited. METHODS This study investigated the GM characteristics in HTN subjects in Northwestern China, and evaluate the associations of GM with blood pressure levels based on sex differences. A total of 87 HTN subjects and 45 controls were recruited with demographic and clinical characteristics documented. Fecal samples were collected for 16S rRNA gene sequencing and metagenomic sequencing. RESULTS GM diversity was observed higher in females compared to males, and principal coordinate analysis showed an obvious segregation of females and males. Four predominant phyla of fecal GM included Firmicutes, Bacteroidetes, Actinobacteria and Proteobacteria. LEfSe analysis indicated that phylum unidentified_Bacteria was enriched in HTN females, while Leuconostocaceae, Weissella and Weissella_cibaria were enriched in control females (P < 0.05). Functionally, ROC analysis revealed that Cellular Processes (0.796, 95% CI 0.620 ~ 0.916), Human Diseases (0.773, 95% CI 0.595 ~ 0.900), Signal transduction (0.806, 95% CI 0.631 ~ 0.922) and Two-component system (0.806, 95% CI 0.631 ~ 0.922) could differentiate HTN females as effective functional classifiers, which were also positively correlated with systolic blood pressure levels. CONCLUSIONS This work provides evidence of fecal GM characteristics in HTN females and males in a northwestern Chinese population, further supporting the notion that GM dysbiosis may participate in the pathogenesis of HTN, and the role of sex differences should be considered. Trial registration Chinese Clinical Trial Registry, ChiCTR1800019191. Registered 30 October 2018 - Retrospectively registered, http://www.chictr.org.cn/ .
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Influence of timing of maternal antibiotic administration during caesarean section on infant microbial colonisation: a randomised controlled trial.
Dierikx, T, Berkhout, D, Eck, A, Tims, S, van Limbergen, J, Visser, D, de Boer, M, de Boer, N, Touw, D, Benninga, M, et al
Gut. 2022;71(9):1803-1811
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Early-life microbiome acquisition and development can be compromised by external perturbations such as delivery via caesarean section (CS), formula feeding and antibiotics. Currently, based on revised international guidelines, all infants born by CS are exposed to broad-spectrum antibiotics via the umbilical cord. Even though there was not an increase in the incidence of neonatal sepsis, the effects on the gut microbiota colonisation and long-term health consequences remain largely unknown. The hypothesis for this study was that exposure to antibiotics in children delivered by CS, related to the revised international guidelines, influences the microbial colonisation process and may impact health outcome. This study is a randomised controlled trial on the microbiome and health state of infants up to 3 years of age. The study enrolled women delivering via CS who received antibiotics prior to skin incision (n=20) or after umbilical cord clamping (n=20) and women who had a vaginal delivery (n=23). Results show that CS delivery in general leads to a profound impact on the initial microbial colonisation. Furthermore, maternal antibiotic administration prior to CS does not lead to a ‘second hit’ on the already compromised microbiome in CS born infants. Authors conclude that early-life microbiome development is strongly affected by mode of delivery.
Abstract
OBJECTIVE Revised guidelines for caesarean section (CS) advise maternal antibiotic administration prior to skin incision instead of after umbilical cord clamping, unintentionally exposing the infant to antibiotics antenatally. We aimed to investigate if timing of intrapartum antibiotics contributes to the impairment of microbiota colonisation in CS born infants. DESIGN In this randomised controlled trial, women delivering via CS received antibiotics prior to skin incision (n=20) or after umbilical cord clamping (n=20). A third control group of vaginally delivering women (n=23) was included. Faecal microbiota was determined from all infants at 1, 7 and 28 days after birth and at 3 years by 16S rRNA gene sequencing and whole-metagenome shotgun sequencing. RESULTS Compared with vaginally born infants, profound differences were found in microbial diversity and composition in both CS groups in the first month of life. A decreased abundance in species belonging to the genera Bacteroides and Bifidobacterium was found with a concurrent increase in members belonging to the phylum Proteobacteria. These differences could not be observed at 3 years of age. No statistically significant differences were observed in taxonomic and functional composition of the microbiome between both CS groups at any of the time points. CONCLUSION We confirmed that microbiome colonisation is strongly affected by CS delivery. Our findings suggest that maternal antibiotic administration prior to CS does not result in a second hit on the compromised microbiome. Future, larger studies should confirm that antenatal antibiotic exposure in CS born infants does not aggravate colonisation impairment and impact long-term health.
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Effect of Hesperidin on Cardiovascular Disease Risk Factors: The Role of Intestinal Microbiota on Hesperidin Bioavailability.
Mas-Capdevila, A, Teichenne, J, Domenech-Coca, C, Caimari, A, Del Bas, JM, Escoté, X, Crescenti, A
Nutrients. 2020;12(5)
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Cardiovascular diseases (CVDs) cause around 31% of all deaths worldwide. Certain dietary patterns have been associated with a reduction in CVDs and so the use of natural-based products has gained importance as a preventive strategy. Hesperidin is a bioactive compound found in high levels in citrus fruits. The reported beneficial properties include antitumor, antioxidant, anti-inflammatory; cholesterol and glucose lowering effects. Many animal studies show multiple beneficial effects but are inconclusive in human studies. The aim of this review is to describe the effects of hesperidin on CVD factors and to highlight the individual differences in its bioavailability and effectiveness. The gut bacteria play an important role in this. Hesperidin is not broken down by the normal digestive process and reaches the colon largely intact. It is the job of the gut bacteria to break it down into bioavailable substances that can be absorbed and utilised. The discrepancies observed in some of the results from human clinical trials may be partly due to individual differences, including that of the gut bacteria. Further clinical trials should be considered as well as classifying individuals according to individual differences in metabotypes.
Abstract
Recently, hesperidin, a flavonone mainly present in citrus fruits, has emerged as a new potential therapeutic agent able to modulate several cardiovascular diseases (CVDs) risk factors. Animal and in vitro studies demonstrate beneficial effects of hesperidin and its derived compounds on CVD risk factors. Thus, hesperidin has shown glucose-lowering and anti-inflammatory properties in diabetic models, dyslipidemia-, atherosclerosis-, and obesity-preventing effects in CVDs and obese models, and antihypertensive and antioxidant effects in hypertensive models. However, there is still controversy about whether hesperidin could contribute to ameliorate glucose homeostasis, lipid profile, adiposity, and blood pressure in humans, as evidenced by several clinical trials reporting no effects of treatments with this flavanone or with orange juice on these cardiovascular parameters. In this review, we focus on hesperidin's beneficial effects on CVD risk factors, paying special attention to the high interindividual variability in response to hesperidin-based acute and chronic interventions, which can be partly attributed to differences in gut microbiota. Based on the current evidence, we suggest that some of hesperidin's contradictory effects in human trials are partly due to the interindividual hesperidin variability in its bioavailability, which in turn is highly dependent on the α-rhamnosidase activity and gut microbiota composition.
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The Role of Glutamine in the Complex Interaction between Gut Microbiota and Health: A Narrative Review.
Perna, S, Alalwan, TA, Alaali, Z, Alnashaba, T, Gasparri, C, Infantino, V, Hammad, L, Riva, A, Petrangolini, G, Allegrini, P, et al
International journal of molecular sciences. 2019;20(20)
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Glutamine is an amino acid, one of the building blocks of protein, and is the most abundant free amino acid in the body. Research shows that glutamine plays an important role in digestive health and immunity by supporting the integrity of the intestinal lining and suppressing inflammation. This review looks at glutamine and its mechanism on gut microbiota; the commensal bacteria which populate the gastro-intestinal tract. Glutamine supplementation was shown to beneficially affect the composition of gut bacteria in obese and overweight subjects, reduce bacterial overgrowth and more specifically reduce harmful strains of Clostridium spp. and Helicobacter spp. The subsequent increase in intestinal-friendly microbiota after supplementation aided symptoms of constipation. This same mechanism may help prevent bacterial infections in chemotherapy cancer patients which is a common side effect of the treatment. Glutamine also supports immune cell activity. White blood cells were shown to use a four-fold amount of glutamine versus glucose. There are indications of glutamine-mediated crosstalk between intestinal microbes and the immune system and that glutamine appears to be helpful in patients with severe digestive disturbances as well as metabolic stress, trauma, infection, burns and muscle-wastage.
Abstract
The scientific literature has demonstrated that glutamine is one of the main beneficial amino acids. It plays an important role in gut microbiota and immunity. This paper provides a critical overview of experimental studies (in vitro, in vivo, and clinical) investigating the efficacy of glutamine and its effect on gut microbiota. As a result of this review, we have summarized that glutamine could affect gut microbiota via different mechanisms including the reduction in the ratio of Firmicutes to Bacteroidetes, with the activation of NF-κB and PI3K-Akt pathways, reducing the intestinal colonization (Eimeria lesions) and bacterial overgrowth or bacterial translocation, increasing the production of secretory immunoglobulin A (SIgA) and immunoglobulin A+ (IgA+) cells in the intestinal lumen, and decreasing asparagine levels. The potential applications of glutamine on gut microbiota include, but are not limited to, the management of obesity, bacterial translocation and community, cytokines profiles, and the management of side effects during post-chemotherapy and constipation periods. Further studies and reviews are needed regarding the effects of glutamine supplementation on other conditions in humans.
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Inflammageing: chronic inflammation in ageing, cardiovascular disease, and frailty.
Ferrucci, L, Fabbri, E
Nature reviews. Cardiology. 2018;15(9):505-522
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Inflammageing is a term used to describe elevated blood inflammatory markers that leads to frailty and increases an individual’s risk for heart disease, kidney disease and other physical and mental illnesses. Whether inflammageing is causal in heart disease is still uncertain. This large review of 310 papers aimed to understand the causes and role of inflammageing in heart disease and other illnesses associated with ageing. Causes of inflammageing were discussed and mechanisms are not fully understood. Genetic susceptibility, obesity, gut microbiota, gut permeability, when cells can no longer divide, and chronic infections were all implicated. The role of inflammageing in heart disease was a focus and the authors deduced that it was likely to be both causal and a result of heart disease. However, the administration of anti-inflammatories in heart disease has not always proved a successful treatment. Possible causes of inflammageing are likely to be linked and cumulative and although inflammation may cause age related diseases, its role in protecting the body means that its benefits outweigh its consequences. It was concluded that controlling inflammageing may prevent heart disease and other diseases associated with ageing. This study could be used by healthcare professionals to help understand what inflammageing is and its role in age related diseases.
Abstract
Most older individuals develop inflammageing, a condition characterized by elevated levels of blood inflammatory markers that carries high susceptibility to chronic morbidity, disability, frailty, and premature death. Potential mechanisms of inflammageing include genetic susceptibility, central obesity, increased gut permeability, changes to microbiota composition, cellular senescence, NLRP3 inflammasome activation, oxidative stress caused by dysfunctional mitochondria, immune cell dysregulation, and chronic infections. Inflammageing is a risk factor for cardiovascular diseases (CVDs), and clinical trials suggest that this association is causal. Inflammageing is also a risk factor for chronic kidney disease, diabetes mellitus, cancer, depression, dementia, and sarcopenia, but whether modulating inflammation beneficially affects the clinical course of non-CVD health problems is controversial. This uncertainty is an important issue to address because older patients with CVD are often affected by multimorbidity and frailty - which affect clinical manifestations, prognosis, and response to treatment - and are associated with inflammation by mechanisms similar to those in CVD. The hypothesis that inflammation affects CVD, multimorbidity, and frailty by inhibiting growth factors, increasing catabolism, and interfering with homeostatic signalling is supported by mechanistic studies but requires confirmation in humans. Whether early modulation of inflammageing prevents or delays the onset of cardiovascular frailty should be tested in clinical trials.
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Gut microbiota varies by opioid use, circulating leptin and oxytocin in African American men with diabetes and high burden of chronic disease.
Barengolts, E, Green, SJ, Eisenberg, Y, Akbar, A, Reddivari, B, Layden, BT, Dugas, L, Chlipala, G
PloS one. 2018;13(3):e0194171
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Obesity and type 2 diabetes (T2D) can lead to alterations of the composition of the gut microbiota. The gut microbiota, in turn, has been suggested to play a role in the development of psychological conditions, such as anxiety, depression and drug addiction. This cross-sectional study included 99 mostly overweight/obese African American men, with or without T2D, and with or without opioid addiction and other psychiatric disorders. The aim of the study was to determine, whether the gut microbiota composition was linked to T2D and the use of opioids in these patients. Furthermore, the researchers looked at the associations between leptin and oxytocin levels in the blood and the gut microbiota, and whether these hormone biomarkers could be indicative of obesity and psychosocial behaviour, such as opioid addiction. The authors found that some bacterial species in the gut were affected by T2D, diabetes medication and opioid use in the studied subjects. A relationship was also observed between leptin and oxytocin levels and the abundance of certain bacteria in the gut in subjects without T2D. The authors conclude that targeting the gut microbiota could be used for the management of T2D and associated psychiatric disorders. However, more studies are needed to provide further understanding of the connections between the gut microbiota and the brain.
Abstract
OBJECTIVE The gut microbiota is known to be related to type 2 diabetes (T2D), psychiatric conditions, and opioid use. In this study, we tested the hypothesis that variability in gut microbiota in T2D is associated with psycho-metabolic health. METHODS A cross-sectional study was conducted among African American men (AAM) (n = 99) that were outpatients at a Chicago VA Medical Center. The main outcome measures included fecal microbiota ecology (by 16S rRNA gene sequencing), psychiatric disorders including opioid use, and circulating leptin and oxytocin as representative hormone biomarkers for obesity and psychological pro-social behavior. RESULTS The study subjects had prevalent overweight/obesity (78%), T2D (50%) and co-morbid psychiatric (65%) and opioid use (45%) disorders. In the analysis of microbiota, the data showed interactions of opioids, T2D and metformin with Bifidobacterium and Prevotella genera. The differential analysis of Bifidobacterium stratified by opioids, T2D and metformin, showed significant interactions among these factors indicating that the effect of one factor was changed by the other (FDR-adjusted p [q] < 0.01). In addition, the pair-wise comparison showed that participants with T2D not taking metformin had a significant 6.74 log2 fold increase in Bifidobacterium in opioid users as compared to non-users (q = 2.2 x 10-8). Since metformin was not included in this pair-wise comparison, the significant 'q' suggested association of opioid use with Bifidobacterium abundance. The differences in Bifidobacterium abundance could possibly be explained by opioids acting as organic cation transporter 1 (OCT1) inhibitors. Analysis stratified by lower and higher leptin and oxytocin (divided by the 50th percentile) in the subgroup without T2D showed lower Dialister in High-Leptin vs. Low-Leptin (p = 0.03). Contrary, the opposite was shown for oxytocin, higher Dialister in High-Oxytocin vs. Low-Oxytocin (p = 0.04). CONCLUSIONS The study demonstrated for the first time that Bifidobacterium and Prevotella abundance was affected by interactions of T2D, metformin and opioid use. Also, in subjects without T2D Dialister abundance varied according to circulating leptin and oxytocin.
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Disruption of the Gut Ecosystem by Antibiotics.
Yoon, MY, Yoon, SS
Yonsei medical journal. 2018;59(1):4-12
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The gut microbiome is a complex ecosystem of different micro-organisms, such as bacteria, viruses and fungi, living in the human intestines. It’s involved in numerous functions, such as extracting energy and nutrition from food, protecting against disease-causing microorganisms, and supporting the immune system of the host, and therefore affecting human health and disease. This paper is a review of studies on the effects of antibiotics on the gut microbiota. It outlines how different types of antibiotics can alter the intestinal environment and the composition of the microbes, resulting in various physiological changes that can trigger disease. Relevant mechanisms, such as inflammatory response and the use of intestinal nutrients by infectious bacteria are discussed. Finally, it discusses faecal microbiota transplantation (FMT) and probiotics as treatment approaches, aimed at restoring a disturbed intestinal environment.
Abstract
The intestinal microbiota is a complex ecosystem consisting of various microorganisms that expands human genetic repertoire and therefore affects human health and disease. The metabolic processes and signal transduction pathways of the host and intestinal microorganisms are intimately linked, and abnormal progression of each process leads to changes in the intestinal environment. Alterations in microbial communities lead to changes in functional structures based on the metabolites produced in the gut, and these environmental changes result in various bacterial infections and chronic enteric inflammatory diseases. Here, we illustrate how antibiotics are associated with an increased risk of antibiotic-associated diseases by driving intestinal environment changes that favor the proliferation and virulence of pathogens. Understanding the pathogenesis caused by antibiotics would be a crucial key to the treatment of antibiotic-associated diseases by mitigating changes in the intestinal environment and restoring it to its original state.
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Gut Microbiota-Immune System Crosstalk and Pancreatic Disorders.
Pagliari, D, Saviano, A, Newton, EE, Serricchio, ML, Dal Lago, AA, Gasbarrini, A, Cianci, R
Mediators of inflammation. 2018;2018:7946431
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Gut microbiota homeostasis plays a central role in modulating the mucosal immune system. Increasing research has shown a correlation between an imbalanced gut microbiota, called dysbiosis, and various pancreatic disorders. The aim of this review was to analyse current data linking the gut microbiome and several pancreatic disorders. The current evidence demonstrates gut dysbiosis is correlated with the duration and prognosis of pancreatic disorders. While this may lead to early detection of several pancreatic disorders, it remains unclear whether dysbiosis is a cause or effect of pancreatic disorders. Based on these results, the authors conclude future studies are required to better understand the crosstalk between gut microbiota and the immune system to improve diagnostic and treatment strategies for pancreatic disorders.
Abstract
Gut microbiota is key to the development and modulation of the mucosal immune system. It plays a central role in several physiological functions, in the modulation of inflammatory signaling and in the protection against infections. In healthy states, there is a perfect balance between commensal and pathogens, and microbiota and the immune system interact to maintain gut homeostasis. The alteration of such balance, called dysbiosis, determines an intestinal bacterial overgrowth which leads to the disruption of the intestinal barrier with systemic translocation of pathogens. The pancreas does not possess its own microbiota, and it is believed that inflammatory and neoplastic processes affecting the gland may be linked to intestinal dysbiosis. Increasing research evidence testifies a correlation between intestinal dysbiosis and various pancreatic disorders, but it remains unclear whether dysbiosis is the cause or an effect. The analysis of specific alterations in the microbiome profile may permit to develop novel tools for the early detection of several pancreatic disorders, utilizing samples, such as blood, saliva, and stools. Future studies will have to elucidate the mechanisms by which gut microbiota is modulated and how it tunes the immune system, in order to be able to develop innovative treatment strategies for pancreatic disorders.
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Prenatal and postnatal antibiotic exposure influences the gut microbiota of preterm infants in neonatal intensive care units.
Zou, ZH, Liu, D, Li, HD, Zhu, DP, He, Y, Hou, T, Yu, JL
Annals of clinical microbiology and antimicrobials. 2018;17(1):9
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Disturbances in gut bacteria could have long-term effects on a baby’s health. The development of healthy gut bacteria is influenced by factors such as the surrounding environment, gestational age, delivery mode, feeding method and exposure to antibiotics. The aim of this study was to investigate the effects of antibiotic exposure on the development of gut bacteria in premature babies. This study was carried out in a hospital in China. 28 premature babies who had been admitted to the neonatal intensive care unit were included in the study. Stool samples were collected when the babies were 7 and 14 days old. The researchers found that the characteristics of the gut bacteria in babies exposed to antibiotics was different to those who were not. The numbers of beneficial Bifidobacterium were significantly lower in those babies who had received antibiotics compared to those who had not. Exposure to antibiotics for more than 7 days led to increases in the presence of some strains of drug-resistant bacteria. The authors concluded that antibiotic exposure may affect the composition of early gut bacteria in premature babies which could potentially increase the risk of contracting harmful infections.
Abstract
BACKGROUND To explore the influences of prenatal antibiotic exposure, the intensity of prenatal and postnatal antibiotic exposure on gut microbiota of preterm infants and whether gut microbiota and drug resistant strains in the neonatal intensive care unit (NICU) over a defined period are related. METHODS Among 28 preterm infants, there were two groups, the PAT (prenatal antibiotic therapy) group (12 cases), and the PAF (prenatal antibiotic free) group (12 cases). Fecal samples from both groups were collected on days 7 and 14. According to the time of prenatal and postnatal antibiotic exposure, cases were divided into two groups, H (high) group (11 cases) and L (low) group (11 cases), and fecal samples on day 14 were collected. Genomic DNA was extracted from the fecal samples and was subjected to high throughput 16S rRNA amplicon sequencing. Bioinformatics methods were used to analyze the sequencing results. RESULTS Prenatal and postnatal antibiotic exposure exercised influence on the early establishment of intestinal microflora of preterm infants. Bacteroidetes decreased significantly in the PAT group (p < 0.05). The number of Bifidobacterium significantly decreased in the PAT group and H group (p < 0.05). The early gut microbiota of preterm infants with prenatal and postnatal antibiotic exposure was similar to resistant bacteria in NICU during the same period. CONCLUSION Prenatal and postnatal antibiotic exposure may affect the composition of early gut microbiota in preterm infants. Antibiotic-resistant bacteria in NICU may play a role in reshaping the early gut microbiota of preterm infants with prenatal and postnatal antibiotic exposure.
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Association between duration of intravenous antibiotic administration and early-life microbiota development in late-preterm infants.
Zwittink, RD, Renes, IB, van Lingen, RA, van Zoeren-Grobben, D, Konstanti, P, Norbruis, OF, Martin, R, Groot Jebbink, LJM, Knol, J, Belzer, C
European journal of clinical microbiology & infectious diseases : official publication of the European Society of Clinical Microbiology. 2018;37(3):475-483
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Premature newborn babies are commonly given antibiotics in hospital to prevent or treat infections such as sepsis. This study, carried out in the Netherlands, looked at the effect of intravenous antibiotics on the development of the gut bacteria in premature babies. Stool samples were taken from 15 premature babies who had been exposed to either no antibiotic treatment, or short (less than 3 days) or long (at least 5 days) treatment with the commonly prescribed antibiotics amoxicillin or ceftazidime. At 3 weeks old, babies who had been treated with both short and long courses of antibiotics had significantly lower abundance of the beneficial bacteria Bifidobacterium than those who had received no antibiotics. In babies who received antibiotic treatment lasting 5 days or more, Bifidobacterium levels didn’t recover until they were 6 weeks old. Antibiotics were effective against Enterobacteriaceae, but allowed Enterococcus to thrive and remain dominant for up to two weeks after antibiotic treatment was stopped. The authors concluded that intravenous antibiotics during the first week of a baby’s life greatly affects the gut bacteria. However, short courses of antibiotics allow for a quicker recovery compared to longer courses. Disturbances in the development of gut bacteria caused by antibiotic treatment could influence the development of infants' immune and digestive systems.
Abstract
Antibiotic treatment is common practice in the neonatal ward for the prevention and treatment of sepsis, which is one of the leading causes of mortality and morbidity in preterm infants. Although the effect of antibiotic treatment on microbiota development is well recognised, little attention has been paid to treatment duration. We studied the effect of short and long intravenous antibiotic administration on intestinal microbiota development in preterm infants. Faecal samples from 15 preterm infants (35 ± 1 weeks gestation and 2871 ± 260 g birth weight) exposed to no, short (≤ 3 days) or long (≥ 5 days) treatment with amoxicillin/ceftazidime were collected during the first six postnatal weeks. Microbiota composition was determined through 16S rRNA gene sequencing and by quantitative polymerase chain reaction (qPCR). Short and long antibiotic treat ment significantly lowered the abundance of Bifidobacterium right after treatment (p = 0.027) till postnatal week three (p = 0.028). Long treatment caused Bifidobacterium abundance to remain decreased till postnatal week six (p = 0.009). Antibiotic treatment was effective against members of the Enterobacteriaceae family, but allowed Enterococcus to thrive and remain dominant for up to two weeks after antibiotic treatment discontinuation. Community richness and diversity were not affected by antibiotic treatment, but were positively associated with postnatal age (p < 0.023) and with abundance of Bifidobacterium (p = 0.003). Intravenous antibiotic administration during the first postnatal week greatly affects the infant's gastrointestinal microbiota. However, quick antibiotic treatment cessation allows for its recovery. Disturbances in microbiota development caused by short and, more extensively, by long antibiotic treatment could affect healthy development of the infant via interference with maturation of the immune system and gastrointestinal tract.