Delayed colonization of Bifidobacterium spp. and low prevalence of B. infantis among infants of Asian ancestry born in Singapore: insights from the GUSTO cohort study.

Background: The loss of ancestral microbes, or the "disappearing microbiota hypothesis" has been proposed to play a critical role in the rise of inflammatory and immune diseases in developed nations. The effect of this loss is most consequential during early-life, as initial colonizers of the newborn gut contribute significantly to the development of the immune system. Methods: In this longitudinal study (day 3, week 3, and month 3 post-birth) of infants of Asian ancestry born in Singapore, we studied how generational immigration status and common perinatal factors affect bifidobacteria and Bifidobacterium longum subsp. infantis (B. infantis) colonization. Cohort registry identifier: NCT01174875. Results: Our findings show that first-generation migratory status, perinatal antibiotics usage, and cesarean section birth, significantly influenced the abundance and acquisition of bifidobacteria in the infant gut. Most importantly, 95.6% of the infants surveyed in this study had undetectable B. infantis, an early and beneficial colonizer of infant gut due to its ability to metabolize the wide variety of human milk oligosaccharides present in breastmilk and its ability to shape the development of a healthy immune system. A comparative analysis of B. infantis in 12 countries by their GDP per capita showed a remarkably low prevalence of this microbe in advanced economies, especially Singapore. Conclusion: This study provides new insights into infant gut microbiota colonization, showing the impact of generational immigration on early-life gut microbiota acquisition. It also warrants the need to closely monitor the declining prevalence of beneficial microbes such as B. infantis in developed nations and its potential link to increasing autoimmune and allergic diseases.

Effects of probiotic and synbiotic supplementation on ponderal and linear growth in severely malnourished young infants in a randomized clinical trial.

Severe acute malnutrition (SAM) is a major global public health problem. We aimed to assess the effects of probiotic and synbiotic supplementation on rate of weight gain and change in length in young SAM infants. This study was substudy of a single-blind randomized clinical trial (NCT0366657). During nutritional rehabilitation, 67 <6 months old SAM infants were enrolled and randomized to receive either probiotic (Bifidobacterium. infantis EVC001) or synbiotic (B. infantis EVC001 + Lacto-N-neotetraose [LNnT]) or placebo (Lactose) for four weeks and were followed for four more weeks after supplementation. In multivariable linear regression model, the mean rate of weight gain in the probiotic arm compared to placebo was higher by 2.03 unit (P < 0.001), and 1.13 unit (P = 0.030) in the synbiotic arm. In linear mixed-effects model, mean WAZ was higher by 0.57 unit (P = 0.018) in probiotic arm compared to placebo. Although not statistically significant, delta length for age z score (LAZ) trended to be higher among children in probiotc (ß = 0.25) and synbiotic (ß = 0.26) arms compared to placebo in multivariable linear regression model. Our study describes that young SAM infants had a higher rate of weight gain when supplemented with probiotic alone, compared to their counterparts with either synbiotic or placebo.

Association of human milk oligosaccharides and nutritional status of young infants among Bangladeshi mother-infant dyads.

Human milk oligosaccharides (HMOs) support the development of a healthy gut microbiome and the growth of infants. We aimed to determine the association of different HMOs with severe acute malnutrition (SAM) among Bangladeshi young infants. This study was nested within a single-blind, randomized, pilot clinical trial (NCT0366657). A total of 45 breastmilk samples from mothers of < 6 months old infants who had SAM (n = 26) or were non-malnourished (n = 19) and were analyzed for constituent HMOs. Of the infants with SAM, 14 (53.85%) had secretor mothers, and 11 (57.89%) of the non-malnourished infants had secretor mothers. A one-unit increase in the relative abundance of sialylated HMOs was associated with higher odds of SAM in age and sex adjusted model (aOR = 2.00, 90% CI 1.30, 3.06), in age, sex, and secretor status adjusted model (aOR = 1.96, 90% CI 1.29, 2.98), and also in age and sex adjusted model among non-secretor mothers (aOR = 2.86, 90% CI 1.07, 7.62). In adjusted models, there was no evidence of a statistically significant association between SAM and fucosylated or undecorated HMOs. Our study demonstrates that a higher relative abundance of sialylated HMOs in mothers' breastmilk may have a negative impact on young infants' nutritional status.

Bifidobacterium infantis treatment promotes weight gain in Bangladeshi infants with severe acute malnutrition.

Disrupted development of the gut microbiota is a contributing cause of childhood malnutrition. Bifidobacterium longum subspecies infantis is a prominent early colonizer of the infant gut that consumes human milk oligosaccharides (HMOs). We found that the absolute abundance of Bifidobacterium infantis is lower in 3- to 24-month-old Bangladeshi infants with severe acute malnutrition (SAM) compared to their healthy age-matched counterparts. A single-blind, placebo-controlled trial (SYNERGIE) was conducted in 2- to 6-month-old Bangladeshi infants with SAM. A commercial U.S. donor-derived B. infantis strain (EVC001) was administered daily with or without the HMO lacto-N-neotetraose for 28 days. This intervention increased fecal B. infantis abundance in infants with SAM, although to levels still 10- to 100-fold lower than in untreated healthy controls. EVC001 treatment promoted weight gain that was associated with reduced intestinal inflammation markers in infants with SAM. We cultured fecal B. infantis strains from Bangladeshi infants and colonized gnotobiotic mice with these cultured strains. The gnotobiotic mice were fed a diet representative of that consumed by 6-month-old Bangladeshi infants, with or without HMO supplementation. One B. infantis strain, Bg_2D9, expressing two gene clusters involved in uptake and utilization of N-glycans and plant-derived polysaccharides, exhibited superior fitness over EVC001. The fitness advantage of Bg_2D9 was confirmed in a gnotobiotic mouse model of mother-to-infant gut microbiota transmission where dams received a pretreatment fecal community from a SAM infant in the SYNERGIE trial. Whether Bg_2D9 is superior to EVC001 for treating malnourished infants who consume a diet with limited breastmilk requires further clinical testing.

Nuclear Resonance Vibrational Spectroscopic Definition of the Fe(IV)2 Intermediate Q in Methane Monooxygenase and Its Reactivity.

Methanotrophic bacteria utilize the nonheme diiron enzyme soluble methane monooxygenase (sMMO) to convert methane to methanol in the first step of their metabolic cycle under copper-limiting conditions. The structure of the sMMO Fe(IV)2 intermediate Q responsible for activating the inert C-H bond of methane (BDE = 104 kcal/mol) remains controversial, with recent studies suggesting both "open" and "closed" core geometries for its active site. In this study, we employ nuclear resonance vibrational spectroscopy (NRVS) to probe the geometric and electronic structure of intermediate Q at cryogenic temperatures. These data demonstrate that Q decays rapidly during the NRVS experiment. Combining data from several years of measurements, we derive the NRVS vibrational features of intermediate Q as well as its cryoreduced decay product. A library of 90 open and closed core models of intermediate Q is generated using density functional theory to analyze the NRVS data of Q and its cryoreduced product as well as prior spectroscopic data on Q. Our analysis reveals that a subset of closed core models reproduce these newly acquired NRVS data as well as prior data. The reaction coordinate with methane is also evaluated using both closed and open core models of Q. These studies show that the potent reactivity of Q toward methane resides in the "spectator oxo" of its Fe(IV)2O2 core, in contrast to nonheme mononuclear Fe(IV)═O enzyme intermediates that H atoms abstract from weaker C-H bonds.

The wider implications of the COVID-19 pandemic: Assessing the impact of accident and emergency use for frequent attenders.

INTRODUCTION: Emergency departments have seen altered patterns of attendance since the beginning of the COVID-19 pandemic, with reductions in the number of attendances for non-COVID-19 - patients. We assessed the use of the emergency department by frequent attenders during the height of the COVID-19 pandemic and explored any changes in emergency department attendance by this group. METHODS: As part of ongoing improvement work, we utilised a cohort design to evaluate the difference in patterns of attendance for the frequent attender group in a single centre. We created a 2019 'top attender' cohort and a similar cohort for 2020. We compared admission patterns between the two time periods in order to understand the impact of the COVID-19 pandemic on this group. RESULTS: Both groups were predominately male. Mental health and substance misuse use problems were common across both cohorts. The majority of patients lived in a socio-economically deprived areas. The median number emergency department visits in 2019, for the top attender cohort was 6 (IQR: 4-9) vs 4 (IQR: 2-7) for the top attender cohort of 2020 (p < .0013). CONCLUSION: This single centre evaluation has shown a significant reduction in emergency department attendances for a frequent attender cohort in a single centre. Future work should investigate the longer-term impact which the COVID-19 pandemic has had on this patient group.

Antibiotic exposure among young infants suffering from diarrhoea in Bangladesh.

AIMS: Appropriate rehydration has always been significant in treating diarrhoeal diseases in children. Irrational antibiotic use among diarrhoeal children has remained a major public health concern. Information regarding antibiotic use in young infants suffering from diarrhoea is very limited and a unique aspect of research. We aimed to investigate the prevalence of antibiotic use in the community among 2-6 months infants with diarrhoeal illnesses and having different nutritional status. METHODS: We investigated a total of 5279 infants aged 2-6 months at Dhaka hospital, International Centre for Diarrhoeal Disease Research, Bangladesh, between September 2018 and June 2019. Among them, 257 infants were suffering from severe acute malnutrition (SAM). History of taking antibiotics was ascertained by direct observation of a prescription by a physician, the bottle of antibiotic or asking the caregiver about the name of antibiotic or its price that is very close to the usual market price of an antibiotic. RESULTS: Overall, 52% of infants received antibiotics before hospital admission. Non-SAM infants had higher odds of receiving antibiotics (adjusted odds ratio [aOR] = 1.52, 95% confidence interval: 1.18, 1.97, P value = 0.003) compared to infants with SAM and use of antibiotics increased with age (aOR = 1.11, 95% confidence interval: 1.06, 1.17, P value<0.001). Commonly used antibiotics were azithromycin (13.3%), ciprofloxacin (7.7%), erythromycin (7.7%) and metronidazole (2.6%). The proportion of receiving ciprofloxacin was significantly lower in infants with SAM compared to their non-SAM counterparts (2.7% vs. 7.97%, P value = 0.004). CONCLUSIONS: The study underscores the excessive use of antibiotics among diarrhoeal infants, which is already a major public health concern in low- and middle-income countries.

Colonization Resistance in the Infant Gut: The Role of B. infantis in Reducing pH and Preventing Pathogen Growth.

Over the past century, there has been a steady increase in the stool pH of infants from industrialized countries. Analysis of historical data revealed a strong association between abundance of Bifidobacterium in the gut microbiome of breasted infants and stool pH, suggesting that this taxon plays a key role in determining the pH in the gut. Bifidobacterium longum subsp. infantis is uniquely equipped to metabolize human milk oligosaccharides (HMO) from breastmilk into acidic end products, mainly lactate and acetate. The presence of these acidic compounds in the infant gut is linked to a lower stool pH. Conversely, infants lacking B. infantis have a significantly higher stool pH, carry a higher abundance of potential pathogens and mucus-eroding bacteria in their gut microbiomes, and have signs of chronic enteric inflammation. This suggests the presence of B. infantis and low intestinal pH may be critical to maintaining a protective environment in the infant gut. Here, we summarize recent studies demonstrating that feeding B. infantis EVC001 to breastfed infants results in significantly lower fecal pH compared to controls and propose that low pH is one critical factor in preventing the invasion and overgrowth of harmful bacteria in the infant gut, a process known as colonization resistance.

Reintroducing B. infantis to the cesarean-born neonate: an ecologically sound alternative to "vaginal seeding".

There is a burgeoning literature highlighting differences in health outcomes between babies born vaginally and by caesarean section (c-section) This has led to the suggestion that infants born by c-section may benefit from vaginal swabbing/seeding. Here, we discuss from an ecological perspective that it is gut-adapted, not vagina-adapted microbes that are likely to take up residence in the gut and have the most beneficial impact on the developing neonate. Further, we caution the practice of 'vaginal seeding' may be potentially unsafe and also give parents and health professionals a false sense of action in restoring the infant gut microbiome following c-section. Instead, we argue that restoring B. longum subsp. infantis, which has evolved to colonize the infant gut, is a safe and ecologically-sound approach to restoring the gut microbiome of infants born by c-section.

The behavior of lipid debris left on cell surfaces from microbubble based ultrasound molecular imaging.

Lipid monolayer coated microbubbles are currently being developed to identify vascular regions that express certain surface proteins as part of the new technique of ultrasound molecular imaging. The microbubbles are functionalized with targeting ligands which bind to the desired cells holding the microbubbles in place as the remaining unbound microbubbles are eliminated from circulation. Subsequent scanning with ultrasound can detect the highly reflectant microbubbles that are left behind. The ultrasound scanning and detection process results in the destruction of the microbubble, creating lipid fragments from the monolayer. Here we demonstrate that microbubbles targeted to 4T1 murine breast cancer cells and human umbilical cord endothelial cells leave behind adhered fragments of the lipid monolayer after exposure to ultrasound with peak negative pressures of 0.18 and 0.8MPa. Most of the observed fragments were large enough to be resistant to receptor mediated endocytosis. The fragments were not observed to incorporate into the lipid membrane of the cell over a period of 96min. They were not observed to break into smaller pieces or significantly change shape but they were observed to undergo translation and rotation across the cell surface as the cells migrated over the substrate. These large fragments will apparently remain on the surface of the targeted cells for significant periods of time and need to be considered for their potential effects on blood flow through the microcapillaries and potential for immune system recognition.

Certification of Total Arsenic in Blood and Urine Standard Reference Materials by Radiochemical Neutron Activation Analysis and Inductively Coupled Plasma - Mass Spectrometry.

A newly developed procedure for determination of arsenic by radiochemical neutron activation analysis (RNAA) was used to measure arsenic at four levels in SRM 955c Toxic Elements in Caprine Blood and at two levels in SRM 2668 Toxic Elements in Frozen Human Urine for the purpose of providing mass concentration values for certification. Samples were freeze-dried prior to analysis followed by neutron irradiation for 3 h at a fluence rate of 1×1014cm-2s-1. After sample dissolution in perchloric and nitric acids, arsenic was separated from the matrix by extraction into zinc diethyldithiocarbamate in chloroform, and 76As quantified by gamma-ray spectroscopy. Differences in chemical yield and counting geometry between samples and standards were monitored by measuring the count rate of a 77As tracer added before sample dissolution. RNAA results were combined with inductively coupled plasma - mass spectrometry (ICP-MS) values from NIST and collaborating laboratories to provide certified values of (10.81 ± 0.54) µg/kg and (213.1 ± 0.73) µg/kg for SRM 2668 Levels I and II, and certified values of (21.66 ± 0.73) µg/kg, (52.7 ± 1.1) µg/kg, and (78.8 ± 4.9) µg/kg for SRM 955c Levels 2, 3, and 4 respectively. Because of discrepancies between values obtained by different methods for SRM 955c Level 1, an information value of < 5 µg/kg was assigned for this material.

A sub-chronic toxicity evaluation of a natural astaxanthin-rich carotenoid extract of Paracoccus carotinifaciens in rats.

Astaxanthin is believed to be beneficial to human health because it possesses strong antioxidant properties. A natural astaxanthin-rich carotenoid extract (ARE) was produced by a well-controlled fermentation of a natural bacteria Paracoccus carotinifaciens, followed by the extraction and enrichment of the final product comprising mixture of carotenoids that is predominantly astaxanthin. The aim of this study was to evaluate the sub-chronic toxicity of the ARE using 6 week old Sprague-Dawley SPF rats [Crl:CD(SD)]. The test article was suspended in olive oil and administered daily to the rats by oral gavage for 13 weeks at doses of 0 (olive oil), 250, 500 or 1000 mg/kg/day. Each group consisted of 10 animals of each sex. No deaths occurred and no treatment-related changes were observed in the detailed clinical observations, manipulative tests, grip strength, motor activity, body weights, food consumption, ophthalmology, urinalysis, hematology, blood chemistry, organ weight, necropsy or histopathology. Dark-red feces were observed throughout the administration period in all treated groups due to excretion of the colored test article. Based on these results, it was concluded that the no observed adverse effect level (NOAEL) for ARE was at least 1000 mg/kg/day for male and female rats, respectively.

Synthesizing evidence-based strategies and community-engaged research: a model to address social determinants of health.

Addressing social determinants of health (SDH) requires multileveled intervention designs. Increasingly, organizations and coalitions face pressure to use evidence-based strategies when seeking to address SDH. Evidence-based strategies, however, must be locally relevant and integrated into existing systems to function efficiently. We propose the incorporation of an effective rapid assessment technique, Rapid Assessment, Response, and Evaluation (RARE), with evidence-based strategies, findings, and recommendations embedded in community-engaged research to increase the likelihood of success in addressing SDH. Our RARE project--a partnership among a community health center, a nonprofit funding agency, and academic faculty researchers--resulted in community- and policy-level interventions for the prevention of childhood obesity in a Southwestern U.S. city.

Pharmacological inhibition of the Wnt acyltransferase PORCN prevents growth of WNT-driven mammary cancer.

Porcupine (PORCN) is a membrane bound O-acyltransferase that is required for Wnt palmitoylation, secretion, and biologic activity. All evaluable human Wnts require PORCN for their activity, suggesting that inhibition of PORCN could be an effective treatment for cancers dependent on excess Wnt activity. In this study, we evaluated the PORCN inhibitor Wnt-C59 (C59), to determine its activity and toxicity in cultured cells and mice. C59 inhibits PORCN activity in vitro at nanomolar concentrations, as assessed by inhibition of Wnt palmitoylation, Wnt interaction with the carrier protein Wntless/WLS, Wnt secretion, and Wnt activation of ß-catenin reporter activity. In mice, C59 displayed good bioavailability, as once daily oral administration was sufficient to maintain blood concentrations well above the IC(50). C59 blocked progression of mammary tumors in MMTV-WNT1 transgenic mice while downregulating Wnt/ß-catenin target genes. Surprisingly, mice exhibit no apparent toxicity, such that at a therapeutically effective dose there were no pathologic changes in the gut or other tissues. These results offer preclinical proof-of-concept that inhibiting mammalian Wnts can be achieved by targeting PORCN with small-molecule inhibitors such as C59, and that this is a safe and feasible strategy in vivo.

'F' is for failure. One patient's experiences provide a compelling lesson in cardiac care for EMS providers.

There are many potential pathologies that cause a patient to have a complaint of shortness of breath and it may not always be easy to differentiate between heart failure, COPD/asthma and pneumonia. Misdiagnosis of heart failure is common and inappropriate treatment may be harmful. It has been shown that 25% of patients given furosemide developed significant electrolyte imbalances and hypotension requiring fluid boluses; adding morphine increased mortality by 22% compared to 2% with only nitroglycerin. If you have any question about the diagnosis, it would be appropriate to treat your patient with bronchodilators, nitroglycerin and NIPSV, avoiding morphine and furosemide. Remember that heart failure might be the result of an AMI, so it is important to consider aspirin as well.

Critical decisions.

As a responder, your actions within the first few moments of arriving on the scene of a motor vehicle crash are crucial to the success of managing the situation. Within these moments, you must size up the situation, mitigate as many hazards as possible, establish incident command, rapidly triage patients and ultimately assess, treat and extricate patients from the scene. In doing so, you must decide when to extricate a patient and what treatment is essential to improve the patient's chances of survival, based on your knowledge, previous experience and a problem-based assessment algorithm.

Plasma phosphatidylcholine docosahexaenoic acid content and risk of dementia and Alzheimer disease: the Framingham Heart Study.

BACKGROUND: Docosahexaenoic acid (DHA) is an abundant fatty acid in the brain. In the diet, DHA is found mostly in fatty fish. The content of DHA has been shown to be decreased in the brain and plasma of patients with dementia. OBJECTIVE: To determine whether plasma phosphatidylcholine (PC) DHA content is associated with the risk of developing dementia. DESIGN, SETTING, AND PARTICIPANTS: A prospective follow-up study in 899 men and women who were free of dementia at baseline, had a median age of 76.0 years, and were followed up for a mean of 9.1 years for the development of all-cause dementia and Alzheimer disease. MAIN OUTCOME MEASURES: Plasma PC fatty acid levels were measured at baseline. Cox proportional regression analysis was used to assess relative risks of all-cause dementia and Alzheimer disease according to baseline plasma levels. RESULTS: Ninety-nine new cases of dementia (including 71 of Alzheimer disease) occurred during the follow-up. After adjustment for age, sex, apolipoprotein E epsilon4 allele, plasma homocysteine concentration, and education level, subjects in the upper quartile of baseline plasma PC DHA levels, compared with subjects in the lower 3 quartiles, had a relative risk of 0.53 of developing all-cause dementia (95% confidence interval, 0.29-0.97; P=.04) and 0.61 of developing Alzheimer disease (95% confidence interval, 0.31-1.18; P=.14). Subjects in the upper quartile of plasma PC DHA levels had a mean DHA intake of 0.18 g/d and a mean fish intake of 3.0 servings per week (P<.001) in a subset of 488 participants. We found no other significant associations. CONCLUSION: The top quartile of plasma PC DHA level was associated with a significant 47% reduction in the risk of developing all-cause dementia in the Framingham Heart Study.