Background Human milk oligosaccharides (HMOs) have important and diverse biological functions in ... more Background Human milk oligosaccharides (HMOs) have important and diverse biological functions in early life. This study tested the safety and efficacy of a starter infant formula containing Limosilactobacillus (L.) reuteri DSM 17938 and supplemented with 2’-fucosyllactose (2’FL). Methods Healthy infants < 14 days old (n = 289) were randomly assigned to a bovine milk-based formula containing L. reuteri DSM 17938 at 1 × 107 CFU/g (control group; CG) or the same formula with added 1.0 g/L 2’FL (experimental group; EG) until 6 months of age. A non-randomized breastfed group served as reference (BF; n = 60). The primary endpoint was weight gain through 4 months of age in the formula-fed infants. Secondary endpoints included additional anthropometric measures, gastrointestinal tolerance, stooling characteristics, adverse events (AEs), fecal microbiota and metabolism, and gut immunity and health biomarkers in all feeding groups. Results Weight gain in EG was non-inferior to CG as shown ...
There is a growing prevalence of sleep problems and insomnia worldwide, urging the development of... more There is a growing prevalence of sleep problems and insomnia worldwide, urging the development of new treatments to tackle this increase. Several studies have suggested that the gut microbiome might influence sleep quality. The gut microbiome affects the host’s health via the production of metabolites and compounds with neuroactive and immunomodulatory properties, which include short-chain fatty acids, secondary bile acids and neurotransmitters. Several of these metabolites and compounds are independently known as wakefulness-promoting (serotonin, epinephrine, dopamine, orexin, histamine, acetylcholine, cortisol) or sleep-promoting (gamma-aminobutyric acid, melatonin). The primary aim of this review was to evaluate the potential of pro-, pre- and postbiotic treatments to improve sleep quality. Additionally, we aimed to evaluate whether each of the treatments could ameliorate stress and anxiety, which are known to bidirectionally correlate with sleep problems. Lastly, we provided a m...
Prevalence of anaemia among Nigerian toddlers is reported to be high, and may cause significant m... more Prevalence of anaemia among Nigerian toddlers is reported to be high, and may cause significant morbidity, affects brain development and function, and results in weakness and fatigue. Although, iron fortification can reduce anaemia, yet the effect on gut microbiota is unclear. This open-label randomised study in anaemic malnourished Nigerian toddlers aimed to decrease anaemia without affecting pathogenic gut bacteria using a multi-nutrient fortified dairy-based drink. The test product was provided daily in different amounts (200, 400 or 600 mL, supplying 2.24, 4.48 and 6.72 mg of elemental iron, respectively) for 6 months. Haemoglobin, ferritin, and C-reactive protein concentrations were measured to determine anaemia, iron deficiency (ID) and iron deficiency anaemia (IDA) prevalence. Faecal samples were collected to analyse gut microbiota composition. All three dosages reduced anaemia prevalence, to 47%, 27% and 18%, respectively. ID and IDA prevalence was low and did not significan...
Infectious diseases are a major cause of morbidity and mortality worldwide. Nutritional intervent... more Infectious diseases are a major cause of morbidity and mortality worldwide. Nutritional interventions may enhance resistance to infectious diseases or help to reduce clinical symptoms. Here, we investigated whether a whey protein concentrate (WPC) could decrease diarrheagenic Escherichia coli-induced changes in reported stool frequency and gastrointestinal complaints in a double-blind, parallel 4-week intervention study. Subjects were randomly assigned to a whey hydrolysate placebo group, a low-dose WPC group or a high-dose WPC group. After 2 weeks of consumption, subjects (n = 121) were orally infected with a high dose of live but attenuated diarrheagenic E. coli (strain E1392/75-2A; 1E10 colony-forming units). Subjects recorded information on stool consistency and the frequency and severity of symptoms in an online diary. The primary outcome parameters were a change in stool frequency (stools per day) and a change in Gastrointestinal Symptom Rating Scale (GSRS) diarrhea score betw...
Specialty section: This article was submitted to Microbial Physiology and Metabolism, a section o... more Specialty section: This article was submitted to Microbial Physiology and Metabolism, a section of the journal
Purpose Adverse effects of iron fortification/supplements such as Micronutrient Powder (MNP) on g... more Purpose Adverse effects of iron fortification/supplements such as Micronutrient Powder (MNP) on gut microbiota have previously been found in infection-prone African settings. This study examined the adversaries of a low-iron MNP compared with the standard MNP on the composition of gut microbiota in Bangladeshi children exposed to a high concentration of iron from potable groundwater. Methods A randomized controlled trial was conducted in 2- to 5-year-old children, drinking groundwater with a high concentration of iron (≥ 2 mg/L). Children were randomized to receive one sachet per day of either standard MNP (12.5 mg iron) or low-iron MNP (5 mg iron), for 2 months. A sub-sample of 53 children was considered for paired assessment of the gut microbiome by 16S rRNA amplicon sequencing. Results At baseline, the gut microbiota consisted of Bifidobacteriaceae (15.6%), Prevotellaceae (12.2%), Lactobacillaceae (3.6%), Clostridiaceae (4.1%) and Enterobacteriaceae (2.8%). Overall, there was no ...
During aging of human skin, a number of intrinsic and extrinsic factors cause the alteration of t... more During aging of human skin, a number of intrinsic and extrinsic factors cause the alteration of the skin’s structure, function and cutaneous physiology. Many studies have investigated the influence of the skin microbiome on these alterations, but the molecular mechanisms that dictate the interplay between these factors and the skin microbiome are still not fully understood. To obtain more insight into the connection between the skin microbiome and the human physiological processes involved in skin aging, we performed a systematic study on interconnected pathways of human and bacterial metabolic processes that are known to play a role in skin aging. The bacterial genes in these pathways were subsequently used to create Hidden Markov Models (HMMs), which were applied to screen for presence of defined functionalities in both genomic and metagenomic datasets of skin-associated bacteria. These models were further applied on 16S rRNA gene sequencing data from skin microbiota samples deriv...
Background Bovine milk-derived oligosaccharides (MOS) containing primarily galacto-oligosaccharid... more Background Bovine milk-derived oligosaccharides (MOS) containing primarily galacto-oligosaccharides with inherent concentrations of sialylated oligosaccharides can be added to infant formula to enhance the oligosaccharide profile. Objective To investigate the effects of an MOS-supplemented infant formula on gut microbiota and intestinal immunity. Methods In a double-blind, randomized, controlled trial, healthy term formula-fed infants aged 21–26 d either received an intact protein cow milk-based formula (control group, CG, n = 112) or the same formula containing 7.2 g MOS/L (experimental group, EG, n = 114) until the age of 6 mo. Exclusively human milk-fed infants (HFI, n = 70) from an observational study served as the reference. Fecal samples collected at baseline, and the ages of 2.5 and 4 mo were assessed for microbiota (16S ribosomal RNA-based approaches), metabolites, and biomarkers of gut health and immune response. Results Aged 2.5 and 4 mo, redundancy analysis (P = 0.002) an...
People experiencing sleep problems may benefit from nutrients supporting serotonin metabolism and... more People experiencing sleep problems may benefit from nutrients supporting serotonin metabolism and stress reduction. We studied the effect of a dairy-based product (DP) containing protein, galacto-oligosaccharides, vitamins and minerals, on sleep quality, stress, and gut-microbiota. In a cross-over RCT (three weeks intervention; three weeks washout), adults (n = 70; 30–50 y) with sleep disturbances (Pittsburgh Sleep Quality Index (PSQI) ≥ 9) consumed products 1 h before bed-time. Sleep quality (PSQI) was measured weekly, stress at base- and end-line (Depression Anxiety Stress Scale and saliva cortisol). Fecal samples were collected in the 1st intervention period only. Compared to placebo (skimmed milk), PSQI was only lower at day 14 in the 2nd intervention period in intention-to-treat (ITT) (p = 0.017; n = 69) and per-protocol (PP) (p = 0.038; n = 64) analyses. Post-hoc analysis (modified-PP: n=47, with baseline PSQI ≥ 9, and endline day 14), however, showed a decrease in PSQI (−1.60...
Background: Bioactive proteins and human milk oligosaccharides (HMOs), important ingredients in b... more Background: Bioactive proteins and human milk oligosaccharides (HMOs), important ingredients in breastmilk, that protect against infections are lacking in young child formula (YCF). This study investigated the effects of new YCFs on respiratory and gastrointestinal infections in toddlers. Methods: 461 healthy Chinese children aged 1-2.5 years were recruited in this randomized, controlled, double-blind, parallel-group clinical trial of different YCFs. They were randomly assigned to either standard milk formula (YCF-Ref) or one of three new YCFs containing bioactive proteins and/or the HMO 2'-fucosyllactose (2'-FL) and/or milk fat for six months. Primary outcomes were incidence of upper respiratory tract infection (URTI) and duration of gastrointestinal tract infections (GITI). Results: There were no significant between-group differences in primary outcomes. For secondary outcomes, subjects receiving 2'-FL-supplemented YCF had longer URTI. Subjects receiving YCF supplemented with milk fat and intact bioactive proteins, and 2'-FL at levels found in breastmilk, had more GITI episodes and shorter time to first GITI but similar effects on URTI duration than YCF-Ref recipients. No effects on URTI and GITI were observed in toddlers receiving YCF with bioactive proteins at lower levels than breastmilk. Occurrence of adverse events and anthropometry were similar in all groups. Conclusions: All three YCFs supplemented with different combinations of intact bioactive proteins, 2'-FL and milk fat are safe in toddlers. No difference is detected among YCFs on URTI incidence and GITI duration. Further studies are needed to verify these findings especially in infants who may benefit most from the immune-boosting effects of bioactive proteins and HMOs.
There is little data on human milk oligosaccharide (HMO) composition in Sub-Saharan Africa. Iron ... more There is little data on human milk oligosaccharide (HMO) composition in Sub-Saharan Africa. Iron fortificants adversely affect the infant gut microbiota, while co-provision of prebiotic galacto-oligosaccharides (GOS) mitigates most of the adverse effects. Whether variations in maternal HMO profile can influence the infant response to iron and/or GOS fortificants is unknown. The aim of this study was to determine HMO profiles and the secretor/non-secretor phenotype of lactating Kenyan mothers and investigate their effects on the maternal and infant gut microbiota, and on the infant response to a fortification intervention with 5 mg iron (2.5 mg as sodium iron ethylenediaminetetraacetate and 2.5 mg as ferrous fumarate) and 7.5 g GOS. We studied mother–infant pairs (n = 80) participating in a 4-month intervention trial in which the infants (aged 6.5–9.5 months) received daily a micronutrient powder without iron, with iron or with iron and GOS. We assessed: (1) maternal secretor status ...
Proton pump inhibitors (PPIs) are used by millions of patients for the treatment of stomach acid-... more Proton pump inhibitors (PPIs) are used by millions of patients for the treatment of stomach acid-reflux diseases. Although PPIs are generally considered safe, about 13% of the users develop hypomagnesemia. Despite rising attention for this issue, the underlying mechanism is still unknown. Here, we examine whether the gut microbiome is involved in the development of PPI-induced hypomagnesemia in wild-type C57BL/6J mice. After 4 wk of treatment under normal or low dietary Mg 2+ availability, omeprazole significantly reduced serum Mg 2+ levels only in mice on a low-Mg 2+ diet without affecting the mRNA expression of colonic or renal Mg 2+ transporters. Overall, 16S rRNA gene sequencing revealed a lower gut microbial diversity in omeprazole-treated mice. Omeprazole induced a shift in microbial composition, which was associated with a 3-and 2-fold increase in the abundance of Lactobacillus and Bifidobacterium, respectively. To examine the metabolic consequences of these microbial alterations, the colonic composition of organic acids was evaluated. Low dietary Mg 2+ intake, independent of omeprazole treatment, resulted in a 10-fold increase in formate levels. Together, these results imply that both omeprazole treatment and low dietary Mg 2+ intake disturb the gut internal milieu and may pose a risk for the malabsorption of Mg 2+ in the colon.-Gommers, L.
ObjectiveMany African infants receiving iron fortificants also receive antibiotics. Antibiotic ef... more ObjectiveMany African infants receiving iron fortificants also receive antibiotics. Antibiotic efficacy against enteropathogens may be modified by high colonic iron concentrations. In this study, we evaluated the effect of antibiotics on the infant gut microbiome and diarrhoea when given with or without iron-containing micronutrient powders (MNPs).DesignIn a controlled intervention trial, four groups of community-dwelling infants (n=28; aged 8–10 months) received either: (A) antibiotics for 5 days and iron-MNPs for 40 days (Fe+Ab+); (B) antibiotics and no-iron-MNPs (Fe−Ab+); (C) no antibiotics and iron-MNPs (Fe+Ab−); or (D) no antibiotics and no-iron-MNPs (Fe−Ab−). We collected a faecal sample before the first antibiotic dose (D0) and after 5, 10, 20 and 40 days (D5–D40) to assess the gut microbiome composition by 16S profiling, enteropathogens by quantitative PCR, faecal calprotectin and pH and assessed morbidity over the 40-day study period.ResultsIn Fe+Ab+, there was a decrease i...
Objective Iron-containing micronutrient powders (MNPs) reduce anaemia in African infants, but the... more Objective Iron-containing micronutrient powders (MNPs) reduce anaemia in African infants, but the current high iron dose (12.5 mg/day) may decrease gut Bifidobacteriaceae and Lactobacillaceae, and increase enteropathogens, diarrhoea and respiratory tract infections (RTIs). We evaluated the efficacy and safety of a new MNP formula with prebiotic galactooligosaccharides (GOS) combined with a low dose (5 mg/ day) of highly bioavailable iron. Design In a 4-month, controlled, double-blind trial, we randomised Kenyan infants aged 6.5-9.5 months (n=155) to receive daily (1) a MNP without iron (control); (2) the identical MNP but with 5 mg iron (2.5 mg as sodium iron ethylenediaminetetraacetate and 2.5 mg as ferrous fumarate) (Fe group); or (3) the identical MNP as the Fe group but with 7.5 g GOS (FeGOS group). results Anaemia decreased by ≈50% in the Fe and FeGOS groups (p<0.001). Compared with the control or FeGOS group, in the Fe group there were (1) lower abundances of Bifidobacterium and Lactobacillus and higher abundances of Clostridiales (p<0.01); (2) higher abundances of virulence and toxin genes (VTGs) of pathogens (p<0.01); (3) higher plasma intestinal fatty acid-binding protein (a biomarker of enterocyte damage) (p<0.05); and (4) a higher incidence of treated RTIs (p<0.05). In contrast, there were no significant differences in these variables comparing the control and FeGOS groups, with the exception that the abundance of VTGs of all pathogens was significantly lower in the FeGOS group compared with the control and Fe groups (p<0.01). conclusion A MNP containing a low dose of highly bioavailable iron reduces anaemia, and the addition of GOS mitigates most of the adverse effects of iron on the gut microbiome and morbidity in African infants. trial registration number NCT02118402. IntrODuctIOn The WHO estimates that 62.3% of preschool children in Africa are anaemic, 1 of which ≈50% is attributable to iron deficiency anaemia (IDA). 2 Iron-containing micronutrient powders (MNPs) added to complementary foods effectively reduce IDA in infants, a strategy described as 'in-home fortification'. 3 However, current MNPs contain a high iron dose (12.5 mg) that is equivalent to the dose provided by oral iron supplements for the treatment of IDA in infancy. 3 The safety of these MNPs is uncertain, 4 5 as recent MNP trials (12.5 mg iron/day) in infants reported increases in diarrhoea and respiratory tract infections (RTIs). 6 7 Iron Gut microbiota
The establishment of the infant gut microbiota is a highly dynamic process dependent on extrinsic... more The establishment of the infant gut microbiota is a highly dynamic process dependent on extrinsic and intrinsic factors. We characterized the faecal microbiota of 4 breastfed infants and 4 formula-fed infants at 17 consecutive time points during the first 12 weeks of life. Microbiota composition was analysed by a combination of 16S rRNA gene sequencing and quantitative PCR (qPCR). In this dataset, individuality was a major driver of microbiota composition (P = 0.002) and was more pronounced in breastfed infants. A developmental signature could be distinguished, characterized by sequential colonisation of i) intrauterine/vaginal birth associated taxa, ii) skin derived taxa and other typical early colonisers such as Streptococcus and Enterobacteriaceae, iii) domination of Bifidobacteriaceae, and iv) the appearance of adultlike taxa, particularly species associated with Blautia, Eggerthella, and the potential pathobiont Clostridium difficile. Low abundance of potential pathogens was de...
Patients with chronic kidney disease (CKD) and loss of kidney function are at increased risk for ... more Patients with chronic kidney disease (CKD) and loss of kidney function are at increased risk for morbidity and mortality. The risks of CKD are attributed to "uremia," an increased concentration of uremic retention solutes (toxins) in the plasma. Recently, a colo-renal axis became clearly apparent and uremia has been associated with an altered gut microbiome composition and metabolism. There is a high prevalence of anemia in patients with CKD, for which patients are often treated with oral or intravenous iron. Recent in vivo and in vitro studies have reported adverse effects of oral iron supplementation on the gut microbiota composition, gut metabolome, and intestinal health, which in turn may result in an increased production of uremic toxins. It may also affect circulating levels of other microbe-derived molecules, that can act as mediators of immune regulation. Changes in body iron levels have also been reported to exert subtle effects on host immune function by modulating immune cell proliferation and differentiation, and by directly regulating cytokine formation and antimicrobial immune effector mechanisms. Based on the foregoing it is conceivable that oral iron supplementation in iron deficient predialysis CKD patients adversely changes gut microbiota composition, the gut and systemic metabolome, and host immunity and infection. Future studies are needed to confirm these hypotheses and to assess whether, compared to IV iron supplementation, oral iron supplementation negatively impacts on morbidity of CKD, and whether these adverse effects depend on the iron bioavailability of the iron formulation to the microbiota.
Oral iron administration in African children can increase the risk for infections. However, it re... more Oral iron administration in African children can increase the risk for infections. However, it remains unclear to what extent supplementary iron affects the intestinal microbiome. We here explored the impact of iron preparations on microbial growth and metabolism in the well-controlled TNO's in vitro model of the large intestine (TIM-2). The model was inoculated with a human microbiota, without supplementary iron, or with 50 or 250 µmol/L ferrous sulfate, 50 or 250 µmol/L ferric citrate, or 50 µmol/L hemin. High resolution responses of the microbiota were examined by 16S rDNA pyrosequencing, microarray analysis, and metagenomic sequencing. The metabolome was assessed by fatty acid quantification, gas chromatography-mass spectrometry (GC-MS), and 1 H-NMR spectroscopy. Cultured intestinal epithelial Caco-2 cells were used to assess fecal water toxicity. Microbiome analysis showed, among others, that supplementary iron induced decreased levels of Bifidobacteriaceae and Lactobacillaceae, while it caused higher levels of Roseburia and Prevotella. Metagenomic analyses showed an enrichment of microbial motility-chemotaxis systems, while the metabolome markedly changed from a saccharolytic to a proteolytic profile in response to iron. Branched chain fatty acids and ammonia levels increased significantly, in particular with ferrous sulfate. Importantly, the metabolite-containing effluent from iron-rich conditions showed increased cytotoxicity to Caco-2 cells. Our explorations indicate that in the absence of host influences, iron induces a more hostile environment characterized by a reduction of microbes that are generally beneficial, and increased levels of bacterial metabolites that can impair the barrier function of a cultured intestinal epithelial monolayer.
Objectives: Primary outcome was change in composition of gut microbiome, after 3 weeks and 4 mont... more Objectives: Primary outcome was change in composition of gut microbiome, after 3 weeks and 4 months. Secondary outcomes were changes in faecal calprotectin, treated diarrhoea, anaemia, iron status and systemic inflammation. Methods: We performed two randomized controlled trials in 6-month-old Kenyan infants consuming home-fortified maize porridge daily for four months. 1) infants received an MNP containing 2.5 mg iron as NaFeEDTA (+2.5 mgFeMNP) or the identical MNP without iron (-2.5 mgFeMNP). 2) a different MNP containing 12.5 mg iron as ferrous fumarate (+12.5 mgFeMNP) or the identical MNP without iron (-12.5 mgFeMNP). Results: We enrolled 117 infants, and 101 infants completed the studies between March 2010 and September 2012. Baseline prevalence of anaemia and systemic inflammation were 67.3% and 29.7%, respectively. At baseline, 63% of the total microbial 16S rRNA could be assigned to Bifidobacteriaceae; using qPCR, Salmonella was detected in 22.8% of infants, B. cereus in 38.6%, S. aureus in 71.3%, C. difficile in 53.5%, and C. perfringens in 86.1%. Body iron stores increased in the +12.5 mgFeMNP (p=0.001), but not in the +2.5 mgFeMNP. Using pyrosequencing, +FeMNPs increased enterobacteria, especially Escherichia/Shigella (p=0.048), the enterobacteria/ bifidobacteria ratio (p=0.020), and Clostridium (p=0.03) compared to-FeMNPs; +FeMNPs also increased faecal calprotectin (p=0.002). Most of these effects were confirmed using qPCR, and many were statistically stronger in ±12.5 mgFeMNP study than in ±2.5 mgFeMNP study. During the trial, 27.3% of infants in the +12.5 mgFeMNP group required treatment for diarrhoea vs. 8.3% in the-12.5 mgFeMNP group (p=0.092). Conclusions: In rural Africa where infectious disease burden is high, provision of iron-containing MNPs to infants increases gut inflammation and modifies the gut microbiome toward a potentially more pathogenic profile
Background Human milk oligosaccharides (HMOs) have important and diverse biological functions in ... more Background Human milk oligosaccharides (HMOs) have important and diverse biological functions in early life. This study tested the safety and efficacy of a starter infant formula containing Limosilactobacillus (L.) reuteri DSM 17938 and supplemented with 2’-fucosyllactose (2’FL). Methods Healthy infants < 14 days old (n = 289) were randomly assigned to a bovine milk-based formula containing L. reuteri DSM 17938 at 1 × 107 CFU/g (control group; CG) or the same formula with added 1.0 g/L 2’FL (experimental group; EG) until 6 months of age. A non-randomized breastfed group served as reference (BF; n = 60). The primary endpoint was weight gain through 4 months of age in the formula-fed infants. Secondary endpoints included additional anthropometric measures, gastrointestinal tolerance, stooling characteristics, adverse events (AEs), fecal microbiota and metabolism, and gut immunity and health biomarkers in all feeding groups. Results Weight gain in EG was non-inferior to CG as shown ...
There is a growing prevalence of sleep problems and insomnia worldwide, urging the development of... more There is a growing prevalence of sleep problems and insomnia worldwide, urging the development of new treatments to tackle this increase. Several studies have suggested that the gut microbiome might influence sleep quality. The gut microbiome affects the host’s health via the production of metabolites and compounds with neuroactive and immunomodulatory properties, which include short-chain fatty acids, secondary bile acids and neurotransmitters. Several of these metabolites and compounds are independently known as wakefulness-promoting (serotonin, epinephrine, dopamine, orexin, histamine, acetylcholine, cortisol) or sleep-promoting (gamma-aminobutyric acid, melatonin). The primary aim of this review was to evaluate the potential of pro-, pre- and postbiotic treatments to improve sleep quality. Additionally, we aimed to evaluate whether each of the treatments could ameliorate stress and anxiety, which are known to bidirectionally correlate with sleep problems. Lastly, we provided a m...
Prevalence of anaemia among Nigerian toddlers is reported to be high, and may cause significant m... more Prevalence of anaemia among Nigerian toddlers is reported to be high, and may cause significant morbidity, affects brain development and function, and results in weakness and fatigue. Although, iron fortification can reduce anaemia, yet the effect on gut microbiota is unclear. This open-label randomised study in anaemic malnourished Nigerian toddlers aimed to decrease anaemia without affecting pathogenic gut bacteria using a multi-nutrient fortified dairy-based drink. The test product was provided daily in different amounts (200, 400 or 600 mL, supplying 2.24, 4.48 and 6.72 mg of elemental iron, respectively) for 6 months. Haemoglobin, ferritin, and C-reactive protein concentrations were measured to determine anaemia, iron deficiency (ID) and iron deficiency anaemia (IDA) prevalence. Faecal samples were collected to analyse gut microbiota composition. All three dosages reduced anaemia prevalence, to 47%, 27% and 18%, respectively. ID and IDA prevalence was low and did not significan...
Infectious diseases are a major cause of morbidity and mortality worldwide. Nutritional intervent... more Infectious diseases are a major cause of morbidity and mortality worldwide. Nutritional interventions may enhance resistance to infectious diseases or help to reduce clinical symptoms. Here, we investigated whether a whey protein concentrate (WPC) could decrease diarrheagenic Escherichia coli-induced changes in reported stool frequency and gastrointestinal complaints in a double-blind, parallel 4-week intervention study. Subjects were randomly assigned to a whey hydrolysate placebo group, a low-dose WPC group or a high-dose WPC group. After 2 weeks of consumption, subjects (n = 121) were orally infected with a high dose of live but attenuated diarrheagenic E. coli (strain E1392/75-2A; 1E10 colony-forming units). Subjects recorded information on stool consistency and the frequency and severity of symptoms in an online diary. The primary outcome parameters were a change in stool frequency (stools per day) and a change in Gastrointestinal Symptom Rating Scale (GSRS) diarrhea score betw...
Specialty section: This article was submitted to Microbial Physiology and Metabolism, a section o... more Specialty section: This article was submitted to Microbial Physiology and Metabolism, a section of the journal
Purpose Adverse effects of iron fortification/supplements such as Micronutrient Powder (MNP) on g... more Purpose Adverse effects of iron fortification/supplements such as Micronutrient Powder (MNP) on gut microbiota have previously been found in infection-prone African settings. This study examined the adversaries of a low-iron MNP compared with the standard MNP on the composition of gut microbiota in Bangladeshi children exposed to a high concentration of iron from potable groundwater. Methods A randomized controlled trial was conducted in 2- to 5-year-old children, drinking groundwater with a high concentration of iron (≥ 2 mg/L). Children were randomized to receive one sachet per day of either standard MNP (12.5 mg iron) or low-iron MNP (5 mg iron), for 2 months. A sub-sample of 53 children was considered for paired assessment of the gut microbiome by 16S rRNA amplicon sequencing. Results At baseline, the gut microbiota consisted of Bifidobacteriaceae (15.6%), Prevotellaceae (12.2%), Lactobacillaceae (3.6%), Clostridiaceae (4.1%) and Enterobacteriaceae (2.8%). Overall, there was no ...
During aging of human skin, a number of intrinsic and extrinsic factors cause the alteration of t... more During aging of human skin, a number of intrinsic and extrinsic factors cause the alteration of the skin’s structure, function and cutaneous physiology. Many studies have investigated the influence of the skin microbiome on these alterations, but the molecular mechanisms that dictate the interplay between these factors and the skin microbiome are still not fully understood. To obtain more insight into the connection between the skin microbiome and the human physiological processes involved in skin aging, we performed a systematic study on interconnected pathways of human and bacterial metabolic processes that are known to play a role in skin aging. The bacterial genes in these pathways were subsequently used to create Hidden Markov Models (HMMs), which were applied to screen for presence of defined functionalities in both genomic and metagenomic datasets of skin-associated bacteria. These models were further applied on 16S rRNA gene sequencing data from skin microbiota samples deriv...
Background Bovine milk-derived oligosaccharides (MOS) containing primarily galacto-oligosaccharid... more Background Bovine milk-derived oligosaccharides (MOS) containing primarily galacto-oligosaccharides with inherent concentrations of sialylated oligosaccharides can be added to infant formula to enhance the oligosaccharide profile. Objective To investigate the effects of an MOS-supplemented infant formula on gut microbiota and intestinal immunity. Methods In a double-blind, randomized, controlled trial, healthy term formula-fed infants aged 21–26 d either received an intact protein cow milk-based formula (control group, CG, n = 112) or the same formula containing 7.2 g MOS/L (experimental group, EG, n = 114) until the age of 6 mo. Exclusively human milk-fed infants (HFI, n = 70) from an observational study served as the reference. Fecal samples collected at baseline, and the ages of 2.5 and 4 mo were assessed for microbiota (16S ribosomal RNA-based approaches), metabolites, and biomarkers of gut health and immune response. Results Aged 2.5 and 4 mo, redundancy analysis (P = 0.002) an...
People experiencing sleep problems may benefit from nutrients supporting serotonin metabolism and... more People experiencing sleep problems may benefit from nutrients supporting serotonin metabolism and stress reduction. We studied the effect of a dairy-based product (DP) containing protein, galacto-oligosaccharides, vitamins and minerals, on sleep quality, stress, and gut-microbiota. In a cross-over RCT (three weeks intervention; three weeks washout), adults (n = 70; 30–50 y) with sleep disturbances (Pittsburgh Sleep Quality Index (PSQI) ≥ 9) consumed products 1 h before bed-time. Sleep quality (PSQI) was measured weekly, stress at base- and end-line (Depression Anxiety Stress Scale and saliva cortisol). Fecal samples were collected in the 1st intervention period only. Compared to placebo (skimmed milk), PSQI was only lower at day 14 in the 2nd intervention period in intention-to-treat (ITT) (p = 0.017; n = 69) and per-protocol (PP) (p = 0.038; n = 64) analyses. Post-hoc analysis (modified-PP: n=47, with baseline PSQI ≥ 9, and endline day 14), however, showed a decrease in PSQI (−1.60...
Background: Bioactive proteins and human milk oligosaccharides (HMOs), important ingredients in b... more Background: Bioactive proteins and human milk oligosaccharides (HMOs), important ingredients in breastmilk, that protect against infections are lacking in young child formula (YCF). This study investigated the effects of new YCFs on respiratory and gastrointestinal infections in toddlers. Methods: 461 healthy Chinese children aged 1-2.5 years were recruited in this randomized, controlled, double-blind, parallel-group clinical trial of different YCFs. They were randomly assigned to either standard milk formula (YCF-Ref) or one of three new YCFs containing bioactive proteins and/or the HMO 2'-fucosyllactose (2'-FL) and/or milk fat for six months. Primary outcomes were incidence of upper respiratory tract infection (URTI) and duration of gastrointestinal tract infections (GITI). Results: There were no significant between-group differences in primary outcomes. For secondary outcomes, subjects receiving 2'-FL-supplemented YCF had longer URTI. Subjects receiving YCF supplemented with milk fat and intact bioactive proteins, and 2'-FL at levels found in breastmilk, had more GITI episodes and shorter time to first GITI but similar effects on URTI duration than YCF-Ref recipients. No effects on URTI and GITI were observed in toddlers receiving YCF with bioactive proteins at lower levels than breastmilk. Occurrence of adverse events and anthropometry were similar in all groups. Conclusions: All three YCFs supplemented with different combinations of intact bioactive proteins, 2'-FL and milk fat are safe in toddlers. No difference is detected among YCFs on URTI incidence and GITI duration. Further studies are needed to verify these findings especially in infants who may benefit most from the immune-boosting effects of bioactive proteins and HMOs.
There is little data on human milk oligosaccharide (HMO) composition in Sub-Saharan Africa. Iron ... more There is little data on human milk oligosaccharide (HMO) composition in Sub-Saharan Africa. Iron fortificants adversely affect the infant gut microbiota, while co-provision of prebiotic galacto-oligosaccharides (GOS) mitigates most of the adverse effects. Whether variations in maternal HMO profile can influence the infant response to iron and/or GOS fortificants is unknown. The aim of this study was to determine HMO profiles and the secretor/non-secretor phenotype of lactating Kenyan mothers and investigate their effects on the maternal and infant gut microbiota, and on the infant response to a fortification intervention with 5 mg iron (2.5 mg as sodium iron ethylenediaminetetraacetate and 2.5 mg as ferrous fumarate) and 7.5 g GOS. We studied mother–infant pairs (n = 80) participating in a 4-month intervention trial in which the infants (aged 6.5–9.5 months) received daily a micronutrient powder without iron, with iron or with iron and GOS. We assessed: (1) maternal secretor status ...
Proton pump inhibitors (PPIs) are used by millions of patients for the treatment of stomach acid-... more Proton pump inhibitors (PPIs) are used by millions of patients for the treatment of stomach acid-reflux diseases. Although PPIs are generally considered safe, about 13% of the users develop hypomagnesemia. Despite rising attention for this issue, the underlying mechanism is still unknown. Here, we examine whether the gut microbiome is involved in the development of PPI-induced hypomagnesemia in wild-type C57BL/6J mice. After 4 wk of treatment under normal or low dietary Mg 2+ availability, omeprazole significantly reduced serum Mg 2+ levels only in mice on a low-Mg 2+ diet without affecting the mRNA expression of colonic or renal Mg 2+ transporters. Overall, 16S rRNA gene sequencing revealed a lower gut microbial diversity in omeprazole-treated mice. Omeprazole induced a shift in microbial composition, which was associated with a 3-and 2-fold increase in the abundance of Lactobacillus and Bifidobacterium, respectively. To examine the metabolic consequences of these microbial alterations, the colonic composition of organic acids was evaluated. Low dietary Mg 2+ intake, independent of omeprazole treatment, resulted in a 10-fold increase in formate levels. Together, these results imply that both omeprazole treatment and low dietary Mg 2+ intake disturb the gut internal milieu and may pose a risk for the malabsorption of Mg 2+ in the colon.-Gommers, L.
ObjectiveMany African infants receiving iron fortificants also receive antibiotics. Antibiotic ef... more ObjectiveMany African infants receiving iron fortificants also receive antibiotics. Antibiotic efficacy against enteropathogens may be modified by high colonic iron concentrations. In this study, we evaluated the effect of antibiotics on the infant gut microbiome and diarrhoea when given with or without iron-containing micronutrient powders (MNPs).DesignIn a controlled intervention trial, four groups of community-dwelling infants (n=28; aged 8–10 months) received either: (A) antibiotics for 5 days and iron-MNPs for 40 days (Fe+Ab+); (B) antibiotics and no-iron-MNPs (Fe−Ab+); (C) no antibiotics and iron-MNPs (Fe+Ab−); or (D) no antibiotics and no-iron-MNPs (Fe−Ab−). We collected a faecal sample before the first antibiotic dose (D0) and after 5, 10, 20 and 40 days (D5–D40) to assess the gut microbiome composition by 16S profiling, enteropathogens by quantitative PCR, faecal calprotectin and pH and assessed morbidity over the 40-day study period.ResultsIn Fe+Ab+, there was a decrease i...
Objective Iron-containing micronutrient powders (MNPs) reduce anaemia in African infants, but the... more Objective Iron-containing micronutrient powders (MNPs) reduce anaemia in African infants, but the current high iron dose (12.5 mg/day) may decrease gut Bifidobacteriaceae and Lactobacillaceae, and increase enteropathogens, diarrhoea and respiratory tract infections (RTIs). We evaluated the efficacy and safety of a new MNP formula with prebiotic galactooligosaccharides (GOS) combined with a low dose (5 mg/ day) of highly bioavailable iron. Design In a 4-month, controlled, double-blind trial, we randomised Kenyan infants aged 6.5-9.5 months (n=155) to receive daily (1) a MNP without iron (control); (2) the identical MNP but with 5 mg iron (2.5 mg as sodium iron ethylenediaminetetraacetate and 2.5 mg as ferrous fumarate) (Fe group); or (3) the identical MNP as the Fe group but with 7.5 g GOS (FeGOS group). results Anaemia decreased by ≈50% in the Fe and FeGOS groups (p<0.001). Compared with the control or FeGOS group, in the Fe group there were (1) lower abundances of Bifidobacterium and Lactobacillus and higher abundances of Clostridiales (p<0.01); (2) higher abundances of virulence and toxin genes (VTGs) of pathogens (p<0.01); (3) higher plasma intestinal fatty acid-binding protein (a biomarker of enterocyte damage) (p<0.05); and (4) a higher incidence of treated RTIs (p<0.05). In contrast, there were no significant differences in these variables comparing the control and FeGOS groups, with the exception that the abundance of VTGs of all pathogens was significantly lower in the FeGOS group compared with the control and Fe groups (p<0.01). conclusion A MNP containing a low dose of highly bioavailable iron reduces anaemia, and the addition of GOS mitigates most of the adverse effects of iron on the gut microbiome and morbidity in African infants. trial registration number NCT02118402. IntrODuctIOn The WHO estimates that 62.3% of preschool children in Africa are anaemic, 1 of which ≈50% is attributable to iron deficiency anaemia (IDA). 2 Iron-containing micronutrient powders (MNPs) added to complementary foods effectively reduce IDA in infants, a strategy described as 'in-home fortification'. 3 However, current MNPs contain a high iron dose (12.5 mg) that is equivalent to the dose provided by oral iron supplements for the treatment of IDA in infancy. 3 The safety of these MNPs is uncertain, 4 5 as recent MNP trials (12.5 mg iron/day) in infants reported increases in diarrhoea and respiratory tract infections (RTIs). 6 7 Iron Gut microbiota
The establishment of the infant gut microbiota is a highly dynamic process dependent on extrinsic... more The establishment of the infant gut microbiota is a highly dynamic process dependent on extrinsic and intrinsic factors. We characterized the faecal microbiota of 4 breastfed infants and 4 formula-fed infants at 17 consecutive time points during the first 12 weeks of life. Microbiota composition was analysed by a combination of 16S rRNA gene sequencing and quantitative PCR (qPCR). In this dataset, individuality was a major driver of microbiota composition (P = 0.002) and was more pronounced in breastfed infants. A developmental signature could be distinguished, characterized by sequential colonisation of i) intrauterine/vaginal birth associated taxa, ii) skin derived taxa and other typical early colonisers such as Streptococcus and Enterobacteriaceae, iii) domination of Bifidobacteriaceae, and iv) the appearance of adultlike taxa, particularly species associated with Blautia, Eggerthella, and the potential pathobiont Clostridium difficile. Low abundance of potential pathogens was de...
Patients with chronic kidney disease (CKD) and loss of kidney function are at increased risk for ... more Patients with chronic kidney disease (CKD) and loss of kidney function are at increased risk for morbidity and mortality. The risks of CKD are attributed to "uremia," an increased concentration of uremic retention solutes (toxins) in the plasma. Recently, a colo-renal axis became clearly apparent and uremia has been associated with an altered gut microbiome composition and metabolism. There is a high prevalence of anemia in patients with CKD, for which patients are often treated with oral or intravenous iron. Recent in vivo and in vitro studies have reported adverse effects of oral iron supplementation on the gut microbiota composition, gut metabolome, and intestinal health, which in turn may result in an increased production of uremic toxins. It may also affect circulating levels of other microbe-derived molecules, that can act as mediators of immune regulation. Changes in body iron levels have also been reported to exert subtle effects on host immune function by modulating immune cell proliferation and differentiation, and by directly regulating cytokine formation and antimicrobial immune effector mechanisms. Based on the foregoing it is conceivable that oral iron supplementation in iron deficient predialysis CKD patients adversely changes gut microbiota composition, the gut and systemic metabolome, and host immunity and infection. Future studies are needed to confirm these hypotheses and to assess whether, compared to IV iron supplementation, oral iron supplementation negatively impacts on morbidity of CKD, and whether these adverse effects depend on the iron bioavailability of the iron formulation to the microbiota.
Oral iron administration in African children can increase the risk for infections. However, it re... more Oral iron administration in African children can increase the risk for infections. However, it remains unclear to what extent supplementary iron affects the intestinal microbiome. We here explored the impact of iron preparations on microbial growth and metabolism in the well-controlled TNO's in vitro model of the large intestine (TIM-2). The model was inoculated with a human microbiota, without supplementary iron, or with 50 or 250 µmol/L ferrous sulfate, 50 or 250 µmol/L ferric citrate, or 50 µmol/L hemin. High resolution responses of the microbiota were examined by 16S rDNA pyrosequencing, microarray analysis, and metagenomic sequencing. The metabolome was assessed by fatty acid quantification, gas chromatography-mass spectrometry (GC-MS), and 1 H-NMR spectroscopy. Cultured intestinal epithelial Caco-2 cells were used to assess fecal water toxicity. Microbiome analysis showed, among others, that supplementary iron induced decreased levels of Bifidobacteriaceae and Lactobacillaceae, while it caused higher levels of Roseburia and Prevotella. Metagenomic analyses showed an enrichment of microbial motility-chemotaxis systems, while the metabolome markedly changed from a saccharolytic to a proteolytic profile in response to iron. Branched chain fatty acids and ammonia levels increased significantly, in particular with ferrous sulfate. Importantly, the metabolite-containing effluent from iron-rich conditions showed increased cytotoxicity to Caco-2 cells. Our explorations indicate that in the absence of host influences, iron induces a more hostile environment characterized by a reduction of microbes that are generally beneficial, and increased levels of bacterial metabolites that can impair the barrier function of a cultured intestinal epithelial monolayer.
Objectives: Primary outcome was change in composition of gut microbiome, after 3 weeks and 4 mont... more Objectives: Primary outcome was change in composition of gut microbiome, after 3 weeks and 4 months. Secondary outcomes were changes in faecal calprotectin, treated diarrhoea, anaemia, iron status and systemic inflammation. Methods: We performed two randomized controlled trials in 6-month-old Kenyan infants consuming home-fortified maize porridge daily for four months. 1) infants received an MNP containing 2.5 mg iron as NaFeEDTA (+2.5 mgFeMNP) or the identical MNP without iron (-2.5 mgFeMNP). 2) a different MNP containing 12.5 mg iron as ferrous fumarate (+12.5 mgFeMNP) or the identical MNP without iron (-12.5 mgFeMNP). Results: We enrolled 117 infants, and 101 infants completed the studies between March 2010 and September 2012. Baseline prevalence of anaemia and systemic inflammation were 67.3% and 29.7%, respectively. At baseline, 63% of the total microbial 16S rRNA could be assigned to Bifidobacteriaceae; using qPCR, Salmonella was detected in 22.8% of infants, B. cereus in 38.6%, S. aureus in 71.3%, C. difficile in 53.5%, and C. perfringens in 86.1%. Body iron stores increased in the +12.5 mgFeMNP (p=0.001), but not in the +2.5 mgFeMNP. Using pyrosequencing, +FeMNPs increased enterobacteria, especially Escherichia/Shigella (p=0.048), the enterobacteria/ bifidobacteria ratio (p=0.020), and Clostridium (p=0.03) compared to-FeMNPs; +FeMNPs also increased faecal calprotectin (p=0.002). Most of these effects were confirmed using qPCR, and many were statistically stronger in ±12.5 mgFeMNP study than in ±2.5 mgFeMNP study. During the trial, 27.3% of infants in the +12.5 mgFeMNP group required treatment for diarrhoea vs. 8.3% in the-12.5 mgFeMNP group (p=0.092). Conclusions: In rural Africa where infectious disease burden is high, provision of iron-containing MNPs to infants increases gut inflammation and modifies the gut microbiome toward a potentially more pathogenic profile
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Papers by Guus Kortman